#!/usr/bin/env bash
#
# Common functions for RLCR loop hooks
#
# This library provides shared functionality used by:
# - loop-read-validator.sh
# - loop-write-validator.sh
# - loop-edit-validator.sh
# - loop-bash-validator.sh
# - loop-plan-file-validator.sh
# - loop-codex-stop-hook.sh
# - setup-rlcr-loop.sh
# - cancel-rlcr-loop.sh
#

# Source guard: prevent double-sourcing (readonly vars would fail)
[[ -n "${_LOOP_COMMON_LOADED:-}" ]] && return 0 2>/dev/null || true
_LOOP_COMMON_LOADED=1

# ========================================
# Constants
# ========================================

# State file field names
readonly FIELD_PLAN_TRACKED="plan_tracked"
readonly FIELD_START_BRANCH="start_branch"
readonly FIELD_BASE_BRANCH="base_branch"
readonly FIELD_BASE_COMMIT="base_commit"
readonly FIELD_PLAN_FILE="plan_file"
readonly FIELD_CURRENT_ROUND="current_round"
readonly FIELD_MAX_ITERATIONS="max_iterations"
readonly FIELD_PUSH_EVERY_ROUND="push_every_round"
readonly FIELD_CODEX_MODEL="codex_model"
readonly FIELD_CODEX_EFFORT="codex_effort"
readonly FIELD_CODEX_TIMEOUT="codex_timeout"
readonly FIELD_REVIEW_STARTED="review_started"
readonly FIELD_FULL_REVIEW_ROUND="full_review_round"
readonly FIELD_ASK_CODEX_QUESTION="ask_codex_question"
readonly FIELD_SESSION_ID="session_id"
readonly FIELD_AGENT_TEAMS="agent_teams"
readonly FIELD_PRIVACY_MODE="privacy_mode"
readonly FIELD_MAINLINE_STALL_COUNT="mainline_stall_count"
readonly FIELD_LAST_MAINLINE_VERDICT="last_mainline_verdict"
readonly FIELD_DRIFT_STATUS="drift_status"

readonly MAINLINE_VERDICT_ADVANCED="advanced"
readonly MAINLINE_VERDICT_STALLED="stalled"
readonly MAINLINE_VERDICT_REGRESSED="regressed"
readonly MAINLINE_VERDICT_UNKNOWN="unknown"

readonly DRIFT_STATUS_NORMAL="normal"
readonly DRIFT_STATUS_REPLAN_REQUIRED="replan_required"

# Default Codex configuration (single source of truth - all scripts reference this)
# Scripts can pre-set DEFAULT_CODEX_MODEL/DEFAULT_CODEX_EFFORT before sourcing to override.
# Config-backed defaults are loaded from the merge hierarchy after config-loader.sh is sourced.
# Precedence: pre-set value > config value > hardcoded fallback (gpt-5.5/high)
#
# The actual assignment happens in the "Config-backed defaults" section below,
# after config-loader.sh has been sourced and merged config is available.

# Codex review markers
readonly MARKER_COMPLETE="COMPLETE"
readonly MARKER_STOP="STOP"

# Exit reasons (used with end_loop function)
# complete   - Codex confirmed all goals achieved (normal success)
# cancel     - User cancelled with /cancel-rlcr-loop
# maxiter    - Reached maximum iterations limit
# stop       - Codex triggered circuit breaker (stagnation detected)
# unexpected - System error or invalid state (e.g., corrupted state file)
readonly EXIT_COMPLETE="complete"
readonly EXIT_CANCEL="cancel"
readonly EXIT_MAXITER="maxiter"
readonly EXIT_STOP="stop"
readonly EXIT_UNEXPECTED="unexpected"

# ========================================
# JSON Input Validation
# ========================================

# Validate JSON input and extract tool_name
# Usage: validate_hook_input "$json_input"
# Returns: 0 if valid JSON with tool_name, 1 if invalid
# Sets: VALIDATED_TOOL_NAME, VALIDATED_TOOL_INPUT
#
# Non-UTF8 handling behavior:
# - Null bytes (0x00): Rejected with exit 1
# - Invalid UTF-8 sequences (0x80-0xFF outside valid UTF-8): Rejected by jq as invalid JSON
# - Valid UTF-8 non-ASCII characters: Accepted (jq handles Unicode correctly)
validate_hook_input() {
    local input="$1"

    # Reject null bytes (security) - portable check without grep -P (BSD incompatible)
    # tr -cd '\0' keeps only null bytes, wc -c counts them
    if [[ $(printf '%s' "$input" | tr -cd '\0' | wc -c) -gt 0 ]]; then
        echo "Error: Input contains null bytes" >&2
        return 1
    fi

    # Reject non-UTF8 bytes (security/consistency)
    # Check for bytes in 0x80-0xFF that are NOT part of valid UTF-8 sequences
    # Skip if iconv is not available (common in minimal containers like Alpine)
    if command -v iconv >/dev/null 2>&1; then
        if ! printf '%s' "$input" | iconv -f UTF-8 -t UTF-8 >/dev/null 2>&1; then
            echo "Error: Input contains invalid UTF-8 sequences" >&2
            return 1
        fi
    fi

    # Validate JSON syntax with jq
    if ! printf '%s' "$input" | jq -e '.' >/dev/null 2>&1; then
        echo "Error: Invalid JSON syntax" >&2
        return 1
    fi

    # Extract tool_name (required)
    VALIDATED_TOOL_NAME=$(printf '%s' "$input" | jq -r '.tool_name // empty')
    if [[ -z "$VALIDATED_TOOL_NAME" ]]; then
        echo "Error: Missing required field: tool_name" >&2
        return 1
    fi

    # Extract tool_input (required for Read/Write/Bash)
    VALIDATED_TOOL_INPUT=$(printf '%s' "$input" | jq -r '.tool_input // empty')

    return 0
}

# Validate that a specific field exists in tool_input
# Usage: require_tool_input_field "$json_input" "field_name"
# Returns: 0 if field exists and is non-empty, 1 otherwise
require_tool_input_field() {
    local input="$1"
    local field="$2"

    local value
    value=$(printf '%s' "$input" | jq -r ".tool_input.$field // empty")

    if [[ -z "$value" ]]; then
        echo "Error: Missing required field: tool_input.$field" >&2
        return 1
    fi

    return 0
}

# Check if JSON is deeply nested (potential DoS)
# Usage: is_deeply_nested "$json_input" [max_depth]
# Returns: 0 if too deeply nested, 1 otherwise
is_deeply_nested() {
    local input="$1"
    local max_depth="${2:-30}"

    # Use jq to check depth - getpath on recursive descent gives us depth
    local actual_depth
    actual_depth=$(printf '%s' "$input" | jq '[paths | length] | max // 0' 2>/dev/null || echo "0")

    if [[ "$actual_depth" -gt "$max_depth" ]]; then
        echo "Error: JSON structure exceeds maximum depth of $max_depth (actual: $actual_depth)" >&2
        return 0
    fi

    return 1
}

# ========================================
# Library Setup
# ========================================

# Source template loader
LOOP_COMMON_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
LOOP_COMMON_PLUGIN_ROOT="$(cd "$LOOP_COMMON_DIR/../.." && pwd)"
export PLUGIN_ROOT="${PLUGIN_ROOT:-$LOOP_COMMON_PLUGIN_ROOT}"

# Shared project-root resolver (CLAUDE_PROJECT_DIR -> git toplevel,
# realpath-canonicalized). Must load before any caller needs PROJECT_ROOT.
source "$LOOP_COMMON_DIR/project-root.sh"

_lc_errexit=false; [[ -o errexit ]] && _lc_errexit=true
_lc_nounset=false; [[ -o nounset ]] && _lc_nounset=true
_lc_pipefail=false; [[ -o pipefail ]] && _lc_pipefail=true
source "$LOOP_COMMON_PLUGIN_ROOT/scripts/lib/config-loader.sh"
$_lc_errexit && set -e || set +e
$_lc_nounset && set -u || set +u
$_lc_pipefail && set -o pipefail || set +o pipefail
unset _lc_errexit _lc_nounset _lc_pipefail

_LOOP_COMMON_PROJECT_ROOT="$(resolve_project_root 2>/dev/null || true)"
# Config loading is best-effort: use || true so a config-load failure does not
# abort sourcing before callers' dependency checks (jq, codex) are reached.
# Stderr is NOT suppressed so malformed config warnings remain visible.
#
# Skip config loading when no project root is available (e.g. humanize.sh is
# sourced from .bashrc/.zshrc in a non-repo directory like $HOME). Passing an
# empty project_root to load_merged_config would surface a usage error on
# stderr every time the shell starts.
if [[ -n "$_LOOP_COMMON_PROJECT_ROOT" ]]; then
    _LOOP_COMMON_CONFIG="$(load_merged_config "$LOOP_COMMON_PLUGIN_ROOT" "$_LOOP_COMMON_PROJECT_ROOT")" || true
else
    _LOOP_COMMON_CONFIG=""
fi

# Load bitlesson model from merged config (controls which CLI bitlesson-select.sh uses)
DEFAULT_BITLESSON_MODEL="$(get_config_value "$_LOOP_COMMON_CONFIG" "bitlesson_model" 2>/dev/null || true)"
DEFAULT_BITLESSON_MODEL="${DEFAULT_BITLESSON_MODEL:-haiku}"

# Load codex model/effort from merged config so .humanize/config.json can set persistent
# defaults for all Codex-using features (RLCR, ask-codex).
# Precedence: pre-set by caller > config value > hardcoded fallback (gpt-5.5/high)
_cfg_codex_model="$(get_config_value "$_LOOP_COMMON_CONFIG" "codex_model" 2>/dev/null || true)"
if [[ -n "$_cfg_codex_model" && ! "$_cfg_codex_model" =~ ^[a-zA-Z0-9._-]+$ ]]; then
    echo "Warning: Invalid codex_model in merged config: $_cfg_codex_model" >&2
    echo "  Ignoring configured codex_model; using caller preset or fallback" >&2
    _cfg_codex_model=""
elif [[ -n "$_cfg_codex_model" && ! "$_cfg_codex_model" =~ ^(gpt-|o[0-9]) ]]; then
    echo "Warning: Unsupported codex_model in merged config: $_cfg_codex_model" >&2
    echo "  Must start with a Codex model prefix: gpt- or o[0-9]" >&2
    echo "  Ignoring configured codex_model; using caller preset or fallback" >&2
    _cfg_codex_model=""
fi
DEFAULT_CODEX_MODEL="${DEFAULT_CODEX_MODEL:-${_cfg_codex_model:-gpt-5.5}}"
_cfg_codex_effort="$(get_config_value "$_LOOP_COMMON_CONFIG" "codex_effort" 2>/dev/null || true)"
if [[ -n "$_cfg_codex_effort" && ! "$_cfg_codex_effort" =~ ^(xhigh|high|medium|low)$ ]]; then
    echo "Warning: Invalid codex_effort in merged config: $_cfg_codex_effort" >&2
    echo "  Must be one of: xhigh, high, medium, low" >&2
    echo "  Ignoring configured codex_effort; using caller preset or fallback" >&2
    _cfg_codex_effort=""
fi
DEFAULT_CODEX_EFFORT="${DEFAULT_CODEX_EFFORT:-${_cfg_codex_effort:-high}}"

# Load agent_teams from merged config (controls whether RLCR uses agent teams by default)
# Precedence: pre-set by caller (e.g. --agent-teams flag) > config value > hardcoded fallback (false)
_cfg_agent_teams="$(get_config_value "$_LOOP_COMMON_CONFIG" "agent_teams" 2>/dev/null || true)"
DEFAULT_AGENT_TEAMS="${DEFAULT_AGENT_TEAMS:-${_cfg_agent_teams:-false}}"
unset _cfg_codex_model _cfg_codex_effort _cfg_agent_teams

unset _LOOP_COMMON_PROJECT_ROOT _LOOP_COMMON_CONFIG

source "$LOOP_COMMON_DIR/template-loader.sh"

# Initialize template directory (can be overridden by sourcing script)
TEMPLATE_DIR="${TEMPLATE_DIR:-$(get_template_dir "$LOOP_COMMON_DIR")}"

# Validate template directory exists (warn but don't fail - allows graceful degradation)
if ! validate_template_dir "$TEMPLATE_DIR" 2>/dev/null; then
    echo "Warning: Template directory validation failed. Using inline fallbacks." >&2
fi

# Extract session_id from hook JSON input
# Usage: extract_session_id "$json_input"
# Outputs the session_id to stdout, or empty string if not available
extract_session_id() {
    local input="$1"
    printf '%s' "$input" | jq -r '.session_id // empty' 2>/dev/null || echo ""
}

# Background-task helpers (expand_leading_tilde, extract_transcript_path,
# derive_loop_start_iso_ts, list/has/count_pending_background_task[_ids],
# handle_bg_task_short_circuit) live in loop-bg-tasks.sh and are sourced
# at the bottom of this file so every existing consumer of loop-common.sh
# continues to get them transparently.

# Resolve the active state file for a loop directory
# Checks for finalize-state.md first, then state.md
# Usage: resolve_active_state_file "$loop_dir"
# Outputs the state file path to stdout, or empty string if none found
resolve_active_state_file() {
    local loop_dir="$1"

    if [[ -f "$loop_dir/methodology-analysis-state.md" ]]; then
        echo "$loop_dir/methodology-analysis-state.md"
    elif [[ -f "$loop_dir/finalize-state.md" ]]; then
        echo "$loop_dir/finalize-state.md"
    elif [[ -f "$loop_dir/state.md" ]]; then
        echo "$loop_dir/state.md"
    else
        echo ""
    fi
}

# Resolve any state file in a loop directory (active or terminal)
# Checks active states first (state.md, finalize-state.md), then falls back
# to any terminal state file (*-state.md such as complete-state.md, cancel-state.md).
# Usage: resolve_any_state_file "$loop_dir"
# Outputs the state file path to stdout, or empty string if none found
resolve_any_state_file() {
    local loop_dir="$1"

    # Prefer active states
    if [[ -f "$loop_dir/methodology-analysis-state.md" ]]; then
        echo "$loop_dir/methodology-analysis-state.md"
        return
    elif [[ -f "$loop_dir/finalize-state.md" ]]; then
        echo "$loop_dir/finalize-state.md"
        return
    elif [[ -f "$loop_dir/state.md" ]]; then
        echo "$loop_dir/state.md"
        return
    fi

    # Fall back to any terminal state file
    local terminal_state
    terminal_state=$(ls -1 "$loop_dir"/*-state.md 2>/dev/null | head -1)
    echo "${terminal_state:-}"
}

# Find the most recent active loop directory matching optional session_id filter
#
# Without session_id filter: only checks the single newest directory.
#   If it has state.md or finalize-state.md, returns it; otherwise returns empty.
#   This preserves zombie-loop protection: older directories are never examined,
#   so a stale state.md in an older directory cannot be accidentally revived.
#
# With session_id filter: finds the newest directory belonging to that session
#   (matching ANY *state.md file including terminal states), then checks whether
#   it is still active. If the session's newest directory is in terminal state
#   (complete-state.md, cancel-state.md, etc.), returns empty immediately --
#   preventing stale older loops from being revived. This enables multiple
#   concurrent RLCR loops with different session IDs in the same project.
#
# Empty stored session_id matches any filter (backward compat for pre-session
# state files).
#
# Third parameter `allow_bg_marker_fallback` (default "false"): when "true",
# the session-filter branch also considers a mismatched-session dir that holds
# a `bg-pending.marker` file AND an active state file. Only the RLCR stop
# hook opts in to this; every other caller (read/write/bash/plan-file
# validators, ...) keeps strict session isolation.
#
# Outputs the directory path to stdout, or empty string if none found
find_active_loop() {
    local loop_base_dir="$1"
    local filter_session_id="${2:-}"
    local allow_bg_marker_fallback="${3:-false}"

    if [[ ! -d "$loop_base_dir" ]]; then
        echo ""
        return
    fi

    if [[ -z "$filter_session_id" ]]; then
        # No filter: only check the single newest directory (zombie-loop protection)
        local newest_dir
        newest_dir=$(ls -1d "$loop_base_dir"/*/ 2>/dev/null | sort -r | head -1)

        if [[ -n "$newest_dir" ]]; then
            local state_file
            state_file=$(resolve_active_state_file "${newest_dir%/}")
            if [[ -n "$state_file" ]]; then
                echo "${newest_dir%/}"
                return
            fi
        fi
        echo ""
        return
    fi

    # Session filter: iterate newest-to-oldest.
    #
    # The caller's own (exact stored session_id) match takes precedence over
    # any marker-based adoption: with multiple active RLCR loops in the same
    # repo, a newer dir parked by a different session must not be returned
    # before an older dir that actually belongs to the caller. Marker
    # candidates are recorded during the scan and only used as a fallback
    # when no exact match is found anywhere. Zombie-loop protection
    # (terminal newest for this session returns empty) still wins over
    # marker fallback.
    local dir
    local marker_candidate=""
    while IFS= read -r dir; do
        [[ -z "$dir" ]] && continue
        local trimmed_dir="${dir%/}"

        local any_state
        any_state=$(resolve_any_state_file "$trimmed_dir")
        if [[ -z "$any_state" ]]; then
            continue
        fi

        local stored_session_id
        stored_session_id=$(sed -n '/^---$/,/^---$/{ /^'"${FIELD_SESSION_ID}"':/{ s/'"${FIELD_SESSION_ID}"': *//; p; } }' "$any_state" 2>/dev/null | tr -d ' ')

        # Empty stored session_id matches any session (backward compat).
        if [[ -z "$stored_session_id" ]] || [[ "$stored_session_id" == "$filter_session_id" ]]; then
            # Newest dir for this session -- only return if active.
            local active_state
            active_state=$(resolve_active_state_file "$trimmed_dir")
            if [[ -n "$active_state" ]]; then
                echo "$trimmed_dir"
                return
            fi
            # Session's newest loop is in terminal state; do not fall through
            # to marker-based adoption either.
            echo ""
            return
        fi

        # Session mismatch. Only the stop hook opts in to marker-based
        # adoption; validators and other callers keep strict isolation, so
        # the candidate is only recorded when the caller explicitly allows
        # it.
        if [[ "$allow_bg_marker_fallback" == "true" ]] \
           && [[ -z "$marker_candidate" ]] \
           && [[ -f "$trimmed_dir/bg-pending.marker" ]]; then
            local candidate_state
            candidate_state=$(resolve_active_state_file "$trimmed_dir")
            if [[ -n "$candidate_state" ]]; then
                marker_candidate="$trimmed_dir"
            fi
            # Marker on a terminal loop is stale; leave it alone.
        fi
    done < <(ls -1d "$loop_base_dir"/*/ 2>/dev/null | sort -r)

    # No exact session match. Fall back to marker-based adoption only when
    # the caller explicitly opted in -- the stop hook uses this to surface
    # a "parked by another session" notice or to resume its own parked
    # loop after a previous session died before the bg completion arrived.
    if [[ "$allow_bg_marker_fallback" == "true" ]] && [[ -n "$marker_candidate" ]]; then
        echo "$marker_candidate"
        return
    fi

    echo ""
}

# Extract current round number from state.md
# Outputs the round number to stdout, defaults to 0
# Note: For full state parsing, use parse_state_file() instead
get_current_round() {
    local state_file="$1"

    local frontmatter
    frontmatter=$(sed -n '/^---$/,/^---$/{ /^---$/d; p; }' "$state_file" 2>/dev/null || echo "")

    local current_round
    current_round=$(echo "$frontmatter" | grep "^${FIELD_CURRENT_ROUND}:" | sed "s/${FIELD_CURRENT_ROUND}: *//" | tr -d ' ')

    echo "${current_round:-0}"
}

# Extract state fields from frontmatter content (internal helper)
# Usage: _parse_state_fields
# Requires STATE_FRONTMATTER to be set before calling
# Sets all STATE_* field variables without applying defaults
_parse_state_fields() {
    # Parse fields with consistent quote handling
    # Legacy quote-stripping kept for backward compatibility with older state files
    STATE_PLAN_TRACKED=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_PLAN_TRACKED}:" | sed "s/${FIELD_PLAN_TRACKED}: *//" | tr -d ' ' || true)
    STATE_START_BRANCH=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_START_BRANCH}:" | sed "s/${FIELD_START_BRANCH}: *//; s/^\"//; s/\"\$//" || true)
    STATE_BASE_BRANCH=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_BASE_BRANCH}:" | sed "s/${FIELD_BASE_BRANCH}: *//; s/^\"//; s/\"\$//" || true)
    STATE_BASE_COMMIT=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_BASE_COMMIT}:" | sed "s/${FIELD_BASE_COMMIT}: *//; s/^\"//; s/\"\$//" || true)
    STATE_PLAN_FILE=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_PLAN_FILE}:" | sed "s/${FIELD_PLAN_FILE}: *//; s/^\"//; s/\"\$//" || true)
    STATE_CURRENT_ROUND=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_CURRENT_ROUND}:" | sed "s/${FIELD_CURRENT_ROUND}: *//" | tr -d ' ' || true)
    STATE_MAX_ITERATIONS=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_MAX_ITERATIONS}:" | sed "s/${FIELD_MAX_ITERATIONS}: *//" | tr -d ' ' || true)
    STATE_PUSH_EVERY_ROUND=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_PUSH_EVERY_ROUND}:" | sed "s/${FIELD_PUSH_EVERY_ROUND}: *//" | tr -d ' ' || true)
    STATE_CODEX_MODEL=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_CODEX_MODEL}:" | sed "s/${FIELD_CODEX_MODEL}: *//" | tr -d ' ' || true)
    STATE_CODEX_EFFORT=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_CODEX_EFFORT}:" | sed "s/${FIELD_CODEX_EFFORT}: *//" | tr -d ' ' || true)
    STATE_CODEX_TIMEOUT=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_CODEX_TIMEOUT}:" | sed "s/${FIELD_CODEX_TIMEOUT}: *//" | tr -d ' ' || true)
    STATE_REVIEW_STARTED=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_REVIEW_STARTED}:" | sed "s/${FIELD_REVIEW_STARTED}: *//" | tr -d ' ' || true)
    STATE_FULL_REVIEW_ROUND=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_FULL_REVIEW_ROUND}:" | sed "s/${FIELD_FULL_REVIEW_ROUND}: *//" | tr -d ' ' || true)
    STATE_ASK_CODEX_QUESTION=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_ASK_CODEX_QUESTION}:" | sed "s/${FIELD_ASK_CODEX_QUESTION}: *//" | tr -d ' ' || true)
    STATE_SESSION_ID=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_SESSION_ID}:" | sed "s/${FIELD_SESSION_ID}: *//" || true)
    STATE_AGENT_TEAMS=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_AGENT_TEAMS}:" | sed "s/${FIELD_AGENT_TEAMS}: *//" | tr -d ' ' || true)
    STATE_PRIVACY_MODE=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_PRIVACY_MODE}:" | sed "s/${FIELD_PRIVACY_MODE}: *//" | tr -d ' ' || true)
    STATE_MAINLINE_STALL_COUNT=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_MAINLINE_STALL_COUNT}:" | sed "s/${FIELD_MAINLINE_STALL_COUNT}: *//" | tr -d ' ' || true)
    STATE_LAST_MAINLINE_VERDICT=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_LAST_MAINLINE_VERDICT}:" | sed "s/${FIELD_LAST_MAINLINE_VERDICT}: *//" | tr -d ' ' || true)
    STATE_DRIFT_STATUS=$(echo "$STATE_FRONTMATTER" | grep "^${FIELD_DRIFT_STATUS}:" | sed "s/${FIELD_DRIFT_STATUS}: *//" | tr -d ' ' || true)
}

# Parse state file frontmatter and set variables (tolerant mode with defaults)
# Usage: parse_state_file "$STATE_FILE"
# Sets the following variables (caller must declare them):
#   STATE_FRONTMATTER - raw frontmatter content
#   STATE_PLAN_TRACKED - "true" or "false"
#   STATE_START_BRANCH - branch name
#   STATE_BASE_BRANCH - base branch for code review
#   STATE_PLAN_FILE - plan file path
#   STATE_CURRENT_ROUND - current round number
#   STATE_MAX_ITERATIONS - max iterations
#   STATE_PUSH_EVERY_ROUND - "true" or "false"
#   STATE_CODEX_MODEL - codex model name
#   STATE_CODEX_EFFORT - codex effort level
#   STATE_CODEX_TIMEOUT - codex timeout in seconds
#   STATE_REVIEW_STARTED - "true" or "false"
#   STATE_FULL_REVIEW_ROUND - interval for Full Alignment Check (default: 5)
#   STATE_ASK_CODEX_QUESTION - "true" or "false" (v1.6.5+)
#   STATE_AGENT_TEAMS - "true" or "false"
#   STATE_MAINLINE_STALL_COUNT - consecutive stalled/regressed implementation rounds
#   STATE_LAST_MAINLINE_VERDICT - advanced/stalled/regressed/unknown
#   STATE_DRIFT_STATUS - normal/replan_required
# Returns: 0 on success, 1 if file not found
# Note: For strict validation, use parse_state_file_strict() instead
parse_state_file() {
    local state_file="$1"

    if [[ ! -f "$state_file" ]]; then
        return 1
    fi

    STATE_FRONTMATTER=$(sed -n '/^---$/,/^---$/{ /^---$/d; p; }' "$state_file" 2>/dev/null || echo "")

    _parse_state_fields

    # Apply defaults for non-schema-critical fields only
    # Note: review_started is NOT defaulted here so we can detect missing schema fields
    # and block with a proper message in the stop hook
    STATE_CURRENT_ROUND="${STATE_CURRENT_ROUND:-0}"
    STATE_MAX_ITERATIONS="${STATE_MAX_ITERATIONS:-10}"
    STATE_PUSH_EVERY_ROUND="${STATE_PUSH_EVERY_ROUND:-false}"
    STATE_FULL_REVIEW_ROUND="${STATE_FULL_REVIEW_ROUND:-5}"
    STATE_ASK_CODEX_QUESTION="${STATE_ASK_CODEX_QUESTION:-true}"
    STATE_AGENT_TEAMS="${STATE_AGENT_TEAMS:-false}"
    # Default privacy_mode to "true" for legacy loops that pre-date this field
    STATE_PRIVACY_MODE="${STATE_PRIVACY_MODE:-true}"
    STATE_MAINLINE_STALL_COUNT="${STATE_MAINLINE_STALL_COUNT:-0}"
    STATE_LAST_MAINLINE_VERDICT="${STATE_LAST_MAINLINE_VERDICT:-$MAINLINE_VERDICT_UNKNOWN}"
    STATE_DRIFT_STATUS="${STATE_DRIFT_STATUS:-$DRIFT_STATUS_NORMAL}"
    # STATE_REVIEW_STARTED left as-is (empty if missing, to allow schema validation)

    return 0
}

# Strict state file parser that rejects malformed files
# Usage: parse_state_file_strict "$STATE_FILE"
# Sets the same variables as parse_state_file()
# Returns: 0 on success, non-zero on validation failure
#   1 - file not found
#   2 - missing YAML frontmatter separators
#   3 - missing required field (current_round or max_iterations)
#   4 - non-numeric current_round value
#   5 - non-numeric max_iterations value
parse_state_file_strict() {
    local state_file="$1"

    if [[ ! -f "$state_file" ]]; then
        echo "Error: State file not found: $state_file" >&2
        return 1
    fi

    # Check for YAML frontmatter separators (must have at least two --- lines)
    local separator_count
    separator_count=$(grep -c '^---$' "$state_file" 2>/dev/null || echo "0")
    if [[ "$separator_count" -lt 2 ]]; then
        echo "Error: Missing YAML frontmatter separators (---)" >&2
        return 2
    fi

    # Extract frontmatter and parse all fields (reuse shared helper, no defaults applied)
    STATE_FRONTMATTER=$(sed -n '/^---$/,/^---$/{ /^---$/d; p; }' "$state_file" 2>/dev/null || echo "")
    _parse_state_fields

    # Validate required fields exist
    if [[ -z "$STATE_CURRENT_ROUND" ]]; then
        echo "Error: Missing required field: current_round" >&2
        return 3
    fi
    if [[ -z "$STATE_MAX_ITERATIONS" ]]; then
        echo "Error: Missing required field: max_iterations" >&2
        return 3
    fi
    if [[ -z "$STATE_REVIEW_STARTED" ]]; then
        echo "Error: Missing required field: review_started" >&2
        return 3
    fi
    if [[ -z "$STATE_BASE_BRANCH" ]]; then
        echo "Error: Missing required field: base_branch" >&2
        return 3
    fi

    # Validate current_round is numeric (including 0 and negative)
    if ! [[ "$STATE_CURRENT_ROUND" =~ ^-?[0-9]+$ ]]; then
        echo "Error: Non-numeric current_round value: $STATE_CURRENT_ROUND" >&2
        return 4
    fi

    # Validate max_iterations is numeric
    if ! [[ "$STATE_MAX_ITERATIONS" =~ ^-?[0-9]+$ ]]; then
        echo "Error: Non-numeric max_iterations value: $STATE_MAX_ITERATIONS" >&2
        return 5
    fi

    # Validate review_started is boolean
    if [[ "$STATE_REVIEW_STARTED" != "true" && "$STATE_REVIEW_STARTED" != "false" ]]; then
        echo "Error: Invalid review_started value (must be true or false): $STATE_REVIEW_STARTED" >&2
        return 6
    fi

    # Apply defaults for optional fields only
    STATE_PUSH_EVERY_ROUND="${STATE_PUSH_EVERY_ROUND:-false}"
    STATE_FULL_REVIEW_ROUND="${STATE_FULL_REVIEW_ROUND:-5}"
    STATE_ASK_CODEX_QUESTION="${STATE_ASK_CODEX_QUESTION:-true}"
    STATE_AGENT_TEAMS="${STATE_AGENT_TEAMS:-false}"
    STATE_PRIVACY_MODE="${STATE_PRIVACY_MODE:-true}"
    STATE_MAINLINE_STALL_COUNT="${STATE_MAINLINE_STALL_COUNT:-0}"
    STATE_LAST_MAINLINE_VERDICT="${STATE_LAST_MAINLINE_VERDICT:-$MAINLINE_VERDICT_UNKNOWN}"
    STATE_DRIFT_STATUS="${STATE_DRIFT_STATUS:-$DRIFT_STATUS_NORMAL}"

    return 0
}

# Normalize mainline progress verdict to a safe enum.
# Usage: normalize_mainline_progress_verdict "ADVANCED"
normalize_mainline_progress_verdict() {
    local verdict_lower
    verdict_lower=$(printf '%s' "$1" | tr '[:upper:]' '[:lower:]' | tr -d '[:space:]')

    case "$verdict_lower" in
        "$MAINLINE_VERDICT_ADVANCED"|"$MAINLINE_VERDICT_STALLED"|"$MAINLINE_VERDICT_REGRESSED")
            echo "$verdict_lower"
            ;;
        *)
            echo "$MAINLINE_VERDICT_UNKNOWN"
            ;;
    esac
}

# Normalize drift status to a safe enum.
# Usage: normalize_drift_status "replan_required"
normalize_drift_status() {
    local status_lower
    status_lower=$(printf '%s' "$1" | tr '[:upper:]' '[:lower:]' | tr -d '[:space:]')

    case "$status_lower" in
        "$DRIFT_STATUS_REPLAN_REQUIRED")
            echo "$DRIFT_STATUS_REPLAN_REQUIRED"
            ;;
        *)
            echo "$DRIFT_STATUS_NORMAL"
            ;;
    esac
}

# Extract "Mainline Progress Verdict" from Codex review content.
# Outputs one of: advanced, stalled, regressed, unknown
# Usage: extract_mainline_progress_verdict "$review_content"
extract_mainline_progress_verdict() {
    local review_content="$1"
    local verdict_line
    local verdict_value

    verdict_line=$(printf '%s\n' "$review_content" | grep -Ei 'Mainline Progress Verdict:[[:space:]]*(ADVANCED|STALLED|REGRESSED)([^A-Za-z]|$)' | tail -1 || true)
    if [[ -z "$verdict_line" ]]; then
        echo "$MAINLINE_VERDICT_UNKNOWN"
        return
    fi

    # Extract the verdict word using grep -oEi (portable) instead of sed /I (GNU-only).
    # The preceding grep -Ei already ensures the line contains one of the three verdicts.
    # Reject lines with multiple verdict keywords (e.g. placeholder template formats)
    # to avoid silently accepting an ambiguous verdict.
    local _verdict_matches
    _verdict_matches=$(printf '%s\n' "$verdict_line" | grep -oEi 'ADVANCED|STALLED|REGRESSED')
    local _match_count
    _match_count=$(printf '%s\n' "$_verdict_matches" | wc -l)
    if [[ "$_match_count" -gt 1 ]]; then
        echo "$MAINLINE_VERDICT_UNKNOWN"
        return
    fi
    verdict_value=$(printf '%s\n' "$_verdict_matches" | head -1)
    normalize_mainline_progress_verdict "$verdict_value"
}

# Upsert simple YAML frontmatter fields in a state file.
# Values must not contain newlines.
# Usage: upsert_state_fields "/path/to/state.md" "field=value" "other=value"
upsert_state_fields() {
    local state_file="$1"
    shift

    local temp_file="${state_file}.tmp.$$"

    awk -v assignments="$*" '
        BEGIN {
            count = split(assignments, pairs, " ");
            for (i = 1; i <= count; i++) {
                eq = index(pairs[i], "=");
                key = substr(pairs[i], 1, eq - 1);
                val = substr(pairs[i], eq + 1);
                keys[key] = val;
                order[i] = key;
            }
            separator_count = 0;
        }
        {
            if ($0 == "---") {
                separator_count++;
                if (separator_count == 2) {
                    for (i = 1; i <= count; i++) {
                        key = order[i];
                        if (!(key in seen)) {
                            print key ": " keys[key];
                            seen[key] = 1;
                        }
                    }
                }
                print;
                next;
            }

            handled = 0;
            for (i = 1; i <= count; i++) {
                key = order[i];
                if ($0 ~ ("^" key ":")) {
                    print key ": " keys[key];
                    seen[key] = 1;
                    handled = 1;
                    break;
                }
            }

            if (!handled) {
                print;
            }
        }
    ' "$state_file" > "$temp_file" && mv "$temp_file" "$state_file"
}

# Detect review issues from codex review log file
# Returns:
#   0 - issues found (caller should continue review loop)
#   1 - no issues found (caller can proceed to finalize)
#   2 - log file missing/empty (hard error - caller must block and require retry)
# Outputs: extracted review content to stdout if issues found
# Arguments: $1=round_number
# Required globals: LOOP_DIR, CACHE_DIR
#
# Algorithm:
# 1. Scan the last 50 lines of the log file for [P?] markers in the first 10
#    characters of each line. Real review issues only appear near the end of the
#    log; scanning the full file risks false positives from earlier debug output
#    and can hit argument-list-too-long limits on very large logs.
# 2. Find the first such line where [P?] (? is a digit) appears in the first 10
#    characters.
# 3. If found: extract from that line to the end and output it.
# 4. If not found: no issues, return 1.
#
# Note: codex review outputs to stderr, so we analyze the combined log file
# which contains both stdout and stderr (redirected with 2>&1).
detect_review_issues() {
    local round="$1"
    local log_file="$CACHE_DIR/round-${round}-codex-review.log"
    local result_file="$LOOP_DIR/round-${round}-review-result.md"

    # Check if log file exists and is not empty
    if [[ ! -f "$log_file" || ! -s "$log_file" ]]; then
        echo "Error: Codex review log file not found or empty: $log_file" >&2
        return 2
    fi

    local total_lines
    total_lines=$(wc -l < "$log_file")
    echo "Analyzing log file: $log_file ($total_lines lines)" >&2

    # Only scan the last 50 lines - real issues always appear near the end
    local scan_lines=50
    local start_line=$((total_lines > scan_lines ? total_lines - scan_lines + 1 : 1))

    # Use awk on the tail to find the first line where [P?] appears in first 10 chars
    local relative_line
    relative_line=$(tail -n "$scan_lines" "$log_file" | awk '
        substr($0, 1, 10) ~ /\[P[0-9]\]/ {
            print NR
            exit
        }
    ')

    if [[ -n "$relative_line" && "$relative_line" -gt 0 ]]; then
        # Convert relative line (within tail) to absolute line in the full file
        local found_line=$((start_line + relative_line - 1))
        echo "Found [P?] issue at line $found_line" >&2

        # Extract from found_line to end
        local extracted_content
        extracted_content=$(sed -n "${found_line},\$p" "$log_file")

        # Save to result file for audit purposes
        printf '%s\n' "$extracted_content" > "$result_file"
        echo "Review issues extracted to: $result_file" >&2

        # Output the content for the caller
        printf '## Codex Review Issues\n\n%s\n' "$extracted_content"
        return 0
    fi

    echo "No [P?] issues found in log file" >&2
    return 1
}

# Convert a string to lowercase
to_lower() {
    echo "$1" | tr '[:upper:]' '[:lower:]'
}

# Check if a path (lowercase) matches a round file pattern
# Usage: is_round_file "$lowercase_path" "summary|prompt|todos|contract"
is_round_file_type() {
    local path_lower="$1"
    local file_type="$2"

    echo "$path_lower" | grep -qE "round-[0-9]+-${file_type}\\.md\$"
}

# Extract round number from a filename
# Usage: extract_round_number "round-5-summary.md"
# Outputs the round number or empty string
extract_round_number() {
    local filename="$1"
    local filename_lower
    filename_lower=$(to_lower "$filename")

    # Use sed for portable regex extraction (works in both bash and zsh)
    echo "$filename_lower" | sed -n 's/.*round-\([0-9][0-9]*\)-\(summary\|prompt\|todos\|contract\)\.md$/\1/p'
}

# Check if a file is in the allowlist for the active loop
# Usage: is_allowlisted_file "$file_path" "$active_loop_dir"
# Returns: 0 if allowlisted, 1 otherwise
is_allowlisted_file() {
    local file_path="$1"
    local active_loop_dir="$2"

    local allowlist=(
        "round-1-todos.md"
        "round-2-todos.md"
        "round-0-summary.md"
        "round-1-summary.md"
    )

    for allowed in "${allowlist[@]}"; do
        if [[ "$file_path" == "$active_loop_dir/$allowed" ]]; then
            return 0
        fi
    done

    return 1
}

# Standard message for blocking todos file access
# Usage: todos_blocked_message "Read|Write|Bash"
todos_blocked_message() {
    local action="$1"
    local fallback="# Todos File Access Blocked

Do NOT create or access round-*-todos.md files. Use the native Task tools instead (TaskCreate, TaskUpdate, TaskList)."

    load_and_render_safe "$TEMPLATE_DIR" "block/todos-file-access.md" "$fallback"
}

# Standard message for blocking prompt file writes
prompt_write_blocked_message() {
    local fallback="# Prompt File Write Blocked

You cannot write to round-*-prompt.md files. These contain instructions FROM Codex TO you."

    load_and_render_safe "$TEMPLATE_DIR" "block/prompt-file-write.md" "$fallback"
}

# Standard message for blocking state file modifications
state_file_blocked_message() {
    local fallback="# State File Modification Blocked

You cannot modify state.md. This file is managed by the loop system."

    load_and_render_safe "$TEMPLATE_DIR" "block/state-file-modification.md" "$fallback"
}

# Standard message for blocking finalize-state file modifications
finalize_state_file_blocked_message() {
    local fallback="# Finalize State File Modification Blocked

You cannot modify finalize-state.md. This file is managed by the loop system during the Finalize Phase."

    load_and_render_safe "$TEMPLATE_DIR" "block/finalize-state-file-modification.md" "$fallback"
}

# Standard message for blocking round contract access during Finalize Phase
# Usage: finalize_contract_blocked_message "read"
finalize_contract_blocked_message() {
    local action="$1"
    local fallback="# Finalize Contract Access Blocked

There is no active round contract during the Finalize Phase.

Do not {{ACTION}} historical round contract files.
Use finalize-summary.md for finalize-only notes and goal-tracker.md for current state."

    load_and_render_safe "$TEMPLATE_DIR" "block/finalize-contract-access.md" "$fallback" \
        "ACTION=$action"
}

# Standard message for blocking summary file modifications via Bash
# Usage: summary_bash_blocked_message "$correct_summary_path"
summary_bash_blocked_message() {
    local correct_path="$1"
    local fallback="# Bash Write Blocked

Do not use Bash commands to modify summary files. Use the Write or Edit tool instead: {{CORRECT_PATH}}"

    load_and_render_safe "$TEMPLATE_DIR" "block/summary-bash-write.md" "$fallback" "CORRECT_PATH=$correct_path"
}

# Standard message for blocking goal-tracker modifications via Bash in Round 0
# Usage: goal_tracker_bash_blocked_message "$correct_goal_tracker_path"
goal_tracker_bash_blocked_message() {
    local correct_path="$1"
    local fallback="# Bash Write Blocked

Do not use Bash commands to modify goal-tracker.md. Use the Write or Edit tool instead: {{CORRECT_PATH}}"

    load_and_render_safe "$TEMPLATE_DIR" "block/goal-tracker-bash-write.md" "$fallback" "CORRECT_PATH=$correct_path"
}

# Check if a path (lowercase) targets goal-tracker.md
is_goal_tracker_path() {
    local path_lower="$1"
    echo "$path_lower" | grep -qE 'goal-tracker\.md$'
}

# Extract the immutable section from a goal-tracker content stream.
# Supports both current trackers (with --- separator) and older trackers
# that jump directly from IMMUTABLE SECTION to MUTABLE SECTION.
extract_goal_tracker_immutable_from_stream() {
    awk '
        /^## IMMUTABLE SECTION[[:space:]]*$/ { capture=1 }
        capture && /^## MUTABLE SECTION[[:space:]]*$/ { exit }
        capture && /^---[[:space:]]*$/ { exit }
        capture { print }
    '
}

# Extract the immutable section from an on-disk goal-tracker file.
# Usage: extract_goal_tracker_immutable_from_file "/path/to/goal-tracker.md"
extract_goal_tracker_immutable_from_file() {
    local tracker_file="$1"
    if [[ ! -f "$tracker_file" ]]; then
        return 1
    fi
    extract_goal_tracker_immutable_from_stream < "$tracker_file"
}

# Extract the immutable section from an in-memory goal-tracker string.
# Usage: extract_goal_tracker_immutable_from_text "$content"
extract_goal_tracker_immutable_from_text() {
    local tracker_content="$1"
    printf '%s' "$tracker_content" | extract_goal_tracker_immutable_from_stream
}

# Check whether a proposed goal-tracker update preserves the immutable section.
# Usage: goal_tracker_mutable_update_allowed "/path/to/current.md" "$new_content"
goal_tracker_mutable_update_allowed() {
    local tracker_file="$1"
    local updated_content="$2"

    local current_immutable=""
    local updated_immutable=""
    current_immutable=$(extract_goal_tracker_immutable_from_file "$tracker_file" 2>/dev/null || true)
    updated_immutable=$(extract_goal_tracker_immutable_from_text "$updated_content" 2>/dev/null || true)

    # Legacy trackers without IMMUTABLE SECTION: allow edits unconditionally.
    [[ -n "$current_immutable" ]] || return 0
    [[ "$current_immutable" == "$updated_immutable" ]]
}

# Render the post-edit contents for a literal Edit operation.
# Returns non-zero if the edit preview cannot be produced.
# Usage: preview_edit_result "/path/to/file" "$old_string" "$new_string" "true|false"
preview_edit_result() {
    local file_path="$1"
    local old_string="$2"
    local new_string="$3"
    local replace_all="${4:-false}"

    command -v perl >/dev/null 2>&1 || return 1

    FILE_PATH="$file_path" \
    OLD_STRING="$old_string" \
    NEW_STRING="$new_string" \
    REPLACE_ALL="$replace_all" \
    perl -0pe '
        BEGIN {
            $old = $ENV{"OLD_STRING"};
            $new = $ENV{"NEW_STRING"};
            $replace_all = $ENV{"REPLACE_ALL"} eq "true";
        }
        if ($replace_all) {
            s/\Q$old\E/$new/g;
        } else {
            s/\Q$old\E/$new/;
        }
    ' "$file_path"
}

# Check if a path (lowercase) targets state.md
is_state_file_path() {
    local path_lower="$1"
    echo "$path_lower" | grep -qE 'state\.md$'
}

# Check if a path (lowercase) targets finalize-state.md
is_finalize_state_file_path() {
    local path_lower="$1"
    echo "$path_lower" | grep -qE 'finalize-state\.md$'
}

# Check if a path (lowercase) targets methodology-analysis-state.md
is_methodology_analysis_state_file_path() {
    local path_lower="$1"
    echo "$path_lower" | grep -qE 'methodology-analysis-state\.md$'
}

# Standard message for blocking methodology-analysis-state file modifications
methodology_analysis_state_file_blocked_message() {
    local fallback="# Methodology Analysis State File Modification Blocked

You cannot modify methodology-analysis-state.md. This file is managed by the loop system during the Methodology Analysis Phase."

    load_and_render_safe "$TEMPLATE_DIR" "block/methodology-analysis-state-file-modification.md" "$fallback"
}

# Check if a path (lowercase) targets finalize-summary.md
is_finalize_summary_path() {
    local path_lower="$1"
    echo "$path_lower" | grep -qE 'finalize-summary\.md$'
}

# Normalize paths by removing /./ and collapsing // to /
# This allows paths like /path/to/./state.md to match /path/to/state.md
_normalize_path() {
    echo "$1" | sed 's|/\./|/|g; s|//|/|g'
}

# Check if cancel operation is authorized via signal file
# Usage: is_cancel_authorized "$active_loop_dir" "$command_lower"
# Returns: 0 if authorized, non-zero otherwise
#   1 - missing signal file
#   2 - security violation (injection, command substitution, etc.)
#   3 - mixed quote styles
#   4 - multiple trailing spaces
#   5 - invalid command structure
#   6 - source file is a symlink (filesystem check)
#
# Security notes:
# - Normalizes $loop_dir/${loop_dir} to actual path before validation
# - Rejects $(cmd) command substitution and backticks
# - Rejects any remaining $ after normalization (prevents hidden vars like ${IFS})
# - Enforces exactly two arguments: state.md or finalize-state.md source and cancel-state.md dest
# - Rejects shell operators for command chaining
# - Rejects mixed quote styles and multiple trailing spaces
# - Rejects if source file is a symlink
is_cancel_authorized() {
    local active_loop_dir="$1"
    local command_lower="$2"

    local cancel_signal="$active_loop_dir/.cancel-requested"

    # Signal file must exist
    if [[ ! -f "$cancel_signal" ]]; then
        return 1
    fi

    # SECURITY: Reject command substitution and backticks
    if echo "$command_lower" | grep -qE '\$\(|`'; then
        return 2
    fi

    # Reject newlines (multi-command injection)
    if [[ "$command_lower" == *$'\n'* ]]; then
        return 2
    fi

    # Reject shell operators for command chaining
    if echo "$command_lower" | grep -qE ';|&&|\|\||\|'; then
        return 2
    fi

    # Reject multiple trailing spaces
    if echo "$command_lower" | grep -qE '[[:space:]]{2,}$'; then
        return 4
    fi

    # Canonicalize the loop dir (idempotent: resolve_project_root already
    # canonicalizes, but callers may supply a non-canonical override). Both
    # sides of the upcoming string comparisons must be canonicalized through
    # the same transformation or a symlinked prefix in the user's command
    # (e.g. /var/... vs /private/var/... on macOS) will spuriously fail the
    # authorization check.
    local canonical_loop_dir
    canonical_loop_dir="$(canonicalize_path "${active_loop_dir%/}")"
    canonical_loop_dir="${canonical_loop_dir:-${active_loop_dir%/}}"

    # Normalize: Replace $loop_dir and ${loop_dir} with actual path
    local normalized="$command_lower"
    local loop_dir_lower
    loop_dir_lower="${canonical_loop_dir}/"
    loop_dir_lower=$(echo "$loop_dir_lower" | tr '[:upper:]' '[:lower:]')

    normalized="${normalized//\$\{loop_dir\}/$loop_dir_lower}"
    normalized="${normalized//\$loop_dir/$loop_dir_lower}"

    # After normalization, reject any remaining $ (prevents hidden vars like ${IFS})
    if echo "$normalized" | grep -qE '\$'; then
        return 2
    fi

    # Must start with mv followed by space
    if ! echo "$normalized" | grep -qE '^mv[[:space:]]+'; then
        return 5
    fi

    # Extract arguments after "mv "
    local args
    args=$(echo "$normalized" | sed 's/^mv[[:space:]]*//')

    # Detect quote types used in both arguments
    # Check for mixed quotes by detecting if both ' and " are used as delimiters
    local has_single=false has_double=false
    local first_char
    first_char=$(echo "$args" | cut -c1)
    if [[ "$first_char" == '"' ]]; then
        has_double=true
    elif [[ "$first_char" == "'" ]]; then
        has_single=true
    fi

    # Skip first argument to check second
    local args_after_first
    if [[ "$first_char" == '"' ]]; then
        args_after_first=$(echo "$args" | sed 's/^"[^"]*"[[:space:]]*//')
    elif [[ "$first_char" == "'" ]]; then
        args_after_first=$(echo "$args" | sed "s/^'[^']*'[[:space:]]*//")
    else
        args_after_first=$(echo "$args" | sed 's/^[^[:space:]]*[[:space:]]*//')
    fi

    local second_char
    second_char=$(echo "$args_after_first" | cut -c1)
    if [[ "$second_char" == '"' ]]; then
        has_double=true
    elif [[ "$second_char" == "'" ]]; then
        has_single=true
    fi

    # Reject mixed quote styles
    if [[ "$has_single" == "true" ]] && [[ "$has_double" == "true" ]]; then
        return 3
    fi

    # Parse arguments, respecting quotes
    local src dest
    if echo "$args" | grep -qE "^[\"']"; then
        local quote_char
        quote_char=$(echo "$args" | cut -c1)
        if [[ "$quote_char" == '"' ]]; then
            src=$(echo "$args" | sed -n 's/^"\([^"]*\)".*/\1/p')
            args=$(echo "$args" | sed 's/^"[^"]*"[[:space:]]*//')
        else
            src=$(echo "$args" | sed -n "s/^'\\([^']*\\)'.*/\\1/p")
            args=$(echo "$args" | sed "s/^'[^']*'[[:space:]]*//")
        fi
    else
        src=$(echo "$args" | sed 's/[[:space:]].*//')
        args=$(echo "$args" | sed 's/^[^[:space:]]*[[:space:]]*//')
    fi

    if echo "$args" | grep -qE "^[\"']"; then
        local quote_char
        quote_char=$(echo "$args" | cut -c1)
        if [[ "$quote_char" == '"' ]]; then
            dest=$(echo "$args" | sed -n 's/^"\([^"]*\)".*/\1/p')
            args=$(echo "$args" | sed 's/^"[^"]*"[[:space:]]*//')
        else
            dest=$(echo "$args" | sed -n "s/^'\\([^']*\\)'.*/\\1/p")
            args=$(echo "$args" | sed "s/^'[^']*'[[:space:]]*//")
        fi
    else
        dest=$(echo "$args" | sed 's/[[:space:]].*//')
        args=$(echo "$args" | sed 's/^[^[:space:]]*//')
    fi

    if [[ -z "$src" ]] || [[ -z "$dest" ]]; then
        return 5
    fi

    # Check for extra arguments
    args=$(echo "$args" | sed 's/^[[:space:]]*//')
    if [[ -n "$args" ]]; then
        return 5
    fi

    # Normalize and validate source path.
    #
    # Use canonicalize_path_prefix (NOT canonicalize_path): we need to resolve
    # symlinks in the parent directory so a symlinked project prefix matches
    # canonical_loop_dir, but we MUST NOT dereference a symlink at the leaf.
    # Otherwise a symlink like /tmp/alias -> <loop>/state.md would canonicalize
    # to <loop>/state.md and pass the check, but `mv` would then operate on
    # the link path itself, escaping the loop directory and/or corrupting
    # loop state. The on-disk symlink rejection below (src_original check)
    # still fires because it probes the real state.md under canonical_loop_dir.
    #
    # Re-lowercase after canonicalization because realpath on case-insensitive
    # filesystems may restore the original casing of path components, which
    # would diverge from the already-lowercased expected_* values.
    src=$(_normalize_path "$src")
    local src_canonical
    src_canonical="$(canonicalize_path_prefix "$src")"
    src_canonical="${src_canonical:-$src}"
    src_canonical=$(echo "$src_canonical" | tr '[:upper:]' '[:lower:]')
    local expected_src_state="${loop_dir_lower}state.md"
    local expected_src_finalize="${loop_dir_lower}finalize-state.md"
    local expected_src_methodology="${loop_dir_lower}methodology-analysis-state.md"
    if [[ "$src_canonical" != "$expected_src_state" ]] && [[ "$src_canonical" != "$expected_src_finalize" ]] && [[ "$src_canonical" != "$expected_src_methodology" ]]; then
        return 5
    fi

    # Normalize and validate destination path. Uses canonicalize_path_prefix
    # for the same reason as src: a symlink alias pointing at the real
    # cancel-state.md must NOT pass authorization, because `mv` onto a
    # symlink replaces the link rather than creating <loop>/cancel-state.md,
    # corrupting loop state and moving state.md outside the loop dir.
    dest=$(_normalize_path "$dest")
    local dest_canonical
    dest_canonical="$(canonicalize_path_prefix "$dest")"
    dest_canonical="${dest_canonical:-$dest}"
    dest_canonical=$(echo "$dest_canonical" | tr '[:upper:]' '[:lower:]')
    local expected_dest="${loop_dir_lower}cancel-state.md"
    if [[ "$dest_canonical" != "$expected_dest" ]]; then
        return 5
    fi

    # SECURITY: Reject if source file is a symlink (filesystem check)
    # Determine source file by comparing against expected paths (not substring match)
    # This avoids vulnerability when loop directory path contains "finalize" or "methodology"
    # Use canonical_loop_dir so the symlink check runs against the real on-disk
    # path rather than a user-supplied non-canonical form.
    local src_original
    if [[ "$src_canonical" == "$expected_src_methodology" ]]; then
        src_original="${canonical_loop_dir}/methodology-analysis-state.md"
    elif [[ "$src_canonical" == "$expected_src_finalize" ]]; then
        src_original="${canonical_loop_dir}/finalize-state.md"
    else
        src_original="${canonical_loop_dir}/state.md"
    fi
    if [[ -L "$src_original" ]]; then
        return 6  # Source is a symlink
    fi

    return 0
}

# Check if a path is inside .humanize/rlcr directory
is_in_humanize_loop_dir() {
    local path="$1"
    echo "$path" | grep -q '\.humanize/rlcr/'
}

# Check if a git add command would add .humanize files to version control
# Usage: git_adds_humanize "$command_lower"
# Returns 0 if the command would add .humanize files, 1 otherwise
#
# IMPORTANT: This function receives LOWERCASED input from the validator.
# Git flags like -A become -a after lowercasing, so we match both.
#
# Handles:
# - git -C <dir> add (git options before add subcommand)
# - Chained commands: cd repo && git add .humanize
# - Shell operators: ;, &&, ||, |
#
# Blocks:
# - git add .humanize or git add .humanize/
# - git add .humanize/* or git add .humanize/**
# - git add -f .humanize* (force add)
# - git add -f . or git add --force . (force add all - bypasses gitignore)
# - git add -f -A or git add --force --all (force add all)
# - git add -fA or similar combined flags
# - git add -A or git add --all (when .humanize exists)
# - git add . or git add * (when .humanize exists and not gitignored)
#
git_adds_humanize() {
    local cmd="$1"

    # Split command on shell operators and check each segment
    # This handles chained commands like: cd repo && git add .humanize
    local segments
    segments=$(echo "$cmd" | sed '
        s/&&/\n/g
        s/||/\n/g
        s/|/\n/g
        s/;/\n/g
    ')

    while IFS= read -r segment; do
        [[ -z "$segment" ]] && continue

        # Check if this segment contains a git add command
        # Pattern: git (with optional flags/options) followed by add
        # Handles:
        # - git add
        # - git -C dir add (short option with separate arg)
        # - git --git-dir=x add (long option with = arg)
        # - git -c key=value add (short option with = arg)
        # The pattern allows any non-add tokens between git and add
        if ! echo "$segment" | grep -qE '(^|[[:space:]])git[[:space:]]+([^[:space:]]+[[:space:]]+)*add([[:space:]]|$)'; then
            continue
        fi

        # Extract the part after "add" for analysis
        local add_args
        add_args=$(echo "$segment" | sed -n 's/.*[[:space:]]add[[:space:]]*//p')

        # Normalize add_args: strip quotes for path matching
        # This handles: git add ".humanize", git add '.humanize'
        local add_args_normalized
        add_args_normalized=$(echo "$add_args" | sed "s/[\"']//g")

        # Check for direct .humanize reference (blocked regardless of other flags)
        # Handles: .humanize, ./.humanize, path/to/.humanize, ".humanize", '.humanize'
        # Pattern matches .humanize at start, after space, after / or ./ AND followed by end, /, or space
        # This avoids over-blocking .humanizeconfig or .humanize-backup.
        if echo "$add_args_normalized" | grep -qE '(^|[[:space:]]|/)\.humanize($|/|[[:space:]])'; then
            return 0
        fi

        # Check for -f or --force flag (including combined flags like -fa, -af)
        local has_force=false
        if echo "$add_args" | grep -qE '(^|[[:space:]])--force([[:space:]]|$)'; then
            has_force=true
        elif echo "$add_args" | grep -qE '(^|[[:space:]])-[a-z]*f[a-z]*([[:space:]]|$)'; then
            has_force=true
        fi

        # Check for -A/--all flag (including combined flags like -fa, -af)
        # Note: input is lowercased, so -A becomes -a
        local has_all=false
        if echo "$add_args" | grep -qE '(^|[[:space:]])--all([[:space:]]|$)'; then
            has_all=true
        elif echo "$add_args" | grep -qE '(^|[[:space:]])-[a-z]*a[a-z]*([[:space:]]|$)'; then
            has_all=true
        fi

        # Check for broad scope targets: . or * alone
        local has_broad_scope=false
        if echo "$add_args" | grep -qE '(^|[[:space:]])(\.|\*)([[:space:]]|$)'; then
            has_broad_scope=true
        fi

        # Force add with any broad scope (force bypasses gitignore entirely)
        if [[ "$has_force" == "true" ]]; then
            if [[ "$has_all" == "true" ]] || [[ "$has_broad_scope" == "true" ]]; then
                return 0
            fi
        fi

        # Check if .humanize exists - needed for non-force blocking
        if [[ ! -d ".humanize" ]]; then
            continue
        fi

        # git add -A/--all when .humanize exists
        # Always block because -A adds all changes including untracked files
        if [[ "$has_all" == "true" ]]; then
            return 0
        fi

        # git add . or git add * when .humanize exists and not gitignored
        # Only block if .humanize is NOT protected by gitignore
        if [[ "$has_broad_scope" == "true" ]]; then
            if ! git check-ignore -q .humanize 2>/dev/null; then
                return 0
            fi
        fi
    done <<< "$segments"

    return 1
}

# Standard message for blocking git add .humanize commands
# Usage: git_add_humanize_blocked_message
git_add_humanize_blocked_message() {
    local fallback="# Git Add Blocked: .humanize Protection

The \`.humanize/\` directory contains local loop state that should NOT be committed.

Your command was blocked because it would add .humanize files to version control.

## Allowed Commands

Use specific file paths instead of broad patterns:

    git add <specific-file>
    git add src/
    git add -p  # patch mode

## Blocked Commands

These commands are blocked when .humanize exists:

    git add .humanize      # direct reference
    git add -A             # adds all including .humanize
    git add --all          # adds all including .humanize
    git add .              # may include .humanize if not gitignored
    git add -f .           # force bypasses gitignore

## Adding .humanize to .gitignore

If you need to add \`.humanize*\` to \`.gitignore\`, follow these steps:

1. Edit \`.gitignore\` to append \`.humanize*\`
2. Run: \`git add .gitignore\`
3. Run: \`git commit -m \"Add humanize local folder into gitignore\"\`

IMPORTANT: The commit message must NOT contain the literal string \".humanize\" to avoid triggering this protection."

    load_and_render_safe "$TEMPLATE_DIR" "block/git-add-humanize.md" "$fallback"
}

# Return success if local Humanize runtime state has entered git tracking or the index.
# Untracked .humanize state is allowed; tracked or staged state must be blocked.
# Usage: git_has_tracked_humanize_state [project_root]
#
# Intentionally scoped to .humanize/ to stay consistent with git_adds_humanize,
# which explicitly allows unrelated paths like .humanize-backup or
# .humanizeconfig (see tests/test-humanize-escape.sh). ls-files covers both
# committed entries and paths staged via git add; paths the user has staged for
# removal via git rm --cached are correctly omitted so the user can unstick
# themselves without being re-blocked.
git_has_tracked_humanize_state() {
    local project_root="${1:-.}"

    if [[ ! -d "$project_root/.git" ]] && ! git -C "$project_root" rev-parse --git-dir >/dev/null 2>&1; then
        return 1
    fi

    if git -C "$project_root" ls-files -- .humanize 2>/dev/null | grep -q '.'; then
        return 0
    fi

    return 1
}

# Standard message for blocking tracked/staged .humanize state.
# Usage: git_tracked_humanize_blocked_message
git_tracked_humanize_blocked_message() {
    local fallback="# Tracked Humanize State Blocked

Detected tracked or staged files under \`.humanize/\`.

These files are local Humanize loop state and must remain outside version control.

## Required Fix

1. Remove Humanize state from the index:

       git rm --cached -r .humanize

2. Keep only real project files staged.
3. Retry the stop action after the local state is no longer tracked.

## Important

- Do NOT use \`git add -f\` on Humanize state files.
- Do NOT commit RLCR trackers, round summaries, contracts, or cancel/finalize markers."

    load_and_render_safe "$TEMPLATE_DIR" "block/git-tracked-humanize.md" "$fallback"
}

# Standard message for blocking direct execution of hook scripts
# Usage: stop_hook_direct_execution_blocked_message
stop_hook_direct_execution_blocked_message() {
    local fallback="# Direct Execution of Hook Scripts Blocked

You are attempting to directly execute a hook script via Bash. This is not allowed during an active loop.

Hook scripts are managed by the hooks system and are triggered automatically at the appropriate time. You should NOT execute them manually.

Simply complete your work and end your response. The hooks system will handle the rest automatically."

    load_and_render_safe "$TEMPLATE_DIR" "block/stop-hook-direct-execution.md" "$fallback"
}

# Check if a shell command attempts to modify a file matching the given pattern
# Usage: command_modifies_file "$command_lower" "goal-tracker\.md"
# Returns 0 if the command tries to modify the file, 1 otherwise
command_modifies_file() {
    local command_lower="$1"
    local file_pattern="$2"

    local patterns=(
        ">[[:space:]]*[^[:space:]]*${file_pattern}"
        ">>[[:space:]]*[^[:space:]]*${file_pattern}"
        "tee[[:space:]]+(-a[[:space:]]+)?[^[:space:]]*${file_pattern}"
        "sed[[:space:]]+-i[^|]*${file_pattern}"
        "awk[[:space:]]+-i[[:space:]]+inplace[^|]*${file_pattern}"
        "perl[[:space:]]+-[^[:space:]]*i[^|]*${file_pattern}"
        "(mv|cp)[[:space:]]+[^[:space:]]+[[:space:]]+[^[:space:]]*${file_pattern}"
        "rm[[:space:]]+(-[rfv]+[[:space:]]+)?[^[:space:]]*${file_pattern}"
        "dd[[:space:]].*of=[^[:space:]]*${file_pattern}"
        "truncate[[:space:]]+[^|]*${file_pattern}"
        "printf[[:space:]].*>[[:space:]]*[^[:space:]]*${file_pattern}"
        "exec[[:space:]]+[0-9]*>[[:space:]]*[^[:space:]]*${file_pattern}"
    )

    for pattern in "${patterns[@]}"; do
        if echo "$command_lower" | grep -qE "$pattern"; then
            return 0
        fi
    done
    return 1
}

# Standard message for blocking goal-tracker modifications after Round 0
# Usage: goal_tracker_blocked_message "$current_round" "$correct_goal_tracker_path"
goal_tracker_blocked_message() {
    local current_round="$1"
    local correct_path="$2"
    local fallback="# Goal Tracker Update Blocked (Round {{CURRENT_ROUND}})

After Round 0, you may update only the **MUTABLE SECTION** of the active goal tracker.

Use Write or Edit on: {{CORRECT_PATH}}

Rules:
- Keep the **IMMUTABLE SECTION** unchanged
- Do not modify `goal-tracker.md` via Bash
- Do not write to an old loop session's tracker"

    load_and_render_safe "$TEMPLATE_DIR" "block/goal-tracker-modification.md" "$fallback" \
        "CURRENT_ROUND=$current_round" \
        "CORRECT_PATH=$correct_path"
}

# End the loop by renaming state.md to indicate exit reason
# Usage: end_loop "$loop_dir" "$state_file" "complete|cancel|maxiter|stop|unexpected"
# Arguments:
#   $1 - loop_dir: Path to the loop directory
#   $2 - state_file: Path to the state.md file
#   $3 - reason: One of complete, cancel, maxiter, stop, unexpected
# Returns: 0 on success, 1 on failure
end_loop() {
    local loop_dir="$1"
    local state_file="$2"
    local reason="$3"  # complete, cancel, maxiter, stop, unexpected

    # Validate reason
    case "$reason" in
        complete|cancel|maxiter|stop|unexpected)
            ;;
        *)
            echo "Error: Invalid end_loop reason: $reason" >&2
            return 1
            ;;
    esac

    local target_name="${reason}-state.md"

    if [[ -f "$state_file" ]]; then
        mv "$state_file" "$loop_dir/$target_name"
        echo "Loop ended: $reason" >&2
        echo "State preserved as: $loop_dir/$target_name" >&2
        return 0
    else
        echo "Warning: State file not found, cannot end loop" >&2
        return 1
    fi
}

# Source background-task helpers. Sourced at the bottom so every function
# above is available to callers that only need loop-common.sh, while bg-aware
# callers (the stop hook, the test suite) still get the bg helpers via a
# single source of loop-common.sh.
#
# _LOOP_COMMON_DIR is set here instead of at the top of the file because
# loop-bg-tasks.sh lives in the same directory as this file and we want to
# locate it regardless of how loop-common.sh was sourced.
_LOOP_COMMON_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
# shellcheck source=loop-bg-tasks.sh
source "$_LOOP_COMMON_DIR/loop-bg-tasks.sh"