# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

from __future__ import annotations

import argparse
import importlib
import json
import os
import sys
from collections.abc import Sequence
from pathlib import Path
from types import SimpleNamespace
from typing import Protocol

os.environ.setdefault("DYNAMO_SKIP_PYTHON_LOG_INIT", "1")

from dynamo.llm import KvRouterConfig, MockEngineArgs
from dynamo.replay import run_synthetic_trace_replay, run_trace_replay
from dynamo.replay.reporting import format_report_table, write_report_json


class PlannerProfileDataResult(Protocol):
    npz_path: Path | None


def resolve_planner_profile_data(
    planner_profile_data: Path | None,
) -> PlannerProfileDataResult:
    try:
        module = importlib.import_module("dynamo.mocker.args")
    except ImportError:
        if planner_profile_data is None:
            return SimpleNamespace(npz_path=None)
        return SimpleNamespace(
            npz_path=planner_profile_data
            if planner_profile_data.suffix == ".npz"
            else None
        )
    return module.resolve_planner_profile_data(planner_profile_data)


def _load_engine_args(raw_args: str | None):
    if raw_args is None:
        return None

    raw = json.loads(raw_args)
    if not isinstance(raw, dict):
        raise ValueError("engine-args must be a JSON object")
    worker_type = raw.pop("worker_type", None)
    if worker_type is not None:
        if "is_prefill" in raw or "is_decode" in raw:
            raise ValueError(
                "worker_type cannot be combined with is_prefill or is_decode"
            )
        if worker_type == "prefill":
            raw["is_prefill"] = True
        elif worker_type == "decode":
            raw["is_decode"] = True
        elif worker_type != "aggregated":
            raise ValueError(
                "worker_type must be one of 'aggregated', 'prefill', or 'decode'"
            )
    if "planner_profile_data" in raw:
        profile_data_result = resolve_planner_profile_data(
            Path(raw["planner_profile_data"])
        )
        if profile_data_result.npz_path is not None:
            raw["planner_profile_data"] = str(profile_data_result.npz_path)
        else:
            del raw["planner_profile_data"]
    return MockEngineArgs.from_json(json.dumps(raw))


def main(argv: Sequence[str] | None = None) -> int:
    parser = argparse.ArgumentParser(prog="python -m dynamo.replay")
    parser.add_argument("trace_file", nargs="?")
    parser.add_argument("--extra-engine-args")
    parser.add_argument("--prefill-engine-args")
    parser.add_argument("--decode-engine-args")
    parser.add_argument("--router-config")
    parser.add_argument("--input-tokens", type=int)
    parser.add_argument("--output-tokens", type=int)
    parser.add_argument(
        "--request-count",
        type=int,
        help="number of synthetic requests; when --turns-per-session > 1, this is the number of sessions",
    )
    parser.add_argument("--arrival-interval-ms", type=float, default=1.0)
    parser.add_argument("--turns-per-session", type=int, default=1)
    parser.add_argument("--shared-prefix-ratio", type=float, default=0.0)
    parser.add_argument("--num-prefix-groups", type=int, default=0)
    parser.add_argument("--inter-turn-delay-ms", type=float, default=0.0)
    parser.add_argument("--num-workers", type=int, default=1)
    parser.add_argument("--num-prefill-workers", type=int, default=1)
    parser.add_argument("--num-decode-workers", type=int, default=1)
    parser.add_argument("--replay-concurrency", type=int)
    parser.add_argument(
        "--replay-mode",
        choices=("offline", "online"),
        default="offline",
    )
    parser.add_argument(
        "--router-mode",
        choices=("round_robin", "kv_router"),
        default="round_robin",
    )
    parser.add_argument("--arrival-speedup-ratio", type=float, default=1.0)
    parser.add_argument(
        "--report-json",
        help="path to save the full replay report JSON; defaults to a timestamped file in the current directory",
    )
    args = parser.parse_args(list(sys.argv[1:] if argv is None else argv))

    using_trace_file = args.trace_file is not None
    synthetic_args = (args.input_tokens, args.output_tokens, args.request_count)
    using_synthetic = any(value is not None for value in synthetic_args) or any(
        (
            args.turns_per_session != 1,
            args.shared_prefix_ratio != 0.0,
            args.num_prefix_groups != 0,
            args.inter_turn_delay_ms != 0.0,
        )
    )

    if using_trace_file == using_synthetic:
        parser.error(
            "provide either trace_file or all of --input-tokens/--output-tokens/--request-count"
        )
    if using_synthetic and not all(value is not None for value in synthetic_args):
        parser.error(
            "synthetic replay requires --input-tokens, --output-tokens, and --request-count"
        )

    extra_engine_args = _load_engine_args(args.extra_engine_args)
    prefill_engine_args = _load_engine_args(args.prefill_engine_args)
    decode_engine_args = _load_engine_args(args.decode_engine_args)
    router_config = (
        KvRouterConfig.from_json(args.router_config)
        if args.router_config is not None
        else None
    )

    if using_trace_file:
        report = run_trace_replay(
            args.trace_file,
            extra_engine_args=extra_engine_args,
            prefill_engine_args=prefill_engine_args,
            decode_engine_args=decode_engine_args,
            router_config=router_config,
            num_workers=args.num_workers,
            num_prefill_workers=args.num_prefill_workers,
            num_decode_workers=args.num_decode_workers,
            replay_concurrency=args.replay_concurrency,
            replay_mode=args.replay_mode,
            router_mode=args.router_mode,
            arrival_speedup_ratio=args.arrival_speedup_ratio,
        )
    else:
        report = run_synthetic_trace_replay(
            args.input_tokens,
            args.output_tokens,
            args.request_count,
            extra_engine_args=extra_engine_args,
            prefill_engine_args=prefill_engine_args,
            decode_engine_args=decode_engine_args,
            router_config=router_config,
            num_workers=args.num_workers,
            num_prefill_workers=args.num_prefill_workers,
            num_decode_workers=args.num_decode_workers,
            replay_concurrency=args.replay_concurrency,
            replay_mode=args.replay_mode,
            router_mode=args.router_mode,
            arrival_speedup_ratio=args.arrival_speedup_ratio,
            arrival_interval_ms=args.arrival_interval_ms,
            turns_per_session=args.turns_per_session,
            shared_prefix_ratio=args.shared_prefix_ratio,
            num_prefix_groups=args.num_prefix_groups,
            inter_turn_delay_ms=args.inter_turn_delay_ms,
        )

    report_path = write_report_json(report, args.report_json)
    sys.stdout.write(format_report_table(report))
    sys.stdout.write("\n")
    sys.stdout.write(f"Saved full report to: {report_path}\n")
    return 0
