import os
import subprocess
import sys

from .parser import RcclLogParser


def run_with_input(
    *,
    command: list[str],
    summary: bool,
    verbose: bool,
    hosts: list[str] | None,
    ranks: list[str] | None,
    rank: int,
):
    """Handle all three input modes: stdin, files, or command execution"""
    log_prefix = f"[Rank {rank}]"

    # Case 1: No command provided - check for stdin
    if not command:
        if not sys.stdin.isatty():
            return _process_stdin(
                summary=summary, verbose=verbose, hosts=hosts, ranks=ranks, rank=rank
            )
        else:
            return None

    # Case 2: Check if first argument is an existing file (treat as log file)
    if os.path.isfile(command[0]):
        return _process_files(
            summary=summary,
            verbose=verbose,
            hosts=hosts,
            ranks=ranks,
            rank=rank,
            log_prefix=log_prefix,
            filenames=command,
        )

    # Case 3: Execute as command
    return _execute_command(
        summary=summary, verbose=verbose, rank=rank, log_prefix=log_prefix, cmd=command
    )


def _process_stdin(
    *, summary: bool, verbose: bool, hosts: list[str] | None, ranks: list[str] | None, rank: int
):
    rccl_parser = RcclLogParser(verbose=verbose, hosts=hosts, ranks=ranks)
    for line in sys.stdin:
        if not summary:
            print(f"{line}", end="", flush=True)
        rccl_parser.collect(line)

    if rank == 0:
        rccl_parser.report()
    return 0


def _process_files(
    *,
    summary: bool,
    verbose: bool,
    hosts: list[str] | None,
    ranks: list[str] | None,
    rank: int,
    log_prefix: str,
    filenames: list[str],
):
    rccl_parser = RcclLogParser(verbose=verbose, hosts=hosts, ranks=ranks)
    for filename in filenames:
        if not os.path.isfile(filename):
            print(f"{log_prefix} Error: File not found: {filename}")
            return 1
        with open(filename, encoding="utf-8", errors="replace") as f:
            for line in f:
                if not summary:
                    print(f"{line}", end="", flush=True)
                rccl_parser.collect(line)

    if rank == 0:
        rccl_parser.report()
    return 0


def _execute_command(*, summary: bool, verbose: bool, rank: int, log_prefix: str, cmd: list[str]):
    env = os.environ.copy()
    env["NCCL_DEBUG"] = "INFO"
    env["NCCL_DEBUG_SUBSYS"] = "ALL"

    print(f"{log_prefix} [Wrapper] Running command: {' '.join(cmd)}")

    parser = RcclLogParser()
    process = subprocess.Popen(
        cmd,
        env=env,
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        text=True,
        bufsize=1,
    )

    if process.stdout is not None:
        for line in process.stdout:
            if not summary:
                print(f"{line}", end="", flush=True)
            parser.collect(line)

    process.wait()

    if rank == 0:
        parser.report(verbose=verbose)

    return process.returncode