# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.

"""
Entry point for running the parser package as a script.

Usage:
    # With output directory:
    python ... --output-dir /path/to/output
"""

import argparse
import concurrent.futures
import os
import shutil
import subprocess
import sys
import tempfile
import traceback

from .config import ApiViewSnapshotConfig, parse_config_file
from .doxygen import get_doxygen_bin, run_doxygen
from .main import build_snapshot
from .path_utils import get_react_native_dir
from .snapshot_diff import validate_snapshots


def run_command(
    cmd: list[str],
    label: str,
    verbose: bool = False,
    **kwargs,
) -> subprocess.CompletedProcess:
    """Run a subprocess command with consistent error handling."""
    result = subprocess.run(cmd, **kwargs)
    if result.returncode != 0:
        stderr_output = result.stderr or ""
        if isinstance(stderr_output, bytes):
            stderr_output = stderr_output.decode("utf-8", errors="replace")
        print(f"{label} failed (exit code {result.returncode})", file=sys.stderr)
        if stderr_output:
            print(stderr_output, file=sys.stderr)
        raise RuntimeError(
            f"{label} finished with error (exit code {result.returncode})"
        )
    elif verbose:
        print(f"{label} finished successfully")
    return result


def build_codegen(
    platform: str,
    verbose: bool = False,
    output_path: str = "./api/codegen",
    label: str = "",
) -> str:
    react_native_dir = os.path.join(get_react_native_dir(), "packages", "react-native")

    node_bin = os.environ.get("NODE_BIN", "node")

    run_command(
        [
            node_bin,
            "./scripts/generate-codegen-artifacts.js",
            "--path",
            "./",
            "--outputPath",
            output_path,
            "--targetPlatform",
            platform,
            "--forceOutputPath",
        ],
        label=f"[{label}] Codegen" if label else "Codegen",
        verbose=verbose,
        cwd=react_native_dir,
        capture_output=True,
        text=True,
    )

    if os.path.isabs(output_path):
        return output_path
    return os.path.join(react_native_dir, output_path)


def build_snapshot_for_view(
    api_view: str,
    react_native_dir: str,
    include_directories: list[str],
    exclude_patterns: list[str],
    definitions: dict[str, str | int],
    output_dir: str,
    codegen_dir: str | None = None,
    verbose: bool = True,
    input_filter: str = None,
    work_dir: str | None = None,
    exclude_symbols: list[str] | None = None,
) -> str:
    if verbose:
        print(f"[{api_view}] Generating API view")

    include_directories = list(include_directories)

    if work_dir is None:
        work_dir = os.path.join(react_native_dir, "api")

    if codegen_dir is not None:
        include_directories.append(codegen_dir)
    elif verbose:
        print(f"[{api_view}] Skipping codegen")

    config_file = f".doxygen.config.{api_view}.generated"

    run_doxygen(
        working_dir=react_native_dir,
        include_directories=include_directories,
        exclude_patterns=exclude_patterns,
        definitions=definitions,
        input_filter=input_filter,
        verbose=verbose,
        output_dir=work_dir,
        config_file=config_file,
        label=api_view,
    )

    if verbose:
        print(f"[{api_view}] Building snapshot")

    snapshot = build_snapshot(
        os.path.join(work_dir, "xml"), exclude_symbols=exclude_symbols
    )
    snapshot_string = snapshot.to_string()

    output_file = os.path.join(output_dir, f"{api_view}Cxx.api")
    os.makedirs(output_dir, exist_ok=True)

    with open(output_file, "w") as f:
        f.write("// @" + "generated by scripts/cxx-api\n\n")
        f.write(snapshot_string)

    return snapshot_string


def build_snapshots(
    snapshot_configs: list[ApiViewSnapshotConfig],
    react_native_dir: str,
    output_dir: str,
    input_filter: str | None,
    verbose: bool,
    view_filter: str | None = None,
    is_test: bool = False,
    keep_xml: bool = False,
) -> None:
    if not is_test:
        configs_to_build = [
            config
            for config in snapshot_configs
            if not view_filter or config.snapshot_name == view_filter
        ]

        with tempfile.TemporaryDirectory(prefix="cxx-api-") as parent_tmp:
            # Run codegen once per unique platform before parallel snapshot generation.
            # Debug/release variants share the same codegen output, and running
            # multiple codegen processes in parallel causes race conditions
            # (e.g. concurrent yarn install in buildCodegenIfNeeded).
            codegen_dirs: dict[str, str] = {}
            for config in configs_to_build:
                platform = config.codegen_platform
                if platform is not None and platform not in codegen_dirs:
                    codegen_output = os.path.join(parent_tmp, f"codegen-{platform}")
                    os.makedirs(codegen_output, exist_ok=True)
                    codegen_dirs[platform] = build_codegen(
                        platform,
                        verbose=verbose,
                        output_path=codegen_output,
                        label=platform,
                    )

            with concurrent.futures.ThreadPoolExecutor() as executor:
                futures = {}
                for config in configs_to_build:
                    work_dir = os.path.join(parent_tmp, config.snapshot_name)
                    os.makedirs(work_dir, exist_ok=True)
                    future = executor.submit(
                        build_snapshot_for_view,
                        api_view=config.snapshot_name,
                        react_native_dir=react_native_dir,
                        include_directories=config.inputs,
                        exclude_patterns=config.exclude_patterns,
                        definitions=config.definitions,
                        output_dir=output_dir,
                        codegen_dir=codegen_dirs.get(config.codegen_platform),
                        verbose=verbose,
                        input_filter=input_filter if config.input_filter else None,
                        work_dir=work_dir,
                        exclude_symbols=config.exclude_symbols,
                    )
                    futures[future] = config.snapshot_name

                errors = []
                for future in concurrent.futures.as_completed(futures):
                    view_name = futures[future]
                    try:
                        future.result()
                    except Exception as e:
                        errors.append((view_name, e))
                        if verbose:
                            print(
                                f"[{view_name}] Error generating:\n"
                                f"{traceback.format_exc()}"
                            )

                if errors:
                    failed_views = ", ".join(name for name, _ in errors)
                    raise RuntimeError(f"Failed to generate snapshots: {failed_views}")
    else:
        work_dir = os.path.join(react_native_dir, "api")
        snapshot = build_snapshot_for_view(
            api_view="Test",
            react_native_dir=react_native_dir,
            include_directories=[],
            exclude_patterns=[],
            definitions={},
            output_dir=output_dir,
            codegen_dir=None,
            verbose=verbose,
            input_filter=input_filter,
            work_dir=work_dir,
        )

        if keep_xml:
            xml_src = os.path.join(work_dir, "xml")
            xml_dst = os.path.join(output_dir, "xml")
            if os.path.exists(xml_dst):
                shutil.rmtree(xml_dst)
            shutil.copytree(xml_src, xml_dst)
            if verbose:
                print(f"XML files saved to {xml_dst}")

        if verbose:
            print(snapshot)


def get_default_snapshot_dir() -> str:
    return os.path.join(get_react_native_dir(), "scripts", "cxx-api", "api-snapshots")


def main():
    parser = argparse.ArgumentParser(
        description="Generate API snapshots from C++ headers"
    )
    parser.add_argument(
        "--output-dir",
        type=str,
        help="Output directory for the snapshot",
    )
    parser.add_argument(
        "--validate",
        action="store_true",
        help="Generate snapshots to a temp directory and compare against committed ones",
    )
    parser.add_argument(
        "--validate-output",
        type=str,
        help="File path to write validate results to (used with --validate)",
    )
    parser.add_argument(
        "--snapshot-dir",
        type=str,
        help="Directory containing committed snapshots for comparison (used with --validate)",
    )
    parser.add_argument(
        "--view",
        type=str,
        help="Name of the API view to generate",
    )
    parser.add_argument(
        "--test",
        action="store_true",
        help="Run on the local test directory instead of the react-native directory",
    )
    parser.add_argument(
        "--xml",
        action="store_true",
        help="Keep the generated Doxygen XML files next to the .api output in a xml/ directory",
    )
    args = parser.parse_args()

    verbose = not args.validate

    doxygen_bin = get_doxygen_bin()
    version_result = subprocess.run(
        [doxygen_bin, "--version"],
        capture_output=True,
        text=True,
    )
    if verbose:
        print(f"Using Doxygen {version_result.stdout.strip()} ({doxygen_bin})")

    react_native_package_dir = (
        os.path.join(get_react_native_dir(), "packages", "react-native")
        if not args.test
        else os.path.join(get_react_native_dir(), "scripts", "cxx-api", "manual_test")
    )
    if verbose:
        print(f"Running in directory: {react_native_package_dir}")

    input_filter_path = os.path.join(
        get_react_native_dir(),
        "scripts",
        "cxx-api",
        "parser",
        "input_filters",
        "main.py",
    )

    input_filter = None
    if os.path.exists(input_filter_path):
        input_filter = f"python3 {input_filter_path}"

    config_path = os.path.join(
        get_react_native_dir(), "scripts", "cxx-api", "config.yml"
    )
    snapshot_configs = parse_config_file(
        config_path,
        get_react_native_dir(),
    )

    with tempfile.TemporaryDirectory() as tmpdir:
        snapshot_output_dir = (
            args.output_dir or tmpdir
            if args.validate
            else args.output_dir or get_default_snapshot_dir()
        )

        build_snapshots(
            output_dir=snapshot_output_dir,
            verbose=not args.validate,
            snapshot_configs=snapshot_configs,
            react_native_dir=react_native_package_dir,
            input_filter=input_filter,
            view_filter=args.view,
            is_test=args.test,
            keep_xml=args.xml,
        )

        if args.validate:
            snapshot_dir = args.snapshot_dir or get_default_snapshot_dir()

            if not validate_snapshots(
                snapshot_output_dir,
                snapshot_dir,
                output_file=args.validate_output,
            ):
                sys.exit(1)

            print("All snapshot validations passed")


if __name__ == "__main__":
    main()