#!/usr/bin/env python3

import argparse
import fnmatch
import json
from pathlib import Path
from typing import Any


def load_changed_files(args: argparse.Namespace) -> list[str]:
    changed_files: list[str] = []

    for path in args.changed_files_file:
        for line in Path(path).read_text().splitlines():
            candidate = line.strip()
            if candidate:
                changed_files.append(candidate)

    changed_files.extend(path.strip() for path in args.changed_file if path.strip())
    return changed_files


def matches_any(path: str, patterns: list[str]) -> bool:
    return any(fnmatch.fnmatchcase(path, pattern) for pattern in patterns)


def detect_changes(config: dict[str, Any], changed_files: list[str]) -> dict[str, Any]:
    workspaces: list[dict[str, Any]] = config["workspaces"]
    all_workspace_names = [workspace["name"] for workspace in workspaces]

    global_changed = any(
        matches_any(path, config["global_paths"])
        for path in changed_files
    )
    shared_crates_changed = any(
        matches_any(path, config["shared_crates_paths"])
        for path in changed_files
    )

    if global_changed:
        changed_workspaces = all_workspace_names
    else:
        changed_workspaces = [
            workspace["name"]
            for workspace in workspaces
            if any(matches_any(path, workspace["paths"]) for path in changed_files)
        ]

    selected_workspaces = set(changed_workspaces)
    build_targets: list[dict[str, str]] = []
    seen_build_targets: set[tuple[str, str]] = set()

    for workspace in workspaces:
        if workspace["name"] not in selected_workspaces:
            continue

        for package in workspace.get("build_packages", []):
            key = (workspace["name"], package)
            if key in seen_build_targets:
                continue
            seen_build_targets.add(key)
            build_targets.append({
                "workspace": workspace["name"],
                "package": package,
            })

    return {
        "workspaces": changed_workspaces,
        "build_targets": build_targets,
        "any_changed": global_changed or bool(changed_workspaces),
        "build_changed": bool(build_targets),
        "global_changed": global_changed,
        "shared_crates_changed": shared_crates_changed,
    }


def write_github_output(path: Path, result: dict[str, Any]) -> None:
    serialized = {
        "workspaces": json.dumps(result["workspaces"], separators=(",", ":")),
        "build_targets": json.dumps(result["build_targets"], separators=(",", ":")),
        "any_changed": str(result["any_changed"]).lower(),
        "build_changed": str(result["build_changed"]).lower(),
        "global_changed": str(result["global_changed"]).lower(),
        "shared_crates_changed": str(result["shared_crates_changed"]).lower(),
    }

    with path.open("a", encoding="utf-8") as handle:
        for key, value in serialized.items():
            handle.write(f"{key}={value}\n")


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Map changed files to PhotonCloud CI workspaces."
    )
    parser.add_argument(
        "--config",
        required=True,
        help="Path to the JSON CI workspace inventory.",
    )
    parser.add_argument(
        "--changed-files-file",
        action="append",
        default=[],
        help="File containing newline-separated changed paths.",
    )
    parser.add_argument(
        "--changed-file",
        action="append",
        default=[],
        help="Single changed path. Can be repeated.",
    )
    parser.add_argument(
        "--github-output",
        help="Optional path to append GitHub Actions step outputs.",
    )
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    config = json.loads(Path(args.config).read_text())
    changed_files = load_changed_files(args)
    result = detect_changes(config, changed_files)

    if args.github_output:
        write_github_output(Path(args.github_output), result)

    print(json.dumps(result, indent=2, sort_keys=True))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())