#!/usr/bin/env python3
"""Synchronize issue labels to a Gitea repository."""

from __future__ import annotations

import argparse
import os
import pathlib
import sys
from typing import Any

from gitea_common import (
    GiteaClient,
    GiteaError,
    infer_target,
    load_dotenv,
    load_json,
    repo_path,
    repo_root,
    require_token,
)


DEFAULT_LABELS_FILE = pathlib.Path(__file__).resolve().parents[1] / "docs" / "gitea-labels.json"


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--root", type=pathlib.Path, default=pathlib.Path.cwd(), help="repository root or child path")
    parser.add_argument("--remote", default="origin", help="git remote to use for target inference")
    parser.add_argument("--labels-file", type=pathlib.Path, default=DEFAULT_LABELS_FILE)
    parser.add_argument("--env-file", type=pathlib.Path, help="dotenv file to read before using GITEA_* values")
    parser.add_argument("--apply", action="store_true", help="create or update labels in Gitea")
    args = parser.parse_args()

    try:
        root = repo_root(args.root)
        load_dotenv(args.env_file or root / ".env")
        target = infer_target(root, args.remote)
        labels = _load_labels(args.labels_file)
        token = require_token() if args.apply else os.environ.get("GITEA_TOKEN")

        print(f"Target: {target.display}")
        print(f"Labels file: {args.labels_file}")

        if not args.apply and not token:
            print("Dry run without GITEA_TOKEN: API comparison skipped.")
            for label in labels:
                print(f"would ensure {label['name']} ({label['color']})")
            return 0

        client = GiteaClient(target, token)
        existing = _labels_by_name(client, target.owner, target.repo)
        creates: list[dict[str, Any]] = []
        updates: list[tuple[dict[str, Any], dict[str, Any]]] = []

        for label in labels:
            current = existing.get(label["name"])
            if current is None:
                creates.append(label)
                continue

            patch = _diff_label(current, label)
            if patch:
                updates.append((current, patch))

        if not creates and not updates:
            print("No label changes needed.")
            return 0

        for label in creates:
            print(f"{'create' if args.apply else 'would create'} {label['name']}")
            if args.apply:
                client.request_json(
                    "POST",
                    repo_path(target.owner, target.repo, "/labels"),
                    body=label,
                )

        for current, patch in updates:
            print(f"{'update' if args.apply else 'would update'} {current['name']}: {', '.join(sorted(patch))}")
            if args.apply:
                client.request_json(
                    "PATCH",
                    repo_path(target.owner, target.repo, f"/labels/{current['id']}"),
                    body=patch,
                )

        return 0
    except GiteaError as exc:
        print(f"error: {exc}", file=sys.stderr)
        return 1


def _load_labels(path: pathlib.Path) -> list[dict[str, Any]]:
    payload = load_json(path)
    if not isinstance(payload, list):
        raise GiteaError(f"{path} must contain a JSON list")

    labels: list[dict[str, Any]] = []
    seen: set[str] = set()
    for index, item in enumerate(payload, start=1):
        if not isinstance(item, dict):
            raise GiteaError(f"label #{index} must be an object")
        label = {
            "name": str(item.get("name", "")).strip(),
            "color": str(item.get("color", "")).strip().lstrip("#").lower(),
            "description": str(item.get("description", "")).strip(),
            "exclusive": bool(item.get("exclusive", False)),
        }
        if not label["name"]:
            raise GiteaError(f"label #{index} is missing name")
        if label["name"] in seen:
            raise GiteaError(f"duplicate label name: {label['name']}")
        if not _is_hex_color(label["color"]):
            raise GiteaError(f"{label['name']} has invalid color {label['color']!r}")
        seen.add(label["name"])
        labels.append(label)
    return labels


def _labels_by_name(client: GiteaClient, owner: str, repo: str) -> dict[str, dict[str, Any]]:
    labels = client.paginate(repo_path(owner, repo, "/labels"))
    return {str(label.get("name")): label for label in labels}


def _diff_label(current: dict[str, Any], desired: dict[str, Any]) -> dict[str, Any]:
    patch: dict[str, Any] = {}
    if _normalize_color(current.get("color")) != desired["color"]:
        patch["color"] = desired["color"]
    if str(current.get("description") or "").strip() != desired["description"]:
        patch["description"] = desired["description"]
    if bool(current.get("exclusive", False)) != desired["exclusive"]:
        patch["exclusive"] = desired["exclusive"]
    return patch


def _normalize_color(value: Any) -> str:
    return str(value or "").strip().lstrip("#").lower()


def _is_hex_color(value: str) -> bool:
    if len(value) != 6:
        return False
    return all(char in "0123456789abcdef" for char in value)


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