"""Gitea webhook: принимает push-события, обновляет кэш, уведомляет подписчиков."""
import hmac
import hashlib
import json
from datetime import datetime
from flask import request, jsonify
from sqlmodel import Session, select
from ..db import engine
from ..models import Project
from ..helpers import (
    _project_subscriber_ids, notify_users,
)
from .. import config, gitea_api


def _verify_signature(raw_body, sig_header):
    if not config.GITEA_WEBHOOK_SECRET:
        return True
    if not sig_header:
        return False
    expected = hmac.new(
        config.GITEA_WEBHOOK_SECRET.encode("utf-8"),
        raw_body, hashlib.sha256).hexdigest()
    return hmac.compare_digest(expected, sig_header)


def register(app):

    @app.route("/webhooks/gitea", methods=["POST"])
    def gitea_webhook():
        raw = request.get_data() or b""
        sig = request.headers.get("X-Gitea-Signature", "")
        if not _verify_signature(raw, sig):
            return jsonify({"ok": False, "error": "invalid_signature"}), 401

        event_type = request.headers.get("X-Gitea-Event", "")
        try:
            payload = json.loads(raw.decode("utf-8"))
        except Exception:
            return jsonify({"ok": False, "error": "bad_json"}), 400

        repo_full = ((payload.get("repository") or {}).get("full_name") or "").strip()
        if not repo_full:
            return jsonify({"ok": False, "error": "no_repo"}), 400

        # Инвалидируем кэш gitea_api
        dropped = gitea_api.invalidate_cache(repo_full)

        # Найдём проект(ы), привязанные к этому репо
        linked_projects = []
        with Session(engine) as db_session:
            for p in db_session.exec(select(Project)).all():
                repo = p.gitea_repo or (gitea_api.extract_repo_from_url(p.gitea_url) if p.gitea_url else None)
                if repo == repo_full:
                    linked_projects.append({"id": p.id, "title": p.title})

        # Уведомления о push
        if event_type == "push":
            commits = payload.get("commits") or []
            pusher = (payload.get("pusher") or {}).get("username") or ""
            branch = (payload.get("ref") or "").replace("refs/heads/", "") or "?"

            if commits:
                n = len(commits)
                first_msg = (commits[0].get("message") or "").split("\n")[0][:100]
                title = f"Новый push в {repo_full} ({n} коммит{'ов' if n > 1 else ''})"
                body = f"Ветка: {branch}\nАвтор: {pusher}\nПервый коммит: {first_msg}"
                with Session(engine) as s:
                    for lp in linked_projects:
                        sub_ids = _project_subscriber_ids(s, lp["id"])
                        if sub_ids:
                            notify_users(sub_ids, title, body,
                                         link_url=f"/projects/{lp['id']}",
                                         kind="info")

        # Gitea ждёт 200-204
        return jsonify({
            "ok": True,
            "event": event_type,
            "repo": repo_full,
            "cache_invalidated_keys": dropped,
            "linked_projects": linked_projects,
        })