import urllib.request
import urllib.parse
import json
import ssl
from datetime import datetime, timezone, timedelta
import wmill

JST = timezone(timedelta(hours=9))


def main():
    # シークレット取得
    api_key = wmill.get_variable("u/admin/NOTIFICATION_API_KEY")
    line_token = wmill.get_variable("u/admin/LINE_CHANNEL_ACCESS_TOKEN")
    line_to = wmill.get_variable("u/admin/LINE_TO")

    # 前回実行時刻を取得（初回は現在時刻 - 10分）
    try:
        last_checked = wmill.get_variable("u/admin/SHIRAOU_LAST_CHECKED_AT")
        if not last_checked:
            last_checked = None
    except Exception:
        last_checked = None

    if last_checked:
        since = last_checked
    else:
        since = (datetime.now(JST) - timedelta(minutes=10)).isoformat()

    print(f"[通知] 変更確認: since={since}")

    # API呼び出し
    ssl_ctx = ssl.create_default_context()
    ssl_ctx.check_hostname = False
    ssl_ctx.verify_mode = ssl.CERT_NONE

    params = urllib.parse.urlencode({"since": since})
    url = f"https://shiraou.keinafarm.net/reservations/api/changes/?{params}"

    req = urllib.request.Request(url, headers={"X-API-Key": api_key})
    with urllib.request.urlopen(req, context=ssl_ctx, timeout=30) as resp:
        data = json.loads(resp.read().decode("utf-8"))

    checked_at = data["checked_at"]
    reservations = data.get("reservations", [])
    usages = data.get("usages", [])

    print(f"[通知] checked_at={checked_at}, 予約={len(reservations)}件, 実績={len(usages)}件")

    # 変更があればLINE通知（エラー時は状態を更新しない）
    if reservations or usages:
        message = _format_message(reservations, usages)
        _send_line(line_token, line_to, message)
        print("[通知] LINE送信完了")
    else:
        print("[通知] 変更なし、通知スキップ")

    # 正常完了時のみ状態更新
    wmill.set_variable("u/admin/SHIRAOU_LAST_CHECKED_AT", checked_at)
    print(f"[通知] last_checked_at更新: {checked_at}")

    return {
        "since": since,
        "checked_at": checked_at,
        "reservations_count": len(reservations),
        "usages_count": len(usages),
        "notified": bool(reservations or usages),
    }


def _format_message(reservations, usages):
    lines = ["\U0001f4cb 営農システム 変更通知\n"]

    OP_R = {
        "create": ("\U0001f7e2", "予約作成"),
        "update": ("\U0001f535", "予約変更"),
        "cancel": ("\U0001f534", "予約キャンセル"),
    }
    OP_U = {
        "create": ("\U0001f7e2", "実績登録"),
        "update": ("\U0001f535", "実績修正"),
        "delete": ("\U0001f534", "実績削除"),
    }

    for r in reservations:
        start = r["start_at"][:16].replace("T", " ")
        end = r["end_at"][:16].replace("T", " ")
        icon, label = OP_R.get(r["operation"], ("\u26aa", r["operation"]))
        lines += [
            f"{icon} {label}",
            f"  機械: {r['machine_name']}",
            f"  利用者: {r['user_name']}",
            f"  日時: {start} \uff5e {end}",
        ]
        if r.get("reason"):
            lines.append(f"  理由: {r['reason']}")
        lines.append("")

    for u in usages:
        start = u["start_at"][:16].replace("T", " ")
        icon, label = OP_U.get(u["operation"], ("\u26aa", u["operation"]))
        lines += [
            f"{icon} {label}",
            f"  機械: {u['machine_name']}",
            f"  利用者: {u['user_name']}",
            f"  利用量: {u['amount']}{u['unit']}",
            f"  日: {start[:10]}",
        ]
        if u.get("reason"):
            lines.append(f"  理由: {u['reason']}")
        lines.append("")

    return "\n".join(lines).strip()


def _send_line(token, to, message):
    payload = json.dumps({
        "to": to,
        "messages": [{"type": "text", "text": message}],
    }).encode("utf-8")

    req = urllib.request.Request(
        "https://api.line.me/v2/bot/message/push",
        data=payload,
        headers={
            "Authorization": f"Bearer {token}",
            "Content-Type": "application/json",
        },
        method="POST",
    )
    with urllib.request.urlopen(req, timeout=30) as resp:
        return resp.read().decode("utf-8")