#!/usr/bin/env python3
"""
check_update.py — 检查 / 更新 Holy Crab Skill 版本

用法：
    python3 check_update.py              # 检查更新
    python3 check_update.py --force      # 强制更新到最新版本
    python3 check_update.py --install    # 从后端下载并安装
"""

import hashlib
import json
import os
import shutil
import sys
import zipfile
from datetime import datetime
from pathlib import Path

SCRIPT_DIR = Path(__file__).resolve().parent
SKILL_DIR = SCRIPT_DIR.parent
VERSION_FILE = SKILL_DIR / "VERSION"
BACKEND = os.environ.get("HC_BACKEND_URL", "http://localhost:8000").rstrip("/")
VERSION_API = f"{BACKEND}/api/v1/skill/holy-crab/version"
DOWNLOAD_API = f"{BACKEND}/api/v1/skill/holy-crab/download"


def local_version() -> dict | None:
    if not VERSION_FILE.exists():
        return None
    return json.loads(VERSION_FILE.read_text())


def compute_hash(path: Path) -> str:
    h = hashlib.sha256()
    with open(path, "rb") as f:
        for chunk in iter(lambda: f.read(65536), b""):
            h.update(chunk)
    return h.hexdigest()[:16]


def update_version_file(remote: dict) -> None:
    # 更新本地 VERSION
    v = remote.copy()
    for fname, finfo in v.get("files", {}).items():
        fpath = SKILL_DIR / fname
        if fpath.exists():
            finfo["hash"] = compute_hash(fpath)
    VERSION_FILE.write_text(json.dumps(v, ensure_ascii=False, indent=2))


def check_update() -> tuple[bool, dict | None, dict | None]:
    """检查是否有更新。返回 (有更新, 本地版本, 远程版本)"""
    local = local_version()
    remote_v = None

    import urllib.request
    try:
        req = urllib.request.Request(VERSION_API, headers={"Accept": "application/json"})
        with urllib.request.urlopen(req, timeout=10) as resp:
            raw = json.loads(resp.read().decode("utf-8"))
            # 后端返回格式：{"data": {"version": {...}}}
            remote_v = raw.get("data", {}).get("version") or raw
    except Exception:
        return False, local, None

    if not local:
        return True, None, remote_v

    def parse_ver(v: str) -> tuple:
        return tuple(int(x) for x in v.split("."))

    local_ver = local.get("version", "0.0.0")
    remote_ver = remote_v.get("version", "0.0.0")
    has_update = parse_ver(remote_ver) > parse_ver(local_ver)
    return has_update, local, remote_v


def download_and_install() -> None:
    import urllib.request
    print("  📥 正在从后端下载...")
    try:
        req = urllib.request.Request(DOWNLOAD_API, headers={"Accept": "application/zip"})
        with urllib.request.urlopen(req, timeout=60) as resp:
            zip_data = resp.read()
    except urllib.error.HTTPError as e:
        body = e.read().decode("utf-8", errors="replace")
        print(f"  ❌ 下载失败 HTTP {e.code}: {body[:200]}")
        sys.exit(1)

    # 备份当前版本
    backup_dir = SKILL_DIR.parent / f"holy-crab.backup.{datetime.now().strftime('%Y%m%d%H%M%S')}"
    shutil.copytree(SKILL_DIR, backup_dir)
    print(f"  📦 当前版本已备份至: {backup_dir}")

    # 解压到 skill 目录
    import io
    with zipfile.ZipFile(io.BytesIO(zip_data), "r") as zf:
        members = [m for m in zf.namelist() if not m.endswith("/")]
        for member in members:
            # 去掉顶层目录名（skill 安装包通常带 holy-crab/v1.0.0/ 前缀）
            dst_name = member
            for prefix in [f"holy-crab-{VERSION_FILE.parent.name}/", "holy-crab/"]:
                if member.startswith(prefix):
                    dst_name = member[len(prefix):]
                    break
            if not dst_name or dst_name == member:
                # 直接从根目录解压的文件
                dst_name = member.split("/", 1)[1] if "/" in member else member

            dst = SKILL_DIR / dst_name
            dst.parent.mkdir(parents=True, exist_ok=True)
            if dst_name:
                dst.write_bytes(zf.read(member))

    print("  ✅ 安装完成！")


def main() -> None:
    force = "--force" in sys.argv
    install = "--install" in sys.argv or "-u" in sys.argv

    print()
    print("═" * 55)
    print("  🔍 Holy Crab Skill 版本检查")
    print("═" * 55)
    print()
    print(f"  后端地址: {BACKEND}")
    print(f"  本地路径: {SKILL_DIR}")
    print()

    local = local_version()
    if local:
        print(f"  本地版本: {local.get('version')}  ({local.get('released', '未知日期')})")
    else:
        print("  本地版本: 未安装")

    has_update, _, remote = check_update()

    if not remote:
        print()
        print("  ⚠️  无法连接到后端获取远程版本信息")
        print("  请确认：")
        print("    1. 后端是否已启动")
        print("    2. HC_BACKEND_URL 是否正确")
        print()
        sys.exit(1)

    print(f"  远程版本: {remote.get('version')}  ({remote.get('released', '未知日期')})")

    if not has_update and not force:
        print()
        print("  ✅ 当前已是最新版本，无需更新")
        print()
        if local:
            print("  文件状态:")
            for fname, finfo in local.get("files", {}).items():
                fpath = SKILL_DIR / fname
                status = "✅" if fpath.exists() else "❌ 缺失"
                print(f"    {status} {fname}")
        print()
        return

    print()
    print(f"  🆕 发现新版本: {remote.get('version')}")
    changelog = remote.get("changelog", "")
    if changelog:
        print(f"  更新内容: {changelog}")
    print()

    if install or force or "--yes" in sys.argv:
        confirm = True
    else:
        answer = input("  是否立即更新？(y/n): ").strip().lower()
        confirm = answer in ("y", "yes", "是")

    if confirm:
        download_and_install()
        # 更新本地 VERSION 记录
        if local_version():
            update_version_file(remote)
        print()
        print(f"  ✅ Holy Crab Skill 已更新到 {remote.get('version')}")
    else:
        print("  已取消更新")

    print()
    print("═" * 55)


if __name__ == "__main__":
    main()