"""db_daily_backup.py — mofin.db 每日在线备份（sqlite3 backup API，一致性快照 + gzip 压缩）

背景（2026-07-21）：I/O 风暴导致 WAL 帧损坏，出现 transient "database disk image is malformed"。
背景（2026-08-27）：DB 严重损坏（101 处页错误），发现磁盘 160G 被未压缩备份占满。
策略（2026-08-28 更新：压缩存储）：
- 每日 07:50（premarket 前）备份到 /home/hmo/MoFin/data/backups/compressed/
- sqlite3 .backup API：在线一致性快照，不锁库
- gzip 压缩后存储（7.5GB → 1.8GB，省 76% 磁盘）
- 备份前源库 quick_check（防备份损坏库）
- 保留最近 14 天压缩版 + 每周一长期版，自动清理
"""
import sqlite3, os, glob, gzip, shutil
from datetime import datetime

# ── 消息通道统一路由(broadcast/xmpp by delivery) ──
# 注：备份脚本不用 messenger hook（stdout 会被块化缓冲，导致备份进度卡住不输出）

SRC = "/home/hmo/MoFin/data/mofin.db"
DST_DIR = "/home/hmo/MoFin/data/backups/compressed"
KEEP_DAILY = 14      # 保留最近 N 天
KEEP_WEEKLY = 12     # 每周一长期保留 N 周


def main():
    # 0. 备份前源库健康检查（防护：不备份损坏库）
    try:
        src_check = sqlite3.connect(f"file:{SRC}?mode=ro", uri=True, timeout=30)
        src_ok = src_check.execute("PRAGMA quick_check").fetchone()[0]
        src_check.close()
        if src_ok != "ok":
            print(f"[BACKUP] ❌ 源库 quick_check={src_ok}，中止备份（不备份损坏库）")
            return 1
        print(f"[BACKUP] 源库 quick_check: ok")
    except Exception as e:
        print(f"[BACKUP] ❌ 源库检查失败: {e}，中止")
        return 1

    os.makedirs(DST_DIR, exist_ok=True)
    stamp = datetime.now().strftime("%Y%m%d")
    dst_gz = os.path.join(DST_DIR, f"mofin_{stamp}.db.gz")

    # 1. sqlite3 backup API 在线快照（不带压缩的临时文件）
    tmp_db = os.path.join(DST_DIR, f".tmp_{stamp}.db")
    try:
        src = sqlite3.connect(f"file:{SRC}?mode=ro", uri=True, timeout=60)
        dst_conn = sqlite3.connect(tmp_db, timeout=60)
        src.backup(dst_conn)
        dst_conn.close()
        src.close()
        print(f"[BACKUP] 快照: {os.path.getsize(tmp_db)/1024/1024:.0f}MB")
    except Exception as e:
        print(f"[BACKUP] ❌ 快照失败: {e}")
        return 1

    # 2. 压缩
    try:
        with open(tmp_db, "rb") as f_in, gzip.open(dst_gz, "wb", compresslevel=1) as f_out:
            shutil.copyfileobj(f_in, f_out, length=1024*1024)
        print(f"[BACKUP] 压缩: {os.path.getsize(dst_gz)/1024/1024:.0f}MB")
        os.remove(tmp_db)
    except Exception as e:
        print(f"[BACKUP] ❌ 压缩失败: {e}")
        return 1

    # 3. 完整性验证（解压并 quick_check）
    try:
        verify_db = os.path.join(DST_DIR, f".verify_{stamp}.db")
        with gzip.open(dst_gz, "rb") as f_in, open(verify_db, "wb") as f_out:
            shutil.copyfileobj(f_in, f_out, length=1024*1024)
        conn = sqlite3.connect(f"file:{verify_db}?mode=ro", uri=True, timeout=30)
        ok = conn.execute("PRAGMA quick_check").fetchone()[0]
        conn.close()
        os.remove(verify_db)
        if ok != "ok":
            print(f"[VERIFY] ❌ quick_check: {ok}")
            return 1
        print(f"[VERIFY] quick_check: ok ✓")
    except Exception as e:
        print(f"[VERIFY] ❌ 验证失败: {e}")
        return 1

    # 4. 清理旧备份（保留最近 KEEP_DAILY 天 + 每周一长期）
    backups = sorted(glob.glob(os.path.join(DST_DIR, "mofin_*.db.gz")))
    # 先删除超过 KEEP_DAILY 的（除了周一）
    for old in backups[:-KEEP_DAILY]:
        fname = os.path.basename(old)  # mofin_YYYYMMDD.db.gz
        date_str = fname.replace("mofin_", "").replace(".db.gz", "")
        try:
            d = datetime.strptime(date_str, "%Y%m%d")
        except ValueError:
            continue
        if d.weekday() == 0:  # 周一 → 长期保留
            continue
        if len([b for b in backups if b >= old]) <= KEEP_DAILY:
            continue
        os.remove(old)
        print(f"[CLEAN] 删除旧备份 {os.path.basename(old)}")

    # 5. 统计
    total = sum(os.path.getsize(f) for f in glob.glob(os.path.join(DST_DIR, "mofin_*.db.gz")))
    print(f"[BACKUP] 备份目录总大小: {total/1024/1024/1024:.1f}GB ({len(glob.glob(os.path.join(DST_DIR, 'mofin_*.db.gz')))} 份)")
    return 0


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