#!/usr/bin/env python3
"""vfspublish：把 .svfs 发布成"一堆按 hash 命名的对象 + 一份清单"。

产出可以直接 `aws s3 sync` / `rclone copy` 到对象存储或静态托管：
对象名就是内容的 sha256，所以客户端的缓存策略可以是"永久"，
而且每个对象都能端到端校验（CDN 换不掉内容）。
"""

import argparse
import os
import sys

from .. import publish
from ..core import VFSFormatError


def publish_objects():
    parser = argparse.ArgumentParser(
        description="把虚拟文件系统导出成内容寻址的对象目录 + 清单"
    )
    parser.add_argument("db_file", help="SQLite数据库文件路径")
    parser.add_argument("out_dir", help="输出目录（会创建 blobs/ 与 manifest.json）")
    parser.add_argument(
        "--snapshot", metavar="ID", help="发布指定快照（默认取最新快照）"
    )
    parser.add_argument(
        "--shard",
        type=int,
        default=publish.DEFAULT_SHARD,
        help=f"blobs 的分片层数，0 表示不分片（默认 {publish.DEFAULT_SHARD}）",
    )
    parser.add_argument(
        "--overwrite",
        action="store_true",
        help="输出目录非空时也继续（会覆盖同名对象与清单）",
    )
    parser.add_argument(
        "--no-objects",
        action="store_true",
        help="只生成清单，不导出对象（用于只更新清单的场景）",
    )

    args = parser.parse_args()

    if not os.path.exists(args.db_file):
        print(f"错误: 数据库文件不存在: {args.db_file}")
        sys.exit(1)

    done = [0]

    def progress(current, total):
        done[0] = current
        if total and (current == total or current % 200 == 0):
            print(f"  导出对象: {current}/{total}", flush=True)

    try:
        if args.no_objects:
            from ..core import SQLiteVFS

            vfs = SQLiteVFS(args.db_file, readonly=True, snapshot_id=args.snapshot)
            try:
                manifest = publish.build_manifest(
                    vfs, snapshot_id=args.snapshot, shard=args.shard
                )
            finally:
                vfs.close()
            os.makedirs(args.out_dir, exist_ok=True)
            import json

            path = os.path.join(args.out_dir, publish.MANIFEST_NAME)
            payload = json.dumps(manifest, ensure_ascii=False, indent=2, sort_keys=True)
            with open(path, "w", encoding="utf-8") as f:
                f.write(payload)
            result = {
                "out_dir": os.path.abspath(args.out_dir),
                "manifest": path,
                "manifest_bytes": len(payload.encode("utf-8")),
                "objects": 0,
                "objects_bytes": 0,
                "files": manifest["stats"]["files"],
                "directories": manifest["stats"]["directories"],
                "dedup_saved": 0,
                "snapshot_id": manifest["snapshot"]["id"],
                "digest": manifest["snapshot"]["digest"],
            }
        else:
            result = publish.export_objects(
                args.db_file,
                args.out_dir,
                snapshot_id=args.snapshot,
                shard=args.shard,
                overwrite=args.overwrite,
                progress=progress,
            )
    except VFSFormatError as e:
        print(f"错误: {e}")
        sys.exit(1)
    except FileExistsError as e:
        print(f"错误: {e}")
        sys.exit(1)
    except Exception as e:
        print(f"错误: 发布失败: {e}")
        sys.exit(1)

    print("发布完成!")
    print(f"  快照: {result['snapshot_id']}  摘要: {(result['digest'] or '')[:16]}")
    print(f"  文件: {result['files']}  目录: {result['directories']}")
    print(f"  对象: {result['objects']} 个，共 {result['objects_bytes'] / 1024:.1f} KB（去重后的原始字节）")
    if result["dedup_saved"]:
        print(f"  去重省下: {result['dedup_saved'] / 1024:.1f} KB（原始总大小 - 去重后）")
    if result.get("compression_saved"):
        print(
            f"  库内实际占用: {result['stored_bytes'] / 1024:.1f} KB"
            f"（压缩省下 {result['compression_saved'] / 1024:.1f} KB）"
        )
    print(f"  清单: {result['manifest']}（{result['manifest_bytes'] / 1024:.1f} KB）")
    print(f"  输出目录: {result['out_dir']}")
    print("  下一步: 把整个输出目录同步到对象存储/静态托管即可")


if __name__ == "__main__":
    publish_objects()