"""
Recovery script: reconstruct directory tree from a specific run.

Usage: python recovery.py <run_id> <output_dir>

For a given run_id, finds all files that existed at that point
(first_seen_run <= run_id AND last_seen_run >= run_id)
and copies them from backup storage to output_dir preserving
the original directory structure.
"""

import os
import sys
import shutil
from indexer.config import DB_CONFIG, BACKUP_PATH
from indexer.db import get_connection
from indexer.backup import blob_path


def recover(run_id: int, output_dir: str):
    conn = get_connection()
    cur = conn.cursor()

    cur.execute(
        """SELECT relative_path, content_hash
           FROM files
           WHERE first_seen_run <= %s AND last_seen_run >= %s""",
        (run_id, run_id)
    )
    rows = cur.fetchall()
    conn.close()

    if not rows:
        print(f"No files found for run #{run_id}.")
        return

    print(f"Recovering {len(rows)} files from run #{run_id} to {output_dir}")
    recovered = 0
    missing = 0

    for relative_path, content_hash in rows:
        source = blob_path(BACKUP_PATH, content_hash)
        target = os.path.join(output_dir, relative_path.replace("/", os.sep))

        if not os.path.exists(source):
            print(f"  MISSING blob: {content_hash.hex()} for {relative_path}")
            missing += 1
            continue

        os.makedirs(os.path.dirname(target), exist_ok=True)
        shutil.copy2(source, target)
        recovered += 1

    print(f"\nRecovered: {recovered}  Missing blobs: {missing}")


if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: python recovery.py <run_id> <output_dir>")
        sys.exit(1)

    run_id = int(sys.argv[1])
    output_dir = sys.argv[2]
    recover(run_id, output_dir)