#!/usr/bin/env bash
#
# Copy the quartermaster SQLite database into backups/ before any schema
# change, data migration, or destructive operation. Safe to run while the
# application is writing to the DB: uses Python's sqlite3.Connection.backup
# (the online backup API), not a plain file copy.
#
# Usage:
#   scripts/backup-db.sh [reason]
#
# `reason` becomes part of the backup filename. Defaults to "manual".
#
# Resolves the database path in this order:
#   1. QUARTERMASTER_DB_URL if it starts with sqlite:/// (uses the path part)
#   2. ./quartermaster.db relative to the repo root
#
# Exit status:
#   0  backup written, or source DB does not exist (nothing to do)
#   1  backup failed, or a non-file sqlite URL was supplied

set -euo pipefail

repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$repo_root"

reason="${1:-manual}"

exec python3 - "$reason" <<'PY'
import os
import re
import sqlite3
import sys
from datetime import datetime
from pathlib import Path

reason = sys.argv[1]

db_path = Path("quartermaster.db")
url = os.environ.get("QUARTERMASTER_DB_URL")
if url:
    if url.startswith("sqlite:///"):
        db_path = Path(url[len("sqlite:///"):])
    elif url.startswith("sqlite://"):
        print(f"backup-db.sh: non-file sqlite URL not supported: {url}", file=sys.stderr)
        sys.exit(1)
    else:
        print(f"backup-db.sh: QUARTERMASTER_DB_URL is not a sqlite URL: {url}", file=sys.stderr)
        sys.exit(1)

if not db_path.is_file():
    print(f"backup-db.sh: no database at {db_path}, nothing to back up.")
    sys.exit(0)

slug = re.sub(r"[^A-Za-z0-9]+", "-", reason).strip("-") or "manual"
timestamp = datetime.now().strftime("%Y%m%d-%H%M%S")
backup_root = os.environ.get("QUARTERMASTER_BACKUP_DIR")
if backup_root:
    dest_dir = Path(backup_root)
else:
    dest_dir = db_path.resolve().parent / "backups"
dest_dir.mkdir(parents=True, exist_ok=True)
dest = dest_dir / f"quartermaster-{timestamp}-{slug}.db"

src = sqlite3.connect(str(db_path))
try:
    dst = sqlite3.connect(str(dest))
    try:
        src.backup(dst)
    finally:
        dst.close()
finally:
    src.close()

print(f"backup-db.sh: {db_path} -> {dest} ({dest.stat().st_size} bytes)")
PY