from pathlib import Path
import sys

from sqlalchemy import text

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))

from app.database import engine  # noqa: E402


TARGET_CHARSET = "utf8mb4"
TARGET_COLLATION = "utf8mb4_unicode_ci"

APP_TABLES = [
    "attendance_points",
    "personnel",
    "person_roles",
    "person_attendance_points",
    "products",
    "equipment",
    "work_schedules",
    "work_sessions",
    "work_session_devices",
    "production_reports",
    "production_report_items",
    "report_audit_logs",
    "device_qrcodes",
    "notices",
    "notice_points",
    "reconciliation_ledger_entries",
]


def quote_identifier(value: str) -> str:
    return f"`{value.replace('`', '``')}`"


def table_exists(conn, table: str) -> bool:
    return bool(conn.execute(text("""
        SELECT COUNT(*)
        FROM information_schema.tables
        WHERE table_schema = DATABASE()
          AND table_name = :table
          AND table_type = 'BASE TABLE'
    """), {"table": table}).scalar_one())


def main() -> None:
    with engine.begin() as conn:
        database = conn.execute(text("SELECT DATABASE()")).scalar_one()
        if database:
            conn.execute(text(
                f"ALTER DATABASE {quote_identifier(database)} "
                f"CHARACTER SET {TARGET_CHARSET} COLLATE {TARGET_COLLATION}"
            ))

        changed = []
        skipped = []
        for table in APP_TABLES:
            if not table_exists(conn, table):
                skipped.append(table)
                continue
            conn.execute(text(
                f"ALTER TABLE {quote_identifier(table)} "
                f"CONVERT TO CHARACTER SET {TARGET_CHARSET} COLLATE {TARGET_COLLATION}"
            ))
            changed.append(table)

    print(f"collation fixed: {', '.join(changed)}")
    if skipped:
        print(f"skipped missing tables: {', '.join(skipped)}")


if __name__ == "__main__":
    main()