"""Seed baseline data for CalMiner in an idempotent manner.

Usage examples
--------------

```powershell
# Use existing environment variables (or load from setup_test.env.example)
python scripts/seed_data.py --currencies --units --defaults

# Dry-run to preview actions
python scripts/seed_data.py --currencies --dry-run
```
"""

from __future__ import annotations

import argparse
import logging
import os
from typing import Iterable, Optional

import psycopg2
from psycopg2 import errors
from psycopg2.extras import execute_values

from scripts.setup_database import DatabaseConfig


logger = logging.getLogger(__name__)

CURRENCY_SEEDS = (
    ("USD", "United States Dollar", "USD$", True),
    ("EUR", "Euro", "EUR", True),
    ("CLP", "Chilean Peso", "CLP$", True),
    ("RMB", "Chinese Yuan", "RMB", True),
    ("GBP", "British Pound", "GBP", True),
    ("CAD", "Canadian Dollar", "CAD$", True),
    ("AUD", "Australian Dollar", "AUD$", True),
)

MEASUREMENT_UNIT_SEEDS = (
    ("tonnes", "Tonnes", "t", "mass", True),
    ("kilograms", "Kilograms", "kg", "mass", True),
    ("pounds", "Pounds", "lb", "mass", True),
    ("liters", "Liters", "L", "volume", True),
    ("cubic_meters", "Cubic Meters", "m3", "volume", True),
    ("kilowatt_hours", "Kilowatt Hours", "kWh", "energy", True),
)


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Seed baseline CalMiner data")
    parser.add_argument("--currencies", action="store_true", help="Seed currency table")
    parser.add_argument("--units", action="store_true", help="Seed unit table")
    parser.add_argument("--defaults", action="store_true", help="Seed default records")
    parser.add_argument("--dry-run", action="store_true", help="Print actions without executing")
    parser.add_argument(
        "--verbose", "-v", action="count", default=0, help="Increase logging verbosity"
    )
    return parser.parse_args()


def _configure_logging(args: argparse.Namespace) -> None:
    level = logging.WARNING - (10 * min(args.verbose, 2))
    logging.basicConfig(level=max(level, logging.INFO), format="%(levelname)s %(message)s")


def main() -> None:
    args = parse_args()
    run_with_namespace(args)


def run_with_namespace(
    args: argparse.Namespace,
    *,
    config: Optional[DatabaseConfig] = None,
) -> None:
    _configure_logging(args)

    if not any((args.currencies, args.units, args.defaults)):
        logger.info("No seeding options provided; exiting")
        return

    config = config or DatabaseConfig.from_env()
    with psycopg2.connect(config.application_dsn()) as conn:
        conn.autocommit = True
        with conn.cursor() as cursor:
            if args.currencies:
                _seed_currencies(cursor, dry_run=args.dry_run)
            if args.units:
                _seed_units(cursor, dry_run=args.dry_run)
            if args.defaults:
                _seed_defaults(cursor, dry_run=args.dry_run)


def _seed_currencies(cursor, *, dry_run: bool) -> None:
    logger.info("Seeding currency table (%d rows)", len(CURRENCY_SEEDS))
    if dry_run:
        for code, name, symbol, active in CURRENCY_SEEDS:
            logger.info("Dry run: would upsert currency %s (%s)", code, name)
        return

    execute_values(
        cursor,
        """
        INSERT INTO currency (code, name, symbol, is_active)
        VALUES %s
        ON CONFLICT (code) DO UPDATE
        SET name = EXCLUDED.name,
            symbol = EXCLUDED.symbol,
            is_active = EXCLUDED.is_active
        """,
        CURRENCY_SEEDS,
    )
    logger.info("Currency seed complete")


def _seed_units(cursor, *, dry_run: bool) -> None:
    total = len(MEASUREMENT_UNIT_SEEDS)
    logger.info("Seeding measurement_unit table (%d rows)", total)
    if dry_run:
        for code, name, symbol, unit_type, _ in MEASUREMENT_UNIT_SEEDS:
            logger.info(
                "Dry run: would upsert measurement unit %s (%s - %s)",
                code,
                name,
                unit_type,
            )
        return

    try:
        execute_values(
            cursor,
            """
            INSERT INTO measurement_unit (code, name, symbol, unit_type, is_active)
            VALUES %s
            ON CONFLICT (code) DO UPDATE
            SET name = EXCLUDED.name,
                symbol = EXCLUDED.symbol,
                unit_type = EXCLUDED.unit_type,
                is_active = EXCLUDED.is_active
            """,
            MEASUREMENT_UNIT_SEEDS,
        )
    except errors.UndefinedTable:
        logger.warning(
            "measurement_unit table does not exist; skipping unit seeding."
        )
        cursor.connection.rollback()
        return

    logger.info("Measurement unit seed complete")


def _seed_defaults(cursor, *, dry_run: bool) -> None:
    logger.info("Seeding default records - not yet implemented")
    if dry_run:
        return


if __name__ == "__main__":
    main()