import os
import pathlib
import re
from typing import Any

import mysql.connector
from loguru import logger
from mysql.connector import pooling

from lib.const import CONST


def create_connection_pool(name: str, size: int) -> pooling.MySQLConnectionPool:
    return pooling.MySQLConnectionPool(
        pool_name=name,
        pool_size=size,
        host="db",
        port=3306,
        database=CONST.MARIADB_DATABASE,
        user=CONST.MARIADB_USER,
        password=CONST.MARIADB_PASSWORD,
        charset="utf8mb4",
        collation="utf8mb4_unicode_ci",
    )


try:
    _cnxpool = create_connection_pool("core-pool", 25)
except mysql.connector.Error as e:
    logger.critical(f"Couldn't create the MySQL connection pool: {e}")
    raise


def execute_query(query: str, values: tuple[Any, ...] | None = None) -> None:
    with _cnxpool.get_connection() as conn, conn.cursor() as cursor:
        cursor.execute(query, values)
        conn.commit()
        return cursor


def select_query(query: str, values: tuple[Any, ...] | None = None) -> list[Any]:
    with _cnxpool.get_connection() as conn, conn.cursor() as cursor:
        cursor.execute(query, values)
        return cursor.fetchall()


def select_query_one(query: str, values: tuple[Any, ...] | None = None) -> Any | None:
    with _cnxpool.get_connection() as conn, conn.cursor() as cursor:
        cursor.execute(query, values)
        output = cursor.fetchone()
        return output[0] if output else None


def select_query_dict(query: str, values: tuple[Any, ...] | None = None) -> list[dict[str, Any]]:
    with _cnxpool.get_connection() as conn, conn.cursor(dictionary=True) as cursor:
        cursor.execute(query, values)
        return cursor.fetchall()


def run_migrations():
    migrations_dir = "db/migrations"
    migration_files = sorted(
        [f for f in os.listdir(migrations_dir) if f.endswith(".sql")],
    )

    with _cnxpool.get_connection() as conn, conn.cursor() as cursor:
        # Create migrations table if it doesn't exist
        cursor.execute("""
                CREATE TABLE IF NOT EXISTS migrations (
                    id INT AUTO_INCREMENT PRIMARY KEY,
                    filename VARCHAR(255) NOT NULL,
                    applied_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
                )
            """)

        for migration_file in migration_files:
            # Check if migration has already been applied
            cursor.execute(
                "SELECT COUNT(*) FROM migrations WHERE filename = %s",
                (migration_file,),
            )
            if cursor.fetchone()[0] > 0:
                logger.debug(
                    f"Migration {migration_file} already applied, skipping.",
                )
                continue

            # Read and execute migration file
            migration_sql = pathlib.Path(migrations_dir) / migration_file
            migration_sql = migration_sql.read_text()
            try:
                # Split the migration file into individual statements
                statements = re.split(r";\s*$", migration_sql, flags=re.MULTILINE)
                for statement in statements:
                    if statement.strip():
                        cursor.execute(statement)

                # Record successful migration
                cursor.execute(
                    "INSERT INTO migrations (filename) VALUES (%s)",
                    (migration_file,),
                )
                conn.commit()
                logger.debug(f"Successfully applied migration: {migration_file}")
            except mysql.connector.Error as e:
                conn.rollback()
                logger.error(f"Error applying migration {migration_file}: {e}")
                raise

    logger.success("All database migrations completed.")