import mysql.connector
from mysql.connector import pooling
from contextlib import contextmanager
from .config import settings

connection_pool = None


def init_db_pool():
    global connection_pool
    connection_pool = pooling.MySQLConnectionPool(
        pool_name="meeting_pool",
        pool_size=5,
        host=settings.DB_HOST,
        port=settings.DB_PORT,
        user=settings.DB_USER,
        password=settings.DB_PASS,
        database=settings.DB_NAME,
    )
    return connection_pool


@contextmanager
def get_db_connection():
    conn = connection_pool.get_connection()
    try:
        yield conn
    finally:
        conn.close()


@contextmanager
def get_db_cursor(commit=False):
    with get_db_connection() as conn:
        cursor = conn.cursor(dictionary=True)
        try:
            yield cursor
            if commit:
                conn.commit()
        finally:
            cursor.close()


def init_tables():
    """Create all required tables if they don't exist."""
    create_statements = [
        """
        CREATE TABLE IF NOT EXISTS meeting_users (
            user_id INT PRIMARY KEY AUTO_INCREMENT,
            email VARCHAR(100) UNIQUE NOT NULL,
            display_name VARCHAR(50),
            role ENUM('admin', 'user') DEFAULT 'user',
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
        """,
        """
        CREATE TABLE IF NOT EXISTS meeting_records (
            meeting_id INT PRIMARY KEY AUTO_INCREMENT,
            uuid VARCHAR(64) UNIQUE,
            subject VARCHAR(200) NOT NULL,
            meeting_time DATETIME NOT NULL,
            location VARCHAR(100),
            chairperson VARCHAR(50),
            recorder VARCHAR(50),
            attendees TEXT,
            transcript_blob LONGTEXT,
            created_by VARCHAR(100),
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )
        """,
        """
        CREATE TABLE IF NOT EXISTS meeting_conclusions (
            conclusion_id INT PRIMARY KEY AUTO_INCREMENT,
            meeting_id INT,
            content TEXT,
            system_code VARCHAR(20),
            FOREIGN KEY (meeting_id) REFERENCES meeting_records(meeting_id) ON DELETE CASCADE
        )
        """,
        """
        CREATE TABLE IF NOT EXISTS meeting_action_items (
            action_id INT PRIMARY KEY AUTO_INCREMENT,
            meeting_id INT,
            content TEXT,
            owner VARCHAR(50),
            due_date DATE,
            status ENUM('Open', 'In Progress', 'Done', 'Delayed') DEFAULT 'Open',
            system_code VARCHAR(20),
            FOREIGN KEY (meeting_id) REFERENCES meeting_records(meeting_id) ON DELETE CASCADE
        )
        """,
    ]

    with get_db_cursor(commit=True) as cursor:
        for statement in create_statements:
            cursor.execute(statement)