#!/usr/bin/env python3
import hashlib
from datetime import datetime, timezone

import pymysql

from config import MYSQL_HOST, MYSQL_PORT, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE


def hash_password(password: str) -> str:
    return hashlib.sha256(password.encode("utf-8")).hexdigest()


def get_conn(database=None):
    return pymysql.connect(
        host=MYSQL_HOST,
        port=MYSQL_PORT,
        user=MYSQL_USER,
        password=MYSQL_PASSWORD,
        database=database,
        charset="utf8mb4",
        autocommit=True,
        cursorclass=pymysql.cursors.DictCursor,
    )


def ensure_database():
    conn = get_conn()
    try:
        with conn.cursor() as cur:
            cur.execute(f"CREATE DATABASE IF NOT EXISTS `{MYSQL_DATABASE}` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci")
    finally:
        conn.close()


def ensure_tables_and_admin():
    conn = get_conn(MYSQL_DATABASE)
    try:
        with conn.cursor() as cur:
            # Legacy migration: reader_pro -> user
            cur.execute("SHOW TABLES LIKE 'reader_pro'")
            has_legacy_user = bool(cur.fetchone())
            cur.execute("SHOW TABLES LIKE 'user'")
            has_user = bool(cur.fetchone())
            if has_legacy_user and not has_user:
                cur.execute("RENAME TABLE reader_pro TO user")

            # Legacy migration: reader_pro_progress -> user_progress
            cur.execute("SHOW TABLES LIKE 'reader_pro_progress'")
            has_legacy_progress = bool(cur.fetchone())
            cur.execute("SHOW TABLES LIKE 'user_progress'")
            has_user_progress = bool(cur.fetchone())
            if has_legacy_progress and not has_user_progress:
                cur.execute("RENAME TABLE reader_pro_progress TO user_progress")

            # Legacy migration: reader_pro_config -> user_config
            cur.execute("SHOW TABLES LIKE 'reader_pro_config'")
            has_legacy_config = bool(cur.fetchone())
            cur.execute("SHOW TABLES LIKE 'user_config'")
            has_user_config = bool(cur.fetchone())
            if has_legacy_config and not has_user_config:
                cur.execute("RENAME TABLE reader_pro_config TO user_config")

            cur.execute(
                """
                CREATE TABLE IF NOT EXISTS user (
                    id BIGINT PRIMARY KEY AUTO_INCREMENT,
                    username VARCHAR(64) NOT NULL UNIQUE,
                    password_hash VARCHAR(255) NOT NULL,
                    is_admin TINYINT(1) NOT NULL DEFAULT 0,
                    is_active TINYINT(1) NOT NULL DEFAULT 1,
                    session_token VARCHAR(128) NULL,
                    session_expires_at DATETIME NULL,
                    last_file VARCHAR(1024) NULL,
                    last_page INT NULL,
                    created_at DATETIME NOT NULL,
                    updated_at DATETIME NOT NULL
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
                """
            )
            cur.execute("SHOW COLUMNS FROM user LIKE 'is_active'")
            if not cur.fetchone():
                cur.execute("ALTER TABLE user ADD COLUMN is_active TINYINT(1) NOT NULL DEFAULT 1 AFTER is_admin")
            cur.execute(
                """
                CREATE TABLE IF NOT EXISTS user_progress (
                    id BIGINT PRIMARY KEY AUTO_INCREMENT,
                    user_id BIGINT NOT NULL,
                    file_path VARCHAR(512) NOT NULL,
                    page INT NOT NULL,
                    updated_at DATETIME NOT NULL,
                    UNIQUE KEY uniq_user_file (user_id, file_path),
                    KEY idx_user_updated (user_id, updated_at),
                    CONSTRAINT fk_user_progress_user
                        FOREIGN KEY (user_id) REFERENCES user(id)
                        ON DELETE CASCADE
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
                """
            )
            cur.execute(
                """
                CREATE TABLE IF NOT EXISTS user_config (
                    config_key VARCHAR(128) PRIMARY KEY,
                    config_value TEXT NULL,
                    updated_at DATETIME NOT NULL
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
                """
            )

            now = datetime.now(timezone.utc).replace(tzinfo=None)
            admin_hash = hash_password("admin123")
            cur.execute("SELECT id FROM user WHERE username=%s", ("admin",))
            row = cur.fetchone()
            if row:
                cur.execute(
                    """
                    UPDATE user
                    SET password_hash=%s, is_admin=1, is_active=1, updated_at=%s
                    WHERE username=%s
                    """,
                    (admin_hash, now, "admin"),
                )
                admin_action = "updated"
            else:
                cur.execute(
                    """
                    INSERT INTO user (username, password_hash, is_admin, is_active, created_at, updated_at)
                    VALUES (%s, %s, 1, 1, %s, %s)
                    """,
                    ("admin", admin_hash, now, now),
                )
                admin_action = "created"
    finally:
        conn.close()

    return admin_action


def main():
    ensure_database()
    admin_action = ensure_tables_and_admin()
    print(f"[OK] Database `{MYSQL_DATABASE}` initialized.")
    print("[OK] Tables: user, user_progress, user_config")
    print(f"[OK] Admin user `admin` {admin_action}, password set to `admin123`")


if __name__ == "__main__":
    main()