CREATE TABLE IF NOT EXISTS channels (
    id INT AUTO_INCREMENT PRIMARY KEY,
    chat_id VARCHAR(64) NOT NULL,
    username VARCHAR(64) NULL,
    title VARCHAR(255) NOT NULL,
    invite_link VARCHAR(255) NULL,
    is_active TINYINT(1) NOT NULL DEFAULT 1,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS files (
    id INT AUTO_INCREMENT PRIMARY KEY,
    code VARCHAR(16) NOT NULL UNIQUE,
    type ENUM('single','album') NOT NULL DEFAULT 'single',
    uploader_id BIGINT NULL,
    download_count INT NOT NULL DEFAULT 0,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS file_items (
    id INT AUTO_INCREMENT PRIMARY KEY,
    file_id INT NOT NULL,
    storage_chat_id VARCHAR(64) NOT NULL,
    storage_message_id BIGINT NOT NULL,
    media_type VARCHAR(32) NULL,
    FOREIGN KEY (file_id) REFERENCES files(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS album_buffer (
    id INT AUTO_INCREMENT PRIMARY KEY,
    media_group_id VARCHAR(64) NOT NULL,
    chat_id BIGINT NOT NULL,
    message_id BIGINT NOT NULL,
    uploader_id BIGINT NULL,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    INDEX idx_group (media_group_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS album_locks (
    media_group_id VARCHAR(64) NOT NULL PRIMARY KEY,
    locked_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS users (
    telegram_id BIGINT NOT NULL PRIMARY KEY,
    first_seen DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS admins (
    id INT AUTO_INCREMENT PRIMARY KEY,
    telegram_id BIGINT NOT NULL UNIQUE,
    added_by BIGINT NULL,
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS bot_states (
    telegram_id BIGINT NOT NULL PRIMARY KEY,
    state VARCHAR(64) NOT NULL,
    data VARCHAR(255) NULL,
    updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;