-- SMS Chat MVP schema
CREATE TABLE IF NOT EXISTS conversations (
  id INT AUTO_INCREMENT PRIMARY KEY,
  contact_name VARCHAR(120) NOT NULL,
  phone VARCHAR(32) NOT NULL,
  channel VARCHAR(20) NOT NULL DEFAULT 'twilio',
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS messages (
  id INT AUTO_INCREMENT PRIMARY KEY,
  conversation_id INT NOT NULL,
  direction VARCHAR(12) NOT NULL,
  body TEXT NOT NULL,
  status VARCHAR(20) NOT NULL DEFAULT 'queued',
  channel_message_id VARCHAR(120) DEFAULT NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  INDEX idx_messages_convo (conversation_id),
  CONSTRAINT fk_messages_convo FOREIGN KEY (conversation_id) REFERENCES conversations(id)
    ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS sms_queue (
  id INT AUTO_INCREMENT PRIMARY KEY,
  message_id INT NOT NULL,
  provider VARCHAR(20) NOT NULL,
  payload TEXT NOT NULL,
  status VARCHAR(20) NOT NULL DEFAULT 'queued',
  attempts INT NOT NULL DEFAULT 0,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  INDEX idx_queue_status (status),
  CONSTRAINT fk_queue_message FOREIGN KEY (message_id) REFERENCES messages(id)
    ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS billing_events (
  id INT AUTO_INCREMENT PRIMARY KEY,
  message_id INT NOT NULL,
  units INT NOT NULL DEFAULT 1,
  unit_price DECIMAL(10,4) NOT NULL DEFAULT 0.0000,
  total_cost DECIMAL(10,4) NOT NULL DEFAULT 0.0000,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  UNIQUE KEY uq_billing_message (message_id),
  CONSTRAINT fk_billing_message FOREIGN KEY (message_id) REFERENCES messages(id)
    ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS settings (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(64) NOT NULL UNIQUE,
  value TEXT NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;