CREATE TABLE IF NOT EXISTS reports (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  reporter_user_id BIGINT UNSIGNED NOT NULL,
  target_type VARCHAR(30) NOT NULL,
  target_id BIGINT UNSIGNED NOT NULL,
  reason_code VARCHAR(50) NOT NULL,
  description VARCHAR(1000) NOT NULL DEFAULT '',
  evidence_json JSON NULL,
  status VARCHAR(20) NOT NULL DEFAULT 'PENDING',
  handled_by BIGINT UNSIGNED NULL,
  handled_at DATETIME(3) NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  KEY idx_reports_status_created (status, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS moderation_tasks (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  target_type VARCHAR(30) NOT NULL,
  target_id BIGINT UNSIGNED NOT NULL,
  content_type VARCHAR(30) NOT NULL,
  risk_score INT NOT NULL DEFAULT 0,
  machine_result JSON NULL,
  status VARCHAR(20) NOT NULL DEFAULT 'PENDING',
  reviewer_id BIGINT UNSIGNED NULL,
  review_result VARCHAR(255) NOT NULL DEFAULT '',
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  reviewed_at DATETIME(3) NULL,
  PRIMARY KEY (id),
  KEY idx_moderation_status_created (status, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS user_risk_profiles (
  user_id BIGINT UNSIGNED NOT NULL,
  risk_score INT NOT NULL DEFAULT 0,
  risk_level TINYINT UNSIGNED NOT NULL DEFAULT 0,
  message_score INT NOT NULL DEFAULT 0,
  device_score INT NOT NULL DEFAULT 0,
  report_score INT NOT NULL DEFAULT 0,
  behavior_score INT NOT NULL DEFAULT 0,
  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
  PRIMARY KEY (user_id),
  KEY idx_risk_level_score (risk_level, risk_score)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS risk_events (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  user_id BIGINT UNSIGNED NOT NULL,
  event_type VARCHAR(50) NOT NULL,
  score_delta INT NOT NULL,
  device_id VARCHAR(100) NOT NULL DEFAULT '',
  ip VARCHAR(45) NOT NULL DEFAULT '',
  metadata JSON NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  KEY idx_risk_event_user_created (user_id, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS notifications (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  user_id BIGINT UNSIGNED NOT NULL,
  type VARCHAR(30) NOT NULL,
  title VARCHAR(100) NOT NULL,
  content VARCHAR(1000) NOT NULL,
  biz_type VARCHAR(30) NOT NULL DEFAULT '',
  biz_id BIGINT UNSIGNED NULL,
  read_at DATETIME(3) NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  KEY idx_notify_user_read_created (user_id, read_at, created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;