CREATE TABLE IF NOT EXISTS shangwutong_classification_caches (
    inbox_id INTEGER PRIMARY KEY REFERENCES inboxes (id) ON DELETE CASCADE,
    conversation_kinds TEXT NOT NULL DEFAULT '[]',
    customer_color_kinds TEXT NOT NULL DEFAULT '[]',
    sync_status VARCHAR(20) NOT NULL DEFAULT 'never',
    synced_at DATETIME,
    last_error_code VARCHAR(100),
    last_error_message TEXT,
    last_sync_event_id VARCHAR(128),
    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX IF NOT EXISTS idx_shangwutong_classification_caches_sync_status
ON shangwutong_classification_caches (sync_status);