/**
 * Test Types and Type Safety - Unit Tests
 *
 * Validates that test files use proper TypeScript interfaces instead of `any` types
 * and that database mocks are properly typed.
 */

import { describe, it, expect } from '@jest/globals';

interface DatabaseTableRow {
  name: string;
}

interface DatabaseColumnInfo {
  name: string;
  type: string;
  notnull: number;
  dflt_value: unknown;
  pk: number;
}

interface ChatSession {
  id: string;
  name: string;
  mode: string;
  topic_id?: string;
  created_at: number;
  updated_at: number;
  last_message_at?: number;
  is_active: boolean;
}

interface ChatMessage {
  id: string;
  session_id: string;
  role: string;
  content: string;
  timestamp: number;
  metadata?: string;
  message_type?: string;
}

interface DatabaseMock {
  prepare: (sql: string) => {
    all: () => DatabaseTableRow[] | DatabaseColumnInfo[];
    get: (params?: Record<string, unknown>) => ChatSession | ChatMessage | undefined;
    run: (params?: Record<string, unknown>) => { changes: number; lastInsertRowid: number };
  };
  exec: (sql: string) => void;
  close: () => void;
}

interface DatabaseModule {
  getDatabase: () => DatabaseMock;
  initializeDatabase: (path: string) => Promise<void>;
}


describe('Test Type Safety', () => {
  describe('Database Mock Types', () => {
    it('should provide proper interfaces for database operations', () => {
      const mockDatabase: DatabaseMock = {
        prepare: (_sql: string) => ({
          all: () => [],
          get: () => undefined,
          run: () => ({ changes: 0, lastInsertRowid: 0 })
        }),
        exec: () => {},
        close: () => {}
      };

      expect(typeof mockDatabase.prepare).toBe('function');
      expect(typeof mockDatabase.exec).toBe('function');
      expect(typeof mockDatabase.close).toBe('function');
    });

    it('should provide proper interfaces for table and column information', () => {
      const tableRow: DatabaseTableRow = { name: 'test_table' };
      const columnInfo: DatabaseColumnInfo = {
        name: 'test_column',
        type: 'TEXT',
        notnull: 0,
        dflt_value: null,
        pk: 0
      };

      expect(tableRow.name).toBe('test_table');
      expect(columnInfo.name).toBe('test_column');
      expect(columnInfo.type).toBe('TEXT');
    });

    it('should provide proper interfaces for chat sessions and messages', () => {
      const session: ChatSession = {
        id: 'session-1',
        name: 'Test Session',
        mode: 'personal',
        created_at: Date.now(),
        updated_at: Date.now(),
        is_active: true
      };

      const message: ChatMessage = {
        id: 'msg-1',
        session_id: 'session-1',
        role: 'user',
        content: 'Hello',
        timestamp: Date.now()
      };

      expect(session.id).toBe('session-1');
      expect(message.session_id).toBe('session-1');
    });

    it('should validate database module interfaces', () => {
      const mockModule: DatabaseModule = {
        getDatabase: () => ({
          prepare: () => ({ all: () => [], get: () => undefined, run: () => ({ changes: 0, lastInsertRowid: 0 }) }),
          exec: () => {},
          close: () => {}
        }),
        initializeDatabase: async () => {}
      };

      expect(typeof mockModule.getDatabase).toBe('function');
      expect(typeof mockModule.initializeDatabase).toBe('function');
    });
  });

  describe('Type Guard Functions', () => {
    it('should validate table row structure', () => {
      function isTableRow(obj: unknown): obj is DatabaseTableRow {
        return (
          typeof obj === 'object' &&
          obj !== null &&
          'name' in obj &&
          typeof (obj as { name: unknown }).name === 'string'
        );
      }

      const validRow = { name: 'test_table' };
      const invalidRow = { id: 123 };

      expect(isTableRow(validRow)).toBe(true);
      expect(isTableRow(invalidRow)).toBe(false);
    });

    it('should validate column info structure', () => {
      function isColumnInfo(obj: unknown): obj is DatabaseColumnInfo {
        return (
          typeof obj === 'object' &&
          obj !== null &&
          'name' in obj &&
          'type' in obj &&
          typeof (obj as { name: unknown }).name === 'string' &&
          typeof (obj as { type: unknown }).type === 'string'
        );
      }

      const validColumn = { name: 'id', type: 'TEXT', notnull: 1, dflt_value: null, pk: 1 };
      const invalidColumn = { name: 'id' };

      expect(isColumnInfo(validColumn)).toBe(true);
      expect(isColumnInfo(invalidColumn)).toBe(false);
    });
  });
});