/**
 * Unit Tests: Drive API Client
 * 
 * Tests T031-T032: Test Drive API client query execution and pagination
 * Tests the drive-client.js module in isolation with mocked googleapis
 * 
 * @module tests/unit/drive-client
 */

import { describe, it, mock } from 'node:test';
import assert from 'node:assert/strict';

// =============================================================================
// T031: Unit test for Drive API client query execution
// =============================================================================

describe('T031: Drive API Client Query Execution', () => {
  it('should call drive.files.list() with correct query parameters', async () => {
    // Mock googleapis drive.files.list() method
    const mockFilesList = mock.fn(async (params) => {
      return {
        data: {
          files: [
            { id: 'doc1', name: 'Test Doc 1', mimeType: 'application/pdf', modifiedTime: '2024-03-01T10:00:00Z' },
            { id: 'doc2', name: 'Test Doc 2', mimeType: 'text/plain', modifiedTime: '2024-03-02T11:00:00Z' }
          ],
          nextPageToken: null
        }
      };
    });

    // TODO: Import queryDocuments function from src/drive-client.js when implemented
    // const { queryDocuments } = await import('../../src/drive-client.js');

    // Mock Drive client
    const mockDriveClient = {
      files: {
        list: mockFilesList
      }
    };

    // Expected query parameters from config/settings.js
    const expectedQuery = 'trashed = false'; // Default query
    const expectedFields = 'files(id, name, mimeType, modifiedTime)';
    const expectedPageSize = 1000;

    // Call queryDocuments (will be implemented)
    // const result = await queryDocuments(mockDriveClient, expectedQuery);

    // Verify drive.files.list() was called with correct parameters
    // assert.equal(mockFilesList.mock.calls.length, 1, 'Should call drive.files.list() once');
    
    // const callArgs = mockFilesList.mock.calls[0].arguments[0];
    // assert.equal(callArgs.q, expectedQuery, 'Should use query from settings');
    // assert.equal(callArgs.fields, expectedFields, 'Should request correct fields');
    // assert.equal(callArgs.pageSize, expectedPageSize, 'Should use correct page size');

    // Verify result contains documents
    // assert.ok(Array.isArray(result), 'Should return array of documents');
    // assert.equal(result.length, 2, 'Should return 2 documents');
    // assert.equal(result[0].id, 'doc1', 'Should have correct document ID');
  });

  it('should use configurable Drive API filter from settings', async () => {
    const mockFilesList = mock.fn(async () => ({
      data: { files: [], nextPageToken: null }
    }));

    const mockDriveClient = {
      files: { list: mockFilesList }
    };

    // Custom query filter (per clarification #9)
    const customQuery = "mimeType contains 'application/pdf' and trashed = false";

    // TODO: Call queryDocuments with custom query
    // await queryDocuments(mockDriveClient, customQuery);

    // Verify custom query was used
    // const callArgs = mockFilesList.mock.calls[0].arguments[0];
    // assert.equal(callArgs.q, customQuery, 'Should use custom query from settings');
  });
});

// =============================================================================
// T032: Unit test for Drive API pagination handling
// =============================================================================

describe('T032: Drive API Pagination Handling', () => {
  it('should handle pageToken to fetch all results across multiple pages', async () => {
    // Mock Drive API with pagination (3 pages)
    let callCount = 0;
    const mockFilesList = mock.fn(async (params) => {
      callCount++;
      
      if (callCount === 1) {
        // First page
        return {
          data: {
            files: [
              { id: 'doc1', name: 'Doc 1', mimeType: 'application/pdf', modifiedTime: '2024-03-01T10:00:00Z' }
            ],
            nextPageToken: 'token_page_2'
          }
        };
      } else if (callCount === 2) {
        // Second page
        assert.equal(params.pageToken, 'token_page_2', 'Should use pageToken from previous response');
        return {
          data: {
            files: [
              { id: 'doc2', name: 'Doc 2', mimeType: 'text/plain', modifiedTime: '2024-03-02T11:00:00Z' }
            ],
            nextPageToken: 'token_page_3'
          }
        };
      } else {
        // Third page (last)
        assert.equal(params.pageToken, 'token_page_3', 'Should use pageToken from previous response');
        return {
          data: {
            files: [
              { id: 'doc3', name: 'Doc 3', mimeType: 'application/pdf', modifiedTime: '2024-03-03T12:00:00Z' }
            ],
            nextPageToken: null // No more pages
          }
        };
      }
    });

    const mockDriveClient = {
      files: { list: mockFilesList }
    };

    // TODO: Call queryDocuments to fetch all pages
    // const result = await queryDocuments(mockDriveClient, 'trashed = false');

    // Verify all pages were fetched
    // assert.equal(mockFilesList.mock.calls.length, 3, 'Should call drive.files.list() 3 times for 3 pages');
    // assert.equal(result.length, 3, 'Should return all 3 documents from all pages');
    // assert.equal(result[0].id, 'doc1', 'Should have doc1 from page 1');
    // assert.equal(result[1].id, 'doc2', 'Should have doc2 from page 2');
    // assert.equal(result[2].id, 'doc3', 'Should have doc3 from page 3');
  });

  it('should collect up to 50,000 documents across pages', async () => {
    // Mock Drive API to return many pages (simulate large Drive)
    const documentsPerPage = 1000;
    const totalDocuments = 5000; // 5 pages
    let currentPage = 0;

    const mockFilesList = mock.fn(async (params) => {
      currentPage++;
      const startId = (currentPage - 1) * documentsPerPage;
      const endId = Math.min(startId + documentsPerPage, totalDocuments);

      const files = [];
      for (let i = startId; i < endId; i++) {
        files.push({
          id: `doc${i}`,
          name: `Document ${i}`,
          mimeType: 'application/pdf',
          modifiedTime: '2024-03-01T10:00:00Z'
        });
      }

      return {
        data: {
          files,
          nextPageToken: currentPage < Math.ceil(totalDocuments / documentsPerPage) ? `token_page_${currentPage + 1}` : null
        }
      };
    });

    const mockDriveClient = {
      files: { list: mockFilesList }
    };

    // TODO: Call queryDocuments
    // const result = await queryDocuments(mockDriveClient, 'trashed = false');

    // Verify all documents were collected
    // assert.equal(result.length, totalDocuments, `Should collect all ${totalDocuments} documents`);
    // assert.equal(mockFilesList.mock.calls.length, Math.ceil(totalDocuments / documentsPerPage), 'Should call API for each page');
  });

  it('should stop pagination at 50,000 document limit', async () => {
    // Mock Drive API to return more than 50k documents
    const documentsPerPage = 1000;
    let currentPage = 0;

    const mockFilesList = mock.fn(async () => {
      currentPage++;
      const files = [];
      for (let i = 0; i < documentsPerPage; i++) {
        files.push({
          id: `doc${currentPage}_${i}`,
          name: `Document ${currentPage}_${i}`,
          mimeType: 'application/pdf',
          modifiedTime: '2024-03-01T10:00:00Z'
        });
      }

      // Always return nextPageToken to simulate unlimited documents
      return {
        data: {
          files,
          nextPageToken: `token_page_${currentPage + 1}`
        }
      };
    });

    const mockDriveClient = {
      files: { list: mockFilesList }
    };

    // TODO: Call queryDocuments - should stop at 50k
    // await assert.rejects(
    //   async () => await queryDocuments(mockDriveClient, 'trashed = false'),
    //   { message: /50,?000/ },
    //   'Should throw error when exceeding 50k document limit'
    // );

    // Verify pagination stopped at 50k
    // assert.ok(currentPage <= 50, 'Should stop pagination before collecting too many documents');
  });
});