/**
 * Unit Tests: Format Selection Logic
 * 
 * Tests the selectExportFormat helper function
 * Verifies priority ordering: Markdown > HTML > PDF
 */

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

// Load helper functions using vm.Script pattern (similar to proxy.js)
import { readFileSync } from 'fs';
import { Script } from 'vm';

// Create VM context with required globals
const vmContext = {
  crypto: globalThis.crypto,
  console: console
};

// Load googleDriveAdapterHelper.js
const helperCode = readFileSync('./src/globalVariables/googleDriveAdapterHelper.js', 'utf8');
const wrappedCode = `(function() {\n${helperCode}\n})()`;
const script = new Script(wrappedCode);
const helpers = script.runInNewContext(vmContext);

describe('Format Selection', () => {
  describe('selectExportFormat', () => {
    it('should prioritize text/x-markdown over other formats', () => {
      const exportLinks = {
        'text/x-markdown': 'https://example.com/export?format=md',
        'text/html': 'https://example.com/export?format=html',
        'application/pdf': 'https://example.com/export?format=pdf'
      };

      const result = helpers.selectExportFormat(exportLinks);

      assert.strictEqual(result.contentType, 'text/x-markdown');
      assert.strictEqual(result.extension, 'md');
      assert.strictEqual(result.url, 'https://example.com/export?format=md');
    });

    it('should select text/html when markdown is unavailable', () => {
      const exportLinks = {
        'text/html': 'https://example.com/export?format=html',
        'application/pdf': 'https://example.com/export?format=pdf'
      };

      const result = helpers.selectExportFormat(exportLinks);

      assert.strictEqual(result.contentType, 'text/html');
      assert.strictEqual(result.extension, 'html');
      assert.strictEqual(result.url, 'https://example.com/export?format=html');
    });

    it('should select application/pdf when markdown and html are unavailable', () => {
      const exportLinks = {
        'application/pdf': 'https://example.com/export?format=pdf'
      };

      const result = helpers.selectExportFormat(exportLinks);

      assert.strictEqual(result.contentType, 'application/pdf');
      assert.strictEqual(result.extension, 'pdf');
      assert.strictEqual(result.url, 'https://example.com/export?format=pdf');
    });

    it('should return null when no supported formats are available', () => {
      const exportLinks = {
        'text/plain': 'https://example.com/export?format=txt',
        'application/json': 'https://example.com/export?format=json'
      };

      const result = helpers.selectExportFormat(exportLinks);

      assert.strictEqual(result, null);
    });

    it('should return null when exportLinks is null', () => {
      const result = helpers.selectExportFormat(null);

      assert.strictEqual(result, null);
    });

    it('should return null when exportLinks is undefined', () => {
      const result = helpers.selectExportFormat(undefined);

      assert.strictEqual(result, null);
    });

    it('should return null when exportLinks is empty object', () => {
      const result = helpers.selectExportFormat({});

      assert.strictEqual(result, null);
    });

    it('should respect priority order even when formats appear in different order', () => {
      const exportLinks = {
        'application/pdf': 'https://example.com/export?format=pdf',
        'text/x-markdown': 'https://example.com/export?format=md',
        'text/html': 'https://example.com/export?format=html'
      };

      const result = helpers.selectExportFormat(exportLinks);

      // Should still select Markdown despite PDF being first in object
      assert.strictEqual(result.contentType, 'text/x-markdown');
    });
  });

  describe('EXPORT_FORMATS constant', () => {
    it('should define correct priority order', () => {
      assert.ok(Array.isArray(helpers.EXPORT_FORMATS));
      assert.strictEqual(helpers.EXPORT_FORMATS.length, 3);
      
      // Verify order: Markdown > HTML > PDF
      assert.strictEqual(helpers.EXPORT_FORMATS[0].mimeType, 'text/x-markdown');
      assert.strictEqual(helpers.EXPORT_FORMATS[0].extension, 'md');
      
      assert.strictEqual(helpers.EXPORT_FORMATS[1].mimeType, 'text/html');
      assert.strictEqual(helpers.EXPORT_FORMATS[1].extension, 'html');
      
      assert.strictEqual(helpers.EXPORT_FORMATS[2].mimeType, 'application/pdf');
      assert.strictEqual(helpers.EXPORT_FORMATS[2].extension, 'pdf');
    });
  });
});