/**
 * Unit Tests: Export Headers Generation
 * 
 * Tests Content-Disposition header generation logic
 * Verifies filename sanitization and extension handling
 */

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

// Load helper functions using vm.Script pattern
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('Export Headers', () => {
  describe('sanitizeFilename', () => {
    it('should preserve valid alphanumeric filenames', () => {
      const result = helpers.sanitizeFilename('MyDocument123');
      assert.strictEqual(result, 'MyDocument123');
    });

    it('should replace spaces with underscores', () => {
      const result = helpers.sanitizeFilename('My Important Document');
      assert.strictEqual(result, 'My_Important_Document');
    });

    it('should preserve hyphens and dots', () => {
      const result = helpers.sanitizeFilename('my-document.v2.final');
      assert.strictEqual(result, 'my-document.v2.final');
    });

    it('should replace special characters with underscores', () => {
      const result = helpers.sanitizeFilename('My<>Document:with*chars?');
      assert.strictEqual(result, 'My__Document_with_chars_');
    });

    it('should remove leading dots', () => {
      const result = helpers.sanitizeFilename('.hidden-file');
      assert.strictEqual(result, 'hidden-file');
    });

    it('should remove trailing dots', () => {
      const result = helpers.sanitizeFilename('document...');
      assert.strictEqual(result, 'document');
    });

    it('should collapse multiple dots', () => {
      const result = helpers.sanitizeFilename('my....document');
      assert.strictEqual(result, 'my.document');
    });

    it('should handle null input', () => {
      const result = helpers.sanitizeFilename(null);
      assert.strictEqual(result, 'document');
    });

    it('should handle undefined input', () => {
      const result = helpers.sanitizeFilename(undefined);
      assert.strictEqual(result, 'document');
    });

    it('should handle empty string', () => {
      const result = helpers.sanitizeFilename('');
      assert.strictEqual(result, 'document');
    });

    it('should truncate very long filenames to 255 characters', () => {
      const longName = 'a'.repeat(300);
      const result = helpers.sanitizeFilename(longName);
      assert.strictEqual(result.length, 255);
    });

    it('should handle unicode characters', () => {
      const result = helpers.sanitizeFilename('Документ 文档');
      // Non-ASCII chars should be replaced
      assert.ok(result.includes('_'));
    });
  });

  describe('getFileExtension', () => {
    it('should return "md" for text/x-markdown', () => {
      const result = helpers.getFileExtension('text/x-markdown');
      assert.strictEqual(result, 'md');
    });

    it('should return "html" for text/html', () => {
      const result = helpers.getFileExtension('text/html');
      assert.strictEqual(result, 'html');
    });

    it('should return "pdf" for application/pdf', () => {
      const result = helpers.getFileExtension('application/pdf');
      assert.strictEqual(result, 'pdf');
    });

    it('should return "txt" for text/plain', () => {
      const result = helpers.getFileExtension('text/plain');
      assert.strictEqual(result, 'txt');
    });

    it('should return "json" for application/json', () => {
      const result = helpers.getFileExtension('application/json');
      assert.strictEqual(result, 'json');
    });

    it('should return "bin" for unknown mime types', () => {
      const result = helpers.getFileExtension('application/octet-stream');
      assert.strictEqual(result, 'bin');
    });

    it('should return "bin" for null input', () => {
      const result = helpers.getFileExtension(null);
      assert.strictEqual(result, 'bin');
    });

    it('should return "bin" for undefined input', () => {
      const result = helpers.getFileExtension(undefined);
      assert.strictEqual(result, 'bin');
    });
  });

  describe('Content-Disposition header integration', () => {
    it('should generate correct header for markdown file', () => {
      const filename = 'Meeting Notes Q1 2026';
      const sanitized = helpers.sanitizeFilename(filename);
      const extension = helpers.getFileExtension('text/x-markdown');
      
      const header = `inline; filename="${sanitized}.${extension}"`;
      
      assert.strictEqual(header, 'inline; filename="Meeting_Notes_Q1_2026.md"');
    });

    it('should generate correct header for html file', () => {
      const filename = 'Project<Plan>';
      const sanitized = helpers.sanitizeFilename(filename);
      const extension = helpers.getFileExtension('text/html');
      
      const header = `inline; filename="${sanitized}.${extension}"`;
      
      assert.strictEqual(header, 'inline; filename="Project_Plan_.html"');
    });

    it('should generate correct header for pdf file', () => {
      const filename = 'Annual Report 2026';
      const sanitized = helpers.sanitizeFilename(filename);
      const extension = helpers.getFileExtension('application/pdf');
      
      const header = `inline; filename="${sanitized}.${extension}"`;
      
      assert.strictEqual(header, 'inline; filename="Annual_Report_2026.pdf"');
    });

    it('should handle filename with existing extension', () => {
      const filename = 'document.old.txt';
      const sanitized = helpers.sanitizeFilename(filename);
      const extension = helpers.getFileExtension('text/x-markdown');
      
      const header = `inline; filename="${sanitized}.${extension}"`;
      
      // Should preserve the dots in filename and add new extension
      assert.strictEqual(header, 'inline; filename="document.old.txt.md"');
    });
  });
});