feat: Initialize k-convert application with core structure, UI components, and conversion logic.

src/adapters/heic-adapter.ts

@@ -0,0 +1,113 @@
+// =============================================================================
+// HEIC Adapter
+// Converts HEIC/HEIF images to any image format
+// Uses heic2any for HEIC→JPEG/PNG, then ImageMagick worker for further conversion
+// =============================================================================
+
+import * as Comlink from 'comlink';
+import heic2any from 'heic2any';
+import type {
+  IFileConverter,
+  SupportedFormat,
+  ConversionRequest,
+  ImageFormat,
+} from '../core/types';
+import type { ImageConverterWorker } from '../workers/image.worker';
+
+// Formats heic2any can directly output
+const HEIC2ANY_OUTPUTS: ImageFormat[] = ['jpeg', 'png'];
+
+// All image formats we support as final output
+const ALL_IMAGE_OUTPUTS: ImageFormat[] = ['jpeg', 'png', 'webp', 'gif', 'bmp', 'tiff', 'ico'];
+
+type WorkerType = Comlink.Remote<ImageConverterWorker>;
+let workerInstance: WorkerType | null = null;
+
+function getWorker(): WorkerType {
+  if (!workerInstance) {
+    const worker = new Worker(
+      new URL('../workers/image.worker.ts', import.meta.url),
+      { type: 'module' }
+    );
+    workerInstance = Comlink.wrap<ImageConverterWorker>(worker);
+  }
+  return workerInstance;
+}
+
+export class HeicAdapter implements IFileConverter {
+  readonly name = 'heic-adapter';
+
+  supports(inputFormat: SupportedFormat, outputFormat: SupportedFormat): boolean {
+    return (
+      inputFormat === 'heic' &&
+      ALL_IMAGE_OUTPUTS.includes(outputFormat as ImageFormat)
+    );
+  }
+
+  async convert(
+    request: ConversionRequest,
+    onProgress?: (progress: number) => void
+  ): Promise<Blob> {
+    const { file, targetFormat, options } = request;
+    const quality = options?.quality ?? 85;
+
+    onProgress?.(5);
+
+    try {
+      // Step 1: Convert HEIC to intermediate format using heic2any (main thread)
+      // Use JPEG as intermediate for efficiency, PNG if target is PNG
+      const intermediateFormat = targetFormat === 'png' ? 'png' : 'jpeg';
+      const toType = intermediateFormat === 'png' ? 'image/png' : 'image/jpeg';
+
+      let intermediateBlob: Blob;
+      try {
+        const result = await heic2any({
+          blob: file,
+          toType,
+          quality: quality / 100,
+        });
+        intermediateBlob = Array.isArray(result) ? result[0] : result;
+      } catch (heicError) {
+        // heic2any failed - provide helpful error message
+        const errorMessage = heicError instanceof Error ? heicError.message : String(heicError);
+        if (errorMessage.includes('LIBHEIF') || errorMessage.includes('format not supported')) {
+          throw new Error(`This HEIC file format is not supported. Try using a different photo or convert it on your iPhone first.`);
+        }
+        throw new Error(`Failed to decode HEIC: ${JSON.stringify(errorMessage)}`);
+      }
+
+      onProgress?.(50);
+
+      // Step 2: If target is JPEG or PNG, we're done
+      if (HEIC2ANY_OUTPUTS.includes(targetFormat as ImageFormat)) {
+        onProgress?.(100);
+        return intermediateBlob;
+      }
+
+      // Step 3: Convert intermediate to final format using ImageMagick worker
+      const arrayBuffer = await intermediateBlob.arrayBuffer();
+      onProgress?.(70);
+
+      const worker = getWorker();
+      const result = await worker.convertImage(
+        arrayBuffer,
+        intermediateFormat,
+        targetFormat as ImageFormat,
+        quality
+      );
+
+      onProgress?.(100);
+      return result;
+
+    } catch (error) {
+      // Re-throw with context
+      if (error instanceof Error) {
+        throw error;
+      }
+      throw new Error(`HEIC conversion failed: ${String(error)}`);
+    }
+  }
+}
+
+// Export singleton instance
+export const heicAdapter = new HeicAdapter();