Replace dependencies with system apis (#8)

* pdf dep rem

* remove stale package

* replace with native share

* rename share module

* revert: restore react-native-share (native replacement had worse perf, negligible size gain)

* cosmetic

android/app/src/main/java/com/lensapp/MainApplication.kt

@@ -17,9 +17,9 @@ class MainApplication : Application(), ReactApplication {
   override val reactNativeHost: ReactNativeHost =
       object : DefaultReactNativeHost(this) {
         override fun getPackages(): List<ReactPackage> {
-          // Packages that cannot be autolinked yet can be added manually here, for example:
-          // packages.add(new MyReactNativePackage());
-          return PackageList(this).packages
+          val packages = PackageList(this).packages.toMutableList()
+          packages.add(PdfGeneratorPackage())
+          return packages
         }
 
         override fun getJSMainModuleName(): String = "index"

android/app/src/main/java/com/lensapp/PdfGeneratorModule.kt

@@ -0,0 +1,55 @@
+package com.lensapp
+
+import android.graphics.BitmapFactory
+import android.graphics.RectF
+import android.graphics.pdf.PdfDocument
+import com.facebook.react.bridge.Promise
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.bridge.ReactContextBaseJavaModule
+import com.facebook.react.bridge.ReactMethod
+import com.facebook.react.bridge.ReadableArray
+import java.io.File
+import java.io.FileOutputStream
+
+class PdfGeneratorModule(private val reactContext: ReactApplicationContext) :
+    ReactContextBaseJavaModule(reactContext) {
+
+    override fun getName() = "PdfGenerator"
+
+    @ReactMethod
+    fun generate(imagePaths: ReadableArray, fileName: String, promise: Promise) {
+        try {
+            val outDir = File(reactContext.filesDir, "pdfs").also { it.mkdirs() }
+            val outFile = File(outDir, "$fileName.pdf")
+            val doc = PdfDocument()
+
+            for (i in 0 until imagePaths.size()) {
+                val path = imagePaths.getString(i)!!.removePrefix("file://")
+                val bitmap = BitmapFactory.decodeFile(path)
+                    ?: throw Exception("Failed to decode image: $path")
+
+                // A4 at 72 DPI: 595 x 842 points
+                val pageWidth = 595
+                val pageHeight = 842
+                val pageInfo = PdfDocument.PageInfo.Builder(pageWidth, pageHeight, i + 1).create()
+                val page = doc.startPage(pageInfo)
+
+                val scale = minOf(pageWidth.toFloat() / bitmap.width, pageHeight.toFloat() / bitmap.height)
+                val scaledW = bitmap.width * scale
+                val scaledH = bitmap.height * scale
+                val left = (pageWidth - scaledW) / 2f
+                val top = (pageHeight - scaledH) / 2f
+
+                page.canvas.drawBitmap(bitmap, null, RectF(left, top, left + scaledW, top + scaledH), null)
+                bitmap.recycle()
+                doc.finishPage(page)
+            }
+
+            FileOutputStream(outFile).use { doc.writeTo(it) }
+            doc.close()
+            promise.resolve("file://${outFile.absolutePath}")
+        } catch (e: Exception) {
+            promise.reject("PDF_ERROR", e.message, e)
+        }
+    }
+}

android/app/src/main/java/com/lensapp/PdfGeneratorPackage.kt

@@ -0,0 +1,14 @@
+package com.lensapp
+
+import com.facebook.react.ReactPackage
+import com.facebook.react.bridge.NativeModule
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.uimanager.ViewManager
+
+class PdfGeneratorPackage : ReactPackage {
+    override fun createNativeModules(reactContext: ReactApplicationContext): List<NativeModule> =
+        listOf(PdfGeneratorModule(reactContext))
+
+    override fun createViewManagers(reactContext: ReactApplicationContext): List<ViewManager<*, *>> =
+        emptyList()
+}

ios/LensApp/PdfGenerator.h

@@ -0,0 +1,4 @@
+#import <React/RCTBridgeModule.h>
+
+@interface PdfGenerator : NSObject <RCTBridgeModule>
+@end

ios/LensApp/PdfGenerator.m

@@ -0,0 +1,58 @@
+#import "PdfGenerator.h"
+#import <UIKit/UIKit.h>
+
+@implementation PdfGenerator
+
+RCT_EXPORT_MODULE();
+
+RCT_EXPORT_METHOD(generate:(NSArray *)imagePaths
+                  fileName:(NSString *)fileName
+                  resolver:(RCTPromiseResolveBlock)resolve
+                  rejecter:(RCTPromiseRejectBlock)reject)
+{
+    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+        NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
+        NSString *pdfsDir = [docPaths[0] stringByAppendingPathComponent:@"pdfs"];
+        [[NSFileManager defaultManager] createDirectoryAtPath:pdfsDir
+                                  withIntermediateDirectories:YES
+                                                   attributes:nil
+                                                        error:nil];
+
+        NSString *outPath = [[pdfsDir stringByAppendingPathComponent:fileName]
+                              stringByAppendingPathExtension:@"pdf"];
+
+        // A4 at 72 DPI: 595 x 842 points
+        CGRect pageRect = CGRectMake(0, 0, 595, 842);
+        UIGraphicsPDFRendererFormat *format = [UIGraphicsPDFRendererFormat defaultFormat];
+        UIGraphicsPDFRenderer *renderer = [[UIGraphicsPDFRenderer alloc] initWithBounds:pageRect format:format];
+
+        NSError *error;
+        BOOL success = [renderer writePDFToURL:[NSURL fileURLWithPath:outPath]
+                                   withActions:^(UIGraphicsPDFRendererContext *ctx) {
+            for (NSString *rawPath in imagePaths) {
+                NSString *path = [rawPath hasPrefix:@"file://"] ? [rawPath substringFromIndex:7] : rawPath;
+                UIImage *image = [UIImage imageWithContentsOfFile:path];
+                if (!image) continue;
+
+                [ctx beginPage];
+
+                CGFloat scale = MIN(pageRect.size.width / image.size.width,
+                                    pageRect.size.height / image.size.height);
+                CGFloat w = image.size.width * scale;
+                CGFloat h = image.size.height * scale;
+                CGFloat x = (pageRect.size.width - w) / 2;
+                CGFloat y = (pageRect.size.height - h) / 2;
+
+                [image drawInRect:CGRectMake(x, y, w, h)];
+            }
+        } error:&error];
+
+        if (success) {
+            resolve([@"file://" stringByAppendingString:outPath]);
+        } else {
+            reject(@"PDF_ERROR", error.localizedDescription, error);
+        }
+    });
+}
+
+@end

package-lock.json

@@ -13,7 +13,6 @@
         "react-native": "0.73.0",
         "react-native-document-scanner-plugin": "^2.0.4",
         "react-native-fs": "^2.20.0",
-        "react-native-html-to-pdf": "^1.3.0",
         "react-native-share": "^12.2.6"
       },
       "devDependencies": {
@@ -12418,19 +12417,6 @@
         }
       }
     },
-    "node_modules/react-native-html-to-pdf": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/react-native-html-to-pdf/-/react-native-html-to-pdf-1.3.0.tgz",
-      "integrity": "sha512-UCbQO1k5yeajaJrEF7Wqq8ojdgpxsTbICQvtorXmuO1LkU/a6B3/tZyLes4zXCiq/5nTMTNA/k9m5bYStg5S0Q==",
-      "license": "MIT",
-      "workspaces": [
-        "example"
-      ],
-      "peerDependencies": {
-        "react": "*",
-        "react-native": "*"
-      }
-    },
     "node_modules/react-native-share": {
       "version": "12.2.6",
       "resolved": "https://registry.npmjs.org/react-native-share/-/react-native-share-12.2.6.tgz",

package.json

@@ -15,7 +15,6 @@
     "react-native": "0.73.0",
     "react-native-document-scanner-plugin": "^2.0.4",
     "react-native-fs": "^2.20.0",
-    "react-native-html-to-pdf": "^1.3.0",
     "react-native-share": "^12.2.6"
   },
   "devDependencies": {

patches/react-native-html-to-pdf+1.3.0.patch

@@ -1,45 +0,0 @@
-diff --git a/node_modules/react-native-html-to-pdf/android/src/main/java/com/htmltopdf/HtmlToPdfPackage.kt b/node_modules/react-native-html-to-pdf/android/src/main/java/com/htmltopdf/HtmlToPdfPackage.kt
-index 5fe5a8d..d2586e0 100644
---- a/node_modules/react-native-html-to-pdf/android/src/main/java/com/htmltopdf/HtmlToPdfPackage.kt
-+++ b/node_modules/react-native-html-to-pdf/android/src/main/java/com/htmltopdf/HtmlToPdfPackage.kt
-@@ -1,33 +1,16 @@
- package com.htmltopdf
- 
--import com.facebook.react.BaseReactPackage
-+import com.facebook.react.ReactPackage
- import com.facebook.react.bridge.NativeModule
- import com.facebook.react.bridge.ReactApplicationContext
--import com.facebook.react.module.model.ReactModuleInfo
--import com.facebook.react.module.model.ReactModuleInfoProvider
--import java.util.HashMap
-+import com.facebook.react.uimanager.ViewManager
- 
--class HtmlToPdfPackage : BaseReactPackage() {
--  override fun getModule(name: String, reactContext: ReactApplicationContext): NativeModule? {
--    return if (name == HtmlToPdfModule.NAME) {
--      HtmlToPdfModule(reactContext)
--    } else {
--      null
--    }
-+class HtmlToPdfPackage : ReactPackage {
-+  override fun createNativeModules(reactContext: ReactApplicationContext): List<NativeModule> {
-+    return listOf(HtmlToPdfModule(reactContext))
-   }
- 
--  override fun getReactModuleInfoProvider(): ReactModuleInfoProvider {
--    return ReactModuleInfoProvider {
--      val moduleInfos: MutableMap<String, ReactModuleInfo> = HashMap()
--      moduleInfos[HtmlToPdfModule.NAME] = ReactModuleInfo(
--        HtmlToPdfModule.NAME,
--        HtmlToPdfModule.NAME,
--        false,  // canOverrideExistingModule
--        false,  // needsEagerInit
--        false,  // isCxxModule
--        true // isTurboModule
--      )
--      moduleInfos
--    }
-+  override fun createViewManagers(reactContext: ReactApplicationContext): List<ViewManager<*, *>> {
-+    return emptyList()
-   }
- }

src/__tests__/generatePdf.test.ts

@@ -1,19 +1,17 @@
-// Mock native modules before importing the module under test
-jest.mock('react-native-fs', () => ({
-  DocumentDirectoryPath: '/mock/documents',
-  readFile: jest.fn().mockResolvedValue('base64data'),
-  mkdir: jest.fn().mockResolvedValue(undefined),
+jest.mock('react-native', () => ({
+  NativeModules: {
+    PdfGenerator: {
+      generate: jest.fn(),
+    },
+  },
 }));
 
-jest.mock('react-native-html-to-pdf', () => ({
-  generatePDF: jest.fn(),
-}));
-
-import RNFS from 'react-native-fs';
-import {generatePDF as mockGeneratePDF} from 'react-native-html-to-pdf';
+import {NativeModules} from 'react-native';
 import {generatePdf} from '../utils/generatePdf';
 import {ScannedPage} from '../types';
 
+const mockGenerate = NativeModules.PdfGenerator.generate as jest.Mock;
+
 const mockPages: ScannedPage[] = [
   {id: 'p1', uri: 'file:///mock/scans/scan1.jpg', width: 1240, height: 1754},
   {id: 'p2', uri: '/mock/scans/scan2.jpg', width: 1240, height: 1754},
@@ -24,73 +22,35 @@ beforeEach(() => {
 });
 
 describe('generatePdf', () => {
-  it('strips file:// before reading and passes base64 to HTML', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({
-      filePath: '/mock/documents/pdfs/test.pdf',
-    });
+  it('passes all image URIs to the native module', async () => {
+    mockGenerate.mockResolvedValue('file:///mock/pdfs/test.pdf');
 
-    await generatePdf(mockPages, 'test doc');
+    await generatePdf(mockPages, 'test');
 
-    // Should have been called for each page
-    expect(RNFS.readFile).toHaveBeenCalledTimes(2);
-    // file:// prefix stripped for first page
-    expect(RNFS.readFile).toHaveBeenCalledWith('/mock/scans/scan1.jpg', 'base64');
-    // path without prefix used as-is for second page
-    expect(RNFS.readFile).toHaveBeenCalledWith('/mock/scans/scan2.jpg', 'base64');
-  });
-
-  it('passes a relative directory name, not an absolute path', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({
-      filePath: '/mock/documents/pdfs/test.pdf',
-    });
-
-    await generatePdf(mockPages, 'My Doc');
-
-    const call = (mockGeneratePDF as jest.Mock).mock.calls[0][0];
-    expect(call.directory).toBe('pdfs');
-    expect(call.directory).not.toContain('/');
-  });
-
-  it('sanitises the file name', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({
-      filePath: '/mock/documents/pdfs/test.pdf',
-    });
-
-    await generatePdf(mockPages, 'Scan 2024/06/15 — page 1');
-
-    const call = (mockGeneratePDF as jest.Mock).mock.calls[0][0];
-    expect(call.fileName).not.toMatch(/[^a-z0-9_\-]/i);
-  });
-
-  it('returns a file:// URI', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({
-      filePath: '/mock/documents/pdfs/test.pdf',
-    });
-
-    const result = await generatePdf(mockPages, 'test');
-    expect(result).toBe('file:///mock/documents/pdfs/test.pdf');
-  });
-
-  it('does not double-prefix an already file:// path', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({
-      filePath: 'file:///mock/documents/pdfs/test.pdf',
-    });
-
-    const result = await generatePdf(mockPages, 'test');
-    expect(result).toBe('file:///mock/documents/pdfs/test.pdf');
-    expect(result).not.toContain('file://file://');
-  });
-
-  it('throws when the library returns no filePath', async () => {
-    (mockGeneratePDF as jest.Mock).mockResolvedValue({filePath: null});
-
-    await expect(generatePdf(mockPages, 'test')).rejects.toThrow(
-      'PDF generation failed',
+    expect(mockGenerate).toHaveBeenCalledWith(
+      ['file:///mock/scans/scan1.jpg', '/mock/scans/scan2.jpg'],
+      'test',
     );
   });
 
-  it('throws when the library rejects', async () => {
-    (mockGeneratePDF as jest.Mock).mockRejectedValue(new Error('native crash'));
+  it('sanitises the file name before passing to native module', async () => {
+    mockGenerate.mockResolvedValue('file:///mock/pdfs/test.pdf');
+
+    await generatePdf(mockPages, 'Scan 2024/06/15 — page 1');
+
+    const fileName = mockGenerate.mock.calls[0][1];
+    expect(fileName).not.toMatch(/[^a-z0-9_\-]/i);
+  });
+
+  it('returns the path resolved by the native module', async () => {
+    mockGenerate.mockResolvedValue('file:///mock/pdfs/test.pdf');
+
+    const result = await generatePdf(mockPages, 'test');
+    expect(result).toBe('file:///mock/pdfs/test.pdf');
+  });
+
+  it('throws when the native module rejects', async () => {
+    mockGenerate.mockRejectedValue(new Error('native crash'));
 
     await expect(generatePdf(mockPages, 'test')).rejects.toThrow('native crash');
   });

src/screens/ViewerScreen.tsx

@@ -36,6 +36,7 @@ export default function ViewerScreen({document, onBack, onDelete, onRename}: Pro
 
   const sharePdf = async (pageIndices?: number[]) => {
     setGenerating(true);
+    await new Promise(resolve => setTimeout(resolve, 0));
     try {
       const pages = pageIndices
         ? pageIndices.map(i => document.pages[i]).filter(Boolean)

src/utils/generatePdf.ts

@@ -1,58 +1,10 @@
-import {generatePDF as rnGeneratePDF} from 'react-native-html-to-pdf';
-import RNFS from 'react-native-fs';
+import {NativeModules} from 'react-native';
 import {ScannedPage} from '../types';
 
-// On Android, `directory` is a relative subdirectory name appended to
-// getExternalFilesDir()/filesDir — NOT an absolute path.
-const PDF_SUBDIR = 'pdfs';
-
-async function pageToBase64(uri: string): Promise<string> {
-  const path = uri.startsWith('file://') ? uri.slice(7) : uri;
-  return RNFS.readFile(path, 'base64');
-}
-
-function toFileUri(p: string): string {
-  return p.startsWith('file://') ? p : `file://${p}`;
-}
-
-export async function generatePdf(
-  pages: ScannedPage[],
-  name: string,
-): Promise<string> {
-  const imageHtml = await Promise.all(
-    pages.map(async p => {
-      const b64 = await pageToBase64(p.uri);
-      return `<div class="page"><img src="data:image/jpeg;base64,${b64}" /></div>`;
-    }),
-  );
-
-  const html = `<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="utf-8" />
-    <style>
-      * { margin: 0; padding: 0; box-sizing: border-box; }
-      body { background: #fff; }
-      .page { width: 100%; page-break-after: always; }
-      .page:last-child { page-break-after: avoid; }
-      img { width: 100%; height: auto; display: block; }
-    </style>
-  </head>
-  <body>${imageHtml.join('\n')}</body>
-</html>`;
+const {PdfGenerator} = NativeModules;
 
+export async function generatePdf(pages: ScannedPage[], name: string): Promise<string> {
+  const imagePaths = pages.map(p => p.uri);
   const fileName = name.replace(/[^a-z0-9_\-]/gi, '_');
-
-  const result = await rnGeneratePDF({
-    html,
-    fileName,
-    directory: PDF_SUBDIR,
-    base64: false,
-  });
-
-  if (!result.filePath) {
-    throw new Error('PDF generation failed: library returned no file path');
-  }
-
-  return toFileUri(result.filePath);
+  return PdfGenerator.generate(imagePaths, fileName);
 }