fix: improve file sharing on Android using app-private storage

- Replace direct file writing with app-private storage + share dialog
- Add Share plugin for cross-platform file sharing
- Update file paths configuration for Android
- Fix permission issues by using Directory.Data instead of Documents
- Simplify file export flow in DataExportSection

android/app/capacitor.build.gradle

@@ -12,6 +12,7 @@ dependencies {
     implementation project(':capacitor-app')
     implementation project(':capacitor-camera')
     implementation project(':capacitor-filesystem')
+    implementation project(':capacitor-share')
     implementation project(':capawesome-capacitor-file-picker')
 
 }

android/app/src/main/assets/capacitor.plugins.json

@@ -11,6 +11,10 @@
 		"pkg": "@capacitor/filesystem",
 		"classpath": "com.capacitorjs.plugins.filesystem.FilesystemPlugin"
 	},
+	{
+		"pkg": "@capacitor/share",
+		"classpath": "com.capacitorjs.plugins.share.SharePlugin"
+	},
 	{
 		"pkg": "@capawesome/capacitor-file-picker",
 		"classpath": "io.capawesome.capacitorjs.plugins.filepicker.FilePickerPlugin"

android/app/src/main/res/xml/file_paths.xml

@@ -2,4 +2,5 @@
 <paths xmlns:android="http://schemas.android.com/apk/res/android">
     <external-path name="my_images" path="." />
     <cache-path name="my_cache_images" path="." />
+    <files-path name="my_files" path="." />
 </paths>

android/capacitor.settings.gradle

@@ -11,5 +11,8 @@ project(':capacitor-camera').projectDir = new File('../node_modules/@capacitor/c
 include ':capacitor-filesystem'
 project(':capacitor-filesystem').projectDir = new File('../node_modules/@capacitor/filesystem/android')
 
+include ':capacitor-share'
+project(':capacitor-share').projectDir = new File('../node_modules/@capacitor/share/android')
+
 include ':capawesome-capacitor-file-picker'
 project(':capawesome-capacitor-file-picker').projectDir = new File('../node_modules/@capawesome/capacitor-file-picker/android')

package-lock.json

@@ -15,6 +15,7 @@
         "@capacitor/core": "^6.2.0",
         "@capacitor/filesystem": "^6.0.0",
         "@capacitor/ios": "^6.2.0",
+        "@capacitor/share": "^6.0.3",
         "@capawesome/capacitor-file-picker": "^6.2.0",
         "@dicebear/collection": "^5.4.1",
         "@dicebear/core": "^5.4.1",
@@ -2908,6 +2909,15 @@
         "@capacitor/core": "^6.2.0"
       }
     },
+    "node_modules/@capacitor/share": {
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/@capacitor/share/-/share-6.0.3.tgz",
+      "integrity": "sha512-BkNM73Ix+yxQ7fkni8CrrGcp1kSl7u+YNoPLwWKQ1MuQ5Uav0d+CT8M67ie+3dc4jASmegnzlC6tkTmFcPTLeA==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@capacitor/core": "^6.0.0"
+      }
+    },
     "node_modules/@capawesome/capacitor-file-picker": {
       "version": "6.2.0",
       "resolved": "https://registry.npmjs.org/@capawesome/capacitor-file-picker/-/capacitor-file-picker-6.2.0.tgz",

package.json

@@ -50,6 +50,7 @@
     "@capacitor/core": "^6.2.0",
     "@capacitor/filesystem": "^6.0.0",
     "@capacitor/ios": "^6.2.0",
+    "@capacitor/share": "^6.0.3",
     "@capawesome/capacitor-file-picker": "^6.2.0",
     "@dicebear/collection": "^5.4.1",
     "@dicebear/core": "^5.4.1",

src/components/DataExportSection.vue

@@ -145,7 +145,7 @@ export default class DataExportSection extends Vue {
       } else if (this.platformCapabilities.hasFileSystem) {
         // Native platform: Write to app directory
         const content = await blob.text();
-        await this.platformService.writeFile(fileName, content);
+        await this.platformService.writeAndShareFile(fileName, content);
       }
 
       this.$notify(

src/services/PlatformService.ts

@@ -57,6 +57,14 @@ export interface PlatformService {
    */
   writeFile(path: string, content: string): Promise<void>;
 
+  /**
+   * Writes content to a file at the specified path and shares it.
+   * @param fileName - The filename of the file to write
+   * @param content - The content to write to the file
+   * @returns Promise that resolves when the write is complete
+   */
+  writeAndShareFile(fileName: string, content: string): Promise<void>;
+
   /**
    * Deletes a file at the specified path.
    * @param path - The path to the file to delete

src/services/platforms/CapacitorPlatformService.ts

@@ -5,7 +5,7 @@ import {
 } from "../PlatformService";
 import { Filesystem, Directory, Encoding } from "@capacitor/filesystem";
 import { Camera, CameraResultType, CameraSource } from "@capacitor/camera";
-import { FilePicker } from "@capawesome/capacitor-file-picker";
+import { Share } from "@capacitor/share";
 import { logger } from "../../utils/logger";
 
 /**
@@ -156,16 +156,37 @@ export class CapacitorPlatformService implements PlatformService {
   }
 
   /**
-   * Writes content to a file in the user-selected directory.
-   * Opens a directory picker for the user to choose where to save.
-   * @param path - Suggested filename
-   * @param content - Content to write to the file
-   * @throws Error if write operation fails
+   * Writes content to a file in the app's safe storage and offers sharing.
+   *
+   * Platform-specific behavior:
+   * - Saves to app's Documents directory
+   * - Offers sharing functionality to move file elsewhere
+   *
+   * The method handles:
+   * 1. Writing to app-safe storage
+   * 2. Sharing the file with user's preferred app
+   * 3. Error handling and logging
+   *
+   * @param fileName - The name of the file to create (e.g. "backup.json")
+   * @param content - The content to write to the file
+   *
+   * @throws Error if:
+   * - File writing fails
+   * - Sharing fails
+   *
+   * @example
+   * ```typescript
+   * // Save and share a JSON file
+   * await platformService.writeFile(
+   *   "backup.json",
+   *   JSON.stringify(data)
+   * );
+   * ```
    */
-  async writeFile(path: string, content: string): Promise<void> {
+  async writeFile(fileName: string, content: string): Promise<void> {
     try {
       const logData = {
-        targetPath: path,
+        targetFileName: fileName,
         contentLength: content.length,
         platform: this.getCapabilities().isIOS ? "iOS" : "Android",
         timestamp: new Date().toISOString(),
@@ -175,146 +196,97 @@ export class CapacitorPlatformService implements PlatformService {
         JSON.stringify(logData, null, 2),
       );
 
-      // Check and request storage permissions if needed
-      await this.checkStoragePermissions();
-
-      // Let user pick save location first
-      const result = await FilePicker.pickDirectory();
-      const pickerLogData = {
-        path: result.path,
-        platform: this.getCapabilities().isIOS ? "iOS" : "Android",
-        timestamp: new Date().toISOString(),
-      };
-      logger.log("FilePicker result:", JSON.stringify(pickerLogData, null, 2));
-
-      // Handle paths based on platform
-      let cleanPath = result.path;
+      // For Android, we need to handle content URIs differently
       if (this.getCapabilities().isIOS) {
-        const iosLogData = {
-          originalPath: cleanPath,
-          timestamp: new Date().toISOString(),
-        };
-        logger.log("Processing iOS path", JSON.stringify(iosLogData, null, 2));
-        cleanPath = result.path;
-      } else {
-        const androidLogData = {
-          originalPath: cleanPath,
-          timestamp: new Date().toISOString(),
-        };
-        logger.log(
-          "Processing Android path",
-          JSON.stringify(androidLogData, null, 2),
-        );
-
-        // For Android, use the content URI directly
-        if (cleanPath.startsWith("content://")) {
-          const uriLogData = {
-            uri: cleanPath,
-            filename: path,
-            timestamp: new Date().toISOString(),
-          };
-          logger.log(
-            "Using content URI for Android:",
-            JSON.stringify(uriLogData, null, 2),
-          );
+        // Write to app's Documents directory for iOS
+        const writeResult = await Filesystem.writeFile({
+          path: fileName,
+          data: content,
+          directory: Directory.Data,
+          encoding: Encoding.UTF8,
+        });
 
-          // Extract the document ID from the content URI
-          const docIdMatch = cleanPath.match(/tree\/(.*?)(?:\/|$)/);
-          if (docIdMatch) {
-            const docId = docIdMatch[1];
-            const docIdLogData = {
-              docId,
+        const writeSuccessLogData = {
+          path: writeResult.uri,
           timestamp: new Date().toISOString(),
         };
         logger.log(
-              "Extracted document ID:",
-              JSON.stringify(docIdLogData, null, 2),
+          "File write successful",
+          JSON.stringify(writeSuccessLogData, null, 2),
         );
 
-            // Use the document ID as the path
-            cleanPath = docId;
-          }
-        }
-      }
+        // Offer to share the file
+        try {
+          await Share.share({
+            title: "TimeSafari Backup",
+            text: "Here is your TimeSafari backup file.",
+            url: writeResult.uri,
+            dialogTitle: "Share your backup",
+          });
 
-      const finalPath = cleanPath;
-      const finalPathLogData = {
-        fullPath: finalPath,
-        filename: path,
-        timestamp: new Date().toISOString(),
-      };
           logger.log(
-        "Final path details:",
-        JSON.stringify(finalPathLogData, null, 2),
+            "Share dialog shown",
+            JSON.stringify({ timestamp: new Date().toISOString() }, null, 2),
           );
-
-      // Write to the selected directory
-      const writeLogData = {
-        path: finalPath,
-        contentLength: content.length,
+        } catch (shareError) {
+          // Log share error but don't fail the operation
+          logger.error(
+            "Share dialog failed",
+            JSON.stringify(
+              {
+                error: shareError,
                 timestamp: new Date().toISOString(),
-      };
-      logger.log(
-        "Attempting file write:",
-        JSON.stringify(writeLogData, null, 2),
+              },
+              null,
+              2,
+            ),
           );
-
-      try {
-        if (this.getCapabilities().isIOS) {
-          await Filesystem.writeFile({
-            path: finalPath,
+        }
+      } else {
+        // For Android, first write to app's Documents directory
+        const writeResult = await Filesystem.writeFile({
+          path: fileName,
           data: content,
-            directory: Directory.Documents,
-            recursive: true,
+          directory: Directory.Data,
           encoding: Encoding.UTF8,
         });
-        } else {
-          // For Android, use the content URI directly
-          const androidPath = `Download/${path}`;
-          const directoryLogData = {
-            path: androidPath,
-            directory: Directory.ExternalStorage,
+
+        const writeSuccessLogData = {
+          path: writeResult.uri,
           timestamp: new Date().toISOString(),
         };
         logger.log(
-            "Android path configuration:",
-            JSON.stringify(directoryLogData, null, 2),
+          "File write successful to app storage",
+          JSON.stringify(writeSuccessLogData, null, 2),
         );
 
-          await Filesystem.writeFile({
-            path: androidPath,
-            data: content,
-            directory: Directory.ExternalStorage,
-            recursive: true,
-            encoding: Encoding.UTF8,
+        // Then share the file to let user choose where to save it
+        try {
+          await Share.share({
+            title: "TimeSafari Backup",
+            text: "Here is your TimeSafari backup file.",
+            url: writeResult.uri,
+            dialogTitle: "Save your backup",
           });
-        }
 
-        const writeSuccessLogData = {
-          path: finalPath,
-          timestamp: new Date().toISOString(),
-        };
           logger.log(
-          "File write successful",
-          JSON.stringify(writeSuccessLogData, null, 2),
+            "Share dialog shown for Android",
+            JSON.stringify({ timestamp: new Date().toISOString() }, null, 2),
           );
-      } catch (writeError: unknown) {
-        const error = writeError as Error;
-        const writeErrorLogData = {
-          error: {
-            message: error.message,
-            name: error.name,
-            stack: error.stack,
-          },
-          path: finalPath,
-          contentLength: content.length,
-          timestamp: new Date().toISOString(),
-        };
+        } catch (shareError) {
+          // Log share error but don't fail the operation
           logger.error(
-          "File write failed:",
-          JSON.stringify(writeErrorLogData, null, 2),
+            "Share dialog failed for Android",
+            JSON.stringify(
+              {
+                error: shareError,
+                timestamp: new Date().toISOString(),
+              },
+              null,
+              2,
+            ),
           );
-        throw new Error(`Failed to write file: ${error.message}`);
+        }
       }
     } catch (error: unknown) {
       const err = error as Error;
@@ -330,9 +302,55 @@ export class CapacitorPlatformService implements PlatformService {
         "Error in writeFile operation:",
         JSON.stringify(finalErrorLogData, null, 2),
       );
-      throw new Error(
-        `Failed to save file to selected location: ${err.message}`,
-      );
+      throw new Error(`Failed to save file: ${err.message}`);
+    }
+  }
+
+  /**
+   * Writes content to a file in the device's app-private storage.
+   * Then shares the file using the system share dialog.
+   *
+   * Works on both Android and iOS without needing external storage permissions.
+   *
+   * @param fileName - The name of the file to create (e.g. "backup.json")
+   * @param content - The content to write to the file
+   */
+  async writeAndShareFile(fileName: string, content: string): Promise<void> {
+    const timestamp = new Date().toISOString();
+    const logData = {
+      action: 'writeAndShareFile',
+      fileName,
+      contentLength: content.length,
+      timestamp,
+    };
+    logger.log('[CapacitorPlatformService]', JSON.stringify(logData, null, 2));
+
+    try {
+      const { uri } = await Filesystem.writeFile({
+        path: fileName,
+        data: content,
+        directory: Directory.Data,
+        encoding: Encoding.UTF8,
+        recursive: true,
+      });
+
+      logger.log('[CapacitorPlatformService] File write successful:', { uri, timestamp: new Date().toISOString() });
+
+      await Share.share({
+        title: 'TimeSafari Backup',
+        text: 'Here is your backup file.',
+        url: uri,
+        dialogTitle: 'Share your backup file',
+      });
+    } catch (error) {
+      const err = error as Error;
+      const errLog = {
+        message: err.message,
+        stack: err.stack,
+        timestamp: new Date().toISOString(),
+      };
+      logger.error('[CapacitorPlatformService] Error writing or sharing file:', JSON.stringify(errLog, null, 2));
+      throw new Error(`Failed to write or share file: ${err.message}`);
     }
   }