Add prompt to make Stirling your default PDF app

frontend/src/desktop/components/AppProviders.tsx

@@ -2,13 +2,18 @@ import { ReactNode } from "react";
 import { AppProviders as ProprietaryAppProviders } from "@proprietary/components/AppProviders";
 import { DesktopConfigSync } from '@app/components/DesktopConfigSync';
 import { DESKTOP_DEFAULT_APP_CONFIG } from '@app/config/defaultAppConfig';
+import { DefaultAppPrompt } from '@app/components/DefaultAppPrompt';
+import { useDefaultAppPrompt } from '@app/hooks/useDefaultAppPrompt';
 
 /**
  * Desktop application providers
  * Wraps proprietary providers and adds desktop-specific configuration
  * - Enables retry logic for app config (needed for Tauri mode when backend is starting)
+ * - Shows default PDF handler prompt on first launch
  */
 export function AppProviders({ children }: { children: ReactNode }) {
+  const { promptOpened, handleSetDefault, handleDismiss } = useDefaultAppPrompt();
+
   return (
     <ProprietaryAppProviders
       appConfigRetryOptions={{
@@ -22,6 +27,11 @@ export function AppProviders({ children }: { children: ReactNode }) {
       }}
     >
       <DesktopConfigSync />
+      <DefaultAppPrompt
+        opened={promptOpened}
+        onSetDefault={handleSetDefault}
+        onDismiss={handleDismiss}
+      />
       {children}
     </ProprietaryAppProviders>
   );

frontend/src/desktop/components/DefaultAppPrompt.tsx

@@ -0,0 +1,78 @@
+import { Modal, Text, Button, Stack, Flex } from '@mantine/core';
+import { useTranslation } from 'react-i18next';
+import PictureAsPdfIcon from '@mui/icons-material/PictureAsPdf';
+import CheckCircleOutlineIcon from '@mui/icons-material/CheckCircleOutline';
+import CancelIcon from '@mui/icons-material/Cancel';
+import { CSSProperties } from 'react';
+
+interface DefaultAppPromptProps {
+  opened: boolean;
+  onSetDefault: () => void;
+  onDismiss: () => void;
+}
+
+const ICON_STYLE: CSSProperties = {
+  fontSize: 48,
+  display: 'block',
+  margin: '0 auto 12px',
+  color: 'var(--mantine-color-blue-6)',
+};
+
+export const DefaultAppPrompt = ({ opened, onSetDefault, onDismiss }: DefaultAppPromptProps) => {
+  const { t } = useTranslation();
+
+  return (
+    <Modal
+      opened={opened}
+      onClose={onDismiss}
+      title={t('defaultApp.title', 'Set as Default PDF App')}
+      centered
+      size="auto"
+      closeOnClickOutside={true}
+      closeOnEscape={true}
+    >
+      <Stack ta="center" p="md" gap="sm">
+        <PictureAsPdfIcon style={ICON_STYLE} />
+        <Text size="lg" fw={500}>
+          {t(
+            'defaultApp.message',
+            'Would you like to set Stirling PDF as your default PDF editor?'
+          )}
+        </Text>
+        <Text size="sm" c="dimmed">
+          {t(
+            'defaultApp.description',
+            'You can change this later in your system settings.'
+          )}
+        </Text>
+      </Stack>
+
+      <Flex
+        mt="md"
+        gap="sm"
+        justify="center"
+        align="center"
+        direction={{ base: 'column', md: 'row' }}
+      >
+        <Button
+          variant="light"
+          color="var(--mantine-color-gray-8)"
+          onClick={onDismiss}
+          leftSection={<CancelIcon fontSize="small" />}
+          w="10rem"
+        >
+          {t('defaultApp.notNow', 'Not Now')}
+        </Button>
+        <Button
+          variant="filled"
+          color="var(--mantine-color-blue-9)"
+          onClick={onSetDefault}
+          leftSection={<CheckCircleOutlineIcon fontSize="small" />}
+          w="10rem"
+        >
+          {t('defaultApp.setDefault', 'Set Default')}
+        </Button>
+      </Flex>
+    </Modal>
+  );
+};

frontend/src/desktop/hooks/useDefaultAppPrompt.ts

@@ -0,0 +1,82 @@
+import { useState, useEffect } from 'react';
+import { defaultAppService } from '@app/services/defaultAppService';
+import { alert } from '@app/components/toast';
+import { useTranslation } from 'react-i18next';
+
+export function useDefaultAppPrompt() {
+  const { t } = useTranslation();
+  const [promptOpened, setPromptOpened] = useState(false);
+  const [isSettingDefault, setIsSettingDefault] = useState(false);
+
+  // Check on mount if we should show the prompt
+  useEffect(() => {
+    const checkShouldPrompt = async () => {
+      try {
+        const shouldShow = await defaultAppService.shouldShowPrompt();
+        if (shouldShow) {
+          // Small delay so it doesn't show immediately on app launch
+          setTimeout(() => setPromptOpened(true), 2000);
+        }
+      } catch (error) {
+        console.error('[DefaultAppPrompt] Failed to check prompt status:', error);
+      }
+    };
+
+    checkShouldPrompt();
+  }, []);
+
+  const handleSetDefault = async () => {
+    setIsSettingDefault(true);
+    try {
+      const result = await defaultAppService.setAsDefaultPdfHandler();
+
+      if (result === 'set_successfully') {
+        alert({
+          alertType: 'success',
+          title: t('defaultApp.success.title', 'Default App Set'),
+          body: t(
+            'defaultApp.success.message',
+            'Stirling PDF is now your default PDF editor'
+          ),
+        });
+      } else if (result === 'opened_settings') {
+        alert({
+          alertType: 'neutral',
+          title: t('defaultApp.settingsOpened.title', 'Settings Opened'),
+          body: t(
+            'defaultApp.settingsOpened.message',
+            'Please select Stirling PDF in your system settings'
+          ),
+        });
+      }
+
+      // Mark as dismissed regardless of outcome
+      defaultAppService.setPromptDismissed(true);
+      setPromptOpened(false);
+    } catch (error) {
+      console.error('[DefaultAppPrompt] Failed to set default handler:', error);
+      alert({
+        alertType: 'error',
+        title: t('defaultApp.error.title', 'Error'),
+        body: t(
+          'defaultApp.error.message',
+          'Failed to set default PDF handler'
+        ),
+      });
+    } finally {
+      setIsSettingDefault(false);
+    }
+  };
+
+  const handleDismiss = () => {
+    defaultAppService.setPromptDismissed(true);
+    setPromptOpened(false);
+  };
+
+  return {
+    promptOpened,
+    isSettingDefault,
+    handleSetDefault,
+    handleDismiss,
+  };
+}

frontend/src/desktop/services/defaultAppService.ts

@@ -0,0 +1,70 @@
+import { invoke } from '@tauri-apps/api/core';
+
+/**
+ * Service for managing default PDF handler settings
+ * Note: Uses localStorage for machine-specific preferences (not synced to server)
+ */
+export const defaultAppService = {
+  /**
+   * Check if Stirling PDF is the default PDF handler
+   */
+  async isDefaultPdfHandler(): Promise<boolean> {
+    try {
+      const result = await invoke<boolean>('is_default_pdf_handler');
+      return result;
+    } catch (error) {
+      console.error('[DefaultApp] Failed to check default handler:', error);
+      return false;
+    }
+  },
+
+  /**
+   * Set or prompt to set Stirling PDF as default PDF handler
+   * Returns a status string indicating what happened
+   */
+  async setAsDefaultPdfHandler(): Promise<'set_successfully' | 'opened_settings' | 'error'> {
+    try {
+      const result = await invoke<string>('set_as_default_pdf_handler');
+      return result as 'set_successfully' | 'opened_settings';
+    } catch (error) {
+      console.error('[DefaultApp] Failed to set default handler:', error);
+      return 'error';
+    }
+  },
+
+  /**
+   * Check if user has dismissed the default app prompt (machine-specific)
+   */
+  hasUserDismissedPrompt(): boolean {
+    try {
+      const dismissed = localStorage.getItem('stirlingpdf_default_app_prompt_dismissed');
+      return dismissed === 'true';
+    } catch {
+      return false;
+    }
+  },
+
+  /**
+   * Mark that user has dismissed the default app prompt (machine-specific)
+   */
+  setPromptDismissed(dismissed: boolean): void {
+    try {
+      localStorage.setItem('stirlingpdf_default_app_prompt_dismissed', dismissed ? 'true' : 'false');
+    } catch (error) {
+      console.error('[DefaultApp] Failed to save prompt preference:', error);
+    }
+  },
+
+  /**
+   * Check if we should show the default app prompt
+   * Returns true if: user hasn't dismissed it AND app is not default handler
+   */
+  async shouldShowPrompt(): Promise<boolean> {
+    if (this.hasUserDismissedPrompt()) {
+      return false;
+    }
+
+    const isDefault = await this.isDefaultPdfHandler();
+    return !isDefault;
+  },
+};