refactor(electron): major ui refactor into modules

electron/main/backend-bridge.js

@@ -0,0 +1,98 @@
+const { app } = require('electron');
+const path = require('path');
+const { spawn } = require('child_process');
+
+// Helper function to run python commands via the bundled backend
+function runPythonCommand(command, kwargs, event) {
+    const buildDir = path.resolve(__dirname, '..', '..', 'build');
+    let backendPath;
+    if (app.isPackaged) {
+        backendPath = path.join(process.resourcesPath, 'fourdst-backend');
+    } else {
+        backendPath = path.join(buildDir, 'electron', 'dist', 'fourdst-backend', 'fourdst-backend');
+    }
+
+    console.log(`[MAIN_PROCESS] Spawning backend: ${backendPath}`);
+    const args = [command, JSON.stringify(kwargs)];
+    console.log(`[MAIN_PROCESS] With args: [${args.join(', ')}]`);
+
+    return new Promise((resolve) => {
+        const process = spawn(backendPath, args);
+        let stdoutBuffer = '';
+        let errorOutput = '';
+
+        process.stderr.on('data', (data) => {
+            errorOutput += data.toString();
+            console.error('Backend STDERR:', data.toString().trim());
+        });
+
+        const isStreaming = command === 'fill_bundle';
+
+        process.stdout.on('data', (data) => {
+            const chunk = data.toString();
+            stdoutBuffer += chunk;
+
+            if (isStreaming && event) {
+                // Process buffer line by line for streaming commands
+                let newlineIndex;
+                while ((newlineIndex = stdoutBuffer.indexOf('\n')) >= 0) {
+                    const line = stdoutBuffer.substring(0, newlineIndex).trim();
+                    stdoutBuffer = stdoutBuffer.substring(newlineIndex + 1);
+
+                    if (line) {
+                        try {
+                            const parsed = JSON.parse(line);
+                            if (parsed.type === 'progress') {
+                                event.sender.send('fill-bundle-progress', parsed.data);
+                            } else {
+                                // Not a progress update, put it back in the buffer for final processing
+                                stdoutBuffer = line + '\n' + stdoutBuffer;
+                                break; // Stop processing lines
+                            }
+                        } catch (e) {
+                            // Ignore parsing errors for intermediate lines in a stream
+                        }
+                    }
+                }
+            }
+        });
+
+        process.on('close', (code) => {
+            console.log(`[MAIN_PROCESS] Backend process exited with code ${code}`);
+            let resultData = null;
+
+            try {
+                // Core functions now return clean JSON directly
+                const finalJson = JSON.parse(stdoutBuffer.trim());
+                resultData = finalJson;  // Use the JSON response directly
+            } catch (e) {
+                console.error(`[MAIN_PROCESS] Could not parse backend output as JSON: ${e}`);
+                console.error(`[MAIN_PROCESS] Raw output: "${stdoutBuffer}"`);
+                // If parsing fails, return a structured error response
+                resultData = { 
+                    success: false, 
+                    error: `JSON parsing failed: ${e.message}`,
+                    raw_output: stdoutBuffer 
+                };
+            }
+
+            const finalError = errorOutput.trim();
+            if (finalError && !resultData) {
+                resolve({ success: false, error: finalError });
+            } else if (resultData) {
+                resolve(resultData);
+            } else {
+                const errorMessage = finalError || `The script finished without returning a result (exit code: ${code})`;
+                resolve({ success: false, error: errorMessage });
+            }
+        });
+
+        process.on('error', (err) => {
+            resolve({ success: false, error: `Failed to start backend process: ${err.message}` });
+        });
+    });
+}
+
+module.exports = {
+    runPythonCommand
+};