Fix LaTeX compile API to use node-pdflatex and improve error messages

app/api/latex/compile/route.ts

@@ -1,4 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server'
+import pdflatex from 'node-pdflatex'
 
 export async function POST(request: NextRequest) {
   try {
@@ -11,47 +12,37 @@ export async function POST(request: NextRequest) {
       )
     }
 
-    console.log('Compiling LaTeX to PDF using LaTeX.Online...')
+    console.log('📄 Compiling LaTeX to PDF using node-pdflatex...')
+    console.log(`   Content length: ${latex.length} characters`)
 
-    // Use LaTeX.Online free API to compile LaTeX to PDF
-    const compileResponse = await fetch('https://latexonline.cc/compile', {
-      method: 'POST',
-      headers: {
-        'Content-Type': 'text/plain',
-      },
-      body: latex
-    })
-
-    if (!compileResponse.ok) {
-      const errorText = await compileResponse.text()
-      console.error('LaTeX compilation failed:', errorText)
-      return NextResponse.json(
-        { 
-          error: 'LaTeX compilation failed',
-          details: errorText 
-        },
-        { status: 500 }
-      )
-    }
-
-    // Get the PDF buffer
-    const pdfBuffer = await compileResponse.arrayBuffer()
+    // Compile LaTeX to PDF using node-pdflatex
+    const pdfBuffer = await pdflatex(latex)
     
-    console.log('LaTeX compiled successfully, PDF size:', pdfBuffer.byteLength, 'bytes')
+    console.log(`✅ LaTeX compiled successfully! PDF size: ${pdfBuffer.byteLength} bytes`)
 
     // Return the PDF
-    const response = new NextResponse(Buffer.from(pdfBuffer))
+    const response = new NextResponse(pdfBuffer)
     response.headers.set('Content-Type', 'application/pdf')
     response.headers.set('Content-Disposition', `attachment; filename="${filename || 'document.pdf'}"`)
 
     return response
 
   } catch (error) {
-    console.error('Error compiling LaTeX:', error)
+    console.error('❌ Error compiling LaTeX:', error)
+    console.error('   Error type:', error instanceof Error ? error.constructor.name : typeof error)
+    console.error('   Error message:', error instanceof Error ? error.message : String(error))
+    
+    // Extract more detailed error info if available
+    let errorDetails = error instanceof Error ? error.message : String(error)
+    if (error && typeof error === 'object' && 'stderr' in error) {
+      errorDetails = (error as any).stderr || errorDetails
+    }
+    
     return NextResponse.json(
       { 
         error: 'Failed to compile LaTeX',
-        details: error instanceof Error ? error.message : String(error)
+        details: errorDetails,
+        message: 'There may be a syntax error in your LaTeX code. Check the console for details.'
       },
       { status: 500 }
     )

app/components/TextEditor.tsx

@@ -128,12 +128,21 @@ export function TextEditor({
         const url = URL.createObjectURL(blob)
         setPdfUrl(url)
       } else {
-        console.error('PDF compilation failed')
-        alert('Failed to compile LaTeX. Check your syntax.')
+        // Try to get error details from response
+        const contentType = response.headers.get('content-type')
+        if (contentType?.includes('application/json')) {
+          const errorData = await response.json()
+          console.error('PDF compilation failed:', errorData)
+          alert(`Failed to compile LaTeX!\n\nError: ${errorData.error || 'Unknown error'}\n\nDetails: ${errorData.details || 'Check console for more info'}`)
+        } else {
+          const errorText = await response.text()
+          console.error('PDF compilation failed:', errorText)
+          alert(`Failed to compile LaTeX!\n\n${errorText.substring(0, 200)}`)
+        }
       }
     } catch (error) {
       console.error('Compilation error:', error)
-      alert('Failed to compile LaTeX')
+      alert(`Failed to compile LaTeX!\n\nError: ${error instanceof Error ? error.message : String(error)}`)
     } finally {
       setIsCompiling(false)
     }