added merge

app.py

@@ -8,11 +8,8 @@ from PyPDF2 import PdfReader, PdfWriter
 with open(os.path.join(os.path.dirname(__file__), "fancy.css")) as f:
     custom_css = f.read()
 
-# Maximum upload size
-MAX_SIZE_BYTES = 1 * 1024 * 1024 * 1024  # 1 GB
-
-# Note: Uploaded PDFs are processed in-memory and not stored on the server.
-# This is a quick solution for splitting PDFs without any external storage.
+# Maximum upload size (1 GB)
+MAX_SIZE_BYTES = 1 * 1024 * 1024 * 1024
 
 def parse_page_ranges(ranges: str, num_pages: int) -> List[int]:
     """
@@ -32,6 +29,7 @@ def parse_page_ranges(ranges: str, num_pages: int) -> List[int]:
                 pages.add(p - 1)
     return sorted(pages)
 
+
 def split_pdf(file, page_ranges: str):
     # Validate file size
     file_size = os.path.getsize(file.name)
@@ -58,40 +56,91 @@ def split_pdf(file, page_ranges: str):
 
     return out_path, None
 
+
+def merge_pdfs(files):
+    # Merge multiple PDFs in upload order
+    if not files:
+        return None, "Please upload at least two PDF files to merge."
+
+    # Validate total size
+    total_size = sum(os.path.getsize(f.name) for f in files)
+    if total_size > MAX_SIZE_BYTES:
+        return None, f"Total file size exceeds 1 GB limit ({total_size / (1024*1024*1024):.2f} GB)."
+
+    writer = PdfWriter()
+    try:
+        for f in files:
+            reader = PdfReader(f.name)
+            for page in reader.pages:
+                writer.add_page(page)
+    except Exception as e:
+        return None, f"Error reading PDFs: {e}"
+
+    out_path = tempfile.NamedTemporaryFile(delete=False, suffix=".pdf").name
+    with open(out_path, "wb") as f_out:
+        writer.write(f_out)
+
+    return out_path, None
+
 # Build Gradio interface
 with gr.Blocks(css=custom_css) as demo:
-    # Header
-    gr.HTML("<h1 id='header'>PDF Splitter</h1>")
-    gr.Markdown("**Free & Quick Solution**: Uploaded PDFs are processed but not stored. Ideal for lazy splitting without installing anything.")
-    gr.Markdown("Upload a PDF (up to 1 GB) and extract specific pages using ranges like `1-3,5,7-9`.")
-
-    with gr.Row(elem_classes="input-row"):
-        pdf_input = gr.File(label="Select PDF file", file_types=['.pdf'])
-        page_input = gr.Textbox(label="Page ranges", placeholder="e.g. 1-3,5,7-9")
-
-    with gr.Row(elem_classes="button-row"):
-        split_button = gr.Button("Split PDF", variant="primary")
-
-    output_file = gr.File(label="Download Split PDF")
-    error_text = gr.Textbox(label="Error Message", interactive=False, visible=False)
-
-    def run_split(file, ranges):
-        if file is None or not ranges:
-            return None, "Please upload a PDF and specify page ranges.", True
-        out_path, error = split_pdf(file, ranges)
-        if error:
-            return None, error, True
-        return out_path, "", False
-
-    split_button.click(
-        fn=run_split,
-        inputs=[pdf_input, page_input],
-        outputs=[output_file, error_text, error_text],
-        api_name="split_pdf"
+    gr.HTML("<h1 id='header'>PDF Splitter & Merger</h1>")
+    gr.Markdown(
+        "**Free & Quick Solution**: Process your PDFs in-memory instantly without storage.\n"
+        "Use the **Split** tab to extract specific pages or the **Merge** tab to combine multiple PDFs into one."
     )
 
-    # Hide error box when no error
-    error_text.change(lambda msg: msg != "", inputs=error_text, outputs=error_text)
+    with gr.Tabs():
+        # Split Tab
+        with gr.TabItem("Split PDF"):
+            with gr.Row(elem_classes="input-row"):
+                pdf_input = gr.File(label="Select PDF to split", file_types=['.pdf'])
+                page_input = gr.Textbox(label="Page ranges", placeholder="e.g. 1-3,5,7-9")
+            with gr.Row(elem_classes="button-row"):
+                split_button = gr.Button("Split PDF", variant="primary")
+            output_split = gr.File(label="Download Split PDF")
+            error_split = gr.Textbox(label="Error Message", interactive=False, visible=False)
+
+            def run_split(file, ranges):
+                if file is None or not ranges:
+                    return None, "Please upload a PDF and specify page ranges.", True
+                out_path, error = split_pdf(file, ranges)
+                if error:
+                    return None, error, True
+                return out_path, "", False
+
+            split_button.click(
+                fn=run_split,
+                inputs=[pdf_input, page_input],
+                outputs=[output_split, error_split, error_split],
+                api_name="split_pdf"
+            )
+            error_split.change(lambda msg: msg != "", inputs=error_split, outputs=error_split)
+
+        # Merge Tab
+        with gr.TabItem("Merge PDF"):
+            with gr.Row(elem_classes="input-row"):
+                merge_inputs = gr.Files(label="Select PDF files to merge", file_types=['.pdf'])
+            with gr.Row(elem_classes="button-row"):
+                merge_button = gr.Button("Merge PDFs", variant="primary")
+            output_merge = gr.File(label="Download Merged PDF")
+            error_merge = gr.Textbox(label="Error Message", interactive=False, visible=False)
+
+            def run_merge(files):
+                if not files or len(files) < 2:
+                    return None, "Please upload at least two PDF files.", True
+                out_path, error = merge_pdfs(files)
+                if error:
+                    return None, error, True
+                return out_path, "", False
+
+            merge_button.click(
+                fn=run_merge,
+                inputs=[merge_inputs],
+                outputs=[output_merge, error_merge, error_merge],
+                api_name="merge_pdfs"
+            )
+            error_merge.change(lambda msg: msg != "", inputs=error_merge, outputs=error_merge)
 
 if __name__ == "__main__":
-    demo.launch(server_name="0.0.0.0", server_port=int(os.environ.get("PORT", 7860)))
+    demo.launch(server_name="0.0.0.0", server_port=int(os.environ.get("PORT", 7860)))