feat: implement server-side image compression for sign image fields.

__init__.py

@@ -1,3 +1,4 @@
 # -*- coding: utf-8 -*-
 
 from . import models
+from . import controllers

controllers/__init__.py

@@ -0,0 +1,2 @@
+# -*- coding: utf-8 -*-
+from . import main

controllers/main.py

@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+import base64
+import io
+import logging
+from PIL import Image
+
+from odoo import http
+from odoo.http import request
+from odoo.tools import image_process
+from odoo.addons.sign.controllers.main import Sign
+
+_logger = logging.getLogger(__name__)
+
+class SignController(Sign):
+
+    @http.route(['/sign/sign/<int:request_id>/<token>'], type='json', auth='public')
+    def sign_document(self, request_id, token, signature=None, items=None, **kwargs):
+        if items:
+            # Filter items that look like images (base64)
+            # We can't easily know the type of item just from the ID without a lookup
+            # But we can try to decode and compress if it looks like a large base64 string
+            
+            # Optimization: Fetch all item types at once to identify image field types
+            item_ids = [int(k) for k in items.keys()]
+            sign_items = request.env['sign.item'].sudo().browse(item_ids)
+            image_items_ids = set(sign_items.filtered(lambda i: i.type_id.item_type == 'image').ids)
+
+            for key, value in items.items():
+                if int(key) in image_items_ids and value and isinstance(value, str):
+                    if value.startswith('/sign/image/'):
+                        # Skip URLs (handled by sign_sequence_field or already processed)
+                        continue
+                        
+                    try:
+                        # Value comes as "data:image/png;base64,..." usually
+                        # But Odoo sometimes strips header or not. 
+                        # sign_image_upload.js sends the full data URL.
+                        
+                        header = None
+                        image_data = value
+                        if ',' in value:
+                            header, image_data = value.split(',', 1)
+                        
+                        # Compress
+                        # Decode
+                        image_bytes = base64.b64decode(image_data)
+                        
+                        # Process image: limit size to max 1920x1920 and reasonable quality
+                        # image_process returns the processed image binary
+                        processed_image = image_process(image_bytes, size=(1920, 1920), quality=80, output_format='JPEG')
+                        
+                        # Re-encode
+                        new_base64 = base64.b64encode(processed_image).decode('utf-8')
+                        
+                        # Re-attach header if it was there, but ensure it matches new format (JPEG)
+                        # Actually, keeping original header type might be misleading if we converted to JPEG.
+                        # But for Odoo chatter/display, usually data:image/jpeg;base64 is safer if we converted.
+                        
+                        new_value = f"data:image/jpeg;base64,{new_base64}"
+                        items[key] = new_value
+                        
+                        _logger.info(f"Compressed image for item {key}: {len(value)} -> {len(new_value)} chars")
+                        
+                    except Exception as e:
+                        _logger.warning(f"Failed to compress image for item {key}: {e}")
+                        # Leave original value if compression fails
+
+        return super().sign_document(request_id, token, signature=signature, items=items, **kwargs)