From 24abd8d32f0cc2237a18ec7011b6798f0d08bb8c Mon Sep 17 00:00:00 2001
From: Guillem Hernandez Sola <guillem.hernandez.sola@gmail.com>
Date: Thu, 9 Apr 2026 16:53:00 +0200
Subject: [PATCH] fix(sync): compress oversized tweet images before Bluesky
 upload

---
 twitter2bsky_daemon.py | 91 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 1 deletion(-)

diff --git a/twitter2bsky_daemon.py b/twitter2bsky_daemon.py
index 40ddc5e..4825ac1 100644
--- a/twitter2bsky_daemon.py
+++ b/twitter2bsky_daemon.py
@@ -28,6 +28,12 @@ BSKY_TEXT_MAX_LENGTH = 275
 VIDEO_MAX_DURATION_SECONDS = 179
 MAX_VIDEO_UPLOAD_SIZE_MB = 45
 
+# Tweet image upload safety limits
+BSKY_IMAGE_MAX_BYTES = 950 * 1024
+BSKY_IMAGE_MAX_DIMENSION = 2000
+BSKY_IMAGE_MIN_JPEG_QUALITY = 45
+
+# External card thumbnail limits
 EXTERNAL_THUMB_MAX_BYTES = 950 * 1024
 EXTERNAL_THUMB_MAX_DIMENSION = 1200
 EXTERNAL_THUMB_MIN_JPEG_QUALITY = 40
@@ -773,6 +779,66 @@ def upload_blob_with_retry(client, binary_data, media_label="media"):
     return None
 
 
+def compress_post_image_to_limit(image_bytes, max_bytes=BSKY_IMAGE_MAX_BYTES):
+    """
+    Compress/resize normal tweet images so they fit within Bluesky image blob limits.
+    Returns JPEG bytes or None.
+    """
+    try:
+        with Image.open(io.BytesIO(image_bytes)) as img:
+            img = img.convert("RGB")
+
+            width, height = img.size
+            max_dim = max(width, height)
+
+            if max_dim > BSKY_IMAGE_MAX_DIMENSION:
+                scale = BSKY_IMAGE_MAX_DIMENSION / max_dim
+                new_size = (max(1, int(width * scale)), max(1, int(height * scale)))
+                img = img.resize(new_size, Image.LANCZOS)
+                logging.info(f"🖼️ Resized post image to {new_size[0]}x{new_size[1]}")
+
+            for quality in [90, 82, 75, 68, 60, 52, BSKY_IMAGE_MIN_JPEG_QUALITY]:
+                out = io.BytesIO()
+                img.save(out, format="JPEG", quality=quality, optimize=True, progressive=True)
+                data = out.getvalue()
+
+                logging.info(
+                    f"🖼️ Post image candidate size at JPEG quality {quality}: "
+                    f"{len(data)} bytes ({len(data) / 1024:.2f} KB)"
+                )
+
+                if len(data) <= max_bytes:
+                    return data
+
+            for target_dim in [1800, 1600, 1400, 1200, 1000]:
+                resized = img.copy()
+                width, height = resized.size
+                max_dim = max(width, height)
+
+                if max_dim > target_dim:
+                    scale = target_dim / max_dim
+                    new_size = (max(1, int(width * scale)), max(1, int(height * scale)))
+                    resized = resized.resize(new_size, Image.LANCZOS)
+
+                for quality in [68, 60, 52, BSKY_IMAGE_MIN_JPEG_QUALITY]:
+                    out = io.BytesIO()
+                    resized.save(out, format="JPEG", quality=quality, optimize=True, progressive=True)
+                    data = out.getvalue()
+
+                    logging.info(
+                        f"🖼️ Post image resized to <= {target_dim}px at quality {quality}: "
+                        f"{len(data)} bytes ({len(data) / 1024:.2f} KB)"
+                    )
+
+                    if len(data) <= max_bytes:
+                        return data
+
+    except Exception as e:
+        logging.warning(f"Could not compress post image: {repr(e)}")
+
+    return None
+
+
 def get_blob_from_url(media_url, client, http_client):
     try:
         r = http_client.get(media_url, timeout=MEDIA_DOWNLOAD_TIMEOUT, follow_redirects=True)
@@ -785,7 +851,30 @@ def get_blob_from_url(media_url, client, http_client):
             logging.warning(f"Could not fetch media {media_url}: empty response body")
             return None
 
-        return upload_blob_with_retry(client, content, media_label=media_url)
+        content_type = (r.headers.get("content-type") or "").lower()
+        upload_bytes = content
+
+        if content_type.startswith("image/"):
+            original_size = len(content)
+            logging.info(f"🖼️ Downloaded post image {media_url} ({original_size} bytes / {original_size / 1024:.2f} KB)")
+
+            if original_size > BSKY_IMAGE_MAX_BYTES:
+                logging.info(
+                    f"🖼️ Post image exceeds safe Bluesky limit "
+                    f"({original_size} bytes > {BSKY_IMAGE_MAX_BYTES} bytes). Compressing..."
+                )
+                compressed = compress_post_image_to_limit(content, BSKY_IMAGE_MAX_BYTES)
+                if compressed:
+                    upload_bytes = compressed
+                    logging.info(
+                        f"✅ Post image compressed to {len(upload_bytes)} bytes "
+                        f"({len(upload_bytes) / 1024:.2f} KB)"
+                    )
+                else:
+                    logging.warning(f"⚠️ Could not compress post image to safe limit: {media_url}")
+                    return None
+
+        return upload_blob_with_retry(client, upload_bytes, media_label=media_url)
 
     except Exception as e:
         logging.warning(f"Could not fetch media {media_url}: {repr(e)}")