Add "optimize alternative icons" insight handling (#417)

NicoHinderling · web-flow · commit 2be5cc9ed3a6 · 2025-10-15T13:20:06.000-07:00
* Add Optimize alternative icons insight handling

* trevor feedback

* get rid of logger.error in image_optimization.py too
diff --git a/src/launchpad/artifacts/apple/zipped_xcarchive.py b/src/launchpad/artifacts/apple/zipped_xcarchive.py
@@ -68,6 +68,32 @@ def get_plist(self) -> dict[str, Any]:
         except Exception as e:
             raise RuntimeError("Failed to parse Info.plist") from e
 
+    def get_icon_info(self) -> tuple[str | None, list[str]]:
+        """Extract primary and alternate icon names from Info.plist.
+
+        Returns:
+            Tuple of (primary_icon_name, alternate_icon_names list)
+        """
+        plist = self.get_plist()
+        bundle_icons = plist.get("CFBundleIcons", {})
+
+        primary_icon_name: str | None = None
+        alternate_icon_names: list[str] = []
+
+        primary_icon = bundle_icons.get("CFBundlePrimaryIcon", {})
+        if isinstance(primary_icon, dict):
+            primary_icon_name = primary_icon.get("CFBundleIconName")
+
+        alternate_icons = bundle_icons.get("CFBundleAlternateIcons", {})
+        if isinstance(alternate_icons, dict):
+            for icon_key, icon_data in alternate_icons.items():
+                if isinstance(icon_data, dict):
+                    icon_name = icon_data.get("CFBundleIconName")
+                    if icon_name:
+                        alternate_icon_names.append(icon_name)
+
+        return primary_icon_name, alternate_icon_names
+
     def generate_ipa(self, output_path: Path):
         """Generate an IPA file
 
diff --git a/src/launchpad/size/analyzers/apple.py b/src/launchpad/size/analyzers/apple.py
@@ -23,6 +23,7 @@
 from launchpad.parsers.apple.swift_symbol_type_aggregator import SwiftSymbolTypeAggregator
 from launchpad.size.constants import APPLE_FILESYSTEM_BLOCK_SIZE
 from launchpad.size.hermes.utils import make_hermes_reports
+from launchpad.size.insights.apple.alternate_icons_optimization import AlternateIconsOptimizationInsight
 from launchpad.size.insights.apple.image_optimization import ImageOptimizationInsight
 from launchpad.size.insights.apple.localized_strings import LocalizedStringsInsight
 from launchpad.size.insights.apple.localized_strings_minify import MinifyLocalizedStringsInsight
@@ -227,6 +228,9 @@ def analyze(self, artifact: AppleArtifact) -> AppleAnalysisResults:
                 unnecessary_files=self._generate_insight_with_tracing(
                     UnnecessaryFilesInsight, insights_input, "unnecessary_files"
                 ),
+                alternate_icons_optimization=self._generate_insight_with_tracing(
+                    AlternateIconsOptimizationInsight, insights_input, "alternate_icons_optimization"
+                ),
                 # TODO: enable audio/video compression insights once we handle ffmpeg
                 # audio_compression=self._generate_insight_with_tracing(
                 #     AudioCompressionInsight, insights_input, "audio_compression"
@@ -293,6 +297,8 @@ def _extract_app_info(self, xcarchive: ZippedXCArchive) -> AppleAppInfo:
             is_code_signature_valid = False
             code_signature_errors = [str(e)]
 
+        primary_icon_name, alternate_icon_names = xcarchive.get_icon_info()
+
         return AppleAppInfo(
             name=plist.get("CFBundleName", "Unknown"),
             app_id=plist.get("CFBundleIdentifier", "unknown.bundle.id"),
@@ -310,6 +316,8 @@ def _extract_app_info(self, xcarchive: ZippedXCArchive) -> AppleAppInfo:
             is_code_signature_valid=is_code_signature_valid,
             code_signature_errors=code_signature_errors,
             main_binary_uuid=xcarchive.get_main_binary_uuid(),
+            primary_icon_name=primary_icon_name,
+            alternate_icon_names=alternate_icon_names,
         )
 
     def _get_profile_type(self, profile_data: dict[str, Any]) -> Tuple[str, str]:
diff --git a/src/launchpad/size/insights/apple/alternate_icons_optimization.py b/src/launchpad/size/insights/apple/alternate_icons_optimization.py
@@ -0,0 +1,76 @@
+from __future__ import annotations
+
+import io
+
+from pathlib import Path
+from typing import List
+
+from PIL import Image
+
+from launchpad.size.insights.apple.image_optimization import BaseImageOptimizationInsight
+from launchpad.size.insights.insight import InsightsInput
+from launchpad.size.models.apple import AppleAppInfo
+from launchpad.size.models.common import FileInfo
+from launchpad.utils.logging import get_logger
+
+logger = get_logger(__name__)
+
+
+class AlternateIconsOptimizationInsight(BaseImageOptimizationInsight):
+    """Analyze alternate app icon optimization opportunities in iOS apps.
+
+    Alternate app icons can be optimized without affecting the App Store listing since
+    only the primary icon is displayed there. This insight identifies alternate icons
+    that could be minified or converted to more efficient formats like HEIC.
+
+    Icons are resized to device display size (180px for iPhone 3x) and back to store
+    size (1024px) before optimization, since they only need quality for homescreen display.
+    """
+
+    IPHONE_3X_ICON_SIZE = 180  # Largest icon size displayed on device
+    APP_STORE_ICON_SIZE = 1024  # Standard App Store icon size
+
+    def _find_images(self, input: InsightsInput) -> List[FileInfo]:
+        if not isinstance(input.app_info, AppleAppInfo):
+            return []
+
+        if not input.app_info.alternate_icon_names:
+            return []
+
+        alternate_icon_names = set(input.app_info.alternate_icon_names)
+        car_files = [f for f in input.file_analysis.files if f.file_type == "car"]
+
+        images: List[FileInfo] = []
+        for car_file in car_files:
+            if not car_file.children or (len(car_file.children) == 1 and car_file.children[0].path.endswith("/Other")):
+                logger.warning(
+                    "Asset catalog %s has no parsed children. ParsedAssets directory may be missing.", car_file.path
+                )
+                continue
+
+            for child in car_file.children:
+                if self._is_alternate_icon_file(child, alternate_icon_names):
+                    images.append(child)
+
+        return list({img.path: img for img in images}.values())
+
+    def _preprocess_image(self, img: Image.Image, file_info: FileInfo) -> tuple[Image.Image, int, int]:
+        resized = self._resize_icon_for_analysis(img)
+
+        fmt = img.format or "PNG"
+        with io.BytesIO() as buf:
+            resized.save(buf, format=fmt)
+            resized_size = buf.tell()
+
+        baseline_savings = max(0, file_info.size - resized_size)
+        return resized, resized_size, baseline_savings
+
+    def _resize_icon_for_analysis(self, img: Image.Image) -> Image.Image:
+        return img.resize((self.IPHONE_3X_ICON_SIZE, self.IPHONE_3X_ICON_SIZE), Image.Resampling.LANCZOS).resize(
+            (self.APP_STORE_ICON_SIZE, self.APP_STORE_ICON_SIZE), Image.Resampling.LANCZOS
+        )
+
+    def _is_alternate_icon_file(self, file_info: FileInfo, alternate_icon_names: set[str]) -> bool:
+        return file_info.file_type.lower() in self.OPTIMIZABLE_FORMATS and any(
+            Path(file_info.path).stem.startswith(name) for name in alternate_icon_names
+        )
diff --git a/src/launchpad/size/insights/apple/image_optimization.py b/src/launchpad/size/insights/apple/image_optimization.py
@@ -3,10 +3,11 @@
 import io
 import logging
 
+from abc import ABC, abstractmethod
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Iterable, List, Sequence
+from typing import List
 
 import pillow_heif  # type: ignore
 
@@ -36,17 +37,37 @@ class _OptimizationResult:
     optimized_size: int
 
 
-class ImageOptimizationInsight(Insight[ImageOptimizationInsightResult]):
-    """Analyse image optimisation opportunities in iOS apps."""
+class BaseImageOptimizationInsight(Insight[ImageOptimizationInsightResult], ABC):
+    """Base class for image optimization insights with shared analysis logic."""
 
     OPTIMIZABLE_FORMATS = {"png", "jpg", "jpeg", "heif", "heic"}
     MIN_SAVINGS_THRESHOLD = 4096
     TARGET_JPEG_QUALITY = 85
     TARGET_HEIC_QUALITY = 85
     _MAX_WORKERS = 4
 
+    @abstractmethod
+    def _find_images(self, input: InsightsInput) -> List[FileInfo]:
+        """Find and return list of images to analyze. Should include deduplication if needed."""
+        pass
+
+    def _preprocess_image(self, img: Image.Image, file_info: FileInfo) -> tuple[Image.Image, int, int]:
+        """Preprocess image before optimization analysis.
+
+        Args:
+            img: The loaded PIL Image
+            file_info: File metadata
+
+        Returns:
+            Tuple of (processed_image, baseline_size, baseline_savings):
+            - processed_image: The image to analyze for optimization
+            - baseline_size: Size of the processed image before optimization
+            - baseline_savings: Savings from preprocessing alone (original - baseline)
+        """
+        return img, file_info.size, 0
+
     def generate(self, input: InsightsInput) -> ImageOptimizationInsightResult | None:  # noqa: D401
-        files = list(self._iter_optimizable_files(input.file_analysis.files))
+        files = self._find_images(input)
         if not files:
             return None
 
@@ -58,9 +79,8 @@ def generate(self, input: InsightsInput) -> ImageOptimizationInsightResult | Non
                     result = future.result()
                     if result and result.potential_savings >= self.MIN_SAVINGS_THRESHOLD:
                         results.append(result)
-                except Exception as exc:  # pragma: no cover
-                    file_info = future_to_file[future]
-                    logger.error("Failed to analyse %s: %s", file_info.path, exc)
+                except Exception:  # pragma: no cover
+                    logger.exception("Failed to analyze image in thread pool")
 
         if not results:
             return None
@@ -77,49 +97,50 @@ def _analyze_image_optimization(
         self,
         file_info: FileInfo,
     ) -> OptimizableImageFile | None:
-        minify_savings = 0
-        conversion_savings = 0
-        minified_size: int | None = None
-        heic_size: int | None = None
-
-        full_path = file_info.full_path
-        file_size = file_info.size
-        file_type = file_info.file_type
-        display_path = file_info.path
-
-        if full_path is None:
-            logger.info("Skipping %s because it has no full path", display_path)
+        if file_info.full_path is None:
+            logger.info("Skipping %s because it has no full path", file_info.path)
             return None
 
         try:
-            with Image.open(full_path) as img:
+            with Image.open(file_info.full_path) as img:
                 img.load()  # type: ignore
-                fmt = (img.format or file_type).lower()
+
+                processed_img, baseline_size, baseline_savings = self._preprocess_image(img, file_info)
+
+                minify_savings = 0
+                conversion_savings = 0
+                minified_size: int | None = None
+                heic_size: int | None = None
+
+                fmt = (processed_img.format or file_info.file_type).lower()
 
                 if fmt in {"png", "jpg", "jpeg"}:
-                    if res := self._check_minification(img, file_size, fmt):
+                    if res := self._check_minification(processed_img, baseline_size, fmt):
                         minify_savings, minified_size = res.savings, res.optimized_size
-                    if res := self._check_heic_conversion(img, file_size):
+                    if res := self._check_heic_conversion(processed_img, baseline_size):
                         conversion_savings, heic_size = res.savings, res.optimized_size
                 elif fmt in {"heif", "heic"}:
-                    if res := self._check_heic_minification(img, file_size):
+                    if res := self._check_heic_minification(processed_img, baseline_size):
                         minify_savings, minified_size = res.savings, res.optimized_size
-        except Exception as exc:
-            logger.error("Failed to process %s: %s", display_path, exc)
-            return None
 
-        if max(minify_savings, conversion_savings) < self.MIN_SAVINGS_THRESHOLD:
+                total_minify = baseline_savings + minify_savings
+                total_conversion = baseline_savings + conversion_savings
+
+                if max(total_minify, total_conversion) < self.MIN_SAVINGS_THRESHOLD:
+                    return None
+
+                return OptimizableImageFile(
+                    file_path=file_info.path,
+                    current_size=file_info.size,
+                    minify_savings=total_minify,
+                    minified_size=minified_size,
+                    conversion_savings=total_conversion,
+                    heic_size=heic_size,
+                )
+        except Exception:
+            logger.exception("Failed to open or process image file")
             return None
 
-        return OptimizableImageFile(
-            file_path=display_path,
-            current_size=file_size,
-            minify_savings=minify_savings,
-            minified_size=minified_size,
-            conversion_savings=conversion_savings,
-            heic_size=heic_size,
-        )
-
     def _check_minification(self, img: Image.Image, file_size: int, fmt: str) -> _OptimizationResult | None:
         try:
             with io.BytesIO() as buf:
@@ -134,8 +155,8 @@ def _check_minification(self, img: Image.Image, file_size: int, fmt: str) -> _Op
                         img.save(buf, format="JPEG", quality=self.TARGET_JPEG_QUALITY, **save_params)
                 new_size = buf.tell()
             return _OptimizationResult(file_size - new_size, new_size) if new_size < file_size else None
-        except Exception as exc:
-            logger.error("Minification check failed: %s", exc)
+        except Exception:
+            logger.exception("Image minification optimization failed")
             return None
 
     def _check_heic_conversion(self, img: Image.Image, file_size: int) -> _OptimizationResult | None:
@@ -144,8 +165,8 @@ def _check_heic_conversion(self, img: Image.Image, file_size: int) -> _Optimizat
                 img.save(buf, format="HEIF", quality=self.TARGET_HEIC_QUALITY)
                 new_size = buf.tell()
             return _OptimizationResult(file_size - new_size, new_size) if new_size < file_size else None
-        except Exception as exc:
-            logger.error("HEIC conversion check failed: %s", exc)
+        except Exception:
+            logger.exception("Image HEIC conversion optimization failed")
             return None
 
     def _check_heic_minification(self, img: Image.Image, file_size: int) -> _OptimizationResult | None:
@@ -154,16 +175,22 @@ def _check_heic_minification(self, img: Image.Image, file_size: int) -> _Optimiz
                 img.save(buf, format="HEIF", quality=self.TARGET_HEIC_QUALITY)
                 new_size = buf.tell()
             return _OptimizationResult(file_size - new_size, new_size) if new_size < file_size else None
-        except Exception as exc:
-            logger.error("HEIC minification check failed: %s", exc)
+        except Exception:
+            logger.exception("HEIC image minification failed")
             return None
 
-    def _iter_optimizable_files(self, files: Sequence[FileInfo]) -> Iterable[FileInfo]:
-        for fi in files:
+
+class ImageOptimizationInsight(BaseImageOptimizationInsight):
+    """Analyse image optimisation opportunities in iOS apps."""
+
+    def _find_images(self, input: InsightsInput) -> List[FileInfo]:
+        images: List[FileInfo] = []
+        for fi in input.file_analysis.files:
             if fi.file_type == "car":
-                yield from (c for c in fi.children if self._is_optimizable_image_file(c))
+                images.extend(c for c in fi.children if self._is_optimizable_image_file(c))
             elif self._is_optimizable_image_file(fi):
-                yield fi
+                images.append(fi)
+        return images
 
     def _is_optimizable_image_file(self, file_info: FileInfo) -> bool:
         if file_info.file_type.lower() not in self.OPTIMIZABLE_FORMATS:
diff --git a/src/launchpad/size/models/apple.py b/src/launchpad/size/models/apple.py
@@ -70,6 +70,10 @@ class AppleAppInfo(BaseAppInfo):
         default_factory=list, description="List of code signature validation errors"
     )
     main_binary_uuid: str | None = Field(None, description="UUID of the main binary")
+    primary_icon_name: str | None = Field(None, description="Primary app icon name from Info.plist")
+    alternate_icon_names: List[str] = Field(
+        default_factory=list, description="Alternate app icon names from Info.plist"
+    )
 
 
 @dataclass
@@ -160,6 +164,9 @@ class AppleInsightResults(BaseModel):
     unnecessary_files: UnnecessaryFilesInsightResult | None = Field(None, description="Unnecessary files analysis")
     audio_compression: AudioCompressionInsightResult | None = Field(None, description="Audio compression analysis")
     video_compression: VideoCompressionInsightResult | None = Field(None, description="Video compression analysis")
+    alternate_icons_optimization: ImageOptimizationInsightResult | None = Field(
+        None, description="Alternate app icons optimization analysis"
+    )
 
 
 @dataclass
diff --git a/src/launchpad/size/utils/file_analysis.py b/src/launchpad/size/utils/file_analysis.py
@@ -279,7 +279,7 @@ def _analyze_asset_catalog(xcarchive: ZippedXCArchive, relative_path: Path) -> L
                 full_path=element.full_path,
                 path=str(relative_path / element.name),
                 size=element.size,
-                file_type=(Path(element.full_path).suffix.lstrip(".") if element.full_path else "other"),
+                file_type=(Path(element.full_path or element.name).suffix.lstrip(".") or "other"),
                 hash=file_hash,
                 treemap_type=TreemapType.ASSETS,
                 is_dir=False,
diff --git a/tests/unit/test_alternate_icons_optimization.py b/tests/unit/test_alternate_icons_optimization.py
