From 1035a5a6c019b2d48597045f2a4a886a48596ecc Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Tue, 3 Apr 2018 10:35:04 +0300
Subject: [PATCH] Better photo size comparison.

GitOrigin-RevId: 630e32213169122a3c67ac8c35b2e8bc5c2a6ae5
---
 td/telegram/MessagesManager.cpp |  4 ++--
 td/telegram/Photo.cpp           | 27 ++++++++++++++++++++++++++-
 td/telegram/Photo.h             |  4 +++-
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index 23812605..38954885 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -21171,7 +21171,7 @@ unique_ptr<MessageContent> MessagesManager::dup_message_content(DialogId dialog_
       }
       if (photo.type == 0) {
         for (const auto &size : result->photo.photos) {
-          if (photo.type == 0 || photo.size < size.size) {
+          if (photo.type == 0 || photo < size) {
             photo = size;
           }
         }
@@ -21186,7 +21186,7 @@ unique_ptr<MessageContent> MessagesManager::dup_message_content(DialogId dialog_
       }
       if (thumbnail.type == 0) {
         for (const auto &size : result->photo.photos) {
-          if (size.type != photo.type && (thumbnail.type == 0 || thumbnail.size > size.size)) {
+          if (size.type != photo.type && (thumbnail.type == 0 || size < thumbnail)) {
             thumbnail = size;
           }
         }
diff --git a/td/telegram/Photo.cpp b/td/telegram/Photo.cpp
index f08007a8..045ffd1e 100644
--- a/td/telegram/Photo.cpp
+++ b/td/telegram/Photo.cpp
@@ -43,6 +43,10 @@ Dimensions get_dimensions(int32 width, int32 height) {
   return result;
 }
 
+static uint32 get_pixel_count(const Dimensions &dimensions) {
+  return static_cast<uint32>(dimensions.width) * static_cast<uint32>(dimensions.height);
+}
+
 bool operator==(const Dimensions &lhs, const Dimensions &rhs) {
   return lhs.width == rhs.width && lhs.height == rhs.height;
 }
@@ -390,7 +394,8 @@ void sort_photo_sizes(vector<td_api::object_ptr<td_api::photoSize>> &sizes) {
     if (lhs->photo_->expected_size_ != rhs->photo_->expected_size_) {
       return lhs->photo_->expected_size_ < rhs->photo_->expected_size_;
     }
-    return lhs->width_ * lhs->height_ < rhs->width_ * rhs->height_;
+    return static_cast<uint32>(lhs->width_) * static_cast<uint32>(lhs->height_) <
+           static_cast<uint32>(rhs->width_) * static_cast<uint32>(rhs->height_);
   });
 }
 
@@ -402,6 +407,26 @@ bool operator!=(const PhotoSize &lhs, const PhotoSize &rhs) {
   return !(lhs == rhs);
 }
 
+bool operator<(const PhotoSize &lhs, const PhotoSize &rhs) {
+  if (lhs.size != rhs.size) {
+    return lhs.size < rhs.size;
+  }
+  auto lhs_pixels = get_pixel_count(lhs.dimensions);
+  auto rhs_pixels = get_pixel_count(rhs.dimensions);
+  if (lhs_pixels != rhs_pixels) {
+    return lhs_pixels < rhs_pixels;
+  }
+  int32 lhs_type = lhs.type == 't' ? -1 : lhs.type;
+  int32 rhs_type = rhs.type == 't' ? -1 : rhs.type;
+  if (lhs_type != rhs_type) {
+    return lhs_type < rhs_type;
+  }
+  if (lhs.file_id != rhs.file_id) {
+    return lhs.file_id.get() < rhs.file_id.get();
+  }
+  return lhs.dimensions.width < rhs.dimensions.width;
+}
+
 StringBuilder &operator<<(StringBuilder &string_builder, const PhotoSize &photo_size) {
   return string_builder << "{type = " << photo_size.type << ", dimensions = " << photo_size.dimensions
                         << ", size = " << photo_size.size << ", file_id = " << photo_size.file_id << "}";
diff --git a/td/telegram/Photo.h b/td/telegram/Photo.h
index f91911fd..6678ac45 100644
--- a/td/telegram/Photo.h
+++ b/td/telegram/Photo.h
@@ -38,7 +38,7 @@ struct ProfilePhoto : public DialogPhoto {
 };
 
 struct PhotoSize {
-  int32 type = 0;  // TODO remove
+  int32 type = 0;
   Dimensions dimensions;
   int32 size = 0;
   FileId file_id;
@@ -90,6 +90,8 @@ void sort_photo_sizes(vector<td_api::object_ptr<td_api::photoSize>> &sizes);
 bool operator==(const PhotoSize &lhs, const PhotoSize &rhs);
 bool operator!=(const PhotoSize &lhs, const PhotoSize &rhs);
 
+bool operator<(const PhotoSize &lhs, const PhotoSize &rhs);
+
 StringBuilder &operator<<(StringBuilder &string_builder, const PhotoSize &photo_size);
 
 Photo get_photo(FileManager *file_manager, tl_object_ptr<telegram_api::photo> &&photo, DialogId owner_dialog_id);