FEATURE: automatically downsize large images

[akshayutture-augment]

Test 1

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Replicated from ai-code-review-evaluation/discourse-copilot#1

[Copilot]

Pull Request Overview

This PR implements automatic downsizing of large uploaded images to meet size constraints. Instead of rejecting oversized images, the system now attempts to reduce their file size through iterative compression.

Key Changes:

• Refactored image optimization API to accept dimension strings directly instead of separate width/height parameters
• Added iterative image downsizing logic that attempts up to 5 compression passes at 80% quality
• Increased client-side upload size limit from configurable to fixed 10MB to accommodate large images before server-side processing

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
app/models/optimized_image.rb	Simplified dimension handling by accepting pre-formatted dimension strings and adding overloaded downsize method
app/controllers/uploads_controller.rb	Added automatic image downsizing loop with configurable attempts and increased initial download limit
app/assets/javascripts/discourse/lib/utilities.js	Replaced dynamic size limit with hardcoded 10MB threshold for client-side validation

[Copilot]

Method name collision: there are now two downsize methods with different arities (one with 4 parameters at line 145, one with 3 parameters at line 149). Ruby will only keep the last definition, making the 4-parameter version unreachable. Consider renaming one method or combining them with optional parameters.

[Copilot]

The allow_animation parameter is passed as a keyword argument, but the method signature shows opts={} as the fourth positional parameter. This should be {allow_animation: SiteSetting.allow_animated_thumbnails} wrapped in curly braces, or the method definition needs to accept keyword arguments.

Suggested change

	OptimizedImage.downsize(tempfile.path, tempfile.path, "80%", allow_animation: SiteSetting.allow_animated_thumbnails)
	OptimizedImage.downsize(tempfile.path, tempfile.path, "80%", { allow_animation: SiteSetting.allow_animated_thumbnails })

[Copilot]

The loop doesn't refresh tempfile.size after downsizing. The file size needs to be re-read from disk after each optimization attempt, otherwise the loop will always run exactly 5 times regardless of whether the target size is reached.

Suggested change

	while attempt > 0 && tempfile.size > SiteSetting.max_image_size_kb.kilobytes
	OptimizedImage.downsize(tempfile.path, tempfile.path, "80%", allow_animation: SiteSetting.allow_animated_thumbnails)
	attempt -= 1
	current_size = File.size(tempfile.path)
	while attempt > 0 && current_size > SiteSetting.max_image_size_kb.kilobytes
	OptimizedImage.downsize(tempfile.path, tempfile.path, "80%", allow_animation: SiteSetting.allow_animated_thumbnails)
	attempt -= 1
	current_size = File.size(tempfile.path)

[Copilot]

Hardcoding the 10MB limit duplicates the magic number from uploads_controller.rb (line 55). Consider making this a shared constant or configuration value to ensure consistency across frontend and backend.

Suggested change

	var maxSizeKB = 10 * 1024; // 10MB
	var maxSizeKB = Discourse.SiteSettings.max_upload_size_kb;

[Copilot]

This is a duplicate of the same hardcoded limit on line 182. The magic number appears three times across two files (including uploads_controller.rb). Consolidate into a single source of truth.

Suggested change

	var maxSizeKB = 10 * 1024; // 10 MB
	var maxSizeKB = Discourse.SiteSettings.max_upload_size_kb; // from site setting