FEATURE: automatically downsize large images

[ShashankFC]

Test 1

Summary by CodeRabbit

• New Features

  • Images exceeding the upload size limit are now automatically downsized to fit within allowed limits.

• Refactor

  • Optimized image upload handling with improved automatic resizing capabilities.

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

[Copilot]

Pull request overview

This PR implements automatic image downsizing functionality to handle images that exceed upload size limits. Instead of rejecting large images outright, the system now attempts to reduce their size automatically before upload.

Changes:

• Modified image optimization methods to accept dimension strings directly (e.g., "80%") instead of separate width/height parameters
• Added automatic image downsizing loop in the upload controller that iteratively reduces oversized images
• Increased client-side and server-side file size limits from configured values to 10MB to allow large images to be uploaded for automatic downsizing

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
app/models/optimized_image.rb	Refactored optimization methods to accept dimension strings and removed the dimensions helper method
app/controllers/uploads_controller.rb	Added automatic downsizing loop for oversized images and increased download limit to 10MB
app/assets/javascripts/discourse/lib/utilities.js	Increased client-side file size validation limit from configured setting to hardcoded 10MB

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[Copilot]

Method overloading is not supported in Ruby. Having two downsize methods with different arities will cause the second definition (lines 149-151) to completely replace the first one (lines 145-147). Callers using the 4-parameter signature will encounter ArgumentError. Consider renaming one method or using optional parameters with different default values.

[Copilot]

The downsizing loop does not refresh tempfile.size after each iteration. Since the method writes to the same file path, tempfile.size will remain unchanged, creating an infinite loop until attempt reaches 0. Consider using File.size(tempfile.path) to get the updated file size after each downsizing operation.

Suggested change

	if tempfile && tempfile.size > 0 && SiteSetting.max_image_size_kb > 0 && FileHelper.is_image?(filename)
	attempt = 5
	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
	end
	end
	upload = Upload.create_for(current_user.id, tempfile, filename, tempfile.size, content_type: content_type, image_type: type)
	current_size = tempfile.size if tempfile
	if tempfile && current_size.to_i > 0 && SiteSetting.max_image_size_kb > 0 && FileHelper.is_image?(filename)
	attempt = 5
	while attempt > 0 && current_size > SiteSetting.max_image_size_kb.kilobytes
	OptimizedImage.downsize(tempfile.path, tempfile.path, "80%", allow_animation: SiteSetting.allow_animated_thumbnails)
	current_size = File.size(tempfile.path)
	attempt -= 1
	end
	end
	upload = Upload.create_for(current_user.id, tempfile, filename, (current_size || tempfile.size), content_type: content_type, image_type: type)

[Copilot]

Hardcoding the 10MB limit in multiple places (lines 182 and 246) creates a magic number that's duplicated across the codebase. Consider defining this as a constant at the module level to ensure consistency and ease maintenance.

[Copilot]

The magic number 5 for retry attempts lacks explanation. Consider extracting this to a named constant (e.g., MAX_DOWNSIZE_ATTEMPTS = 5) to improve code clarity and maintainability.