Fixes #3313

Executive summary

So what is going on here?

The problem is that the ordering of the photos from the API is not necessarily the same as the ordering of the photos in the timeline. The timeline is constructed from the photos taken_at data and if not provided, created_at data.
This is split into different chunks based on the granularity. If the ordering is done by created_at, and the order of the photos match, we do not have problems. But if one of the photos has a different taken_at date, that does not match the order, then all the following photos are "moved" to different place which does not match the original index ordering.

When we click on a photo, the index returned refers to the original ordering of the photos. As a result, if the timeline is enabled, we first do the split and then merge the photos so that the ordering is updated to reflect the timeline.

Note that this is not something that can be fixed in the backend as we would need to assume that all the dates are set properly. Furthermore, this would make the functionality unavailable if sorting by title is done. By doing it in the front-end, we are able to display the photos by blocks of time, and within the block, the ordering is done as expected.

Copilot summary

This pull request introduces significant changes to enhance the handling of photo timelines and improve the modularity of the codebase. The key updates include adding support for photo timelines in various components, refactoring timeline-related logic for better maintainability, and introducing new utility functions in the splitter module. Below is a categorized summary of the most important changes:

Timeline Support and Refactoring

• Added photosTimeline as a new prop to components like AlbumPanel, PhotoThumbPanel, and ResultPanel to support displaying photos grouped by timeline. This includes updating computed properties and templates to use the new timeline data. [1] [2] [3]
• Refactored timeline splitting logic to ensure proper ordering of photos when timelines are enabled. Introduced a merge function to reconstruct photos from timeline chunks and a verifyOrder function for debugging timeline data integrity. [1] [2]

Component Updates

• Updated PhotoThumbPanelList to replace idx with groupIdx for better clarity when working with grouped timeline data. Adjusted related logic for event handling and lazy loading. [1] [2]
• Added validation and reactivity for timeline data in PhotoThumbPanel and AlbumThumbPanel, including onMounted and watch hooks to handle changes in album or timeline state. [1] [2]

Utility Enhancements

• Enhanced the splitter module with new functions: merge for combining split data back into a single array and verifyOrder for ensuring timeline data matches the original photo order. These utilities improve the robustness of timeline handling.

Service and API Adjustments

• Updated the AlbumService.get method to handle different response structures, accommodating changes in how album data is retrieved.

Codebase Integration

• Integrated timeline-related changes into the useAlbumRefresher composable, ensuring that photos and timelines are properly synchronized and merged when timelines are enabled. [1] [2]

These changes collectively improve the user experience by introducing timeline-based photo organization while enhancing the maintainability and modularity of the codebase.