Raccoon/docs/tech_manual/tech_stack.md

## Tech stack

Here is a list of the technologies used in the project, with a short historical explanation in the
cases where the initial choice changed over time and the reasons why the change was made.

<dl>
<dt>Dependency Injection</dt>
<dd>
The choice here is the <a href="https://github.com/InsertKoinIO/koin">Koin</a> library. The main 
reason it was selected because of its great multiplatform support and the integration with the 
navigation library (which at the beginning of the project was not there yet, but was added later and
proved to work great). You can find module definitions (beware, Gradle modules and Koin modules are
two different concepts and should not be confused) in a `di` package inside each subproject, modules
can include each other and all top-level modules are included in the shared module, more on it in
"Module overview and dependencies".
</dd>

<dt>Navigation</dt>
<dd>
For navigation the <a href="https://github.com/adrielcafe/voyager">Voyager</a> library has been
selected. Again, the choice was driven by its multi-platform support, its very practical approach 
and ease to set up and get going, compared to other multi-platform libraries like Decompose that
were used in the past. Nonetheless, and this lesson was learned the hard way, easiness of use and
compactness mean that things will go smooth in the future, and as the project grew the navigation
library started to show its limits. Part of them were addressed by encapsulating the transition 
logic (to push/pop screens into the navigation stack and open/close modal bottom sheets) into a 
centralized component <a href="https://github.com/diegoberaldin/RaccoonForLemmy/blob/master/core/navigation/src/commonMain/kotlin/com/github/diegoberaldin/raccoonforlemmy/core/navigation/NavigationCoordinator.kt">NavigationCoordinator.kt</a>.
Something similar was done for the navigation drawer in <a href="https://github.com/diegoberaldin/RaccoonForLemmy/blob/master/core/navigation/src/commonMain/kotlin/com/github/diegoberaldin/raccoonforlemmy/core/navigation/DrawerCoordinator.kt">DrawerCoordinator.kt</a>.
Even the DI integration with Koin was not pain-free, the <code>:core:navigation</code> module contains
some glue code that is used to work around some of the issues that were encountered.
</dd>

<dt>Networking</dt>
<dd>Here, at least for Android developers, no surprises: the choice was <a href="https://github.com/ktorio/ktor">Ktor</a>
which has great multiplatform support. Instead of using Retrofit, to create network adapters the
<a href="https://github.com/Foso/Ktorfit">Ktorfit</a> library is used, which uses KSP to parse 
annotations and generate code.
</dd>

<dt>Resource management</dt>
<dd>
Initially the project used the <a href="https://github.com/icerockdev/moko-resources">Moko resources</a>
library to load fonts, icons and all the localized messages used in the UI. It worked great, since in those areas
Compose multiplatform missed the needed functionalities. But as long as the project grew in size and 
more complex KSP configurations were needed, having all modules depend on resources became unmaintainable.
This is why I migrated drawable and font loading to Compose build-in system. And, for localization, the choice was the
<a href="https://github.com/adrielcafe/lyricist">Lyricist</a> library, which better handles dynamic language changes.
</dd>

<dt>Image loading</dt>
<dd>
This was something that was expected to be simpler but unfortunately it wasn't. Popular kotlin libraries
do not support multiplatform yet and the only library that advertised it was <a href="https://github.com/Kamel-Media/Kamel">Kamel</a>
which had a major bug while rendering large images, which took a long time to be considered (and possibly
has not been fixed yet). The project was already relying on Kamel for many things, from loading images on demand
to Markdown rendering, so deciding to switch was not easy at all. In the end, the iOS part of the project 
continues using it (Raccoon for iOS has by far bigger problems than image rendering, being a virtually
inexistent platform) while the Android counterpart was migrated to <a href="https://github.com/coil-kt/coil">Coil</a>.
Things will change when Coil 3.x will be release, because it will go multiplatform as well.
</dd>

<dt>Preference storage</dt>
<dd>
Here the choice was the <a href="https://github.com/russhwolf/multiplatform-settings">Multiplatform settings</a>
libary which not only works great but also offers support for encryption.
</dd>

<dt>Primary persistence</dt>
<dd>
This project was a chance to experiment with <a href="https://github.com/cashapp/sqldelight">SQLDelight</a>
(in other multiplatform projects other libraries were tested like Exposed), whereas database encryption
is obtained through <a href="https://www.zetetic.net/sqlcipher/sqlcipher-for-android">SQLCipher Android</a>, 
formerly <a href="https://github.com/sqlcipher/android-database-sqlcipher">Android Database SQLCipher</a>.
</dd>

<dt>Markdown rendering</dt>
<dd>
This was another part, like image loading, where KMP was at the beginning quite lacky. After having given
up for some time and used Markwon (Java + Views) on the Android part of the app, I decided to give a 
second chance to <a href="https://github.com/mikepenz/multiplatform-markdown-renderer">Multiplatform Markdown Renderer</a>
which was initially user for the multiplatform source set. The project grew and matured over time and 
it made it possible to add custom handlers (like modular plug-ins) which made possible to support 
Lemmy's custom features like spoilers. The migration from multiplatform renderer to Markwon and back to 
multiplatform renderer was not easy, but this project is about KMP so, as a consequence, a pure Kotlin and 
pure Compose solution <em>had to</em> be preferred. Even if it implies to sacrifice some functionality.
</dd>

<dt>Video playback</dt>
<dd>
This had to be native, the Android implementation relies on <code>Exoplayer</code> whereas the iOS implementation
on <code>AVPlayer</code> as usual.
</dd>

<dt>Theme generation</dt>
<dd>
The application allows to select a custom color and generate a Material 3 color scheme as a
palette originate from that seed color. This is achieved by using the <a href="https://github.com/jordond/MaterialKolor">MaterialKolor</a>
library which was designed to be multiplatform and works as a charm for the purpose. Thanks!
</dd>

<dt>Reorderable lists</dt>
<dd>
The ability to reorder lists is achieved thanks to the <a href="https://github.com/Calvin-LL/Reorderable">Reorderable</a>
library which starting from version 1.3.1 has become multiplatform. This functionality is still 
experimental and is used only in the instance selection bottom sheet for anonymous users.
</dd>
</dl>