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+# Architecture
+The base unit of abstraction in the application are Controllers extending the
+class ControllerBase. They have an well defined lifecycle, ie. are initialized
+and disposed exactly once, and have exactly one owner at a time. They,
+themselves, are made of internal state, other subcontrollers and
+ValueListenables, which expose some part of the controller state at any given
+time. They are constructed using map, bind and other operations, and also have
+an well defined lifecycle, allowing complex usages like streams, which need to
+get cleaned up. The datatypes on this app are generated using adt_generator,
+and are products, sums, records, or opaques. This allows very rich typesafe
+apis. The chosen database was hive, an sinple key-value store. For storing
+undoable stuff, the doubly linked event sourced model from utils was used,
+allowing an simple api for this complex usecase. The sudoku generation is made
+with libsudoku on another isolate for maximum performance and best ux. The ui
+is made with the material_widgets package, implementing the material design 3
+spec.
+
+# Directory structure
+
+## Module
+Modules are free controllers (Not subcontrollers of another controller), which
+have no associated view, and are reused across multiple other controllers.
+
+### Base
+The base module implements the low level api for interacting with a sudoku game
+and while storing it in the database. It exposes an SudokuAppState,
+whether or not it can undo, and allows undoing, setting a number, setting a
+possibility, resetting the board and clearing a tile.
+
+### Theme
+The theme module controls the theming across the application. It exposes the
+currently enabled theme, the user themes, every theme, and stores this in a
+database.
+
+### Animation
+The animation module controls the animation options across the application.
+It exposes the current animation options and speed, and allows modifying both,
+while storing in a database.
+
+## Navigation
+Contains the routing stuff for the application.
+
+## Sudoku Generation
+The sudoku_generation subdirectory is responsible for generating sudokus in an
+non-blocking way. To do so, it has an streaming sudoku generation function,
+which uses some blocking primitives. This function is then ran in an isolate,
+if possible, and on the main thread otherwise. The blocking primitives can be
+from two sources: libsudoku ffi bindings, or an wrapper api from sudoku_core
+from the old application. I plan on writing an webworker implementation of the
+streaming version but this is not ready for now.
+
+## Util
+Some misc utils.
+
+## View
+An view is an flutter widget that is associated to an viewmodel. Each viewmodel
+has an single view, otherwise the business logic would become complicated.
+The widgets may need to create controllers, and when they do so, they own the
+controller, and, therefore, are responsible for the initialization and
+disposal. This is normally accomplished using an widget from
+package:value_notifier that does so automatically, using the State.dispose
+method.
+
+## Viewmodel
+An viewmodel is an controller that has an associated view. They normally talk
+with other modules or viewmodels via value listenables.
+
+### Create Theme
+The create theme viewmodel controls the create theme dialog. It exposes the
+current created theme, it's name, it's primary seed, it's secondary seed, it's
+background, and allows modifying those.
+
+### Home
+The home viewmodel controls the home view. It exposes whether or not we can
+continue, the current side, the current difficulty, and stores those values in
+a database.
+
+### Preferences dialog
+The preferences dialog viewmodel controls the preferences dialog.
+It has two subcontrollers, one for managing the theme preferences and one for
+managing the animation preferences
+
+#### Theme
+It exposes the theme that will be set and the user theme list that will be set,
+and it allows adding new themes and changing the current theme.
+
+#### Animation
+It exposes the animation options that will be set, and it allows changing the
+text animation options, selection animation options and animation speed.
+
+### Sudoku Board
+The sudoku board viewmodel controls the sudoku board view. It is responsible for
+managing the board navigation pattern and has three
+subcontrollers, one for managing the actions bar, one for managing the keypad
+and one for managing the board itself.
+
+### Sudoku generation
+The sudoku generation viewmodel controls the sudoku generation view. It is
+resposible for generating the sudoku, using the streaming sudoku generation api,
+and the view is responsible for creating an sudoku controller using this
+generated board.
+
+## Widget
+The widgets in this directory may or may not be reusable and dont have any
+controller associated with them.
+