The current WiiSave code is extremely messy, as it exposes all kinds of
implementation details in the header (including internal struct
definitions and magic numbers that don't have to be).
The read/write code is intermingled, so it's hard to tell which members
are used, or when/where they are set at all.
It also implicitly relies on some functions being called in a specific
order since it doesn't seek manually every time, which makes the code
even more fragile.
The logic is also hardcoded to only support bin->nand or nand->bin,
even though it would be useful to support nand->nand (for the
Movie save copying code, for example).
This commit attempts to solve these problems by getting rid of the
WiiSave class:
* Read/write code is moved to new Storage classes (NandStorage and
DataBinStorage) with small, clear functions that do one and only
one thing.
* The import/export logic was refactored into a generic Copy function
that takes two storages as parameters.
* The existing import and export functions are now just small wrappers
that call Copy with the appropriate storages.
Export and ExportAll now open a directory picker (that defaults to the
previous default directory, i.e. the Dolphin user dir).
Also removes the need to return the path in the export functions since
the user knows which path they chose.
This moves the result dialogs to DolphinQt2, since WiiSave should not
really be responsible for interacting with the user as a simple
Wii save importing/exporting class.
This also fixes Wii save import/export showing result dialogs twice,
once from WiiSave, and another time from DolphinQt2.
Move the import/export operation into separate functions, as it doesn't
really make sense for the constructor to do *everything*, including
printing success/failure message boxes.
The existing constructor was split into two: one that takes a path,
and another taking a title ID. This makes it more obvious what is
actually done when a path/TID is passed and also clarifies what
parameters should be passed. (No more magic 0 or "" value.)