Sudoku is a popular puzzle featuring a 9x9 grid with requirements and constraints. Using C# and ASP.NET, create a Sudoku puzzle solver that accomplishes the following:

1. Accepts user provided puzzle definitions via text file
2. Accepts user provided puzzle dimensions
3. Accepts user provided alphabet
4. Displays solution for solvable puzzles
5. Displays error for unsolvable puzzles
6. Displays notification for empty puzzles
7. Supports both console and ASP.NET user interfaces

Along with code implementation,

1. Include high level class UML
2. Create unit tests for majority code coverage
3. A couple of tests have been included for you but many classes are untested
4. Even if a method has already been implemented, unit tests should still be created
5. Feel free to use any substitution or mocking framework to assist with unit testing
6. Include any additional assemblies used

1. Do not remove any existing code unless instructed otherwise via existing code comments
2. Refactoring of a code file is allowed
3. Implement all TODO's
4. Add any additional classes that may be required to the appropriate project
5. Use included text files in Puzzles directory
6. Ask questions via email

Please submit via:

1. Email ZIP named <first.last.candidate.project>.zip