@testable import class Todos.Todo
@testable import protocol Todos.TodoRepository

/// A mock implementation of the TodoRepository protocol for unit testing.
///
/// This mock repository provides a simple in-memory storage mechanism for testing
/// without requiring a full SwiftData ModelContext setup. It tracks inserted and
/// deleted todos, allowing tests to verify repository operations.
final class MockTodoRepository {

    // MARK: Properties

    /// Array of todo tasks managed by this mock repository.
    ///
    /// This property tracks all todos in the repository, maintaining state across
    /// insert and delete operations. It serves as the in-memory storage for the mock,
    /// allowing tests to verify repository behavior without requiring SwiftData.
    private(set) var todos: [Todo]

    // MARK: Initializers

    /// Creates a new mock repository with an optional initial set of todo tasks.
    ///
    /// This initializer allows tests to set up a repository with pre-existing todos
    /// or start with an empty repository. The default parameter value provides
    /// convenient initialization for most test cases.
    ///
    /// - Parameter todos: An array of todo tasks to initialize the repository with. Defaults to an empty array.
    init(todos: [Todo] = []) {
        self.todos = todos
    }

}

// MARK: - TodoRepository

extension MockTodoRepository: TodoRepository {

    // MARK: Functions

    func delete(_ todo: Todo) {
        todos.removeAll { $0.id == todo.id }
    }

    func insert(_ todo: Todo) {
        todos.append(todo)
    }

}