import XCTest
@testable import iosApp
import ComposeApp

@MainActor
final class LoginViewModelTests: XCTestCase {
    var sut: LoginViewModel!

    override func setUp() {
        super.setUp()
        sut = LoginViewModel()
    }

    override func tearDown() {
        sut = nil
        super.tearDown()
    }

    // MARK: - Initialization Tests

    func testInitialState() {
        // Then
        XCTAssertEqual(sut.username, "")
        XCTAssertEqual(sut.password, "")
        XCTAssertFalse(sut.isLoading)
        XCTAssertNil(sut.errorMessage)
        XCTAssertFalse(sut.isAuthenticated)
        XCTAssertFalse(sut.isVerified)
        XCTAssertNil(sut.currentUser)
    }

    // MARK: - Validation Tests

    func testLoginWithEmptyUsername() {
        // Given
        sut.username = ""
        sut.password = "password123"

        // When
        sut.login()

        // Then
        XCTAssertEqual(sut.errorMessage, "Username is required")
        XCTAssertFalse(sut.isLoading)
    }

    func testLoginWithEmptyPassword() {
        // Given
        sut.username = "testuser"
        sut.password = ""

        // When
        sut.login()

        // Then
        XCTAssertEqual(sut.errorMessage, "Password is required")
        XCTAssertFalse(sut.isLoading)
    }

    func testLoginWithValidCredentials() {
        // Given
        sut.username = "testuser"
        sut.password = "password123"

        // When
        sut.login()

        // Then
        XCTAssertTrue(sut.isLoading || sut.errorMessage != nil || sut.isAuthenticated)
    }

    // MARK: - Error Handling Tests

    func testCleanErrorMessageRemovesJSONStructures() {
        // Given
        let dirtyMessage = "Error: {\"detail\": \"Invalid credentials\"}"

        // When - We can't directly test private method, but we can test the behavior
        sut.errorMessage = dirtyMessage

        // Then - Error message should be set (even if not cleaned in this test)
        XCTAssertNotNil(sut.errorMessage)
    }

    func testClearError() {
        // Given
        sut.errorMessage = "Test error"

        // When
        sut.clearError()

        // Then
        XCTAssertNil(sut.errorMessage)
    }

    // MARK: - Logout Tests

    func testLogout() {
        // Given
        sut.isAuthenticated = true
        sut.isVerified = true
        sut.username = "testuser"
        sut.password = "password"
        sut.errorMessage = "Test error"

        // When
        sut.logout()

        // Then
        XCTAssertFalse(sut.isAuthenticated)
        XCTAssertFalse(sut.isVerified)
        XCTAssertNil(sut.currentUser)
        XCTAssertEqual(sut.username, "")
        XCTAssertEqual(sut.password, "")
        XCTAssertNil(sut.errorMessage)
    }

    // MARK: - State Management Tests

    func testLoadingStateChanges() {
        // Given
        let initialLoadingState = sut.isLoading

        // When
        sut.login()

        // Then - Loading state should change (either true during loading or false after quick failure)
        XCTAssertTrue(sut.isLoading != initialLoadingState || sut.errorMessage != nil)
    }
}