//
// Copyright 2021 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import XCTest
import RiotSwiftUI

class AuthenticationLoginUITests: MockScreenTest {

    override class var screenType: MockScreenState.Type {
        return MockAuthenticationLoginScreenState.self
    }

    override class func createTest() -> MockScreenTest {
        return AuthenticationLoginUITests(selector: #selector(verifyAuthenticationLoginScreen))
    }
    
    func verifyAuthenticationLoginScreen() throws {
        guard let screenState = screenState as? MockAuthenticationLoginScreenState else { fatalError("no screen") }
        switch screenState {
        case .matrixDotOrg:
            let state = "matrix.org"
            validateServerDescriptionIsVisible(for: state)
            validateLoginFormIsVisible(for: state)
            validateSSOButtonsAreShown(for: state)
        case .passwordOnly:
            let state = "a password only server"
            validateServerDescriptionIsHidden(for: state)
            validateLoginFormIsVisible(for: state)
            validateSSOButtonsAreHidden(for: state)
            
            validateNextButtonIsDisabled(for: state)
        case .passwordWithCredentials:
            let state = "a password only server with credentials entered"
            validateNextButtonIsEnabled(for: state)
        case .ssoOnly:
            let state = "an SSO only server"
            validateServerDescriptionIsHidden(for: state)
            validateLoginFormIsHidden(for: state)
            validateSSOButtonsAreShown(for: state)
        }
    }
    
    /// Checks that the server description label is shown.
    func validateServerDescriptionIsVisible(for state: String) {
        let descriptionLabel = app.staticTexts["serverDescriptionText"]
        
        XCTAssertTrue(descriptionLabel.exists, "The server description should be shown for \(state).")
        XCTAssertEqual(descriptionLabel.label, VectorL10n.authenticationServerInfoMatrixDescription, "The server description should be correct for \(state).")
    }
    
    /// Checks that the server description label is hidden.
    func validateServerDescriptionIsHidden(for state: String) {
        let descriptionLabel = app.staticTexts["serverDescriptionText"]
        XCTAssertFalse(descriptionLabel.exists, "The server description should be shown for \(state).")
    }
    
    /// Checks that the username and password text fields are shown along with the next button.
    func validateLoginFormIsVisible(for state: String) {
        let usernameTextField = app.textFields.element
        let passwordTextField = app.secureTextFields.element
        let nextButton = app.buttons["nextButton"]
        
        XCTAssertTrue(usernameTextField.exists, "Username input should be shown for \(state).")
        XCTAssertTrue(passwordTextField.exists, "Password input should be shown for \(state).")
        XCTAssertTrue(nextButton.exists, "The next button should be shown for \(state).")
    }
    
    /// Checks that the username and password text fields are hidden along with the next button.
    func validateLoginFormIsHidden(for state: String) {
        let usernameTextField = app.textFields.element
        let passwordTextField = app.secureTextFields.element
        let nextButton = app.buttons["nextButton"]
        
        XCTAssertFalse(usernameTextField.exists, "Username input should not be shown for \(state).")
        XCTAssertFalse(passwordTextField.exists, "Password input should not be shown for \(state).")
        XCTAssertFalse(nextButton.exists, "The next button should not be shown for \(state).")
    }
    
    /// Checks that there is at least one SSO button shown on the screen.
    func validateSSOButtonsAreShown(for state: String) {
        let ssoButtons = app.buttons.matching(identifier: "ssoButton")
        XCTAssertGreaterThan(ssoButtons.count, 0, "There should be at least 1 SSO button shown for \(state).")
    }
    
    /// Checks that no SSO buttons shown on the screen.
    func validateSSOButtonsAreHidden(for state: String) {
        let ssoButtons = app.buttons.matching(identifier: "ssoButton")
        XCTAssertEqual(ssoButtons.count, 0, "There should not be any SSO buttons shown for \(state).")
    }
    
    /// Checks that the next button is shown but is disabled.
    func validateNextButtonIsDisabled(for state: String) {
        let nextButton = app.buttons["nextButton"]
        XCTAssertTrue(nextButton.exists, "The next button should be shown.")
        XCTAssertFalse(nextButton.isEnabled, "The next button should be disabled for \(state).")
    }
    
    /// Checks that the next button is shown and is enabled.
    func validateNextButtonIsEnabled(for state: String) {
        let nextButton = app.buttons["nextButton"]
        XCTAssertTrue(nextButton.exists, "The next button should be shown.")
        XCTAssertTrue(nextButton.isEnabled, "The next button should be enabled for \(state).")
    }
    
}