//
//  CameraFlowUITests.swift
//  PlantGuideUITests
//
//  Created on 2026-01-21.
//
//  UI tests for the camera and plant identification flow including
//  permission handling, capture, and photo preview.
//

import XCTest

final class CameraFlowUITests: XCTestCase {

    // MARK: - Properties

    var app: XCUIApplication!

    // MARK: - Setup & Teardown

    override func setUpWithError() throws {
        continueAfterFailure = false
        app = XCUIApplication()
    }

    override func tearDownWithError() throws {
        app = nil
    }

    // MARK: - Permission Request Tests

    /// Tests that camera permission request view appears for new users.
    ///
    /// Note: This test assumes the app is launched in a state where
    /// camera permission has not been determined. The actual system
    /// permission dialog behavior depends on the device state.
    @MainActor
    func testCameraPermissionRequestViewAppears() throws {
        // Given: App launched with clean state (permission not determined)
        app.launchWithCleanState()

        // When: App is on Camera tab (default tab)
        // The Camera tab should be selected by default based on MainTabView

        // Then: Permission request view should display for new users
        // Look for the permission request UI elements
        let permissionTitle = app.staticTexts["Camera Access Required"]
        let permissionDescription = app.staticTexts.matching(
            NSPredicate(format: "label CONTAINS[c] 'camera access'")
        ).firstMatch

        // Give time for the permission request view to appear
        let titleExists = permissionTitle.waitForExistence(timeout: 5)
        let descriptionExists = permissionDescription.waitForExistence(timeout: 2)

        // At least one of these elements should exist if permission is not determined
        // or the camera view itself if already authorized
        let cameraIcon = app.images.matching(
            NSPredicate(format: "identifier == 'camera.fill' OR label CONTAINS[c] 'camera'")
        ).firstMatch

        XCTAssertTrue(
            titleExists || descriptionExists || cameraIcon.waitForExistence(timeout: 2),
            "Camera permission request view or camera UI should appear"
        )
    }

    /// Tests that the permission denied view shows appropriate messaging.
    ///
    /// Note: This test verifies the UI elements that appear when camera
    /// access is denied. Actual permission state cannot be controlled in UI tests.
    @MainActor
    func testCameraPermissionDeniedViewElements() throws {
        // Given: App launched (permission state depends on device)
        app.launchWithCleanState()

        // When: Camera permission is denied (if in denied state)
        // We check for the presence of permission denied UI elements

        // Then: Look for denied state elements
        let deniedTitle = app.staticTexts["Camera Access Denied"]
        let openSettingsButton = app.buttons["Open Settings"]

        // These will exist only if permission is actually denied
        // We verify the test setup is correct
        if deniedTitle.waitForExistence(timeout: 3) {
            XCTAssertTrue(deniedTitle.exists, "Denied title should be visible")
            XCTAssertTrue(
                openSettingsButton.waitForExistence(timeout: 2),
                "Open Settings button should be visible when permission denied"
            )

            // Verify the description text
            let description = app.staticTexts.matching(
                NSPredicate(format: "label CONTAINS[c] 'enable camera access in Settings'")
            ).firstMatch
            XCTAssertTrue(description.exists, "Description should explain how to enable camera")
        }
    }

    // MARK: - Capture Button Tests

    /// Tests that the capture button exists when camera is authorized.
    ///
    /// Note: This test assumes camera permission has been granted.
    /// The test will check for the capture button's presence.
    @MainActor
    func testCaptureButtonExistsWhenAuthorized() throws {
        // Given: App launched (assuming camera permission granted)
        app.launchWithMockData()

        // When: Navigate to Camera tab (or stay if default)
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Then: Look for capture button (circular button with specific accessibility)
        let captureButton = app.buttons["Capture photo"]

        // If camera is authorized, capture button should exist
        // If not authorized, we skip the assertion
        if captureButton.waitForExistence(timeout: 5) {
            XCTAssertTrue(captureButton.exists, "Capture button should exist when camera authorized")
            XCTAssertTrue(captureButton.isEnabled, "Capture button should be enabled")
        } else {
            // Camera might not be authorized - check for permission views
            let permissionView = app.staticTexts["Camera Access Required"].exists ||
                                 app.staticTexts["Camera Access Denied"].exists
            XCTAssertTrue(permissionView, "Should show either capture button or permission view")
        }
    }

    /// Tests capture button has correct accessibility label and hint.
    @MainActor
    func testCaptureButtonAccessibility() throws {
        // Given: App launched with camera access
        app.launchWithMockData()
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // When: Capture button is available
        let captureButton = app.buttons["Capture photo"]

        if captureButton.waitForExistence(timeout: 5) {
            // Then: Check accessibility properties
            XCTAssertEqual(
                captureButton.label,
                "Capture photo",
                "Capture button should have correct accessibility label"
            )
        }
    }

    // MARK: - Photo Preview Tests

    /// Tests that photo preview appears after capture (mock scenario).
    ///
    /// Note: In UI tests, we cannot actually trigger a real camera capture.
    /// This test verifies the preview UI when the app is in the appropriate state.
    @MainActor
    func testPhotoPreviewUIElements() throws {
        // Given: App launched
        app.launchWithMockData()
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Check if capture button exists (camera authorized)
        let captureButton = app.buttons["Capture photo"]

        if captureButton.waitForExistence(timeout: 5) {
            // When: Capture button is tapped
            // Note: This may not actually capture in simulator without mock
            captureButton.tap()

            // Then: Either capturing overlay or preview should appear
            // Look for capturing state
            let capturingText = app.staticTexts["Capturing..."]
            let retakeButton = app.buttons["Retake photo"]
            let usePhotoButton = app.buttons["Use this photo"]

            // Wait for either capturing state or preview to appear
            let capturingAppeared = capturingText.waitForExistence(timeout: 3)
            let previewAppeared = retakeButton.waitForExistence(timeout: 5) ||
                                  usePhotoButton.waitForExistence(timeout: 2)

            // In a mocked environment, one of these states should occur
            // If camera isn't available, we just verify no crash occurred
            XCTAssertTrue(
                capturingAppeared || previewAppeared || captureButton.exists,
                "App should handle capture attempt gracefully"
            )
        }
    }

    /// Tests that retake button is functional in preview mode.
    @MainActor
    func testRetakeButtonInPreview() throws {
        // Given: App with potential captured image state
        app.launchWithConfiguration(mockData: true, additionalEnvironment: [
            "MOCK_CAPTURED_IMAGE": "YES"
        ])
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Look for retake button (indicates preview state)
        let retakeButton = app.buttons["Retake photo"]

        if retakeButton.waitForExistence(timeout: 5) {
            // When: Retake button exists and is tapped
            XCTAssertTrue(retakeButton.isEnabled, "Retake button should be enabled")
            retakeButton.tap()

            // Then: Should return to camera view
            let captureButton = app.buttons["Capture photo"]
            XCTAssertTrue(
                captureButton.waitForExistence(timeout: 5),
                "Should return to camera view after retake"
            )
        }
    }

    /// Tests that "Use Photo" button is present in preview mode.
    @MainActor
    func testUsePhotoButtonInPreview() throws {
        // Given: App with potential captured image state
        app.launchWithConfiguration(mockData: true, additionalEnvironment: [
            "MOCK_CAPTURED_IMAGE": "YES"
        ])
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Look for use photo button (indicates preview state)
        let usePhotoButton = app.buttons["Use this photo"]

        if usePhotoButton.waitForExistence(timeout: 5) {
            // Then: Use Photo button should have correct properties
            XCTAssertTrue(usePhotoButton.isEnabled, "Use Photo button should be enabled")

            // Check for the prompt text
            let promptText = app.staticTexts["Ready to identify this plant?"]
            XCTAssertTrue(promptText.exists, "Prompt text should appear above Use Photo button")
        }
    }

    // MARK: - Camera View State Tests

    /// Tests camera view handles different permission states gracefully.
    @MainActor
    func testCameraViewStateHandling() throws {
        // Given: App launched
        app.launchWithCleanState()

        // When: Camera tab is displayed
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Then: One of three states should be visible:
        // 1. Permission request (not determined)
        // 2. Permission denied
        // 3. Camera preview with capture button

        let permissionRequest = app.staticTexts["Camera Access Required"]
        let permissionDenied = app.staticTexts["Camera Access Denied"]
        let captureButton = app.buttons["Capture photo"]

        let hasValidState = permissionRequest.waitForExistence(timeout: 3) ||
                            permissionDenied.waitForExistence(timeout: 2) ||
                            captureButton.waitForExistence(timeout: 2)

        XCTAssertTrue(hasValidState, "Camera view should show a valid state")
    }

    /// Tests that camera controls are disabled during capture.
    @MainActor
    func testCameraControlsDisabledDuringCapture() throws {
        // Given: App with camera access
        app.launchWithConfiguration(mockData: true, additionalEnvironment: [
            "MOCK_API_RESPONSE_DELAY": "3"  // Slow response to observe disabled state
        ])
        app.navigateToTab(AccessibilityID.TabBar.camera)

        let captureButton = app.buttons["Capture photo"]

        if captureButton.waitForExistence(timeout: 5) && captureButton.isEnabled {
            // When: Capture is initiated
            captureButton.tap()

            // Then: During capture, controls may be disabled
            // Look for capturing overlay
            let capturingOverlay = app.staticTexts["Capturing..."]
            if capturingOverlay.waitForExistence(timeout: 2) {
                // Verify UI shows capturing state
                XCTAssertTrue(capturingOverlay.exists, "Capturing indicator should be visible")
            }
        }
    }

    // MARK: - Error Handling Tests

    /// Tests that camera errors are displayed to the user.
    @MainActor
    func testCameraErrorAlert() throws {
        // Given: App launched
        app.launchWithMockData()
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Error alerts are shown via .alert modifier
        // We verify the alert can be dismissed if it appears
        let errorAlert = app.alerts["Error"]

        if errorAlert.waitForExistence(timeout: 3) {
            // Then: Error alert should have OK button to dismiss
            let okButton = errorAlert.buttons["OK"]
            XCTAssertTrue(okButton.exists, "Error alert should have OK button")
            okButton.tap()

            // Alert should dismiss
            XCTAssertTrue(
                errorAlert.waitForNonExistence(timeout: 2),
                "Error alert should dismiss after tapping OK"
            )
        }
    }

    // MARK: - Navigation Tests

    /// Tests that camera tab is the default selected tab.
    @MainActor
    func testCameraTabIsDefault() throws {
        // Given: App freshly launched
        app.launchWithCleanState()

        // Then: Camera tab should be selected
        let cameraTab = app.tabBars.buttons[AccessibilityID.TabBar.camera]
        XCTAssertTrue(cameraTab.waitForExistence(timeout: 5), "Camera tab should exist")
        XCTAssertTrue(cameraTab.isSelected, "Camera tab should be selected by default")
    }

    /// Tests navigation from camera to identification flow.
    @MainActor
    func testNavigationToIdentificationFlow() throws {
        // Given: App with captured image ready
        app.launchWithConfiguration(mockData: true, additionalEnvironment: [
            "MOCK_CAPTURED_IMAGE": "YES"
        ])
        app.navigateToTab(AccessibilityID.TabBar.camera)

        // Look for use photo button
        let usePhotoButton = app.buttons["Use this photo"]

        if usePhotoButton.waitForExistence(timeout: 5) {
            // When: Use Photo is tapped
            usePhotoButton.tap()

            // Then: Should navigate to identification view (full screen cover)
            // The identification view might show loading or results
            let identificationView = app.otherElements.matching(
                NSPredicate(format: "identifier CONTAINS[c] 'identification'")
            ).firstMatch

            // Or look for common identification view elements
            let loadingText = app.staticTexts.matching(
                NSPredicate(format: "label CONTAINS[c] 'identifying' OR label CONTAINS[c] 'analyzing'")
            ).firstMatch

            let viewAppeared = identificationView.waitForExistence(timeout: 5) ||
                               loadingText.waitForExistence(timeout: 3)

            // If mock data doesn't trigger full flow, just verify no crash
            XCTAssertTrue(
                viewAppeared || app.exists,
                "App should handle navigation to identification"
            )
        }
    }
}