//
//  MockPlantClassificationService.swift
//  PlantGuideTests
//
//  Mock implementations for ML-related services for unit testing.
//  Provides configurable behavior and call tracking for verification.
//

import Foundation
import CoreGraphics
import UIKit
@testable import PlantGuide

// MARK: - MockPlantClassificationService

/// Mock implementation of PlantClassificationServiceProtocol for testing
final actor MockPlantClassificationService: PlantClassificationServiceProtocol {

    // MARK: - Call Tracking

    private(set) var classifyCallCount = 0

    // MARK: - Error Configuration

    var shouldThrowOnClassify = false
    var errorToThrow: Error = PlantClassificationError.modelLoadFailed

    // MARK: - Return Value Configuration

    var predictionsToReturn: [PlantPrediction] = []

    // MARK: - Captured Values

    private(set) var lastClassifiedImage: CGImage?

    // MARK: - PlantClassificationServiceProtocol

    func classify(image: CGImage) async throws -> [PlantPrediction] {
        classifyCallCount += 1
        lastClassifiedImage = image

        if shouldThrowOnClassify {
            throw errorToThrow
        }

        // Return configured predictions or empty array
        return predictionsToReturn
    }

    // MARK: - Helper Methods

    /// Resets all state for clean test setup
    func reset() {
        classifyCallCount = 0
        shouldThrowOnClassify = false
        errorToThrow = PlantClassificationError.modelLoadFailed
        predictionsToReturn = []
        lastClassifiedImage = nil
    }

    /// Configures the mock to return predictions for common test plants
    func configureMockPredictions(_ predictions: [PlantPrediction]) {
        predictionsToReturn = predictions
    }

    /// Creates a default set of mock predictions
    func configureDefaultPredictions() {
        predictionsToReturn = [
            PlantPrediction(
                speciesIndex: 0,
                confidence: 0.92,
                scientificName: "Monstera deliciosa",
                commonNames: ["Swiss Cheese Plant", "Monstera"]
            ),
            PlantPrediction(
                speciesIndex: 1,
                confidence: 0.75,
                scientificName: "Philodendron bipinnatifidum",
                commonNames: ["Split Leaf Philodendron"]
            ),
            PlantPrediction(
                speciesIndex: 2,
                confidence: 0.45,
                scientificName: "Epipremnum aureum",
                commonNames: ["Pothos", "Devil's Ivy"]
            )
        ]
    }

    /// Configures throw behavior from outside the actor
    func setThrowBehavior(shouldThrow: Bool, error: Error) {
        shouldThrowOnClassify = shouldThrow
        errorToThrow = error
    }

    /// Configures low confidence predictions for testing fallback behavior
    func configureLowConfidencePredictions() {
        predictionsToReturn = [
            PlantPrediction(
                speciesIndex: 0,
                confidence: 0.35,
                scientificName: "Unknown plant",
                commonNames: ["Unidentified"]
            )
        ]
    }
}

// MARK: - MockImagePreprocessor

/// Mock implementation of ImagePreprocessorProtocol for testing
struct MockImagePreprocessor: ImagePreprocessorProtocol, Sendable {

    // MARK: - Configuration

    var shouldThrow = false
    var errorToThrow: Error = ImagePreprocessorError.cgImageCreationFailed

    // MARK: - Return Value Configuration

    var imageToReturn: CGImage?

    // MARK: - ImagePreprocessorProtocol

    func preprocess(_ image: UIImage) async throws -> CGImage {
        if shouldThrow {
            throw errorToThrow
        }

        // Return configured image or create one from the input
        if let configuredImage = imageToReturn {
            return configuredImage
        }

        guard let cgImage = image.cgImage else {
            throw ImagePreprocessorError.cgImageCreationFailed
        }

        return cgImage
    }
}

// MARK: - MockIdentifyPlantUseCase

/// Mock implementation of IdentifyPlantUseCaseProtocol for testing
final class MockIdentifyPlantUseCase: IdentifyPlantUseCaseProtocol, @unchecked Sendable {

    // MARK: - Configuration

    var shouldThrow = false
    var errorToThrow: Error = IdentifyPlantOnDeviceUseCaseError.noMatchesFound

    // MARK: - Return Value Configuration

    var predictionsToReturn: [ViewPlantPrediction] = []

    // MARK: - IdentifyPlantUseCaseProtocol

    func execute(image: UIImage) async throws -> [ViewPlantPrediction] {
        if shouldThrow {
            throw errorToThrow
        }
        return predictionsToReturn
    }

    // MARK: - Factory Methods

    /// Creates a mock that returns high-confidence predictions
    static func withHighConfidencePredictions() -> MockIdentifyPlantUseCase {
        let mock = MockIdentifyPlantUseCase()
        mock.predictionsToReturn = [
            ViewPlantPrediction(
                id: UUID(),
                speciesName: "Monstera deliciosa",
                commonName: "Swiss Cheese Plant",
                confidence: 0.95
            )
        ]
        return mock
    }

    /// Creates a mock that returns low-confidence predictions
    static func withLowConfidencePredictions() -> MockIdentifyPlantUseCase {
        let mock = MockIdentifyPlantUseCase()
        mock.predictionsToReturn = [
            ViewPlantPrediction(
                id: UUID(),
                speciesName: "Unknown",
                commonName: nil,
                confidence: 0.35
            )
        ]
        return mock
    }

    /// Creates a mock that throws an error
    static func withError(_ error: Error = IdentifyPlantOnDeviceUseCaseError.noMatchesFound) -> MockIdentifyPlantUseCase {
        let mock = MockIdentifyPlantUseCase()
        mock.shouldThrow = true
        mock.errorToThrow = error
        return mock
    }
}

// MARK: - MockIdentifyPlantOnlineUseCase

/// Mock implementation of IdentifyPlantOnlineUseCaseProtocol for testing
final class MockIdentifyPlantOnlineUseCase: IdentifyPlantOnlineUseCaseProtocol, @unchecked Sendable {

    // MARK: - Configuration

    var shouldThrow = false
    var errorToThrow: Error = IdentifyPlantOnlineUseCaseError.noMatchesFound

    // MARK: - Return Value Configuration

    var predictionsToReturn: [ViewPlantPrediction] = []

    // MARK: - IdentifyPlantOnlineUseCaseProtocol

    func execute(image: UIImage) async throws -> [ViewPlantPrediction] {
        if shouldThrow {
            throw errorToThrow
        }
        return predictionsToReturn
    }

    // MARK: - Factory Methods

    /// Creates a mock that returns API predictions
    static func withPredictions() -> MockIdentifyPlantOnlineUseCase {
        let mock = MockIdentifyPlantOnlineUseCase()
        mock.predictionsToReturn = [
            ViewPlantPrediction(
                id: UUID(),
                speciesName: "Monstera deliciosa",
                commonName: "Swiss Cheese Plant",
                confidence: 0.98
            )
        ]
        return mock
    }

    /// Creates a mock that throws an error
    static func withError(_ error: Error = IdentifyPlantOnlineUseCaseError.noMatchesFound) -> MockIdentifyPlantOnlineUseCase {
        let mock = MockIdentifyPlantOnlineUseCase()
        mock.shouldThrow = true
        mock.errorToThrow = error
        return mock
    }
}