//
//  CameraController.swift
//  Plugin
//
//  Created by Ariel Hernandez Musa on 7/14/19.
//  Copyright © 2019 Max Lynch. All rights reserved.
//

import AVFoundation
import UIKit

class CameraController: NSObject {
    var captureSession: AVCaptureSession?

    var currentCameraPosition: CameraPosition?

    var frontCamera: AVCaptureDevice?
    var frontCameraInput: AVCaptureDeviceInput?

    var dataOutput: AVCaptureVideoDataOutput?
    var photoOutput: AVCapturePhotoOutput?

    var rearCamera: AVCaptureDevice?
    var rearCameraInput: AVCaptureDeviceInput?

    var previewLayer: AVCaptureVideoPreviewLayer?

    var flashMode = AVCaptureDevice.FlashMode.off
    var photoCaptureCompletionBlock: ((UIImage?, Error?) -> Void)?

    var sampleBufferCaptureCompletionBlock: ((UIImage?, Error?) -> Void)?

    var highResolutionOutput: Bool = false

    var audioDevice: AVCaptureDevice?
    var audioInput: AVCaptureDeviceInput?

    var zoomFactor: CGFloat = 1.0
}

extension CameraController {
    func prepare(cameraPosition: String, disableAudio: Bool, completionHandler: @escaping (Error?) -> Void) {
        func createCaptureSession() {
            self.captureSession = AVCaptureSession()
        }

        func configureCaptureDevices() throws {

            let session = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .unspecified)

            let cameras = session.devices.compactMap { $0 }
            guard !cameras.isEmpty else { throw CameraControllerError.noCamerasAvailable }

            for camera in cameras {
                if camera.position == .front {
                    self.frontCamera = camera
                }

                if camera.position == .back {
                    self.rearCamera = camera

                    try camera.lockForConfiguration()
                    camera.focusMode = .continuousAutoFocus
                    camera.unlockForConfiguration()
                }
            }
            if disableAudio == false {
                self.audioDevice = AVCaptureDevice.default(for: AVMediaType.audio)
            }
        }

        func configureDeviceInputs() throws {
            guard let captureSession = self.captureSession else { throw CameraControllerError.captureSessionIsMissing }

            if cameraPosition == "rear" {
                if let rearCamera = self.rearCamera {
                    self.rearCameraInput = try AVCaptureDeviceInput(device: rearCamera)

                    if captureSession.canAddInput(self.rearCameraInput!) { captureSession.addInput(self.rearCameraInput!) }

                    self.currentCameraPosition = .rear
                }
            } else if cameraPosition == "front" {
                if let frontCamera = self.frontCamera {
                    self.frontCameraInput = try AVCaptureDeviceInput(device: frontCamera)

                    if captureSession.canAddInput(self.frontCameraInput!) { captureSession.addInput(self.frontCameraInput!) } else { throw CameraControllerError.inputsAreInvalid }

                    self.currentCameraPosition = .front
                }
            } else { throw CameraControllerError.noCamerasAvailable }

            // Add audio input
            if disableAudio == false {
                if let audioDevice = self.audioDevice {
                    self.audioInput = try AVCaptureDeviceInput(device: audioDevice)
                    if captureSession.canAddInput(self.audioInput!) {
                        captureSession.addInput(self.audioInput!)
                    } else {
                        throw CameraControllerError.inputsAreInvalid
                    }
                }
            }
        }

        func configurePhotoOutput() throws {
            guard let captureSession = self.captureSession else { throw CameraControllerError.captureSessionIsMissing }

            self.photoOutput = AVCapturePhotoOutput()
            self.photoOutput!.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format: [AVVideoCodecKey: AVVideoCodecType.jpeg])], completionHandler: nil)
            self.photoOutput?.isHighResolutionCaptureEnabled = self.highResolutionOutput
            if captureSession.canAddOutput(self.photoOutput!) { captureSession.addOutput(self.photoOutput!) }
            captureSession.startRunning()
        }

        func configureDataOutput() throws {
            guard let captureSession = self.captureSession else { throw CameraControllerError.captureSessionIsMissing }

            self.dataOutput = AVCaptureVideoDataOutput()
            self.dataOutput?.videoSettings = [
                (kCVPixelBufferPixelFormatTypeKey as String): NSNumber(value: kCVPixelFormatType_32BGRA as UInt32)
            ]
            self.dataOutput?.alwaysDiscardsLateVideoFrames = true
            if captureSession.canAddOutput(self.dataOutput!) {
                captureSession.addOutput(self.dataOutput!)
            }

            captureSession.commitConfiguration()

            let queue = DispatchQueue(label: "DataOutput", attributes: [])
            self.dataOutput?.setSampleBufferDelegate(self, queue: queue)
        }

        DispatchQueue(label: "prepare").async {
            do {
                createCaptureSession()
                try configureCaptureDevices()
                try configureDeviceInputs()
                try configurePhotoOutput()
                try configureDataOutput()
                // try configureVideoOutput()
            } catch {
                DispatchQueue.main.async {
                    completionHandler(error)
                }

                return
            }

            DispatchQueue.main.async {
                completionHandler(nil)
            }
        }
    }

    func displayPreview(on view: UIView) throws {
        guard let captureSession = self.captureSession, captureSession.isRunning else { throw CameraControllerError.captureSessionIsMissing }

        self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        self.previewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill

        view.layer.insertSublayer(self.previewLayer!, at: 0)
        self.previewLayer?.frame = view.frame

        updateVideoOrientation()
    }

    func setupGestures(target: UIView, enableZoom: Bool) {
        setupTapGesture(target: target, selector: #selector(handleTap(_:)), delegate: self)
        if enableZoom {
            setupPinchGesture(target: target, selector: #selector(handlePinch(_:)), delegate: self)
        }
    }

    func setupTapGesture(target: UIView, selector: Selector, delegate: UIGestureRecognizerDelegate?) {
        let tapGesture = UITapGestureRecognizer(target: self, action: selector)
        tapGesture.delegate = delegate
        target.addGestureRecognizer(tapGesture)
    }

    func setupPinchGesture(target: UIView, selector: Selector, delegate: UIGestureRecognizerDelegate?) {
        let pinchGesture = UIPinchGestureRecognizer(target: self, action: selector)
        pinchGesture.delegate = delegate
        target.addGestureRecognizer(pinchGesture)
    }

    func updateVideoOrientation() {
        assert(Thread.isMainThread) // UIKit access requires main thread

        let currentOrientation = UIApplication.shared.connectedScenes
            .first(where: { $0 is UIWindowScene })
            .flatMap({ $0 as? UIWindowScene })?.interfaceOrientation ?? .unknown

        let videoOrientation: AVCaptureVideoOrientation
        switch currentOrientation {
        case .portrait:
            videoOrientation = .portrait
        case .landscapeLeft:
            videoOrientation = .landscapeLeft
        case .landscapeRight:
            videoOrientation = .landscapeRight
        case .portraitUpsideDown:
            videoOrientation = .portraitUpsideDown
        case .unknown:
            fallthrough
        @unknown default:
            videoOrientation = .portrait
        }

        previewLayer?.connection?.videoOrientation = videoOrientation
        dataOutput?.connections.forEach { $0.videoOrientation = videoOrientation }
        photoOutput?.connections.forEach { $0.videoOrientation = videoOrientation }
    }

    func switchCameras() throws {
        guard let currentCameraPosition = currentCameraPosition, let captureSession = self.captureSession, captureSession.isRunning else { throw CameraControllerError.captureSessionIsMissing }

        captureSession.beginConfiguration()

        func switchToFrontCamera() throws {

            guard let rearCameraInput = self.rearCameraInput, captureSession.inputs.contains(rearCameraInput),
                  let frontCamera = self.frontCamera else { throw CameraControllerError.invalidOperation }

            self.frontCameraInput = try AVCaptureDeviceInput(device: frontCamera)

            captureSession.removeInput(rearCameraInput)

            if captureSession.canAddInput(self.frontCameraInput!) {
                captureSession.addInput(self.frontCameraInput!)

                self.currentCameraPosition = .front
            } else {
                throw CameraControllerError.invalidOperation
            }
        }

        func switchToRearCamera() throws {

            guard let frontCameraInput = self.frontCameraInput, captureSession.inputs.contains(frontCameraInput),
                  let rearCamera = self.rearCamera else { throw CameraControllerError.invalidOperation }

            self.rearCameraInput = try AVCaptureDeviceInput(device: rearCamera)

            captureSession.removeInput(frontCameraInput)

            if captureSession.canAddInput(self.rearCameraInput!) {
                captureSession.addInput(self.rearCameraInput!)

                self.currentCameraPosition = .rear
            } else { throw CameraControllerError.invalidOperation }
        }

        switch currentCameraPosition {
        case .front:
            try switchToRearCamera()

        case .rear:
            try switchToFrontCamera()
        }

        captureSession.commitConfiguration()
    }

    func captureImage(completion: @escaping (UIImage?, Error?) -> Void) {
        guard let captureSession = captureSession, captureSession.isRunning else { completion(nil, CameraControllerError.captureSessionIsMissing); return }
        let settings = AVCapturePhotoSettings()

        settings.flashMode = self.flashMode
        settings.isHighResolutionPhotoEnabled = self.highResolutionOutput

        self.photoOutput?.capturePhoto(with: settings, delegate: self)
        self.photoCaptureCompletionBlock = completion
    }

    func captureSample(completion: @escaping (UIImage?, Error?) -> Void) {
        guard let captureSession = captureSession,
              captureSession.isRunning else {
            completion(nil, CameraControllerError.captureSessionIsMissing)
            return
        }

        self.sampleBufferCaptureCompletionBlock = completion
    }

    func getSupportedFlashModes() throws -> [String] {
        var currentCamera: AVCaptureDevice?
        switch currentCameraPosition {
        case .front:
            currentCamera = self.frontCamera!
        case .rear:
            currentCamera = self.rearCamera!
        default: break
        }

        guard
            let device = currentCamera
        else {
            throw CameraControllerError.noCamerasAvailable
        }

        var supportedFlashModesAsStrings: [String] = []
        if device.hasFlash {
            guard let supportedFlashModes: [AVCaptureDevice.FlashMode] = self.photoOutput?.supportedFlashModes else {
                throw CameraControllerError.noCamerasAvailable
            }

            for flashMode in supportedFlashModes {
                var flashModeValue: String?
                switch flashMode {
                case AVCaptureDevice.FlashMode.off:
                    flashModeValue = "off"
                case AVCaptureDevice.FlashMode.on:
                    flashModeValue = "on"
                case AVCaptureDevice.FlashMode.auto:
                    flashModeValue = "auto"
                default: break
                }
                if flashModeValue != nil {
                    supportedFlashModesAsStrings.append(flashModeValue!)
                }
            }
        }
        if device.hasTorch {
            supportedFlashModesAsStrings.append("torch")
        }
        return supportedFlashModesAsStrings

    }

    func setFlashMode(flashMode: AVCaptureDevice.FlashMode) throws {
        var currentCamera: AVCaptureDevice?
        switch currentCameraPosition {
        case .front:
            currentCamera = self.frontCamera!
        case .rear:
            currentCamera = self.rearCamera!
        default: break
        }

        guard let device = currentCamera else {
            throw CameraControllerError.noCamerasAvailable
        }

        guard let supportedFlashModes: [AVCaptureDevice.FlashMode] = self.photoOutput?.supportedFlashModes else {
            throw CameraControllerError.invalidOperation
        }
        if supportedFlashModes.contains(flashMode) {
            do {
                try device.lockForConfiguration()

                if device.hasTorch && device.isTorchAvailable && device.torchMode == AVCaptureDevice.TorchMode.on {
                    device.torchMode = AVCaptureDevice.TorchMode.off
                }
                self.flashMode = flashMode
                let photoSettings = AVCapturePhotoSettings()
                photoSettings.flashMode = flashMode
                self.photoOutput?.photoSettingsForSceneMonitoring = photoSettings

                device.unlockForConfiguration()
            } catch {
                throw CameraControllerError.invalidOperation
            }
        } else {
            throw CameraControllerError.invalidOperation
        }
    }

    func setTorchMode() throws {
        var currentCamera: AVCaptureDevice?
        switch currentCameraPosition {
        case .front:
            currentCamera = self.frontCamera!
        case .rear:
            currentCamera = self.rearCamera!
        default: break
        }

        guard
            let device = currentCamera,
            device.hasTorch,
            device.isTorchAvailable
        else {
            throw CameraControllerError.invalidOperation
        }

        do {
            try device.lockForConfiguration()
            if device.isTorchModeSupported(AVCaptureDevice.TorchMode.on) {
                device.torchMode = AVCaptureDevice.TorchMode.on
            } else if device.isTorchModeSupported(AVCaptureDevice.TorchMode.auto) {
                device.torchMode = AVCaptureDevice.TorchMode.auto
            } else {
                device.torchMode = AVCaptureDevice.TorchMode.off
            }
            device.unlockForConfiguration()
        } catch {
            throw CameraControllerError.invalidOperation
        }

    }

    func captureVideo(completion: @escaping (URL?, Error?) -> Void) {
        guard let captureSession = self.captureSession, captureSession.isRunning else {
            completion(nil, CameraControllerError.captureSessionIsMissing)
            return
        }
        let path = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0]
        let identifier = UUID()
        let randomIdentifier = identifier.uuidString.replacingOccurrences(of: "-", with: "")
        let finalIdentifier = String(randomIdentifier.prefix(8))
        let fileName="cpcp_video_"+finalIdentifier+".mp4"

        let fileUrl = path.appendingPathComponent(fileName)
        try? FileManager.default.removeItem(at: fileUrl)
        /*videoOutput!.startRecording(to: fileUrl, recordingDelegate: self)
         self.videoRecordCompletionBlock = completion*/
    }

    func stopRecording(completion: @escaping (Error?) -> Void) {
        guard let captureSession = self.captureSession, captureSession.isRunning else {
            completion(CameraControllerError.captureSessionIsMissing)
            return
        }
        // self.videoOutput?.stopRecording()
    }
}

extension CameraController: UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

    @objc
    func handleTap(_ tap: UITapGestureRecognizer) {
        guard let device = self.currentCameraPosition == .rear ? rearCamera : frontCamera else { return }

        let point = tap.location(in: tap.view)
        let devicePoint = self.previewLayer?.captureDevicePointConverted(fromLayerPoint: point)

        do {
            try device.lockForConfiguration()
            defer { device.unlockForConfiguration() }

            let focusMode = AVCaptureDevice.FocusMode.autoFocus
            if device.isFocusPointOfInterestSupported && device.isFocusModeSupported(focusMode) {
                device.focusPointOfInterest = CGPoint(x: CGFloat(devicePoint?.x ?? 0), y: CGFloat(devicePoint?.y ?? 0))
                device.focusMode = focusMode
            }

            let exposureMode = AVCaptureDevice.ExposureMode.autoExpose
            if device.isExposurePointOfInterestSupported && device.isExposureModeSupported(exposureMode) {
                device.exposurePointOfInterest = CGPoint(x: CGFloat(devicePoint?.x ?? 0), y: CGFloat(devicePoint?.y ?? 0))
                device.exposureMode = exposureMode
            }
        } catch {
            debugPrint(error)
        }
    }

    @objc
    private func handlePinch(_ pinch: UIPinchGestureRecognizer) {
        guard let device = self.currentCameraPosition == .rear ? rearCamera : frontCamera else { return }

        func minMaxZoom(_ factor: CGFloat) -> CGFloat { return max(1.0, min(factor, device.activeFormat.videoMaxZoomFactor)) }

        func update(scale factor: CGFloat) {
            do {
                try device.lockForConfiguration()
                defer { device.unlockForConfiguration() }

                device.videoZoomFactor = factor
            } catch {
                debugPrint(error)
            }
        }

        switch pinch.state {
        case .began: fallthrough
        case .changed:
            let newScaleFactor = minMaxZoom(pinch.scale * zoomFactor)
            update(scale: newScaleFactor)
        case .ended:
            zoomFactor = device.videoZoomFactor
        default: break
        }
    }
}

extension CameraController: AVCapturePhotoCaptureDelegate {
    public func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        if let error = error {
            self.photoCaptureCompletionBlock?(nil, error)
            return
        }

        if let data = photo.fileDataRepresentation(), let image = UIImage(data: data) {
            self.photoCaptureCompletionBlock?(image.fixedOrientation(), nil)
        } else {
            self.photoCaptureCompletionBlock?(nil, CameraControllerError.unknown)
        }
    }
}

extension CameraController: AVCaptureVideoDataOutputSampleBufferDelegate {
    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        guard let completion = sampleBufferCaptureCompletionBlock else { return }

        guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else {
            completion(nil, CameraControllerError.unknown)
            return
        }

        CVPixelBufferLockBaseAddress(imageBuffer, .readOnly)
        defer { CVPixelBufferUnlockBaseAddress(imageBuffer, .readOnly) }

        let baseAddress = CVPixelBufferGetBaseAddress(imageBuffer)
        let bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer)
        let width = CVPixelBufferGetWidth(imageBuffer)
        let height = CVPixelBufferGetHeight(imageBuffer)
        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo: UInt32 = CGBitmapInfo.byteOrder32Little.rawValue |
            CGImageAlphaInfo.premultipliedFirst.rawValue

        let context = CGContext(
            data: baseAddress,
            width: width,
            height: height,
            bitsPerComponent: 8,
            bytesPerRow: bytesPerRow,
            space: colorSpace,
            bitmapInfo: bitmapInfo
        )

        guard let cgImage = context?.makeImage() else {
            completion(nil, CameraControllerError.unknown)
            return
        }

        let image = UIImage(cgImage: cgImage)
        completion(image.fixedOrientation(), nil)

        sampleBufferCaptureCompletionBlock = nil
    }
}

enum CameraControllerError: Swift.Error {
    case captureSessionAlreadyRunning
    case captureSessionIsMissing
    case inputsAreInvalid
    case invalidOperation
    case noCamerasAvailable
    case unknown
}

public enum CameraPosition {
    case front
    case rear
}

extension CameraControllerError: LocalizedError {
    public var errorDescription: String? {
        switch self {
        case .captureSessionAlreadyRunning:
            return NSLocalizedString("Capture Session is Already Running", comment: "Capture Session Already Running")
        case .captureSessionIsMissing:
            return NSLocalizedString("Capture Session is Missing", comment: "Capture Session Missing")
        case .inputsAreInvalid:
            return NSLocalizedString("Inputs Are Invalid", comment: "Inputs Are Invalid")
        case .invalidOperation:
            return NSLocalizedString("Invalid Operation", comment: "invalid Operation")
        case .noCamerasAvailable:
            return NSLocalizedString("Failed to access device camera(s)", comment: "No Cameras Available")
        case .unknown:
            return NSLocalizedString("Unknown", comment: "Unknown")

        }
    }
}

extension UIImage {

    func fixedOrientation() -> UIImage? {

        guard imageOrientation != UIImage.Orientation.up else {
            // This is default orientation, don't need to do anything
            return self.copy() as? UIImage
        }

        guard let cgImage = self.cgImage else {
            // CGImage is not available
            return nil
        }

        guard let colorSpace = cgImage.colorSpace, let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else {
            return nil // Not able to create CGContext
        }

        var transform: CGAffineTransform = CGAffineTransform.identity
        switch imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: size.height)
            transform = transform.rotated(by: CGFloat.pi)
            print("down")
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.rotated(by: CGFloat.pi / 2.0)
            print("left")
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: size.height)
            transform = transform.rotated(by: CGFloat.pi / -2.0)
            print("right")
        case .up, .upMirrored:
            break
        }

        // Flip image one more time if needed to, this is to prevent flipped image
        switch imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: size.height, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .up, .down, .left, .right:
            break
        }

        ctx.concatenate(transform)

        switch imageOrientation {
        case .left, .leftMirrored, .right, .rightMirrored:
            ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
        default:
            ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
        }
        guard let newCGImage = ctx.makeImage() else { return nil }
        return UIImage.init(cgImage: newCGImage, scale: 1, orientation: .up)
    }
}

extension CameraController: AVCaptureFileOutputRecordingDelegate {
    func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
        /*if error == nil {
         self.videoRecordCompletionBlock?(outputFileURL, nil)
         } else {
         self.videoRecordCompletionBlock?(nil, error)
         }*/
    }
}