// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import UIKit
import SessionUIKit
import SessionUtilitiesKit
import SignalUtilitiesKit

final class VoiceMessageRecordingView: UIView {
    private let voiceMessageButtonFrame: CGRect
    private weak var delegate: VoiceMessageRecordingViewDelegate?
    private lazy var slideToCancelStackViewTrailingConstraint = slideToCancelStackView.pin(.trailing, to: .trailing, of: self)
    private lazy var slideToCancelLabelCenterHorizontalConstraint = slideToCancelLabel.center(.horizontal, in: self)
    private lazy var pulseViewWidthConstraint = pulseView.set(.width, to: VoiceMessageRecordingView.circleSize)
    private lazy var pulseViewHeightConstraint = pulseView.set(.height, to: VoiceMessageRecordingView.circleSize)
    private lazy var lockViewBottomConstraint = lockView.pin(.bottom, to: .top, of: self, withInset: Values.mediumSpacing)
    private let recordingStartDate = Date()
    private var recordingTimer: Timer?

    // MARK: - UI Components
    
    private lazy var iconImageView: UIImageView = {
        let result: UIImageView = UIImageView()
        result.image = UIImage(named: "Microphone")?
            .withRenderingMode(.alwaysTemplate)
        result.themeTintColor = .white
        result.contentMode = .scaleAspectFit
        result.set(.width, to: VoiceMessageRecordingView.iconSize)
        result.set(.height, to: VoiceMessageRecordingView.iconSize)
        
        return result
    }()

    private lazy var circleView: UIView = {
        let result: UIView = UIView()
        result.clipsToBounds = true
        result.themeBackgroundColor = .danger
        result.set(.width, to: VoiceMessageRecordingView.circleSize)
        result.set(.height, to: VoiceMessageRecordingView.circleSize)
        result.layer.cornerRadius = (VoiceMessageRecordingView.circleSize / 2)
        
        return result
    }()

    private lazy var pulseView: UIView = {
        let result: UIView = UIView()
        result.themeBackgroundColor = .danger
        result.layer.cornerRadius = (VoiceMessageRecordingView.circleSize / 2)
        result.layer.masksToBounds = true
        result.alpha = 0.5
        
        return result
    }()

    private lazy var slideToCancelStackView: UIStackView = {
        let result: UIStackView = UIStackView()
        result.axis = .horizontal
        result.spacing = Values.smallSpacing
        result.alignment = .center
        
        return result
    }()

    private lazy var chevronImageView: UIImageView = {
        let result: UIImageView = UIImageView(
            image: (CurrentAppContext().isRTL ?
                    UIImage(named: "small_chevron_left")?.withHorizontallyFlippedOrientation() :
                    UIImage(named: "small_chevron_left")
                )?
                .withRenderingMode(.alwaysTemplate)
        )
        result.themeTintColor = .textPrimary
        result.contentMode = .scaleAspectFit
        result.alpha = Values.mediumOpacity
        result.set(.width, to: VoiceMessageRecordingView.chevronSize)
        result.set(.height, to: VoiceMessageRecordingView.chevronSize)
        
        return result
    }()

    private lazy var slideToCancelLabel: UILabel = {
        let result: UILabel = UILabel()
        result.font = .systemFont(ofSize: Values.smallFontSize)
        result.text = "vc_conversation_voice_message_cancel_message".localized()
        result.themeTextColor = .textPrimary
        result.alpha = Values.mediumOpacity
        
        return result
    }()

    private lazy var cancelButton: UIButton = {
        let result: UIButton = UIButton()
        result.setTitle("cancel".localized(), for: .normal)
        result.titleLabel?.font = .boldSystemFont(ofSize: Values.smallFontSize)
        result.setThemeTitleColor(.textPrimary, for: .normal)
        result.addTarget(self, action: #selector(handleCancelButtonTapped), for: UIControl.Event.touchUpInside)
        result.alpha = 0
        
        return result
    }()

    private lazy var durationStackView: UIStackView = {
        let result: UIStackView = UIStackView()
        result.axis = .horizontal
        result.spacing = Values.smallSpacing
        result.alignment = .center
        
        return result
    }()

    private lazy var dotView: UIView = {
        let result: UIView = UIView()
        result.clipsToBounds = true
        result.themeBackgroundColor = .danger
        result.set(.width, to: VoiceMessageRecordingView.dotSize)
        result.set(.height, to: VoiceMessageRecordingView.dotSize)
        result.layer.cornerRadius = (VoiceMessageRecordingView.dotSize / 2)
        
        return result
    }()

    private lazy var durationLabel: UILabel = {
        let result: UILabel = UILabel()
        result.font = .systemFont(ofSize: Values.smallFontSize)
        result.themeTextColor = .textPrimary
        result.text = "0:00"
        
        return result
    }()

    private lazy var lockView = LockView()

    // MARK: - Settings
    
    private static let circleSize: CGFloat = 96
    private static let pulseSize: CGFloat = 24
    private static let iconSize: CGFloat = 28
    private static let chevronSize: CGFloat = 16
    private static let dotSize: CGFloat = 16
    private static let lockViewHitMargin: CGFloat = 40

    // MARK: - Lifecycle
    
    init(voiceMessageButtonFrame: CGRect, delegate: VoiceMessageRecordingViewDelegate?) {
        self.voiceMessageButtonFrame = voiceMessageButtonFrame
        self.delegate = delegate
        
        super.init(frame: CGRect.zero)
        
        setUpViewHierarchy()
        recordingTimer = Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { [weak self] _ in
            self?.updateDurationLabel()
        }
    }

    override init(frame: CGRect) {
        preconditionFailure("Use init(voiceMessageButtonFrame:) instead.")
    }

    required init?(coder: NSCoder) {
        preconditionFailure("Use init(voiceMessageButtonFrame:) instead.")
    }

    deinit {
        recordingTimer?.invalidate()
    }

    private func setUpViewHierarchy() {
        // Icon
        let iconSize = VoiceMessageRecordingView.iconSize
        addSubview(iconImageView)
        
        // Note: We intentionally pin to '.left' here as the frame calculations don't take
        // LRT/RTL language direction into account
        let voiceMessageButtonCenter = voiceMessageButtonFrame.center
        iconImageView.pin(.left, to: .left, of: self, withInset: (voiceMessageButtonCenter.x - (iconSize / 2)))
        iconImageView.pin(.top, to: .top, of: self, withInset: (voiceMessageButtonCenter.y - (iconSize / 2)))
        
        // Circle
        insertSubview(circleView, at: 0)
        circleView.center(in: iconImageView)
        
        // Pulse
        insertSubview(pulseView, at: 0)
        pulseView.center(in: circleView)
        
        // Slide to cancel stack view
        slideToCancelStackView.addArrangedSubview(chevronImageView)
        slideToCancelStackView.addArrangedSubview(slideToCancelLabel)
        addSubview(slideToCancelStackView)
        slideToCancelStackViewTrailingConstraint.isActive = true
        slideToCancelStackView.center(.vertical, in: iconImageView)
        
        // Cancel button
        addSubview(cancelButton)
        cancelButton.center(.horizontal, in: self)
        cancelButton.center(.vertical, in: iconImageView)
        
        // Duration stack view
        durationStackView.addArrangedSubview(dotView)
        durationStackView.addArrangedSubview(durationLabel)
        addSubview(durationStackView)
        
        durationStackView.pin(.leading, to: .leading, of: self, withInset: Values.largeSpacing)
        durationStackView.center(.vertical, in: iconImageView)
        
        // Lock view
        addSubview(lockView)
        lockView.centerXAnchor.constraint(equalTo: iconImageView.centerXAnchor, constant: 2).isActive = true
        lockViewBottomConstraint.isActive = true
    }

    // MARK: - Updating
    
    @objc private func updateDurationLabel() {
        let interval = Date().timeIntervalSince(recordingStartDate)
        durationLabel.text = interval.formatted(format: .hoursMinutesSeconds)
    }

    // MARK: - Animation
    
    func animate() {
        layoutIfNeeded()
        
        slideToCancelStackViewTrailingConstraint.isActive = false
        slideToCancelLabelCenterHorizontalConstraint.isActive = true
        lockViewBottomConstraint.constant = -Values.mediumSpacing
        
        UIView.animate(withDuration: 0.25, animations: { [weak self] in
            self?.alpha = 1
            self?.layoutIfNeeded()
        }, completion: { [weak self] _ in
            self?.fadeOutDotView()
            self?.pulse()
        })
    }

    private func fadeOutDotView() {
        UIView.animate(withDuration: 0.5, animations: { [weak self] in
            self?.dotView.alpha = 0
        }, completion: { [weak self] _ in
            self?.fadeInDotView()
        })
    }

    private func fadeInDotView() {
        UIView.animate(withDuration: 0.5, animations: { [weak self] in
            self?.dotView.alpha = 1
        }, completion: { [weak self] _ in
            self?.fadeOutDotView()
        })
    }

    private func pulse() {
        let collapsedSize = VoiceMessageRecordingView.circleSize
        let collapsedFrame = CGRect(center: pulseView.center, size: CGSize(width: collapsedSize, height: collapsedSize))
        let expandedSize = VoiceMessageRecordingView.circleSize + VoiceMessageRecordingView.pulseSize
        let expandedFrame = CGRect(center: pulseView.center, size: CGSize(width: expandedSize, height: expandedSize))
        pulseViewWidthConstraint.constant = expandedSize
        pulseViewHeightConstraint.constant = expandedSize
        
        UIView.animate(withDuration: 1, animations: { [weak self] in
            self?.layoutIfNeeded()
            self?.pulseView.frame = expandedFrame
            self?.pulseView.layer.cornerRadius = (expandedSize / 2)
            self?.pulseView.alpha = 0
        }, completion: { [weak self] _ in
            self?.pulseViewWidthConstraint.constant = collapsedSize
            self?.pulseViewHeightConstraint.constant = collapsedSize
            self?.pulseView.frame = collapsedFrame
            self?.pulseView.layer.cornerRadius = (collapsedSize / 2)
            self?.pulseView.alpha = 0.5
            self?.pulse()
        })
    }

    // MARK: - Interaction
    
    func handleLongPressMoved(to location: CGPoint) {
        if (!CurrentAppContext().isRTL && location.x < bounds.center.x) || (CurrentAppContext().isRTL && location.x > bounds.center.x) {
            let translationX = location.x - bounds.center.x
            let sign: CGFloat = (CurrentAppContext().isRTL ? 1 : -1)
            let chevronDamping: CGFloat = 4
            let labelDamping: CGFloat = 3
            let chevronX = (chevronDamping * (sqrt(abs(translationX)) / sqrt(chevronDamping))) * sign
            let labelX = (labelDamping * (sqrt(abs(translationX)) / sqrt(labelDamping))) * sign
            
            chevronImageView.transform = CGAffineTransform(translationX: chevronX, y: 0)
            slideToCancelLabel.transform = CGAffineTransform(translationX: labelX, y: 0)
        }
        else {
            chevronImageView.transform = .identity
            slideToCancelLabel.transform = .identity
        }
        
        if isValidLockViewLocation(location) {
            if !lockView.isExpanded {
                UIView.animate(withDuration: 0.25) {
                    self.lockViewBottomConstraint.constant = -Values.mediumSpacing + LockView.expansionMargin
                }
            }
            lockView.expandIfNeeded()
        }
        else {
            if lockView.isExpanded {
                UIView.animate(withDuration: 0.25) {
                    self.lockViewBottomConstraint.constant = -Values.mediumSpacing
                }
            }
            lockView.collapseIfNeeded()
        }
    }

    func handleLongPressEnded(at location: CGPoint) {
        if pulseView.frame.contains(location) {
            delegate?.endVoiceMessageRecording()
        }
        else if isValidLockViewLocation(location) {
            let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleCircleViewTap))
            circleView.addGestureRecognizer(tapGestureRecognizer)
            
            UIView.animate(withDuration: 0.25, delay: 0, options: .transitionCrossDissolve, animations: {
                self.lockView.alpha = 0
                self.iconImageView.image = UIImage(named: "ArrowUp")?.withRenderingMode(.alwaysTemplate)
                self.slideToCancelStackView.alpha = 0
                self.cancelButton.alpha = 1
            }, completion: { _ in
                // Do nothing
            })
        }
        else {
            delegate?.cancelVoiceMessageRecording()
        }
    }

    @objc private func handleCircleViewTap() {
        delegate?.endVoiceMessageRecording()
    }

    @objc private func handleCancelButtonTapped() {
        delegate?.cancelVoiceMessageRecording()
    }

    // MARK: - Convenience
    
    private func isValidLockViewLocation(_ location: CGPoint) -> Bool {
        let lockViewHitMargin = VoiceMessageRecordingView.lockViewHitMargin
        
        return location.y < 0 && location.x > (lockView.frame.minX - lockViewHitMargin) && location.x < (lockView.frame.maxX + lockViewHitMargin)
    }
}

// MARK: - Lock View

extension VoiceMessageRecordingView {
    fileprivate final class LockView: UIView {
        private lazy var widthConstraint = set(.width, to: LockView.width)
        private(set) var isExpanded = false

        private lazy var stackView: UIStackView = {
            let result: UIStackView = UIStackView()
            result.axis = .vertical
            result.spacing = Values.smallSpacing
            result.alignment = .center
            result.isLayoutMarginsRelativeArrangement = true
            result.layoutMargins = UIEdgeInsets(top: 12, leading: 0, bottom: 8, trailing: 0)
            
            return result
        }()

        private static let width: CGFloat = 44
        static let expansionMargin: CGFloat = 3
        private static let lockIconSize: CGFloat = 20
        private static let chevronIconSize: CGFloat = 20

        override init(frame: CGRect) {
            super.init(frame: frame)
            
            setUpViewHierarchy()
        }

        required init?(coder: NSCoder) {
            super.init(coder: coder)
            
            setUpViewHierarchy()
        }

        private func setUpViewHierarchy() {
            // Background & blur
            let backgroundView: UIView = UIView()
            backgroundView.themeBackgroundColor = .backgroundSecondary
            backgroundView.alpha = Values.lowOpacity
            addSubview(backgroundView)
            backgroundView.pin(to: self)
            
            let blurView = UIVisualEffectView()
            addSubview(blurView)
            blurView.pin(to: self)
            
            ThemeManager.onThemeChange(observer: blurView) { [weak blurView] theme, _ in
                switch theme.interfaceStyle {
                    case .light: blurView?.effect = UIBlurEffect(style: .light)
                    default: blurView?.effect = UIBlurEffect(style: .dark)
                }
            }
            
            // Size & shape
            widthConstraint.isActive = true
            layer.cornerRadius = (LockView.width / 2)
            layer.masksToBounds = true
            
            // Border
            themeBorderColor = .borderSeparator
            layer.borderWidth = 1
            
            // Lock icon
            let lockIconImageView: UIImageView = UIImageView(
                image: UIImage(named: "ic_lock_outline")?
                    .withRenderingMode(.alwaysTemplate)
            )
            lockIconImageView.themeTintColor = .textPrimary
            lockIconImageView.set(.width, to: LockView.lockIconSize)
            lockIconImageView.set(.height, to: LockView.lockIconSize)
            stackView.addArrangedSubview(lockIconImageView)
            
            // Chevron icon
            let chevronIconImageView: UIImageView = UIImageView(
                image: UIImage(named: "ic_chevron_up")?
                    .withRenderingMode(.alwaysTemplate)
            )
            chevronIconImageView.themeTintColor = .textPrimary
            chevronIconImageView.set(.width, to: LockView.chevronIconSize)
            chevronIconImageView.set(.height, to: LockView.chevronIconSize)
            stackView.addArrangedSubview(chevronIconImageView)
            
            // Stack view
            addSubview(stackView)
            stackView.pin(to: self)
        }

        func expandIfNeeded() {
            guard !isExpanded else { return }
            
            isExpanded = true
            
            let expansionMargin = LockView.expansionMargin
            let newWidth = LockView.width + 2 * expansionMargin
            
            widthConstraint.constant = newWidth
            
            UIView.animate(withDuration: 0.25) {
                self.layer.cornerRadius = newWidth / 2
                self.stackView.layoutMargins = UIEdgeInsets(top: 12 + expansionMargin, leading: 0, bottom: 8 + expansionMargin, trailing: 0)
                self.layoutIfNeeded()
            }
        }

        func collapseIfNeeded() {
            guard isExpanded else { return }
            
            isExpanded = false
            
            let newWidth = LockView.width
            widthConstraint.constant = newWidth
            
            UIView.animate(withDuration: 0.25) {
                self.layer.cornerRadius = newWidth / 2
                self.stackView.layoutMargins = UIEdgeInsets(top: 12, leading: 0, bottom: 8, trailing: 0)
                self.layoutIfNeeded()
            }
        }
    }
}

// MARK: - Delegate

protocol VoiceMessageRecordingViewDelegate: AnyObject {
    func startVoiceMessageRecording()
    func endVoiceMessageRecording()
    func cancelVoiceMessageRecording()
}
