//
//  MailViewController.swift
//
//  Created by Jeremy Koch
//  Copyright © 2017 Jeremy Koch. All rights reserved.
//

import UIKit
import SwipeCellKit

class MailCollectioViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
    var emails: [Email] = []

    var defaultOptions = SwipeTableOptions()
    var isSwipeRightEnabled = true
    var buttonDisplayMode: ButtonDisplayMode = .titleAndImage
    var buttonStyle: ButtonStyle = .backgroundColor

    // MARK: - Lifecycle

    override func viewDidLoad() {
//        let flow = collectionView?.collectionViewLayout as! UICollectionViewFlowLayout
//        flow.estimatedItemSize = CGSize(width: 320, height: 100)

        navigationItem.rightBarButtonItem = editButtonItem

        view.layoutMargins.left = 32

        resetData()
    }

    // MARK: - Collection view data source

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return emails.count
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "MailCell", for: indexPath) as! MailCollectionCell
        cell.delegate = self
        cell.selectedBackgroundView = createSelectedBackgroundView()

        let email = emails[indexPath.row]
        cell.fromLabel.text = email.from
        cell.dateLabel.text = email.relativeDateString
        cell.subjectLabel.text = email.subject
        cell.bodyLabel.text = email.body
        cell.unread = email.unread
        cell.canDelete = true

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: collectionView.bounds.width, height: 120)
    }

    // MARK: - Actions

    @IBAction func moreTapped(_ sender: Any) {
        let controller = UIAlertController(title: "Swipe Transition Style", message: nil, preferredStyle: .actionSheet)
        controller.addAction(UIAlertAction(title: "Border", style: .default, handler: { _ in self.defaultOptions.transitionStyle = .border }))
        controller.addAction(UIAlertAction(title: "Drag", style: .default, handler: { _ in self.defaultOptions.transitionStyle = .drag }))
        controller.addAction(UIAlertAction(title: "Reveal", style: .default, handler: { _ in self.defaultOptions.transitionStyle = .reveal }))
        controller.addAction(UIAlertAction(title: "\(isSwipeRightEnabled ? "Disable" : "Enable") Swipe Right", style: .default, handler: { _ in self.isSwipeRightEnabled = !self.isSwipeRightEnabled }))
        controller.addAction(UIAlertAction(title: "Button Display Mode", style: .default, handler: { _ in self.buttonDisplayModeTapped() }))
        controller.addAction(UIAlertAction(title: "Button Style", style: .default, handler: { _ in self.buttonStyleTapped() }))
        controller.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        controller.addAction(UIAlertAction(title: "Reset", style: .destructive, handler: { _ in self.resetData() }))
        present(controller, animated: true, completion: nil)
    }

    func buttonDisplayModeTapped() {
        let controller = UIAlertController(title: "Button Display Mode", message: nil, preferredStyle: .actionSheet)
        controller.addAction(UIAlertAction(title: "Image + Title", style: .default, handler: { _ in self.buttonDisplayMode = .titleAndImage }))
        controller.addAction(UIAlertAction(title: "Image Only", style: .default, handler: { _ in self.buttonDisplayMode = .imageOnly }))
        controller.addAction(UIAlertAction(title: "Title Only", style: .default, handler: { _ in self.buttonDisplayMode = .titleOnly }))
        controller.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        present(controller, animated: true, completion: nil)
    }

    func buttonStyleTapped() {
        let controller = UIAlertController(title: "Button Style", message: nil, preferredStyle: .actionSheet)
        controller.addAction(UIAlertAction(title: "Background Color", style: .default, handler: { _ in
            self.buttonStyle = .backgroundColor
            self.defaultOptions.transitionStyle = .border
        }))
        controller.addAction(UIAlertAction(title: "Circular", style: .default, handler: { _ in
            self.buttonStyle = .circular
            self.defaultOptions.transitionStyle = .reveal
        }))
        controller.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        present(controller, animated: true, completion: nil)

    }

    // MARK: - Helpers

    func createSelectedBackgroundView() -> UIView {
        let view = UIView()
        view.backgroundColor = UIColor.lightGray.withAlphaComponent(0.2)
        return view
    }

    func resetData() {
        emails = mockEmails
        emails.forEach { $0.unread = false }
        collectionView?.reloadData()
    }
}

extension MailCollectioViewController: SwipeCollectionViewCellDelegate {
    func collectionView(_ collectionView: UICollectionView, editActionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> [SwipeAction]? {
        let email = emails[indexPath.row]

        if orientation == .left {
            guard isSwipeRightEnabled else { return nil }

            let read = SwipeAction(style: .default, title: nil) { action, indexPath in
                let updatedStatus = !email.unread
                email.unread = updatedStatus

                let cell = collectionView.cellForItem(at: indexPath) as! MailCollectionCell
                cell.setUnread(updatedStatus, animated: true)
            }

            read.hidesWhenSelected = true
            read.accessibilityLabel = email.unread ? "Mark as Read" : "Mark as Unread"

            let descriptor: ActionDescriptor = email.unread ? .read : .unread
            configure(action: read, with: descriptor)

            return [read]
        } else {
            let flag = SwipeAction(style: .default, title: nil, handler: nil)
            flag.hidesWhenSelected = true
            configure(action: flag, with: .flag)

            let delete = SwipeAction(style: .destructive, title: nil) { action, indexPath in
                self.emails.remove(at: indexPath.row)
            }
            configure(action: delete, with: .trash)

            let cell = collectionView.cellForItem(at: indexPath) as! MailCollectionCell
            let closure: (UIAlertAction) -> Void = { _ in cell.hideSwipe(animated: true) }
            let more = SwipeAction(style: .default, title: nil) { action, indexPath in
                let controller = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
                controller.addAction(UIAlertAction(title: "Reply", style: .default, handler: closure))
                controller.addAction(UIAlertAction(title: "Forward", style: .default, handler: closure))
                controller.addAction(UIAlertAction(title: "Mark...", style: .default, handler: closure))
                controller.addAction(UIAlertAction(title: "Notify Me...", style: .default, handler: closure))
                controller.addAction(UIAlertAction(title: "Move Message...", style: .default, handler: closure))
                controller.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: closure))
                self.present(controller, animated: true, completion: nil)
            }
            configure(action: more, with: .more)

            return [delete, flag, more]
        }
    }

    func collectionView(_ collectionView: UICollectionView, editActionsOptionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> SwipeTableOptions {
        var options = SwipeTableOptions()
        options.expansionStyle = orientation == .left ? .selection : .destructive
        options.transitionStyle = defaultOptions.transitionStyle

        switch buttonStyle {
        case .backgroundColor:
            options.buttonSpacing = 11
        case .circular:
            options.buttonSpacing = 4
            options.backgroundColor = #colorLiteral(red: 0.9467939734, green: 0.9468161464, blue: 0.9468042254, alpha: 1)
        }

        return options
    }

    func configure(action: SwipeAction, with descriptor: ActionDescriptor) {
        action.title = descriptor.title(forDisplayMode: buttonDisplayMode)
        action.image = descriptor.image(forStyle: buttonStyle, displayMode: buttonDisplayMode)

        switch buttonStyle {
        case .backgroundColor:
            action.backgroundColor = descriptor.color
        case .circular:
            action.backgroundColor = .clear
            action.textColor = descriptor.color
            action.font = .systemFont(ofSize: 13)
            action.transitionDelegate = ScaleTransition.default
        }
    }
}