/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import IGListKit
import UIKit

final class MixedDataViewController: UIViewController, ListAdapterDataSource, ListAdapterMoveDelegate {

    lazy var adapter: ListAdapter = {
        return ListAdapter(updater: ListAdapterUpdater(), viewController: self)
    }()
    let collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())

    var data: [Any] = [
        "Maecenas faucibus mollis interdum. Duis mollis, est non commodo luctus, nisi erat porttitor ligula, eget lacinia odio sem nec elit.",
        GridItem(color: UIColor(red: 237 / 255.0, green: 73 / 255.0, blue: 86 / 255.0, alpha: 1), itemCount: 6),
        User(pk: 2, name: "Ryan Olson", handle: "ryanolsonk"),
        "Praesent commodo cursus magna, vel scelerisque nisl consectetur et.",
        User(pk: 4, name: "Oliver Rickard", handle: "ocrickard"),
        GridItem(color: UIColor(red: 56 / 255.0, green: 151 / 255.0, blue: 240 / 255.0, alpha: 1), itemCount: 5),
        "Nullam quis risus eget urna mollis ornare vel eu leo. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.",
        User(pk: 3, name: "Jesse Squires", handle: "jesse_squires"),
        GridItem(color: UIColor(red: 112 / 255.0, green: 192 / 255.0, blue: 80 / 255.0, alpha: 1), itemCount: 3),
        "Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.",
        GridItem(color: UIColor(red: 163 / 255.0, green: 42 / 255.0, blue: 186 / 255.0, alpha: 1), itemCount: 7),
        User(pk: 1, name: "Ryan Nystrom", handle: "_ryannystrom")
        ]

    let segments: [(String, Any.Type?)] = [
        ("All", nil),
        ("Colors", GridItem.self),
        ("Text", String.self),
        ("Users", User.self)
    ]

    var selectedClass: Any.Type?

    override func viewDidLoad() {
        super.viewDidLoad()

        let control = UISegmentedControl(items: segments.map { return $0.0 })
        control.selectedSegmentIndex = 0
        control.addTarget(self, action: #selector(MixedDataViewController.onControl(_:)), for: .valueChanged)
        navigationItem.titleView = control

        if #available(iOS 9.0, *) {
            let longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(MixedDataViewController.handleLongGesture(gesture:)))
            collectionView.addGestureRecognizer(longPressGesture)
        }

        view.addSubview(collectionView)
        adapter.collectionView = collectionView
        adapter.dataSource = self
        if #available(iOS 9.0, *) {
            adapter.moveDelegate = self
        }
    }

    @available(iOS 9.0, *)
    @objc func handleLongGesture(gesture: UILongPressGestureRecognizer) {
        switch gesture.state {
        case .began:
            let touchLocation = gesture.location(in: self.collectionView)
            guard let selectedIndexPath = collectionView.indexPathForItem(at: touchLocation) else {
                break
            }
            collectionView.beginInteractiveMovementForItem(at: selectedIndexPath)
        case .changed:
            if let view = gesture.view {
                let position = gesture.location(in: view)
                collectionView.updateInteractiveMovementTargetPosition(position)
            }
        case .ended:
            collectionView.endInteractiveMovement()
        default:
            collectionView.cancelInteractiveMovement()
        }
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        collectionView.frame = view.bounds
    }

    @objc func onControl(_ control: UISegmentedControl) {
        selectedClass = segments[control.selectedSegmentIndex].1
        adapter.performUpdates(animated: true, completion: nil)
    }

    // MARK: ListAdapterDataSource

    func objects(for listAdapter: ListAdapter) -> [ListDiffable] {
        guard selectedClass != nil else {
            return data.map { $0 as! ListDiffable }
        }
        return data.filter { type(of: $0) == selectedClass! }
            .map { $0 as! ListDiffable }
    }

    func listAdapter(_ listAdapter: ListAdapter, sectionControllerFor object: Any) -> ListSectionController {
        switch object {
        case is String:   return ExpandableSectionController()
        case is GridItem: return GridSectionController(isReorderable: true)
        default:          return UserSectionController(isReorderable: true)
        }
    }

    func emptyView(for listAdapter: ListAdapter) -> UIView? { return nil }

    // MARK: - ListAdapterMoveDelegate

    func listAdapter(_ listAdapter: ListAdapter, move object: Any, from previousObjects: [Any], to objects: [Any]) {
        data = objects
    }
}