//
//  TrendingLinksViewController.swift
//  Tusker
//
//  Created by Shadowfacts on 4/2/22.
//  Copyright © 2022 Shadowfacts. All rights reserved.
//

import UIKit
import Pachyderm
import WebURLFoundationExtras
import SafariServices

class TrendingLinksViewController: EnhancedTableViewController {
    
    weak var mastodonController: MastodonController!
    
    private var dataSource: UITableViewDiffableDataSource<Section, Item>!
    
    init(mastodonController: MastodonController) {
        self.mastodonController = mastodonController
        
        super.init(style: .grouped)
        
        dragEnabled = true
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        title = NSLocalizedString("Trending Links", comment: "trending links screen title")
        
        tableView.register(TrendingLinkTableViewCell.self, forCellReuseIdentifier: "trendingLinkCell")
        tableView.estimatedRowHeight = 100
        tableView.allowsFocus = true
        tableView.backgroundColor = .appGroupedBackground
        
        dataSource = UITableViewDiffableDataSource(tableView: tableView, cellProvider: { tableView, indexPath, item in
            let cell = tableView.dequeueReusableCell(withIdentifier: "trendingLinkCell", for: indexPath) as! TrendingLinkTableViewCell
            cell.updateUI(card: item.card)
            return cell
        })
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        let request = Client.getTrendingLinks()
        Task {
            guard let (links, _) = try? await mastodonController.run(request) else {
                return
            }
            var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
            snapshot.appendSections([.links])
            snapshot.appendItems(links.map(Item.init))
            await dataSource.apply(snapshot)
        }
    }
    
    // MARK: - Table View Delegate
    
    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        guard let item = dataSource.itemIdentifier(for: indexPath),
              let url = URL(item.card.url) else {
            return
        }
        selected(url: url)
    }
    
    override func tableView(_ tableView: UITableView, contextMenuConfigurationForRowAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
        guard let item = dataSource.itemIdentifier(for: indexPath),
              let url = URL(item.card.url) else {
            return nil
        }
        return UIContextMenuConfiguration(identifier: nil) {
            let vc = SFSafariViewController(url: url)
            vc.preferredControlTintColor = Preferences.shared.accentColor.color
            return vc
        } actionProvider: { _ in
            return UIMenu(children: self.actionsForTrendingLink(card: item.card))
        }
    }

}

extension TrendingLinksViewController {
    enum Section {
        case links
    }
    struct Item: Hashable {
        let card: Card
        
        static func ==(lhs: Item, rhs: Item) -> Bool {
            return lhs.card.url == rhs.card.url
        }
        
        func hash(into hasher: inout Hasher) {
            hasher.combine(card.url)
        }
    }
}

extension TrendingLinksViewController: TuskerNavigationDelegate {
    var apiController: MastodonController! { mastodonController }
}

extension TrendingLinksViewController: ToastableViewController {
}

extension TrendingLinksViewController: MenuActionProvider {
}