//
//  SelectActivityVC.swift
//  QuickLocation
//

import UIKit
import RxSwift
import RxCocoa
import Kingfisher

final class SelectActivityCell: UITableViewCell {
    static let reuseId = "SelectActivityCell"

    private let iconView = UIImageView()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        iconView.contentMode = .scaleAspectFill
        iconView.layer.cornerRadius = 10
        iconView.clipsToBounds = true
        contentView.addSubview(iconView)
        iconView.layoutChain.left(16).centerY().width(40).height(40)
        textLabel?.layoutChain.leftToRightOfView(iconView, offset: 12).centerY().right(16)
        selectionStyle = .default
    }

    required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") }

    func configure(item: AppCatalogItem) {
        textLabel?.text = item.name
        textLabel?.font = .systemFont(ofSize: 16, weight: .medium)
        textLabel?.textColor = UIColor(hexStr: "#293445")
        AppCatalogStore.setIcon(for: iconView, item: item)
    }

    override func prepareForReuse() {
        super.prepareForReuse()
        iconView.kf.cancelDownloadTask()
        iconView.image = nil
    }
}

final class SelectActivityVC: BaseViewController {
    var onSelect: ((AppCatalogItem) -> Void)?

    private let searchField = UITextField()
    private let tableView = UITableView(frame: .zero, style: .plain)
    private let activityIndicator = UIActivityIndicatorView(style: .medium)
    private var items: [AppCatalogItem] = AppCatalogStore.sharedItems
    private var searchTask: Task<Void, Never>?

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        title = "选取应用"
        navigationItem.leftBarButtonItem = UIBarButtonItem(title: "取消", style: .plain, target: self, action: #selector(cancel))

        searchField.placeholder = "搜索应用"
        searchField.borderStyle = .roundedRect
        searchField.font = .systemFont(ofSize: 15)
        searchField.clearButtonMode = .whileEditing
        searchField.returnKeyType = .search
        searchField.addTarget(self, action: #selector(searchChanged), for: .editingChanged)
        view.addSubview(searchField)
        searchField.layoutChain.top(12).left(16).right(16).height(40)

        activityIndicator.hidesWhenStopped = true
        view.addSubview(activityIndicator)
        activityIndicator.layoutChain.centerX().topToBottomOfView(searchField, offset: 8)

        tableView.register(SelectActivityCell.self, forCellReuseIdentifier: SelectActivityCell.reuseId)
        tableView.dataSource = self
        tableView.delegate = self
        tableView.rowHeight = 56
        tableView.keyboardDismissMode = .onDrag
        view.addSubview(tableView)
        tableView.layoutChain.topToBottomOfView(searchField, offset: 12).edgesHorzontal().bottom()
    }

    @objc private func cancel() {
        dismiss(animated: true)
    }

    @objc private func searchChanged() {
        let query = searchField.text ?? ""
        searchTask?.cancel()

        let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines)
        if trimmed.isEmpty {
            activityIndicator.stopAnimating()
            items = AppCatalogStore.sharedItems
            tableView.reloadData()
            return
        }

        let localHits = AppCatalogStore.search(query)
        items = localHits
        tableView.reloadData()
        activityIndicator.startAnimating()

        searchTask = Task { [weak self] in
            try? await Task.sleep(nanoseconds: 300_000_000)
            guard let self, !Task.isCancelled else { return }
            do {
                let remote = try await ITunesSearchService.search(term: trimmed)
                guard !Task.isCancelled else { return }
                await MainActor.run {
                    self.activityIndicator.stopAnimating()
                    self.items = ITunesSearchService.mergedResults(local: localHits, remote: remote)
                    self.tableView.reloadData()
                }
            } catch {
                await MainActor.run {
                    self.activityIndicator.stopAnimating()
                    if self.items.isEmpty {
                        self.items = localHits
                        self.tableView.reloadData()
                    }
                    DLToast.show(text: "搜索失败，请检查网络")
                }
            }
        }
    }
}

extension SelectActivityVC: UITableViewDataSource, UITableViewDelegate {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        items.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: SelectActivityCell.reuseId, for: indexPath) as! SelectActivityCell
        cell.configure(item: items[indexPath.row])
        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let item = items[indexPath.row]
        onSelect?(item)
        dismiss(animated: true)
    }
}