//
//  OrderTailUploadViewControllers.swift
//  suixinkan
//

import PhotosUI
import SnapKit
import UIKit
import UniformTypeIdentifiers

/// 多点旅拍任务上传页，负责选择打卡点和素材后提交到订单接口。
final class MultiTravelTaskUploadViewController: UIViewController {

    private let viewModel: MultiTravelTaskUploadViewModel

    private let orderField = UITextField()
    private let spotButton = UIButton(type: .system)
    private let cloudListLabel = UILabel()
    private let localListLabel = UILabel()
    private let submitButton = UIButton(type: .system)

    /// 初始化实例。
    init(initialOrderNumber: String) {
        self.viewModel = MultiTravelTaskUploadViewModel(initialOrderNumber: initialOrderNumber)
        super.init(nibName: nil, bundle: nil)
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { fatalError() }

    /// 视图加载完成后的 UI 初始化与数据绑定。
    override func viewDidLoad() {
        super.viewDidLoad()
        title = "任务上传"
        view.backgroundColor = UIColor(hex: 0xF5F7FA)
        setupForm()
        bindViewModel()
        Task { await viewModel.loadSpots(api: appServices.ordersAPI) }
    }

    /// 绑定ViewModel回调或数据。
    private func bindViewModel() {
        viewModel.onChange = { [weak self] in
            self?.applyViewModel()
        }
    }

    /// 初始化Form相关 UI 或状态。
    private func setupForm() {
        orderField.borderStyle = .roundedRect
        orderField.placeholder = "关联订单号"
        orderField.autocorrectionType = .no
        orderField.autocapitalizationType = .none
        orderField.text = viewModel.orderNumber
        orderField.addTarget(self, action: #selector(orderChanged), for: .editingChanged)

        spotButton.setTitle("选择打卡点", for: .normal)
        spotButton.addTarget(self, action: #selector(selectSpot), for: .touchUpInside)

        cloudListLabel.numberOfLines = 0
        cloudListLabel.font = .systemFont(ofSize: AppMetrics.FontSize.subheadline)
        localListLabel.numberOfLines = 0
        localListLabel.font = .systemFont(ofSize: AppMetrics.FontSize.subheadline)

        submitButton.configuration = .filled()
        submitButton.configuration?.title = "保存任务素材"
        submitButton.configuration?.baseBackgroundColor = AppDesignUIKit.primary
        submitButton.addTarget(self, action: #selector(submitTapped), for: .touchUpInside)

        let refreshButton = UIButton(type: .system)
        refreshButton.setTitle("刷新打卡点", for: .normal)
        refreshButton.addTarget(self, action: #selector(refreshSpots), for: .touchUpInside)

        let pickLocalButton = UIButton(type: .system)
        pickLocalButton.setTitle("选择图片/视频", for: .normal)
        pickLocalButton.addTarget(self, action: #selector(pickLocalFiles), for: .touchUpInside)

        let stack = UIStackView(arrangedSubviews: [
            labeledRow("订单号", orderField),
            refreshButton,
            spotButton,
            labeledRow("云盘素材", cloudListLabel),
            pickLocalButton,
            labeledRow("本地素材", localListLabel),
            submitButton
        ])
        stack.axis = .vertical
        stack.spacing = 12
        view.addSubview(stack)
        stack.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide).offset(16)
            make.leading.trailing.equalToSuperview().inset(16)
        }
        applyViewModel()
    }

    /// labeled行相关逻辑。
    private func labeledRow(_ title: String, _ content: UIView) -> UIStackView {
        let label = UILabel()
        label.text = title
        label.font = .systemFont(ofSize: AppMetrics.FontSize.body, weight: .semibold)
        let row = UIStackView(arrangedSubviews: [label, content])
        row.axis = .vertical
        row.spacing = 8
        return row
    }

    /// apply视图模型相关逻辑。
    private func applyViewModel() {
        orderField.text = viewModel.orderNumber
        spotButton.setTitle(viewModel.isLoadingSpots ? "加载中..." : viewModel.selectedSpotName, for: .normal)
        spotButton.isEnabled = !viewModel.isLoadingSpots

        if viewModel.selectedCloudFiles.isEmpty {
            cloudListLabel.text = "未选择云盘文件"
        } else {
            cloudListLabel.text = viewModel.selectedCloudFiles.map(\.fileName).joined(separator: "\n")
        }

        if viewModel.selectedLocalFiles.isEmpty {
            localListLabel.text = "未选择本地文件"
        } else {
            localListLabel.text = viewModel.selectedLocalFiles.map { file in
                "\(file.fileName) \(file.statusText)"
            }.joined(separator: "\n")
        }

        submitButton.isEnabled = viewModel.canSubmit
        submitButton.configuration?.title = viewModel.isSubmitting ? "保存中..." : "保存任务素材"
    }

    /// order变更相关逻辑。
    @objc private func orderChanged() {
        viewModel.orderNumber = orderField.text ?? ""
    }

    /// 刷新Spots展示。
    @objc private func refreshSpots() {
        Task { await viewModel.loadSpots(api: appServices.ordersAPI) }
    }

    /// select打卡点相关逻辑。
    @objc private func selectSpot() {
        guard !viewModel.spots.isEmpty else { return }
        let sheet = UIAlertController(title: "选择打卡点", message: nil, preferredStyle: .actionSheet)
        for spot in viewModel.spots {
            let title = spot.name.isEmpty ? "打卡点 \(spot.id)" : spot.name
            sheet.addAction(UIAlertAction(title: title, style: .default) { [weak self] _ in
                self?.viewModel.selectSpot(id: spot.id)
            })
        }
        sheet.addAction(UIAlertAction(title: "取消", style: .cancel))
        present(sheet, animated: true)
    }

    /// pick本地Files相关逻辑。
    @objc private func pickLocalFiles() {
        var config = PHPickerConfiguration()
        config.selectionLimit = 9
        config.filter = .any(of: [.images, .videos])
        let picker = PHPickerViewController(configuration: config)
        picker.delegate = self
        present(picker, animated: true)
    }

    /// 提交Tapped。
    @objc private func submitTapped() {
        Task {
            let success = await viewModel.submit(
                api: appServices.ordersAPI,
                uploadService: appServices.ossUploadService,
                scenicId: appServices.accountContext.currentScenic?.id
            )
            if success {
                showToast("提交成功")
                navigationController?.popViewController(animated: true)
            } else if let message = viewModel.errorMessage {
                showToast(message)
            }
            applyViewModel()
        }
    }
}

extension MultiTravelTaskUploadViewController: PHPickerViewControllerDelegate {
    /// picker 业务逻辑。
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        picker.dismiss(animated: true)
        guard !results.isEmpty else { return }
        for result in results {
            let provider = result.itemProvider
            if provider.hasItemConformingToTypeIdentifier(UTType.movie.identifier) {
                provider.loadFileRepresentation(forTypeIdentifier: UTType.movie.identifier) { [weak self] url, _ in
                    guard let self, let url else { return }
                    let data = (try? Data(contentsOf: url)) ?? Data()
                    DispatchQueue.main.async {
                        self.viewModel.addLocalFile(data: data, fileName: url.lastPathComponent)
                        self.applyViewModel()
                    }
                }
            } else if provider.canLoadObject(ofClass: UIImage.self) {
                provider.loadObject(ofClass: UIImage.self) { [weak self] object, _ in
                    guard let self, let image = object as? UIImage, let data = image.jpegData(compressionQuality: 0.9) else { return }
                    DispatchQueue.main.async {
                        self.viewModel.addLocalFile(data: data, fileName: "upload_\(Int(Date().timeIntervalSince1970)).jpg")
                        self.applyViewModel()
                    }
                }
            }
        }
    }
}

// MARK: - Historical Shooting Diffable 标识

private typealias HistoricalShootingSection = Int
private typealias HistoricalShootingRow = String

/// 历史拍摄 section 索引。
private enum HistoricalShootingSectionID {
    static let summary = 0
    static let spots = 1
}

/// 历史拍摄行标识。
private enum HistoricalShootingRowID {
    static let project = "historicalShooting:project"
    static let projectType = "historicalShooting:projectType"
    static let empty = "historicalShooting:empty"
    static func spot(_ id: String) -> String { "historicalShooting:spot:\(id)" }
}

/// 历史拍摄信息页。
final class HistoricalShootingInfoViewController: UIViewController, UITableViewDelegate {

    private let orderNumber: String
    private let viewModel = HistoricalShootingInfoViewModel()

    private lazy var tableView: UITableView = {
        let table = UITableView(frame: .zero, style: .insetGrouped)
        table.delegate = self
        return table
    }()

    /// Diffable 数据源，驱动历史拍摄摘要与点位列表刷新。
    private var tableDataSource: UITableViewDiffableDataSource<HistoricalShootingSection, HistoricalShootingRow>!

    /// 初始化实例。
    init(orderNumber: String) {
        self.orderNumber = orderNumber
        super.init(nibName: nil, bundle: nil)
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { fatalError() }

    /// 视图加载完成后的 UI 初始化与数据绑定。
    override func viewDidLoad() {
        super.viewDidLoad()
        title = "历史拍摄"
        configureTableDataSource()
        view.addSubview(tableView)
        tableView.snp.makeConstraints { make in make.edges.equalToSuperview() }
        viewModel.onChange = { [weak self] in self?.applyTableSnapshot(reconfigure: true) }
        Task { await loadData() }
    }

    /// 配置 Diffable 数据源。
    private func configureTableDataSource() {
        tableDataSource = UITableViewDiffableDataSource<HistoricalShootingSection, HistoricalShootingRow>(
            tableView: tableView
        ) { [weak self] (_: UITableView, _: IndexPath, row: HistoricalShootingRow) -> UITableViewCell? in
            guard let self else { return UITableViewCell() }
            let cell = UITableViewCell(style: .value1, reuseIdentifier: nil)
            cell.selectionStyle = .none
            switch row {
            case HistoricalShootingRowID.project:
                cell.textLabel?.text = "项目"
                cell.detailTextLabel?.text = self.viewModel.projectName
            case HistoricalShootingRowID.projectType:
                cell.textLabel?.text = "项目类型"
                cell.detailTextLabel?.text = self.viewModel.projectTypeName
            case HistoricalShootingRowID.empty:
                cell.textLabel?.text = self.viewModel.errorMessage ?? "暂无历史拍摄"
            default:
                if row.hasPrefix("historicalShooting:spot:") {
                    let id = row.replacingOccurrences(of: "historicalShooting:spot:", with: "")
                    if let spot = self.viewModel.spots.first(where: { $0.id == id }) {
                        cell.textLabel?.text = spot.scenicSpotName
                        cell.detailTextLabel?.text = "\(spot.files.count) 个文件 · \(spot.photographerDisplayName)"
                    }
                }
            }
            return cell
        }
        applyTableSnapshot(animated: false)
    }

    /// 构建 Diffable snapshot。
    private func buildTableSnapshot() -> NSDiffableDataSourceSnapshot<HistoricalShootingSection, HistoricalShootingRow> {
        var snapshot = NSDiffableDataSourceSnapshot<HistoricalShootingSection, HistoricalShootingRow>()
        snapshot.appendSections([HistoricalShootingSectionID.summary, HistoricalShootingSectionID.spots])
        snapshot.appendItems([HistoricalShootingRowID.project, HistoricalShootingRowID.projectType], toSection: HistoricalShootingSectionID.summary)
        if viewModel.spots.isEmpty {
            snapshot.appendItems([HistoricalShootingRowID.empty], toSection: HistoricalShootingSectionID.spots)
        } else {
            snapshot.appendItems(viewModel.spots.map { HistoricalShootingRowID.spot($0.id) }, toSection: HistoricalShootingSectionID.spots)
        }
        return snapshot
    }

    /// 应用 snapshot 刷新列表。
    private func applyTableSnapshot(animated: Bool = true, reconfigure: Bool = false) {
        var snapshot = buildTableSnapshot()
        if reconfigure, !snapshot.itemIdentifiers.isEmpty {
            snapshot.reconfigureItems(snapshot.itemIdentifiers)
        }
        tableDataSource.apply(snapshot, animatingDifferences: animated)
    }

    /// 加载Data数据。
    private func loadData() async {
        await appServices.globalLoading.withLoading {
            await viewModel.load(api: appServices.ordersAPI, orderNumber: orderNumber)
        }
        applyTableSnapshot()
        if let message = viewModel.errorMessage { showToast(message) }
    }

    /// UITableView 代理：section 标题。
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        guard let sectionID = tableDataSource.snapshot().sectionIdentifiers[safe: section] else { return nil }
        return sectionID == HistoricalShootingSectionID.spots ? "拍摄点位" : nil
    }
}

/// 安全下标，避免 section 越界。
private extension Array {
    subscript(safe index: Int) -> Element? {
        indices.contains(index) ? self[index] : nil
    }
}