//
//  OrderDetailViewControllers.swift
//  suixinkan
//

import SnapKit
import UIKit

// MARK: - Store Order Diffable 标识

private typealias StoreOrderDetailSection = Int
private typealias StoreOrderDetailRow = String

/// 门店订单详情 section 索引。
private enum StoreOrderDetailSectionID {
    static let context = 0
    static let orderInfo = 1
    static let payment = 2
    static let customer = 3
    static let shooting = 4
    static let actions = 5
}

/// 门店订单详情行标识。
private enum StoreOrderDetailRowID {
    static let context = "storeDetail:context"
    static func orderInfo(_ index: Int) -> String { "storeDetail:orderInfo:\(index)" }
    static func payment(_ index: Int) -> String { "storeDetail:payment:\(index)" }
    static func customer(_ index: Int) -> String { "storeDetail:customer:\(index)" }
    static func shooting(_ id: String) -> String { "storeDetail:shooting:\(id)" }
    static func action(_ index: Int) -> String { "storeDetail:action:\(index)" }
}

// MARK: - Write-Off Diffable 标识

/// 核销详情行标识。
private enum WriteOffDetailRowID {
    static let orderNumber = "writeOff:orderNumber"
    static let project = "writeOff:project"
    static let phone = "writeOff:phone"
    static let amount = "writeOff:amount"
    static let status = "writeOff:status"
    static let verificationTime = "writeOff:verificationTime"
}

/// 门店订单详情页，展示订单接口补全后的支付、客户、项目和拍摄点信息。
final class StoreOrderDetailViewController: UIViewController, UITableViewDelegate {

    private let item: OrderEntity
    private let viewModel: OrderDetailViewModel
    private let refundViewModel = OrderRefundViewModel()

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

    /// Diffable 数据源，驱动多 section 订单详情刷新。
    private var tableDataSource: UITableViewDiffableDataSource<StoreOrderDetailSection, StoreOrderDetailRow>!

    /// 初始化实例。
    init(item: OrderEntity) {
        self.item = item
        self.viewModel = OrderDetailViewModel(item: item)
        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 = "订单详情"
        view.backgroundColor = AppDesignUIKit.pageBackground
        configureTableDataSource()
        view.addSubview(tableView)
        tableView.snp.makeConstraints { make in make.edges.equalToSuperview() }

        viewModel.onChange = { [weak self] in self?.applyTableSnapshot(reconfigure: true) }
        Task { await loadDetail() }
    }

    /// 配置 Diffable 数据源。
    private func configureTableDataSource() {
        tableDataSource = UITableViewDiffableDataSource<StoreOrderDetailSection, StoreOrderDetailRow>(
            tableView: tableView
        ) { [weak self] (_: UITableView, indexPath: IndexPath, row: StoreOrderDetailRow) -> UITableViewCell? in
            guard let self else { return UITableViewCell() }
            return self.configureDetailCell(row: row)
        }
        applyTableSnapshot(animated: false)
    }

    /// 构建 Diffable snapshot。
    private func buildTableSnapshot() -> NSDiffableDataSourceSnapshot<StoreOrderDetailSection, StoreOrderDetailRow> {
        var snapshot = NSDiffableDataSourceSnapshot<StoreOrderDetailSection, StoreOrderDetailRow>()

        if viewModel.contextMessage != nil {
            snapshot.appendSections([StoreOrderDetailSectionID.context])
            snapshot.appendItems([StoreOrderDetailRowID.context], toSection: StoreOrderDetailSectionID.context)
        }

        snapshot.appendSections([StoreOrderDetailSectionID.orderInfo])
        snapshot.appendItems((0..<7).map { StoreOrderDetailRowID.orderInfo($0) }, toSection: StoreOrderDetailSectionID.orderInfo)

        snapshot.appendSections([StoreOrderDetailSectionID.payment])
        snapshot.appendItems((0..<4).map { StoreOrderDetailRowID.payment($0) }, toSection: StoreOrderDetailSectionID.payment)

        snapshot.appendSections([StoreOrderDetailSectionID.customer])
        snapshot.appendItems((0..<4).map { StoreOrderDetailRowID.customer($0) }, toSection: StoreOrderDetailSectionID.customer)

        if !viewModel.shootingList.isEmpty {
            snapshot.appendSections([StoreOrderDetailSectionID.shooting])
            let shootingRows = viewModel.shootingList.enumerated().map { index, shooting in
                StoreOrderDetailRowID.shooting("\(shooting.id)-\(index)")
            }
            snapshot.appendItems(shootingRows, toSection: StoreOrderDetailSectionID.shooting)
        }

        snapshot.appendSections([StoreOrderDetailSectionID.actions])
        snapshot.appendItems((0..<5).map { StoreOrderDetailRowID.action($0) }, toSection: StoreOrderDetailSectionID.actions)

        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)
    }

    /// 配置详情 Cell 内容。
    private func configureDetailCell(row: StoreOrderDetailRow) -> UITableViewCell {
        let cell = UITableViewCell(style: .value1, reuseIdentifier: nil)
        cell.selectionStyle = .none
        cell.textLabel?.numberOfLines = 1
        cell.textLabel?.textColor = nil
        cell.accessoryType = .none
        cell.isUserInteractionEnabled = true
        let display = viewModel.display

        if row == StoreOrderDetailRowID.context {
            cell.textLabel?.text = viewModel.contextMessage
            cell.textLabel?.numberOfLines = 0
            return cell
        }

        if row.hasPrefix("storeDetail:orderInfo:") {
            let index = Int(row.split(separator: ":").last ?? "") ?? 0
            let rows = ["订单号", "状态", "类型", "创建时间", "付款时间", "完成时间", "复制订单号"]
            cell.textLabel?.text = rows[index]
            switch index {
            case 0: cell.detailTextLabel?.text = display.orderNumber
            case 1: cell.detailTextLabel?.text = display.orderStatusName
            case 2: cell.detailTextLabel?.text = display.orderTypeLabel
            case 3: cell.detailTextLabel?.text = display.createdAt
            case 4: cell.detailTextLabel?.text = display.payTime
            case 5: cell.detailTextLabel?.text = display.completeTime
            default:
                cell.textLabel?.textColor = AppDesignUIKit.primary
                cell.selectionStyle = .default
            }
            return cell
        }

        if row.hasPrefix("storeDetail:payment:") {
            let index = Int(row.split(separator: ":").last ?? "") ?? 0
            let rows = ["付款金额", "退款金额", "付款方式", "用户 UID"]
            cell.textLabel?.text = rows[index]
            switch index {
            case 0: cell.detailTextLabel?.text = "¥\(emptyToZero(display.actualPayAmount))"
            case 1: cell.detailTextLabel?.text = "¥\(emptyToZero(display.actualRefundAmount))"
            case 2: cell.detailTextLabel?.text = display.payTypeName
            default: cell.detailTextLabel?.text = "\(display.userId)"
            }
            return cell
        }

        if row.hasPrefix("storeDetail:customer:") {
            let index = Int(row.split(separator: ":").last ?? "") ?? 0
            let rows = ["手机号", "关联项目", "项目 ID", "备注"]
            cell.textLabel?.text = rows[index]
            switch index {
            case 0: cell.detailTextLabel?.text = display.phone
            case 1: cell.detailTextLabel?.text = display.projectName
            case 2: cell.detailTextLabel?.text = "\(display.projectId)"
            default: cell.detailTextLabel?.text = display.remark
            }
            return cell
        }

        if row.hasPrefix("storeDetail:shooting:") {
            let suffix = row.replacingOccurrences(of: "storeDetail:shooting:", with: "")
            let indexPart = suffix.split(separator: "-").last.flatMap { Int($0) } ?? 0
            if indexPart < viewModel.shootingList.count {
                let shooting = viewModel.shootingList[indexPart]
                cell.textLabel?.text = shooting.scenicSpotName
                cell.detailTextLabel?.text = shooting.staffName.isEmpty ? "状态 \(shooting.status)" : shooting.staffName
            }
            return cell
        }

        if row.hasPrefix("storeDetail:action:") {
            let index = Int(row.split(separator: ":").last ?? "") ?? 0
            let actions = ["历史拍摄", "任务上传", "视频预告", "尾片上传", "退款"]
            cell.textLabel?.text = actions[index]
            cell.accessoryType = .disclosureIndicator
            cell.selectionStyle = .default
            if index == 4, !refundViewModel.canRefund(item) {
                cell.isUserInteractionEnabled = false
                cell.textLabel?.textColor = AppDesignUIKit.textSecondary
            }
            return cell
        }

        return cell
    }

    /// 加载Detail数据。
    private func loadDetail() async {
        await appServices.globalLoading.withLoading(message: "加载详情中...") {
            await viewModel.load(api: appServices.ordersAPI, fallbackStoreId: appServices.accountContext.currentStore?.id)
        }
        applyTableSnapshot(reconfigure: true)
        if let error = viewModel.errorMessage {
            showToast(error)
        }
    }

    /// 复制订单Number。
    private func copyOrderNumber() {
        UIPasteboard.general.string = viewModel.display.orderNumber
        showToast("订单号已复制")
    }

    /// 弹出Refund页面。
    private func presentRefund() {
        refundViewModel.begin(item: item)
        let alert = UIAlertController(title: "订单退款", message: "可退 ¥\(refundViewModel.availableAmountText(for: item))", preferredStyle: .alert)
        alert.addTextField { $0.placeholder = "退款原因" }
        alert.addAction(UIAlertAction(title: "取消", style: .cancel))
        alert.addAction(UIAlertAction(title: "提交", style: .default) { [weak self] _ in
            guard let self else { return }
            self.refundViewModel.reason = alert.textFields?.first?.text ?? ""
            Task {
                let success = await self.refundViewModel.submit(api: self.appServices.ordersAPI, item: self.item)
                if success {
                    self.showToast("退款申请已提交")
                    await self.viewModel.load(api: self.appServices.ordersAPI, fallbackStoreId: self.appServices.accountContext.currentStore?.id, forceReload: true)
                } else if let message = self.refundViewModel.errorMessage {
                    self.showToast(message)
                }
            }
        })
        present(alert, animated: true)
    }

    /// 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 }
        switch sectionID {
        case StoreOrderDetailSectionID.orderInfo: return "订单信息"
        case StoreOrderDetailSectionID.payment: return "支付信息"
        case StoreOrderDetailSectionID.customer: return "客户与项目"
        case StoreOrderDetailSectionID.shooting: return "拍摄点"
        case StoreOrderDetailSectionID.actions: return "后续功能"
        default: return nil
        }
    }

    /// UITableView 代理：处理行选中。
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        guard let row = tableDataSource.itemIdentifier(for: indexPath) else { return }

        if row == StoreOrderDetailRowID.orderInfo(6) {
            copyOrderNumber()
            return
        }

        guard row.hasPrefix("storeDetail:action:") else { return }
        let index = Int(row.split(separator: ":").last ?? "") ?? -1
        let orderNumber = viewModel.display.orderNumber
        switch index {
        case 0:
            appServices.appNavigator.push(.orders(.historicalShooting(orderNumber: orderNumber)), from: self)
        case 1 where item.orderType == 19:
            appServices.appNavigator.push(.orders(.multiTravelTaskUpload(orderNumber: orderNumber)), from: self)
        case 2:
            appServices.appNavigator.push(.orders(.orderTrailer(orderNumber: orderNumber, title: "视频预告")), from: self)
        case 3:
            appServices.appNavigator.push(.orders(.orderTrailer(orderNumber: orderNumber, title: "尾片上传")), from: self)
        case 4:
            presentRefund()
        default:
            break
        }
    }

    private var displayPayTime: String {
        let payTime = viewModel.display.payTime
        if payTime.isEmpty || payTime == "0" || payTime.hasPrefix("1970") { return item.depositPayTime }
        return payTime
    }

    /// empty至Zero相关逻辑。
    private func emptyToZero(_ value: String) -> String {
        value.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ? "0" : value
    }
}

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

/// 核销订单详情页，展示核销列表项摘要信息。
final class WriteOffOrderDetailViewController: SimpleTableDiffableViewController {

    private let item: WriteOffOrderItem

    /// 初始化实例。
    init(item: WriteOffOrderItem) {
        self.item = item
        super.init(style: .insetGrouped)
    }

    @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 = "核销详情"
        tableView.backgroundColor = AppDesignUIKit.pageBackground
    }

    /// 构建 Diffable snapshot。
    override func buildSnapshot() -> NSDiffableDataSourceSnapshot<SimpleTableSection, SimpleTableRow> {
        var snapshot = NSDiffableDataSourceSnapshot<SimpleTableSection, SimpleTableRow>()
        snapshot.appendSections([0])
        snapshot.appendItems([
            WriteOffDetailRowID.orderNumber,
            WriteOffDetailRowID.project,
            WriteOffDetailRowID.phone,
            WriteOffDetailRowID.amount,
            WriteOffDetailRowID.status,
            WriteOffDetailRowID.verificationTime
        ], toSection: 0)
        return snapshot
    }

    /// 配置 Cell 展示内容。
    override func configureCell(_ cell: UITableViewCell, row: SimpleTableRow, at indexPath: IndexPath) {
        cell.selectionStyle = .none
        switch row {
        case WriteOffDetailRowID.orderNumber:
            cell.textLabel?.text = "订单号"
            cell.detailTextLabel?.text = item.orderNumber
        case WriteOffDetailRowID.project:
            cell.textLabel?.text = "项目"
            cell.detailTextLabel?.text = item.projectName
        case WriteOffDetailRowID.phone:
            cell.textLabel?.text = "手机号"
            cell.detailTextLabel?.text = item.userPhone
        case WriteOffDetailRowID.amount:
            cell.textLabel?.text = "金额"
            cell.detailTextLabel?.text = "¥\(item.orderAmount)"
        case WriteOffDetailRowID.status:
            cell.textLabel?.text = "状态"
            cell.detailTextLabel?.text = item.orderStatusName
        case WriteOffDetailRowID.verificationTime:
            cell.textLabel?.text = "核销时间"
            cell.detailTextLabel?.text = item.orderVerificationTime
        default:
            break
        }
    }
}