//
//  TaskOrderSelectViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 任务关联订单选择页，对齐 Android `OrderSelectScreen`。
final class TaskOrderSelectViewController: BaseViewController {

    var onConfirmed: ((String?) -> Void)?

    private let viewModel: TaskOrderSelectViewModel
    private let taskAPI = NetworkServices.shared.taskAPI

    private let tableView = UITableView(frame: .zero, style: .plain)
    private let confirmButton = AppButton(title: "确定")
    private let emptyLabel = UILabel()
    private let bottomBar = UIView()

    init(initialOrderNumber: String? = nil) {
        viewModel = TaskOrderSelectViewModel(initialOrderNumber: initialOrderNumber)
        super.init(nibName: nil, bundle: nil)
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func setupNavigationBar() {
        title = "订单列表"
    }

    override func setupUI() {
        tableView.backgroundColor = AppColor.pageBackground
        tableView.separatorStyle = .none
        tableView.register(TaskOrderCell.self, forCellReuseIdentifier: TaskOrderCell.reuseIdentifier)
        tableView.dataSource = self
        tableView.delegate = self

        emptyLabel.text = "无有效订单"
        emptyLabel.font = .app(.body)
        emptyLabel.textColor = AppColor.textPrimary
        emptyLabel.textAlignment = .center
        emptyLabel.isHidden = true

        bottomBar.backgroundColor = .white
        view.addSubview(tableView)
        view.addSubview(emptyLabel)
        view.addSubview(bottomBar)
        bottomBar.addSubview(confirmButton)
    }

    override func setupConstraints() {
        bottomBar.snp.makeConstraints { make in
            make.leading.trailing.bottom.equalToSuperview()
        }
        confirmButton.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(AppSpacing.md)
        }
        tableView.snp.makeConstraints { make in
            make.top.leading.trailing.equalTo(view.safeAreaLayoutGuide)
            make.bottom.equalTo(bottomBar.snp.top)
        }
        emptyLabel.snp.makeConstraints { make in
            make.center.equalTo(tableView)
        }
    }

    override func bindActions() {
        viewModel.onStateChange = { [weak self] in
            Task { @MainActor in self?.applyViewModel() }
        }
        viewModel.onShowMessage = { [weak self] message in
            Task { @MainActor in self?.showToast(message) }
        }
        confirmButton.addTarget(self, action: #selector(confirmTapped), for: .touchUpInside)
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        Task { await viewModel.loadOrders(api: taskAPI) }
    }

    @MainActor
    private func applyViewModel() {
        emptyLabel.isHidden = viewModel.isLoading || !viewModel.orders.isEmpty
        tableView.reloadData()
        if viewModel.isLoading {
            showLoading()
        } else {
            hideLoading()
        }
    }

    @objc private func confirmTapped() {
        onConfirmed?(viewModel.confirmedOrderNumber())
        navigationController?.popViewController(animated: true)
    }
}

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

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(
            withIdentifier: TaskOrderCell.reuseIdentifier,
            for: indexPath
        ) as! TaskOrderCell
        let order = viewModel.orders[indexPath.row]
        cell.apply(
            order: order,
            isSelected: viewModel.selectedOrderNumber == order.orderNumber
        )
        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        viewModel.toggleSelection(orderNumber: viewModel.orders[indexPath.row].orderNumber)
    }
}

/// 订单选择卡片 cell。
private final class TaskOrderCell: UITableViewCell {

    static let reuseIdentifier = "TaskOrderCell"

    private let cardView = UIView()
    private let projectRow = TaskInfoRowView(label: "项目名称:")
    private let statusRow = TaskInfoRowView(label: "订单状态:")
    private let numberRow = TaskInfoRowView(label: "订单编号:")
    private let payTimeRow = TaskInfoRowView(label: "付款时间:")

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        selectionStyle = .none
        backgroundColor = .clear
        contentView.backgroundColor = .clear

        cardView.backgroundColor = .white
        cardView.layer.cornerRadius = AppRadius.sm
        cardView.layer.borderWidth = 1
        cardView.layer.borderColor = AppColor.border.cgColor

        contentView.addSubview(cardView)
        cardView.addSubview(projectRow)
        cardView.addSubview(statusRow)
        cardView.addSubview(numberRow)
        cardView.addSubview(payTimeRow)

        cardView.snp.makeConstraints { make in
            make.edges.equalToSuperview().inset(UIEdgeInsets(top: 0, left: AppSpacing.md, bottom: AppSpacing.sm, right: AppSpacing.md))
        }
        projectRow.snp.makeConstraints { make in
            make.top.leading.trailing.equalToSuperview().inset(AppSpacing.md)
        }
        statusRow.snp.makeConstraints { make in
            make.top.equalTo(projectRow.snp.bottom).offset(AppSpacing.xs)
            make.leading.trailing.equalTo(projectRow)
        }
        numberRow.snp.makeConstraints { make in
            make.top.equalTo(statusRow.snp.bottom).offset(AppSpacing.xs)
            make.leading.trailing.equalTo(projectRow)
        }
        payTimeRow.snp.makeConstraints { make in
            make.top.equalTo(numberRow.snp.bottom).offset(AppSpacing.xs)
            make.leading.trailing.bottom.equalToSuperview().inset(AppSpacing.md)
        }
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func apply(order: AvailableOrder, isSelected: Bool) {
        projectRow.apply(value: order.projectName.isEmpty ? "--" : order.projectName)
        statusRow.apply(value: order.orderStatusLabel.isEmpty ? "--" : order.orderStatusLabel)
        numberRow.apply(value: order.orderNumber)
        payTimeRow.apply(value: order.payTime.isEmpty ? "--" : order.payTime)
        cardView.layer.borderColor = isSelected ? AppColor.danger.cgColor : AppColor.border.cgColor
        cardView.layer.borderWidth = isSelected ? 2 : 1
    }
}

/// 订单信息行。
private final class TaskInfoRowView: UIView {
    private let labelView = UILabel()
    private let valueView = UILabel()

    init(label: String) {
        super.init(frame: .zero)
        labelView.text = label
        labelView.font = .app(.body)
        labelView.textColor = AppColor.textSecondary
        valueView.font = .app(.body)
        valueView.textColor = AppColor.textPrimary
        valueView.numberOfLines = 0

        addSubview(labelView)
        addSubview(valueView)
        labelView.snp.makeConstraints { make in
            make.leading.top.bottom.equalToSuperview()
            make.width.equalTo(80)
        }
        valueView.snp.makeConstraints { make in
            make.leading.equalTo(labelView.snp.trailing).offset(AppSpacing.xs)
            make.trailing.top.bottom.equalToSuperview()
        }
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func apply(value: String) {
        valueView.text = value
    }
}