//
//  CooperationOrderListViewController.swift
//  suixinkan
//

import SnapKit
import UIKit

/// 合作订单列表页，对齐 Android `CooperationOrderListScreen`。
final class CooperationOrderListViewController: BaseViewController, UITableViewDataSource, UITableViewDelegate {

    private let viewModel = CooperationOrderListViewModel()
    private let orderAPI = NetworkServices.shared.orderAPI

    private let tabBarView = CooperationOrderTabBar()
    private let searchBar = CooperationOrderSearchBar()
    private let tableView = UITableView(frame: .zero, style: .plain)
    private let refreshControl = UIRefreshControl()
    private let loadingIndicator = UIActivityIndicatorView(style: .medium)
    private let footerSpinner = UIActivityIndicatorView(style: .medium)
    private let footerLabel = UILabel()
    private let emptyLabel = UILabel()
    private var isApplyingTab = false
    private var isSearchBarVisible = false
    private var searchBarHeightConstraint: Constraint?

    override func setupNavigationBar() {
        title = "合作订单"
        navigationItem.rightBarButtonItem = UIBarButtonItem(
            title: "合作获客员",
            style: .plain,
            target: self,
            action: #selector(openAcquirer)
        )
        navigationItem.rightBarButtonItem?.tintColor = AppColor.primary
    }

    override func setupUI() {
        view.backgroundColor = AppColor.pageBackground
        searchBar.isHidden = true

        tableView.backgroundColor = .clear
        tableView.separatorStyle = .none
        tableView.contentInset.top = AppSpacing.sm
        tableView.verticalScrollIndicatorInsets.top = AppSpacing.sm
        tableView.dataSource = self
        tableView.delegate = self
        tableView.register(ReferralLeadCell.self, forCellReuseIdentifier: ReferralLeadCell.reuseIdentifier)
        tableView.register(AcquisitionOrderCell.self, forCellReuseIdentifier: AcquisitionOrderCell.reuseIdentifier)
        tableView.refreshControl = refreshControl

        loadingIndicator.hidesWhenStopped = true
        loadingIndicator.color = AppColor.primary
        footerSpinner.hidesWhenStopped = true
        footerSpinner.color = AppColor.primary
        footerLabel.font = .systemFont(ofSize: 14)
        footerLabel.textColor = AppColor.textTertiary
        footerLabel.textAlignment = .center
        footerLabel.text = "没有更多"

        emptyLabel.text = "暂无相关合作订单"
        emptyLabel.font = .systemFont(ofSize: 14)
        emptyLabel.textColor = AppColor.textTertiary
        emptyLabel.textAlignment = .center
        emptyLabel.isHidden = true

        view.addSubview(tabBarView)
        view.addSubview(searchBar)
        view.addSubview(tableView)
        view.addSubview(loadingIndicator)
        view.addSubview(emptyLabel)
    }

    override func setupConstraints() {
        tabBarView.snp.makeConstraints { make in
            make.top.equalTo(view.safeAreaLayoutGuide)
            make.leading.trailing.equalToSuperview()
        }
        searchBar.snp.makeConstraints { make in
            make.top.equalTo(tabBarView.snp.bottom)
            make.leading.trailing.equalToSuperview()
            searchBarHeightConstraint = make.height.equalTo(0).constraint
        }
        tableView.snp.makeConstraints { make in
            make.top.equalTo(searchBar.snp.bottom)
            make.leading.trailing.bottom.equalToSuperview()
        }
        loadingIndicator.snp.makeConstraints { make in
            make.center.equalTo(tableView)
        }
        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) }
        }

        tabBarView.onTabSelected = { [weak self] index in
            guard let self else { return }
            self.viewModel.onTabSelected(index)
            Task { await self.viewModel.refreshCurrentTab(api: self.orderAPI) }
        }
        searchBar.onSearchTextChange = { [weak self] text in
            self?.viewModel.onSearchTextChange(text)
        }
        searchBar.onSearch = { [weak self] in
            guard let self else { return }
            Task { await self.viewModel.refreshAcquisitionOrders(api: self.orderAPI) }
        }
        refreshControl.addTarget(self, action: #selector(refreshTriggered), for: .valueChanged)
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        guard CooperationOrderFeature.hasPermission(in: AppStore.shared.permissions.permissionItems()) else {
            showToast("暂无合作订单权限")
            navigationController?.popViewController(animated: false)
            return
        }
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        Task { await viewModel.refreshCurrentTab(api: orderAPI) }
    }

    @objc private func openAcquirer() {
        navigationController?.pushViewController(CooperationAcquirerViewController(), animated: true)
    }

    @objc private func refreshTriggered() {
        Task { await viewModel.refreshCurrentTab(api: orderAPI) }
    }

    private func applyViewModel() {
        if !isApplyingTab {
            isApplyingTab = true
            tabBarView.setSelectedTab(viewModel.selectedTab)
            isApplyingTab = false
        }
        updateSearchBarVisibility(viewModel.selectedTab == 1)
        searchBar.textField.text = viewModel.searchText

        let isEmpty = viewModel.selectedTab == 0 ? viewModel.leads.isEmpty : viewModel.orders.isEmpty
        let isLoading = viewModel.isRefreshing && isEmpty

        if viewModel.isRefreshing {
            if !refreshControl.isRefreshing { refreshControl.beginRefreshing() }
        } else {
            refreshControl.endRefreshing()
        }

        if isLoading {
            loadingIndicator.startAnimating()
            emptyLabel.isHidden = true
            tableView.tableFooterView = nil
        } else {
            loadingIndicator.stopAnimating()
            emptyLabel.isHidden = !isEmpty
            tableView.tableFooterView = tableFooterView(isEmpty: isEmpty)
        }
        tableView.reloadData()
    }

    private func updateSearchBarVisibility(_ isVisible: Bool) {
        guard isSearchBarVisible != isVisible else { return }
        isSearchBarVisible = isVisible
        searchBarHeightConstraint?.update(offset: isVisible ? 62 : 0)
        if isVisible {
            searchBar.isHidden = false
        } else {
            searchBar.textField.resignFirstResponder()
        }
        UIView.animate(withDuration: 0.2, delay: 0, options: [.curveEaseInOut]) {
            self.view.layoutIfNeeded()
        } completion: { _ in
            if self.isSearchBarVisible == isVisible {
                self.searchBar.isHidden = !isVisible
            }
        }
    }

    private func tableFooterView(isEmpty: Bool) -> UIView? {
        guard !isEmpty else { return nil }
        if viewModel.isLoadingMore {
            let container = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.width, height: 44))
            footerSpinner.center = CGPoint(x: container.bounds.midX, y: container.bounds.midY)
            footerSpinner.autoresizingMask = [.flexibleLeftMargin, .flexibleRightMargin]
            container.addSubview(footerSpinner)
            footerSpinner.startAnimating()
            return container
        }
        footerSpinner.stopAnimating()
        guard !viewModel.canLoadMore else { return nil }
        footerLabel.frame = CGRect(x: 0, y: 0, width: tableView.bounds.width, height: 44)
        return footerLabel
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        viewModel.selectedTab == 0 ? viewModel.leads.count : viewModel.orders.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if viewModel.selectedTab == 0 {
            guard let cell = tableView.dequeueReusableCell(
                withIdentifier: ReferralLeadCell.reuseIdentifier,
                for: indexPath
            ) as? ReferralLeadCell else {
                return UITableViewCell()
            }
            cell.configure(with: viewModel.leads[indexPath.row])
            cell.onImageTap = { [weak self] index, urls in
                let preview = ImagePreviewViewController(imageURLs: urls, startIndex: index)
                self?.present(preview, animated: true)
            }
            return cell
        }
        guard let cell = tableView.dequeueReusableCell(
            withIdentifier: AcquisitionOrderCell.reuseIdentifier,
            for: indexPath
        ) as? AcquisitionOrderCell else {
            return UITableViewCell()
        }
        cell.configure(with: viewModel.orders[indexPath.row])
        return cell
    }

    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
        guard viewModel.shouldLoadMore(at: indexPath.row) else { return }
        Task { await viewModel.loadMore(api: orderAPI) }
    }
}