import SwiftUI

/// 装配当前节点的详情会话；查询、参数装载与命令均留在共用视图之外。
struct CatalogNodeDetailView: View {
  @Environment(\.locale) private var locale
  @Environment(\.timeZone) private var timeZone
  @ObservedObject var workflow: CatalogWorkflow
  @ObservedObject var activation: ActivationFeedbackState
  let nodeID: NodeID
  let isActiveTarget: Bool
  /// 子树含活动目标（严格后代），与行级空心闪电同源判定。
  let containsActiveTarget: Bool
  let errors: ErrorAlertPresenter
  @StateObject private var parameters = ServerDetailParameters()

  private var node: CatalogTreeNode? { workflow.tree.node(withID: nodeID) }
  private var eligibility: ActivationEligibility? { workflow.activationEligibility(for: nodeID) }

  var body: some View {
    if let node {
      Group {
        if let module = workflow.connectivity {
          ObservedConnectivityProperties(
            module: module, node: node, serverName: workflow.displayName(for:)
          ) { properties in
            detailView(for: node, connectivity: properties)
          }
        } else {
          detailView(for: node)
        }
      }
      .onAppear {
        if !node.isGroup {
          parameters.showServer(nodeID, load: workflow.serverDetailPluginOptions)
        }
      }
      .onReceive(workflow.serverDetailChanges) { affected in
        parameters.didRefresh(affectedServers: affected, load: workflow.serverDetailPluginOptions)
      }
    }
  }

  private func detailView(
    for node: CatalogTreeNode, connectivity: NodeDetailPresentation.Properties? = nil
  ) -> some View {
    var detail = presentation(for: node)
    if let connectivity { detail.properties.append(connectivity) }
    return NodeDetailView(detail: detail) {
      primaryActions(for: node)
    } secondaryActions: {
      if let module = workflow.connectivity {
        ConnectivityTestButton(module: module, node: node)
      }
      Button(
        workflow.isFavorite(nodeID)
          ? String(localized: "取消收藏", table: "ServerDetails")
          : String(localized: "收藏", table: "ServerDetails")
      ) {
        do {
          try workflow.setFavorite(nodeID, isFavorite: !workflow.isFavorite(nodeID))
        } catch {
          errors.present(error)
        }
      }
      if !node.isGroup && parameters.failure != nil {
        Button(String(localized: "重新加载", table: "ServerDetails")) {
          parameters.reload(load: workflow.serverDetailPluginOptions)
        }
      }
    } feedback: {
      ActivationDetailFeedbackView(
        messages: detail.activationMessages,
        completion: activation.completion?.targetID == nodeID ? activation.completion : nil)
      if let subscription = subscriptionSummary(for: node) {
        SubscriptionRefreshFeedbackView(
          isRefreshing: workflow.refreshingSubscriptionIDs.contains(subscription.id),
          completion: workflow.subscriptionRefreshCompletions[subscription.id]
        )
        .id(subscription.id)
      }
    } propertiesFooter: { group in
      if group.id == .subscription,
        let fraction = subscriptionSummary(for: node)?.information?.usedFraction
      {
        ProgressView(value: fraction) {
          Text("流量消耗")
        } currentValueLabel: {
          Text(fraction, format: .percent.precision(.fractionLength(0)))
        }
        .progressViewStyle(.linear)
        .tint(.accentColor)
      } else {
        nil
      }
    }
  }

  @ViewBuilder
  private func primaryActions(for node: CatalogTreeNode) -> some View {
    Button(
      activation.pendingTargetID == nodeID
        ? String(localized: "激活中…", table: "ServerDetails")
        : String(localized: "激活", table: "ServerDetails"),
      systemImage: "bolt.fill"
    ) {
      Task { @MainActor in
        do {
          _ = try await activation.activate(nodeID, via: workflow)
        } catch {
          // 激活状态记录失败，详情在 feedback 区域显示结果。
        }
      }
    }
    .disabled(!(eligibility?.canActivate ?? false) || activation.isPending)
    if let subscription = subscriptionSummary(for: node) {
      Button(
        workflow.refreshingSubscriptionIDs.contains(subscription.id)
          ? String(localized: "更新中…", table: "ServerDetails")
          : String(localized: "更新", table: "ServerDetails"),
        systemImage: "arrow.clockwise"
      ) {
        Task { await workflow.refreshSubscription(subscription.id) }
      }
      .disabled(workflow.refreshingSubscriptionIDs.contains(subscription.id))
    }
  }

  private func presentation(for node: CatalogTreeNode) -> NodeDetailPresentation {
    let server = node.isGroup ? nil : workflow.serverDetailPresentation(for: nodeID)
    let subscription = subscriptionSummary(for: node)
    var detail = NodeDetailPresentation(
      node: node, server: server, eligibility: eligibility, isActiveTarget: isActiveTarget,
      containsActiveTarget: containsActiveTarget,
      subscription: subscription, locale: locale, timeZone: timeZone)
    if let server, server.plugin.selection != .none {
      if parameters.failure != nil {
        detail.appendPluginParameterFailure()
      } else {
        detail.appendPluginParameters(parameters.options.rawText)
      }
    }
    return detail
  }

  private func subscriptionSummary(for node: CatalogTreeNode) -> SubscriptionSummary? {
    guard node.isRootSubscriptionGroup else { return nil }
    return workflow.subscriptions.first { $0.groupID == node.id }
  }
}

/// 只观察测试资料并生成属性；布局由通用节点详情负责。
private struct ObservedConnectivityProperties<Content: View>: View {
  @Environment(\.locale) private var locale
  @Environment(\.timeZone) private var timeZone
  @ObservedObject var module: ServerConnectivity
  let node: CatalogTreeNode
  let serverName: (NodeID) -> String
  @ViewBuilder let content: (NodeDetailPresentation.Properties) -> Content

  var body: some View {
    if node.isGroup {
      TimelineView(.periodic(from: .now, by: 1)) { context in
        content(
          NodeDetailPresentation.connectivitySummary(
            module.summary(for: node.connectivityServerIDs, at: context.date),
            serverName: serverName, locale: locale, timeZone: timeZone))
      }
    } else {
      content(
        NodeDetailPresentation.connectivityHistory(
          module.history(for: node.id), locale: locale, timeZone: timeZone))
    }
  }
}