import SwiftUI

struct SettingsView: View {
  @StateObject private var model: SettingsViewModel
  @ObservedObject private var themeStore = ThemeStore.shared
  @State private var showsClearDialog = false

  init(model: SettingsViewModel? = nil) {
    _model = StateObject(wrappedValue: model ?? DefaultContainer.makeSettingsModel())
  }

  var body: some View {
    ScrollView {
      LazyVStack(spacing: 12) {
        if let errorMessage = model.errorMessage {
          AIStatusBanner(
            errorMessage, tint: AITheme.danger, systemImage: "exclamationmark.triangle")
        }
        if let notice = model.notice {
          AIStatusBanner(notice, tint: AITheme.success, systemImage: "checkmark.circle")
        }

        runtimeCard
        themeCard
        storageCard
        securityCard
        dangerZoneCard
      }
      .padding(16)
      .padding(.bottom, 8)
    }
    .background(AITheme.canvas.ignoresSafeArea())
    .navigationTitle("设置")
    .toolbar {
      ToolbarItemGroup(placement: .primaryAction) {
        AIToolbarButton(
          "刷新",
          systemImage: "arrow.clockwise",
          kind: .primary
        ) {
          Task { await model.refresh() }
        }
        .disabled(model.isLoading)
      }
    }
    .refreshable {
      await model.refresh()
    }
    .confirmationDialog(
      "确认清除运行日志？此操作不可恢复。",
      isPresented: $showsClearDialog,
      titleVisibility: .visible
    ) {
      Button("清除运行日志", role: .destructive) {
        Task { await model.clearRuntimeLogs() }
      }
      Button("取消", role: .cancel) {}
    }
    .task {
      await model.refresh()
    }
  }

  private var runtimeCard: some View {
    AICard {
      VStack(alignment: .leading, spacing: 12) {
        AISectionTitle("应用信息", systemImage: "info.circle")
        if let runtime = model.runtime {
          AIKeyValueRow("版本", value: "\(runtime.marketingVersion) (\(runtime.buildVersion))")
          AIKeyValueRow("设备", value: runtime.deviceModel)
        } else {
          Text("正在读取应用信息…")
            .font(.subheadline)
            .foregroundStyle(AITheme.muted)
        }
      }
    }
  }

  private var themeCard: some View {
    AICard {
      VStack(alignment: .leading, spacing: 12) {
        AISectionTitle("外观", systemImage: "circle.lefthalf.filled", detail: themeStore.mode.label)
        AISegmentedControl(
          "主题模式",
          selection: Binding(
            get: { themeStore.mode },
            set: { themeStore.set($0) }
          ),
          options: ThemeMode.allCases.map { (value: $0, title: $0.label) }
        )
      }
    }
  }

  private var storageCard: some View {
    AICard {
      NavigationLink {
        LogsView()
      } label: {
        VStack(alignment: .leading, spacing: 12) {
          HStack(spacing: 10) {
            AISectionTitle("本地数据", systemImage: "externaldrive")
              .frame(maxWidth: .infinity, alignment: .leading)
            Image(systemName: "chevron.right")
              .font(.footnote.weight(.semibold))
              .foregroundStyle(AITheme.muted)
              .accessibilityHidden(true)
          }
          AIKeyValueRow("数据位置", value: "仅保存在本机设备")
          AIKeyValueRow("当前占用", value: model.storageLabel)
        }
      }
      .buttonStyle(.plain)
      .accessibilityHint("进入日志与诊断")
    }
  }

  private var securityCard: some View {
    AICard {
      VStack(alignment: .leading, spacing: 12) {
        AISectionTitle("隐私与数据", systemImage: "lock.shield")
        AIKeyValueRow("节点信息", value: "仅保存在本机设备")
        AIKeyValueRow("实例密码", value: "保存在本地数据文件中")
        AIKeyValueRow("登录会话", value: "应用关闭后自动清除")
        AIStatusBanner(
          "节点地址、实例密码和运行数据都保存在本机。应用只连接你添加的节点，登录会话关闭应用后即被清除。",
          tint: AITheme.primary,
          systemImage: "shield.checkered"
        )
      }
    }
  }

  private var dangerZoneCard: some View {
    AICard {
      VStack(alignment: .leading, spacing: 12) {
        AISectionTitle("数据清理", systemImage: "trash.square", detail: "不可恢复")
        Button {
          showsClearDialog = true
        } label: {
          Label("清除运行日志", systemImage: "trash")
        }
        .buttonStyle(AIButtonStyle(kind: .danger, size: .regular, fillsWidth: true))
      }
    }
  }
}