import SwiftUI

struct SettingsView: View {
    @StateObject private var model: SettingsViewModel
    @State private var showsClearDialog = false

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

    var body: some View {
        ZStack {
            AITheme.canvas.ignoresSafeArea()
            ScrollView {
                LazyVStack(spacing: 12) {
                    if let errorMessage = model.errorMessage {
                        AICard {
                            Text(errorMessage)
                                .font(.subheadline)
                                .foregroundStyle(AITheme.danger)
                        }
                    }
                    if let notice = model.notice {
                        AICard {
                            Text(notice)
                                .font(.subheadline)
                                .foregroundStyle(AITheme.success)
                        }
                    }

                    runtimeCard
                    storageCard
                    securityCard
                    backgroundCard
                }
                .padding(16)
            }
        }
        .navigationTitle("设置")
        .toolbar {
            ToolbarItemGroup(placement: .primaryAction) {
                Button {
                    Task { await model.refresh() }
                } label: {
                    Label("刷新", systemImage: "arrow.clockwise")
                }
                .buttonStyle(AIButtonStyle(kind: .secondary, size: .regular))
                .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) {
                sectionTitle("应用信息", systemImage: "info.circle")
                if let runtime = model.runtime {
                    infoRow("名称", runtime.appName)
                    infoRow("版本", "\(runtime.marketingVersion) (\(runtime.buildVersion))")
                    infoRow("标识符", AppMetadata.bundleIdentifier)
                    infoRow("设备", "\(runtime.platform) · \(runtime.deviceModel)")
                } else {
                    Text("正在读取应用信息…")
                        .font(.subheadline)
                        .foregroundStyle(AITheme.muted)
                }
            }
        }
    }

    private var storageCard: some View {
        AICard {
            VStack(alignment: .leading, spacing: 12) {
                sectionTitle("本地数据", systemImage: "externaldrive")
                infoRow("实例配置", "App Documents/instances.json")
                infoRow("日志中心", "App Documents/log-center.json")
                infoRow("日志数量", model.storageLabel)
                Button {
                    showsClearDialog = true
                } label: {
                    Label("清除运行日志", systemImage: "trash")
                }
                .buttonStyle(AIButtonStyle(kind: .danger, size: .regular))
            }
        }
    }

    private var securityCard: some View {
        AICard {
            VStack(alignment: .leading, spacing: 12) {
                sectionTitle("安全与登录", systemImage: "lock.shield")
                infoRow("实例密码", "保存在 iOS 钥匙串")
                infoRow("登录会话", "仅保存在内存")
                infoRow("访问密码", "已停用")
            }
        }
    }

    private var backgroundCard: some View {
        AICard {
            VStack(alignment: .leading, spacing: 12) {
                sectionTitle("后台能力", systemImage: "clock.badge.exclamationmark")
                Text(model.serverCapabilitiesNotice)
                    .font(.subheadline)
                    .foregroundStyle(AITheme.muted)
                if model.serverCapabilities.isEmpty {
                    AITag("无后台任务", tint: AITheme.muted)
                } else {
                    ForEach(model.serverCapabilities) { capability in
                        infoRow(capability.name, capability.detail)
                    }
                }
            }
        }
    }

    private func sectionTitle(_ title: String, systemImage: String) -> some View {
        HStack(spacing: 8) {
            Image(systemName: systemImage)
                .foregroundStyle(AITheme.primary)
            Text(title)
                .font(.headline.weight(.bold))
            Spacer()
        }
    }

    private func infoRow(_ title: String, _ value: String) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            Text(title)
                .font(.caption)
                .foregroundStyle(AITheme.muted)
            Text(value)
                .font(.subheadline)
                .frame(maxWidth: .infinity, alignment: .leading)
                .textSelection(.enabled)
        }
    }
}