import SwiftUI

struct SettingsView: View {
    @ObservedObject var setup: SetupCoordinator
    @ObservedObject var actions: LocationActionCoordinator
    @ObservedObject private var proxy = ProxyManager.shared
    @ObservedObject private var runtimeMode = ProxyRuntimeModeStore.shared
    @ObservedObject private var thirdPartyProxy = ThirdPartyProxyManager.shared
    @ObservedObject private var thirdPartyClient = ThirdPartyProxyClientStore.shared
    @ObservedObject private var motionSimulation = MotionSimulationStore.shared
    @ObservedObject private var moduleSource = ThirdPartyModuleSourceStore.shared
    @Environment(\.dismiss) private var dismiss
    @State private var activeTip: TipKind?
    @State private var proxyOperationError = ""
    @State private var proxyOperationAlertTitle = "代理操作失败"
    @State private var modeOperationRunning = false
    @State private var copiedClient: ThirdPartyProxyClient?
    @State private var showCertificateResetConfirmation = false
    @State private var githubDestination: SafariDestination?

    var body: some View {
        Form {
            Section("运行模式") {
                Picker("模式", selection: runtimeModeBinding) {
                    ForEach(ProxyRuntimeMode.allCases) { mode in
                        Text(mode.displayName).tag(mode)
                    }
                }
                .pickerStyle(.inline)
                .disabled(modeOperationRunning || actions.state.isBusy || thirdPartyProxy.isRequesting)

            }

            Section("状态") {
                if runtimeMode.mode == .localWiFi {
                    HStack {
                        Label("本机代理", systemImage: proxy.isRunning ? "play.circle.fill" : "stop.circle")
                        Spacer()
                        Toggle("", isOn: proxyBinding).labelsHidden()
                            .tint(.blue)
                            .disabled(actions.state.isBusy)
                    }
                } else {
                    HStack {
                        Label("第三方模块", systemImage: thirdPartyStatusIcon)
                        Spacer()
                        Text(thirdPartyStatusText).foregroundStyle(.secondary)
                    }
                    Button {
                        detectThirdPartyConnection()
                    } label: {
                        if thirdPartyProxy.isRequesting {
                            HStack { ProgressView(); Text("正在检测…") }
                        } else {
                            Label("检测连接", systemImage: "network")
                        }
                    }
                    .disabled(thirdPartyProxy.isRequesting)
                }
                HStack {
                    Label("虚拟定位", systemImage: virtualLocationIsActive ? "location.fill" : "location.slash")
                    Spacer()
                    Text(virtualLocationStatusText).foregroundStyle(.secondary)
                }
            }

            Section("定位模拟") {
                Toggle("运动状态模拟", isOn: motionSimulationBinding)
                    .disabled(modeOperationRunning || actions.state.isBusy || thirdPartyProxy.isRequesting)
                Text("实验性功能，默认关闭。开启后会同时模拟定位响应中的运动状态。")
                    .font(.footnote)
                    .foregroundStyle(.secondary)
            }

            if runtimeMode.mode == .thirdParty {
                thirdPartyConfigurationSection
            } else {
                Section("说明") {
                    Button {
                        activeTip = .activation
                    } label: {
                        Label("生效说明", systemImage: "checklist")
                    }
                    Button {
                        activeTip = .deactivation
                    } label: {
                        Label("失效说明", systemImage: "arrow.uturn.backward.circle")
                    }
                    Button {
                        activeTip = .removeProxy
                    } label: {
                        Label("关闭 WiFi 代理", systemImage: "wifi.slash")
                    }
                }

            }

            Section("工作原理") {
                Text(workflowDescription)
                .font(.footnote)
                .foregroundStyle(.secondary)
            }

            Section("应用") {
                if runtimeMode.mode == .localWiFi {
                    Button {
                        setup.requestSetup()
                    } label: {
                        Label("进入引导页", systemImage: "arrow.clockwise.circle")
                    }
                }
                valueRow("版本", value: versionText)
            }

            if runtimeMode.mode == .localWiFi {
                Section("证书") {
                    Button(role: .destructive) {
                        showCertificateResetConfirmation = true
                    } label: {
                        Label("重置证书", systemImage: "arrow.clockwise.circle")
                    }
                    .disabled(modeOperationRunning || actions.state.isBusy)

                    Text("仅删除 App 钥匙串中的设备 CA。iOS 中已经安装的旧证书需要在系统设置里手动移除。")
                        .font(.footnote)
                        .foregroundStyle(.secondary)
                }
            }

            Section("支持") {
                NavigationLink {
                    BugReportView(setup: setup)
                } label: {
                    Label("报告 Bug", systemImage: "ladybug")
                }

                Button {
                    githubDestination = SafariDestination(url: GitHubSubmission.usageHelpURL)
                } label: {
                    Label("使用帮助", systemImage: "questionmark.circle")
                }

                Button {
                    githubDestination = SafariDestination(url: GitHubSubmission.featureRequestURL)
                } label: {
                    Label("功能建议", systemImage: "lightbulb")
                }

                if runtimeMode.mode == .thirdParty {
                    Button {
                        UIPasteboard.general.string = GitHubSubmission.communityContributionTemplate(
                            for: thirdPartyClient.selectedClient,
                            systemVersion: UIDevice.current.systemVersion
                        )
                        githubDestination = SafariDestination(
                            url: GitHubSubmission.communityContributionURL
                        )
                    } label: {
                        Label("分享第三方配置", systemImage: "square.and.arrow.up")
                    }
                }
            }

            Section("关于") {
                Button {
                    if let url = URL(string: "https://github.com/xweiba/location-spoofer") {
                        UIApplication.shared.open(url)
                    }
                } label: {
                    Label("xweiba/location-spoofer", systemImage: "link")
                }
                Text("如果觉得好用，欢迎去 GitHub 给项目点个 Star")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
            }

            Section("致谢") {
                Button {
                    if let url = URL(string: "https://github.com/Yu9191/wloc") {
                        UIApplication.shared.open(url)
                    }
                } label: {
                    Label("核心定位改写逻辑移植自 Yu9191/wloc", systemImage: "heart.fill")
                        .foregroundStyle(.pink)
                }
            }
        }
        .navigationTitle("设置")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) { Button("完成") { dismiss() } }
        }
        .sheet(item: $activeTip) { kind in
            TipSheetView(kind: kind)
        }
        .sheet(item: $githubDestination) { destination in
            SafariView(url: destination.url)
                .ignoresSafeArea()
        }
        .alert(proxyOperationAlertTitle, isPresented: Binding(
            get: { !proxyOperationError.isEmpty },
            set: { if !$0 { proxyOperationError = "" } }
        )) {
            Button("知道了", role: .cancel) {}
        } message: {
            Text(proxyOperationError)
        }
        .confirmationDialog(
            "重置证书？",
            isPresented: $showCertificateResetConfirmation,
            titleVisibility: .visible
        ) {
            Button("重置并生成新证书", role: .destructive) {
                resetCertificateAuthority()
            }
            Button("取消", role: .cancel) {}
        } message: {
            Text("当前虚拟定位和本地代理将停止。App 会删除钥匙串中的设备 CA、立即生成新证书，并打开安装与信任引导。你还需要前往 iOS「设置 → 通用 → VPN 与设备管理」手动删除旧证书，然后重新下载安装并完全信任新证书。")
        }
    }

    private func valueRow(_ title: String, value: String) -> some View {
        HStack { Text(title); Spacer(); Text(value).font(.footnote.monospaced()).foregroundStyle(.secondary) }
    }

    private var versionText: String {
        let v = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "?"
        let b = Bundle.main.object(forInfoDictionaryKey: "CFBundleVersion") as? String ?? "?"
        return "\(v) (\(b))"
    }

    private var proxyBinding: Binding<Bool> {
        Binding(get: { proxy.isRunning }, set: { on in
            Task {
                if on {
                    do {
                        try await proxy.start()
                    } catch {
                        proxy.error = error.localizedDescription
                        proxyOperationAlertTitle = "代理操作失败"
                        proxyOperationError = error.localizedDescription
                    }
                } else {
                    if actions.virtualLocationEnabled {
                        actions.clear()
                        RuntimeLogger.info("APP", "Settings", "关闭代理前已同步关闭虚拟定位")
                    }
                    proxy.stop()
                }
            }
        })
    }

    private var runtimeModeBinding: Binding<ProxyRuntimeMode> {
        Binding(
            get: { runtimeMode.mode },
            set: { newMode in switchRuntimeMode(to: newMode) }
        )
    }

    private var motionSimulationBinding: Binding<Bool> {
        Binding(
            get: { motionSimulation.isEnabled },
            set: { enabled in
                if runtimeMode.mode == .localWiFi {
                    proxy.applyMotionSimulation(enabled)
                    return
                }
                guard thirdPartyProxy.activeSettings?.success == true else {
                    motionSimulation.setEnabled(enabled)
                    return
                }
                modeOperationRunning = true
                Task { @MainActor in
                    do {
                        _ = try await thirdPartyProxy.updateMotionSimulation(enabled)
                        motionSimulation.setEnabled(enabled)
                    } catch {
                        RuntimeLogger.error(
                            "APP",
                            "ThirdPartyProxy",
                            "同步运动状态设置失败",
                            error: error,
                            details: ["当前客户端": thirdPartyClient.selectedClient.name]
                        )
                        setup.requestThirdPartySetup(message: error.localizedDescription)
                    }
                    modeOperationRunning = false
                }
            }
        )
    }

    @ViewBuilder
    private var thirdPartyConfigurationSection: some View {
        Section("第三方代理配置") {
            Picker("客户端", selection: Binding(
                get: { thirdPartyClient.selectedClient },
                set: { thirdPartyClient.select($0) }
            )) {
                ForEach(ThirdPartyProxyClient.allCases) { client in
                    Text(client.name).tag(client)
                }
            }

            Toggle("使用国内镜像下载模块", isOn: Binding(
                get: { moduleSource.useMirror },
                set: { moduleSource.setUseMirror($0) }
            ))
            Text("仅影响之后复制和重新导入的模块地址；已安装模块需要重新导入后切换来源。")
                .font(.footnote)
                .foregroundStyle(.secondary)

            if let verificationText = thirdPartyClient.selectedClient.verificationText {
                HStack {
                    Text("验证状态")
                    Spacer()
                    Text(verificationText)
                        .font(.footnote)
                        .foregroundStyle(.orange)
                }
            }

            Button {
                UIPasteboard.general.string = thirdPartyClient.selectedClient.subscriptionURL.absoluteString
                copiedClient = thirdPartyClient.selectedClient
            } label: {
                Label(copiedClient == thirdPartyClient.selectedClient ? "已复制模块订阅地址" : "复制模块订阅地址", systemImage: "doc.on.doc")
            }

            Button {
                openThirdPartyClient(thirdPartyClient.selectedClient)
            } label: {
                Label("打开 \(thirdPartyClient.selectedClient.name)", systemImage: "arrow.up.forward.app")
            }

            Button {
                setup.requestThirdPartyOnboarding()
                dismiss()
            } label: {
                Label("重新打开配置引导", systemImage: "arrow.clockwise.circle")
            }

            if thirdPartyClient.selectedClient == .egern {
                Text("Egern 直接使用 Surge 的 .sgmodule 模块。")
                    .font(.footnote).foregroundStyle(.secondary)
            } else if thirdPartyClient.selectedClient == .stash {
                Text("Stash 直接订阅 .stoverride，不要通过 Script Hub 转换。")
                    .font(.footnote).foregroundStyle(.secondary)
            }

            Text("复制模块订阅地址后，在对应代理客户端中添加模块/重写订阅，并启用 MITM。第三方客户端保存坐标后，即使关闭本 App，坐标仍由代理客户端持久化并继续生效。")
                .font(.footnote).foregroundStyle(.secondary)
        }
    }

    private var thirdPartyStatusIcon: String {
        switch thirdPartyProxy.connectionState {
        case .unknown: return "questionmark.circle"
        case .connected: return "checkmark.circle.fill"
        case .failed: return "xmark.circle.fill"
        }
    }

    private var thirdPartyStatusText: String {
        switch thirdPartyProxy.connectionState {
        case .unknown: return "未检测"
        case .connected(let active): return active ? "已连接，有坐标" : "已连接，无坐标"
        case .failed: return "连接失败"
        }
    }

    private var virtualLocationStatusText: String {
        if runtimeMode.mode == .localWiFi {
            return actions.virtualLocationEnabled ? "已开启" : "已关闭"
        }
        if case .connected(let active) = thirdPartyProxy.connectionState {
            return active ? "第三方已保存" : "未保存"
        }
        return "未知"
    }

    private var workflowDescription: String {
        if runtimeMode.mode == .thirdParty {
            return "App 只负责地图选点、收藏和发送 WGS-84 坐标。第三方代理客户端通过模块拦截 Apple WLOC 请求并持久化当前坐标；本模式不启动本机代理，不使用 App 的 CA，也不需要配置 127.0.0.1:8888。"
        }
        return """
        App 在设备本地运行一个代理服务器（127.0.0.1:8888）。

        通过 WiFi 手动代理配置，让系统的定位请求（gs-loc.apple.com/clls/wloc）经过这个本地代理。代理使用已安装的 CA 证书对 HTTPS 流量做中间人解密，把 Apple 返回的定位坐标改写为你设置的虚拟坐标，再加密返回给系统，从而实现虚拟定位。
        """
    }

    private func switchRuntimeMode(to newMode: ProxyRuntimeMode) {
        guard newMode != runtimeMode.mode, !modeOperationRunning else { return }
        modeOperationRunning = true
        Task { @MainActor in
            defer { modeOperationRunning = false }
            switch newMode {
            case .thirdParty:
                if actions.virtualLocationEnabled { actions.clear() }
                proxy.stop()
                setup.completeSetup()
                runtimeMode.setMode(.thirdParty)
                if runtimeMode.isInitialized(.thirdParty) {
                    do {
                        _ = try await thirdPartyProxy.validateVersion()
                        _ = try await thirdPartyProxy.query()
                        proxyOperationAlertTitle = "模式已切换"
                        proxyOperationError = "第三方代理模式检测通过。请关闭 Wi-Fi 中的 127.0.0.1:8888 手动代理，避免双重拦截。"
                    } catch {
                        openThirdPartySetup(for: error)
                    }
                } else {
                    setup.requestThirdPartyOnboarding()
                    dismiss()
                }
            case .localWiFi:
                do {
                    try await thirdPartyProxy.clear()
                } catch {
                    RuntimeLogger.warning("APP", "Mode", "切换 APP 模式前无法清除第三方坐标", details: [
                        "错误": error.localizedDescription
                    ])
                }
                runtimeMode.setMode(.localWiFi)
                await setup.prepareLocalServices()
                if runtimeMode.isInitialized(.localWiFi) {
                    let result = await setup.runVerificationTest()
                    setup.applyVerificationResult(result)
                    if result.isSuccess {
                        proxyOperationAlertTitle = "模式已切换"
                        proxyOperationError = "APP 模式环境检测通过。请停用第三方 WLOC 模块或代理连接，避免双重拦截。"
                    } else {
                        dismiss()
                    }
                } else {
                    setup.requestSetup()
                    dismiss()
                }
            }
        }
    }

    private func detectThirdPartyConnection() {
        let client = thirdPartyClient.selectedClient
        let startedAt = Date()
        Task { @MainActor in
            do {
                _ = try await thirdPartyProxy.validateVersion()
                _ = try await thirdPartyProxy.query()
                RuntimeLogger.info("APP", "ThirdPartyProxy", "设置页第三方连接检测通过", details: [
                    "当前客户端": client.name,
                    "请求动作": "WLOC query",
                    "耗时毫秒": String(Int(Date().timeIntervalSince(startedAt) * 1_000))
                ])
                runtimeMode.markInitialized(.thirdParty)
            } catch {
                RuntimeLogger.error(
                    "APP",
                    "ThirdPartyProxy",
                    "设置页第三方连接检测失败",
                    error: error,
                    details: [
                        "当前客户端": client.name,
                        "请求动作": "WLOC query",
                        "连接状态": String(describing: thirdPartyProxy.connectionState),
                        "耗时毫秒": String(Int(Date().timeIntervalSince(startedAt) * 1_000)),
                        "处理建议": "检查模块、MITM、证书和代理/VPN连接"
                    ]
                )
                openThirdPartySetup(for: error)
            }
        }
    }

    private func openThirdPartySetup(for error: Error) {
        setup.requestThirdPartySetup(message: error.localizedDescription)
        dismiss()
    }

    private func resetCertificateAuthority() {
        guard runtimeMode.mode == .localWiFi, !modeOperationRunning else { return }
        modeOperationRunning = true
        Task { @MainActor in
            defer { modeOperationRunning = false }
            if actions.virtualLocationEnabled {
                actions.clear()
            }
            proxy.stop()
            do {
                try setup.certificateStore.reset()
                runtimeMode.resetInitialization(.localWiFi)
                guard await setup.prepareLocalServices() else {
                    proxyOperationAlertTitle = "证书重置失败"
                    proxyOperationError = setup.message
                    return
                }
                setup.requestCertificateSetup()
                dismiss()
            } catch {
                proxyOperationAlertTitle = "证书重置失败"
                proxyOperationError = error.localizedDescription
            }
        }
    }

    private func openThirdPartyClient(_ client: ThirdPartyProxyClient) {
        guard let url = client.launchURL else { return }
        UIApplication.shared.open(url, options: [:]) { opened in
            guard !opened else { return }
            Task { @MainActor in
                proxyOperationAlertTitle = "无法打开客户端"
                proxyOperationError = "无法打开 \(client.name)，请确认客户端已安装后手动打开。"
            }
        }
    }

    private var virtualLocationIsActive: Bool {
        if runtimeMode.mode == .localWiFi {
            return actions.virtualLocationEnabled
        }
        if case .connected(let active) = thirdPartyProxy.connectionState {
            return active
        }
        return false
    }
}