// Build with the Windows .NET Framework C# compiler; no third-party UI packages.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Web.Script.Serialization;
using System.Windows.Forms;

namespace EchoEarFlasher
{
    internal static class Program
    {
        [STAThread]
        private static int Main(string[] args)
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            bool offline = args.Length == 2 && (args[0] == "--render-preview" || args[0] == "--ui-smoke-test");
            using (FlashForm form = new FlashForm(offline))
            {
                if (offline)
                {
                    if (args[0] == "--render-preview") form.RenderPreview(args[1]);
                    else return form.RunSmokeTest(args[1]);
                    return 0;
                }
                if (args.Length != 0) return 2;
                Application.Run(form);
            }
            return 0;
        }
    }

    internal sealed class PortItem
    {
        internal string Port;
        internal string Description;
        internal bool Known;
        public override string ToString() { return Port + "  ·  " + Description; }
    }

    internal sealed class BridgeResult
    {
        internal int ExitCode;
        internal Dictionary<string, object> Payload;
        internal string Error;
    }

    internal sealed class FlashForm : Form
    {
        private static readonly Color Navy = Color.FromArgb(21, 40, 65);
        private static readonly Color Teal = Color.FromArgb(0, 126, 128);
        private static readonly Color TextColor = Color.FromArgb(35, 51, 69);
        private static readonly Color Muted = Color.FromArgb(106, 122, 137);
        private static readonly Color Line = Color.FromArgb(224, 233, 238);
        private const string KnownMac = "B4:3A:45:16:34:A8";
        private const string AdminUrl = "https://82.157.201.114/maintenance?area=devices";
        private readonly bool offline;
        private readonly JavaScriptSerializer json = new JavaScriptSerializer();
        private readonly List<Control> inputs = new List<Control>();
        private readonly List<Panel> cards = new List<Panel>();
        private string bridgePath;
        private string sessionFile;
        private string lastBackup;
        private Dictionary<string, object> previewSummary;
        private bool busy;
        private bool loading;
        private Panel workspace;
        private FlowLayoutPanel stack;
        private Panel advancedCard;
        private TextBox credential;
        private TextBox mac;
        private TextBox build;
        private TextBox python;
        private TextBox output;
        private ComboBox ports;
        private RadioButton identity;
        private RadioButton full;
        private CheckBox acknowledged;
        private Button refresh;
        private Button previewButton;
        private Button flashButton;
        private Button advancedToggle;
        private Button backupButton;
        private Label sidebarPort;
        private Label sidebarStage;
        private Label stageDetail;
        private Label status;
        private Label summaryLine;
        private Label summaryPlatform;
        private Label summaryFirmware;
        private Label previewBadge;
        private RichTextBox log;
        private DataGridView regions;
        private ProgressBar progress;

        internal FlashForm(bool offlineMode)
        {
            offline = offlineMode;
            loading = true;
            Text = "EchoEar 设备烧录助手";
            Font = new Font("Microsoft YaHei UI", 9F);
            BackColor = Color.FromArgb(242, 246, 249);
            ForeColor = TextColor;
            ClientSize = new Size(1120, 838);
            MinimumSize = new Size(920, 650);
            StartPosition = FormStartPosition.CenterScreen;
            AutoScaleMode = AutoScaleMode.Dpi;
            BuildSidebar();
            workspace = new Panel { Dock = DockStyle.Fill, Padding = new Padding(24, 20, 18, 14) };
            Controls.Add(workspace);
            workspace.BringToFront();
            Panel heading = new Panel { Dock = DockStyle.Top, Height = 74 };
            heading.Controls.Add(LabelAt("设备初始化与固件烧录", 0, 0, 730, 34, 21, Navy, true));
            heading.Controls.Add(LabelAt("导入后台烧录信息，确认设备身份，再备份和写入。", 1, 41, 730, 25, 10, Muted, false));
            stack = new FlowLayoutPanel { Dock = DockStyle.Fill, FlowDirection = FlowDirection.TopDown, WrapContents = false, AutoScroll = true, Padding = new Padding(0, 3, 2, 8) };
            workspace.Controls.Add(stack);
            workspace.Controls.Add(heading);
            BuildConfiguration();
            BuildAdvanced();
            BuildPreview();
            BuildExecution();
            FindDefaults();
            WireChanges();
            loading = false;
            Resize += delegate { ResizeCards(); };
            Shown += async delegate { ResizeCards(); if (!offline) await RefreshPorts(); };
            FormClosing += delegate(object sender, FormClosingEventArgs e) {
                if (busy) { e.Cancel = true; SetStatus("操作正在进行，请等待结束后关闭窗口。", false); }
            };
            ResizeCards();
            UpdateActions();
        }

        private Label LabelAt(string text, int x, int y, int width, int height, float size, Color color, bool bold)
        {
            return new Label { Text = text, Location = new Point(x, y), Size = new Size(width, height), Font = new Font("Microsoft YaHei UI", size, bold ? FontStyle.Bold : FontStyle.Regular), ForeColor = color, AutoEllipsis = true, TextAlign = ContentAlignment.MiddleLeft };
        }

        private Button ButtonAt(string text, int x, int y, int width, bool primary)
        {
            Button button = new Button { Text = text, Location = new Point(x, y), Size = new Size(width, 34), FlatStyle = FlatStyle.Flat, BackColor = primary ? Teal : Color.White, ForeColor = primary ? Color.White : TextColor, Cursor = Cursors.Hand, UseVisualStyleBackColor = false };
            button.FlatAppearance.BorderColor = primary ? Teal : Line;
            button.FlatAppearance.BorderSize = 1;
            return button;
        }

        private TextBox InputAt(Panel parent, int x, int y, int width)
        {
            TextBox input = new TextBox { Location = new Point(x, y), Width = width, BorderStyle = BorderStyle.FixedSingle, Font = new Font("Microsoft YaHei UI", 9.5F), BackColor = Color.White, Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right };
            parent.Controls.Add(input);
            inputs.Add(input);
            return input;
        }

        private Panel Card(int height)
        {
            Panel panel = new Panel { BackColor = Color.White, Height = height, Width = 816, Margin = new Padding(0, 0, 0, 12) };
            panel.Paint += delegate(object sender, PaintEventArgs e) { using (Pen p = new Pen(Line)) e.Graphics.DrawRectangle(p, 0, 0, panel.Width - 1, panel.Height - 1); };
            cards.Add(panel);
            stack.Controls.Add(panel);
            return panel;
        }

        private void BuildSidebar()
        {
            Panel side = new Panel { Dock = DockStyle.Left, Width = 222, Height = ClientSize.Height, BackColor = Navy };
            side.Controls.Add(LabelAt("ECHOEAR", 24, 27, 176, 32, 22, Color.White, true));
            side.Controls.Add(LabelAt("设备烧录助手", 25, 69, 175, 24, 11, Color.FromArgb(177, 204, 221), false));
            Panel accent = new Panel { BackColor = Color.FromArgb(54, 196, 182), Location = new Point(25, 113), Size = new Size(37, 4) };
            side.Controls.Add(accent);
            side.Controls.Add(LabelAt("当前设备", 25, 149, 172, 24, 9, Color.FromArgb(161, 181, 201), false));
            side.Controls.Add(LabelAt("EchoEar S3", 25, 176, 174, 30, 17, Color.White, true));
            side.Controls.Add(LabelAt("ESP32-S3  /  16 MB", 25, 210, 176, 28, 10, Color.FromArgb(205, 220, 232), false));
            sidebarPort = LabelAt("串口  ·  尚未选择", 25, 247, 176, 28, 10, Color.FromArgb(87, 216, 198), true);
            side.Controls.Add(sidebarPort);
            side.Controls.Add(LabelAt("操作状态", 25, 314, 172, 24, 9, Color.FromArgb(161, 181, 201), false));
            sidebarStage = LabelAt("等待导入", 25, 345, 174, 32, 17, Color.White, true);
            side.Controls.Add(sidebarStage);
            stageDetail = LabelAt("选择后台下载的 JSON\n然后检查并生成预览。", 25, 387, 172, 76, 10, Color.FromArgb(205, 220, 232), false);
            stageDetail.AutoEllipsis = false;
            side.Controls.Add(stageDetail);
            Label flow = LabelAt("01  导入与检查\n\n02  备份与写入\n\n03  重启与配网", 25, 503, 173, 136, 10, Color.FromArgb(178, 201, 218), false);
            side.Controls.Add(flow);
            Button admin = ButtonAt("打开设备管理后台  ↗", 24, 700, 174, false);
            admin.Anchor = AnchorStyles.Left | AnchorStyles.Bottom;
            admin.BackColor = Color.FromArgb(31, 57, 82);
            admin.ForeColor = Color.White;
            admin.FlatAppearance.BorderColor = Color.FromArgb(57, 80, 101);
            admin.Location = new Point(24, ClientSize.Height - 97);
            admin.Click += delegate { OpenTarget(AdminUrl); };
            side.Controls.Add(admin);
            Label foot = LabelAt("本地操作 · 密钥不显示", 25, ClientSize.Height - 50, 175, 24, 9, Color.FromArgb(161, 181, 201), false);
            foot.Anchor = AnchorStyles.Left | AnchorStyles.Bottom;
            side.Controls.Add(foot);
            Controls.Add(side);
        }

        private void BuildConfiguration()
        {
            Panel card = Card(213);
            card.Controls.Add(LabelAt("1  选择烧录内容", 18, 11, 350, 27, 12, Navy, true));
            identity = new RadioButton { Text = "重新初始化（保留固件）", Checked = true, Location = new Point(19, 47), Size = new Size(235, 28) };
            full = new RadioButton { Text = "完整固件 + 初始化", Location = new Point(272, 47), Size = new Size(224, 28) };
            inputs.Add(identity); inputs.Add(full);
            card.Controls.Add(identity); card.Controls.Add(full);
            card.Controls.Add(LabelAt("烧录信息", 19, 91, 80, 26, 9, Muted, false));
            credential = InputAt(card, 104, 93, 586);
            Button browse = ButtonAt("选择 JSON", 704, 88, 94, false);
            browse.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            browse.Click += delegate { ChooseFile(credential, "后台烧录信息 (*.json)|*.json", "选择后台下载的烧录信息 JSON"); };
            inputs.Add(browse); card.Controls.Add(browse);
            card.Controls.Add(LabelAt("设备串口", 19, 135, 80, 26, 9, Muted, false));
            ports = new ComboBox { Location = new Point(104, 136), Size = new Size(315, 28), DropDownStyle = ComboBoxStyle.DropDownList, Anchor = AnchorStyles.Top | AnchorStyles.Left };
            inputs.Add(ports); card.Controls.Add(ports);
            refresh = ButtonAt("刷新", 432, 131, 70, false);
            refresh.Click += async delegate { await RefreshPorts(); };
            inputs.Add(refresh); card.Controls.Add(refresh);
            card.Controls.Add(LabelAt("设备 MAC", 517, 135, 79, 26, 9, Muted, false));
            mac = InputAt(card, 600, 136, 197);
            mac.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right;
            mac.Text = KnownMac;
            card.Controls.Add(LabelAt("连接设备 USB；自动识别已知设备，其余串口请手动选择。", 104, 171, 682, 27, 9, Muted, false));
        }

        private void BuildAdvanced()
        {
            advancedCard = Card(39);
            advancedToggle = ButtonAt("▸  高级设置：固件目录、Python、备份位置", 10, 2, 510, false);
            advancedToggle.FlatAppearance.BorderSize = 0;
            advancedToggle.TextAlign = ContentAlignment.MiddleLeft;
            advancedToggle.Click += delegate {
                bool expanding = advancedCard.Height < 100;
                advancedCard.Height = expanding ? 188 : 39;
                advancedToggle.Text = (expanding ? "▾" : "▸") + "  高级设置：固件目录、Python、备份位置";
                ResizeCards();
            };
            inputs.Add(advancedToggle); advancedCard.Controls.Add(advancedToggle);
            advancedCard.Controls.Add(LabelAt("固件目录", 19, 48, 80, 26, 9, Muted, false));
            build = InputAt(advancedCard, 104, 50, 586);
            Button buildBrowse = ButtonAt("选择目录", 704, 45, 94, false);
            buildBrowse.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            buildBrowse.Click += delegate { ChooseFolder(build, "选择包含 flasher_args.json 的固件 build 目录"); };
            inputs.Add(buildBrowse); advancedCard.Controls.Add(buildBrowse);
            advancedCard.Controls.Add(LabelAt("Python", 19, 91, 80, 26, 9, Muted, false));
            python = InputAt(advancedCard, 104, 93, 586);
            Button pythonBrowse = ButtonAt("选择程序", 704, 88, 94, false);
            pythonBrowse.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            pythonBrowse.Click += delegate { ChooseFile(python, "Python 程序 (python.exe)|python.exe|应用程序 (*.exe)|*.exe", "选择已安装 esptool、pyserial 的 Python"); };
            inputs.Add(pythonBrowse); advancedCard.Controls.Add(pythonBrowse);
            advancedCard.Controls.Add(LabelAt("备份位置", 19, 134, 80, 26, 9, Muted, false));
            output = InputAt(advancedCard, 104, 136, 586);
            Button outputBrowse = ButtonAt("选择目录", 704, 131, 94, false);
            outputBrowse.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            outputBrowse.Click += delegate { ChooseFolder(output, "选择备份与初始化文件的保存位置"); };
            inputs.Add(outputBrowse); advancedCard.Controls.Add(outputBrowse);
        }

        private void BuildPreview()
        {
            Panel card = Card(231);
            card.Controls.Add(LabelAt("2  检查写入预览", 18, 10, 350, 28, 12, Navy, true));
            previewBadge = LabelAt("尚未生成", 669, 12, 128, 24, 9, Muted, true);
            previewBadge.TextAlign = ContentAlignment.MiddleRight;
            previewBadge.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            card.Controls.Add(previewBadge);
            summaryLine = LabelAt("设备编号  —    型号  —", 19, 44, 779, 24, 9, TextColor, false);
            summaryPlatform = LabelAt("平台地址  —", 19, 70, 779, 24, 9, Muted, false);
            summaryFirmware = LabelAt("固件  保留设备当前固件", 19, 96, 779, 24, 9, Teal, true);
            foreach (Label label in new[] { summaryLine, summaryPlatform, summaryFirmware }) { label.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right; card.Controls.Add(label); }
            regions = new DataGridView { Location = new Point(19, 128), Size = new Size(778, 83), Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right, BackgroundColor = Color.White, BorderStyle = BorderStyle.None, ReadOnly = true, AllowUserToAddRows = false, AllowUserToDeleteRows = false, AllowUserToResizeRows = false, RowHeadersVisible = false, AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill, SelectionMode = DataGridViewSelectionMode.FullRowSelect, CellBorderStyle = DataGridViewCellBorderStyle.SingleHorizontal, GridColor = Line, EnableHeadersVisualStyles = false, ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing, ColumnHeadersHeight = 27, MultiSelect = false };
            regions.ColumnHeadersDefaultCellStyle = new DataGridViewCellStyle { BackColor = Color.FromArgb(242, 246, 249), ForeColor = Muted, Font = new Font("Microsoft YaHei UI", 8.5F) };
            regions.DefaultCellStyle = new DataGridViewCellStyle { BackColor = Color.White, ForeColor = TextColor, SelectionBackColor = Color.FromArgb(225, 244, 241), SelectionForeColor = TextColor, Font = new Font("Microsoft YaHei UI", 8.5F), Padding = new Padding(2) };
            regions.RowTemplate.Height = 26;
            regions.Columns.Add("name", "写入区域"); regions.Columns.Add("offset", "起始地址"); regions.Columns.Add("size", "大小"); regions.Columns.Add("hash", "SHA-256 校验摘要");
            regions.Columns[0].FillWeight = 26; regions.Columns[1].FillWeight = 19; regions.Columns[2].FillWeight = 19; regions.Columns[3].FillWeight = 36;
            card.Controls.Add(regions);
        }

        private void BuildExecution()
        {
            Panel card = Card(239);
            acknowledged = new CheckBox { Text = "我已了解：会清除旧 Wi-Fi 和语音运行配置，完成后需重新配网。", Location = new Point(19, 12), Size = new Size(775, 29), Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right };
            acknowledged.CheckedChanged += delegate { UpdateActions(); };
            inputs.Add(acknowledged); card.Controls.Add(acknowledged);
            previewButton = ButtonAt("1  检查并生成预览", 19, 50, 178, false);
            previewButton.Click += async delegate { await PreparePreview(); };
            card.Controls.Add(previewButton);
            flashButton = ButtonAt("2  开始烧录", 210, 50, 178, true);
            flashButton.Enabled = false;
            flashButton.Click += async delegate { await Flash(); };
            card.Controls.Add(flashButton);
            backupButton = ButtonAt("打开备份文件夹", 639, 50, 158, false);
            backupButton.Anchor = AnchorStyles.Top | AnchorStyles.Right;
            backupButton.Click += delegate {
                string path = String.IsNullOrEmpty(lastBackup) ? output.Text.Trim() : lastBackup;
                if (Directory.Exists(path)) OpenTarget(path);
                else
                {
                    string parent = Path.GetDirectoryName(path);
                    string available = Directory.Exists(parent) ? parent : output.Text.Trim();
                    if (Directory.Exists(available)) OpenTarget(available);
                    SetStatus("当前操作尚未生成备份；已打开可用的会话或保存目录。", false);
                }
            };
            card.Controls.Add(backupButton);
            progress = new ProgressBar { Location = new Point(19, 97), Size = new Size(778, 4), Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right, Style = ProgressBarStyle.Blocks, Value = 0, MarqueeAnimationSpeed = 0 };
            card.Controls.Add(progress);
            status = LabelAt("准备就绪。检查只生成预览，不会写入设备。", 19, 109, 778, 27, 9, Muted, false);
            status.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right;
            card.Controls.Add(status);
            log = new RichTextBox { Location = new Point(19, 146), Size = new Size(778, 75), Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right, ReadOnly = true, BorderStyle = BorderStyle.None, BackColor = Color.FromArgb(246, 248, 250), ForeColor = Muted, Font = new Font("Microsoft YaHei UI", 8.5F), DetectUrls = false, ScrollBars = RichTextBoxScrollBars.Vertical };
            card.Controls.Add(log);
        }

        private void ResizeCards()
        {
            if (stack == null) return;
            // Configuration remains readable; horizontal scrolling is available at small sizes/high DPI.
            int width = Math.Max(816, stack.ClientSize.Width - 23);
            stack.SuspendLayout();
            foreach (Panel panel in cards) panel.Width = width;
            stack.ResumeLayout();
        }

        private void FindDefaults()
        {
            string executableRoot = AppDomain.CurrentDomain.BaseDirectory.TrimEnd(Path.DirectorySeparatorChar);
            string distributedBridge = Path.Combine(executableRoot, "engine", "flash_app_bridge.py");
            bool distributed = File.Exists(distributedBridge);
            if (distributed) bridgePath = distributedBridge;
            else
            {
                DirectoryInfo cursor = new DirectoryInfo(executableRoot);
                for (int depth = 0; cursor != null && depth < 8; depth++, cursor = cursor.Parent)
                {
                    string candidate = Path.Combine(cursor.FullName, "flash_app_bridge.py");
                    if (File.Exists(candidate)) { bridgePath = candidate; break; }
                    candidate = Path.Combine(cursor.FullName, "tools", "flash_app_bridge.py");
                    if (File.Exists(candidate)) { bridgePath = candidate; break; }
                }
            }
            string projectRoot = bridgePath == null ? executableRoot : Directory.GetParent(Path.GetDirectoryName(bridgePath)).FullName;
            build.Text = Path.Combine(distributed ? executableRoot : projectRoot, distributed ? "firmware-build" : "build");
            output.Text = distributed ? Path.Combine(executableRoot, "backups") : Path.Combine(projectRoot, "backups", "gui");
            python.Text = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".espressif", "python_env", "idf5.5_py3.12_env", "Scripts", "python.exe");
            string portablePython = Path.Combine(executableRoot, "python", "python.exe");
            if (File.Exists(portablePython)) python.Text = portablePython;
        }

        private void WireChanges()
        {
            foreach (TextBox input in new[] { credential, mac, build, python, output }) input.TextChanged += delegate { InvalidatePreview(); };
            identity.CheckedChanged += delegate { InvalidatePreview(); };
            full.CheckedChanged += delegate { InvalidatePreview(); };
            ports.SelectedIndexChanged += delegate {
                PortItem port = ports.SelectedItem as PortItem;
                sidebarPort.Text = port == null ? "串口  ·  尚未选择" : "串口  ·  " + port.Port;
                InvalidatePreview();
            };
        }

        private void InvalidatePreview()
        {
            if (loading) return;
            bool wasValid = !String.IsNullOrEmpty(sessionFile);
            sessionFile = null;
            previewSummary = null;
            acknowledged.Checked = false;
            previewBadge.Text = "需要重新检查";
            previewBadge.ForeColor = Muted;
            summaryLine.Text = "设备编号  —    型号  —";
            summaryPlatform.Text = "平台地址  —";
            summaryFirmware.Text = identity.Checked ? "固件  保留设备当前固件" : "固件  检查后显示待写入版本；文件校验通过不等于真机验收";
            regions.Rows.Clear();
            if (wasValid) SetStatus("配置已更改，请重新检查并生成预览。", false);
            UpdateActions();
        }

        private void UpdateActions()
        {
            if (flashButton == null) return;
            flashButton.Enabled = !busy && !String.IsNullOrEmpty(sessionFile) && acknowledged.Checked;
            flashButton.BackColor = flashButton.Enabled ? Teal : Color.FromArgb(223, 230, 235);
            flashButton.ForeColor = flashButton.Enabled ? Color.White : Muted;
            flashButton.FlatAppearance.BorderColor = flashButton.Enabled ? Teal : Color.FromArgb(210, 220, 227);
            previewButton.Enabled = !busy;
            backupButton.Enabled = !busy;
        }

        private void SetBusy(bool value, string stage)
        {
            busy = value;
            foreach (Control input in inputs) input.Enabled = !value;
            UseWaitCursor = value;
            progress.Style = value ? ProgressBarStyle.Marquee : ProgressBarStyle.Blocks;
            progress.MarqueeAnimationSpeed = value ? 35 : 0;
            if (!value) progress.Value = 0;
            if (!String.IsNullOrEmpty(stage)) sidebarStage.Text = stage;
            UpdateActions();
        }

        private void SetStatus(string message, bool error)
        {
            status.Text = message;
            status.ForeColor = error ? Color.FromArgb(175, 64, 47) : Muted;
        }

        private void AppendLog(string message)
        {
            if (log.TextLength > 28000) log.Clear();
            log.AppendText(DateTime.Now.ToString("HH:mm:ss") + "  " + message.Replace("\r", " ").Replace("\n", " ") + Environment.NewLine);
            log.SelectionStart = log.TextLength;
            log.ScrollToCaret();
        }

        private void ChooseFile(TextBox destination, string filter, string title)
        {
            using (OpenFileDialog dialog = new OpenFileDialog { Filter = filter, Title = title, CheckFileExists = true })
                if (dialog.ShowDialog(this) == DialogResult.OK) destination.Text = dialog.FileName;
        }

        private void ChooseFolder(TextBox destination, string title)
        {
            using (FolderBrowserDialog dialog = new FolderBrowserDialog { Description = title, SelectedPath = Directory.Exists(destination.Text) ? destination.Text : "" })
                if (dialog.ShowDialog(this) == DialogResult.OK) destination.Text = dialog.SelectedPath;
        }

        private void OpenTarget(string target)
        {
            try { Process.Start(new ProcessStartInfo(target) { UseShellExecute = true }); }
            catch { SetStatus("无法打开，请在资源管理器或浏览器中手动打开。", true); }
        }

        private bool CheckEngine()
        {
            if (offline) { SetStatus("当前为离线界面验证模式，已禁用设备操作。", true); return false; }
            if (String.IsNullOrEmpty(bridgePath) || !File.Exists(bridgePath)) { SetStatus("未找到烧录引擎 flash_app_bridge.py，请使用完整程序包。", true); return false; }
            if (!File.Exists(python.Text.Trim()))
            {
                advancedCard.Height = 188;
                advancedToggle.Text = "▾  高级设置：固件目录、Python、备份位置";
                SetStatus("请选择 Python 程序：高级设置中需使用已安装 esptool、pyserial 的环境。", true);
                return false;
            }
            return true;
        }

        private async Task RefreshPorts()
        {
            if (busy || !CheckEngine()) return;
            InvalidatePreview();
            SetBusy(true, "识别串口");
            SetStatus("正在枚举 USB 串口…", false);
            BridgeResult result = await RunBridge("ports", new Dictionary<string, object>(), "ports");
            if (result.ExitCode == 0 && result.Payload != null)
            {
                ports.Items.Clear();
                PortItem known = null;
                foreach (object entry in Items(result.Payload, "ports"))
                {
                    Dictionary<string, object> item = entry as Dictionary<string, object>;
                    if (item == null) continue;
                    string serial = Regex.Replace(Get(item, "serial_number"), "[^a-fA-F0-9]", "").ToUpperInvariant();
                    int vid = 0; Int32.TryParse(Get(item, "vid"), out vid);
                    PortItem port = new PortItem { Port = Get(item, "port"), Description = Get(item, "description"), Known = vid == 0x303A && serial == "B43A451634A8" };
                    if (String.IsNullOrEmpty(port.Port)) continue;
                    if (port.Known) { known = port; port.Description += " · 已知设备"; }
                    ports.Items.Add(port);
                }
                if (known != null) ports.SelectedItem = known;
                SetStatus(known != null ? "已识别已知设备。选择后台 JSON 后生成预览。" : (ports.Items.Count > 0 ? "找到串口，请手动选择目标设备并核对 MAC。" : "未发现串口，请检查 USB 线与设备连接后刷新。"), false);
                AppendLog(known != null ? "已识别已知设备串口 " + known.Port + "。" : "串口列表已刷新；未自动选择未知设备。");
            }
            else ReportFailure(result, "串口识别失败");
            SetBusy(false, "等待导入");
        }

        private async Task PreparePreview()
        {
            if (busy || !CheckEngine()) return;
            PortItem selected = ports.SelectedItem as PortItem;
            if (!File.Exists(credential.Text.Trim())) { SetStatus("请先选择后台下载的烧录信息 JSON。", true); return; }
            if (selected == null) { SetStatus("请选择目标设备串口。", true); return; }
            if (!Regex.IsMatch(mac.Text.Trim(), "^[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}$")) { SetStatus("设备 MAC 格式应为 B4:3A:45:16:34:A8。", true); return; }
            if (!Directory.Exists(build.Text.Trim())) { SetStatus("固件参考目录不存在，请在高级设置中选择 build 目录。", true); return; }
            if (String.IsNullOrWhiteSpace(output.Text)) { SetStatus("请选择备份保存位置。", true); return; }
            Dictionary<string, object> request = new Dictionary<string, object> {
                { "credential_path", credential.Text.Trim() }, { "build_dir", build.Text.Trim() }, { "mode", identity.Checked ? "identity" : "full" },
                { "expected_mac", mac.Text.Trim().ToUpperInvariant() }, { "output_root", output.Text.Trim() }, { "port", selected.Port }
            };
            InvalidatePreview();
            SetBusy(true, "检查信息");
            SetStatus("正在检查烧录信息和文件，生成写入预览…", false);
            AppendLog("开始检查。本步骤不会写入设备。");
            BridgeResult result = await RunBridge("preview", request, "preview");
            if (result.ExitCode == 0 && result.Payload != null)
            {
                Dictionary<string, object> summary = Dict(result.Payload, "summary");
                string session = Get(result.Payload, "session_file");
                if (summary == null || String.IsNullOrEmpty(session)) { result.Error = "烧录引擎未返回完整预览，请重新检查。"; ReportFailure(result, "检查失败"); }
                else
                {
                    ApplyPreview(session, summary);
                    SetStatus("预览已生成。请核对设备和区域，再勾选配网提示。", false);
                    AppendLog("预览检查完成；尚未开始备份或写入。");
                }
            }
            else ReportFailure(result, "检查失败");
            SetBusy(false, String.IsNullOrEmpty(sessionFile) ? "检查失败" : "预览就绪");
            stageDetail.Text = String.IsNullOrEmpty(sessionFile) ? "根据下方提示修正后\n重新检查。" : "核对设备身份与写入内容。\n开始烧录前还会再次确认。";
        }

        private void ApplyPreview(string session, Dictionary<string, object> summary)
        {
            previewSummary = summary;
            sessionFile = session;
            // A new attempt must never send the user to an earlier device's backup.
            lastBackup = Get(summary, "backup_dir");
            acknowledged.Checked = false;
            previewBadge.Text = "检查通过 · 待确认";
            previewBadge.ForeColor = Teal;
            summaryLine.Text = "设备编号  " + Get(summary, "device_id") + "    型号  " + Get(summary, "model");
            summaryPlatform.Text = "平台  " + Get(summary, "origin") + "    密钥版本  " + Get(summary, "key_version");
            summaryFirmware.Text = Get(summary, "mode") == "identity" ? "固件  保留设备当前固件 · 只更新身份并清除运行配置" : "固件  将写入 " + Get(summary, "firmware_version") + "（尚未实机验收）· 文件校验不代表真机验收";
            regions.Rows.Clear();
            foreach (object entry in Items(summary, "regions"))
            {
                Dictionary<string, object> region = entry as Dictionary<string, object>;
                if (region == null) continue;
                string hash = Get(region, "sha256");
                string offset = Get(region, "offset");
                long numeric; if (Int64.TryParse(offset, out numeric)) offset = "0x" + numeric.ToString("X");
                string size = Get(region, "size");
                if (Int64.TryParse(size, out numeric)) size = numeric.ToString("N0") + " B";
                int index = regions.Rows.Add(Get(region, "name"), offset, size, hash.Length > 20 ? hash.Substring(0, 20) + "…" : hash);
                regions.Rows[index].Cells[3].ToolTipText = hash;
            }
            regions.ClearSelection();
            UpdateActions();
        }

        private async Task Flash()
        {
            if (offline || busy || String.IsNullOrEmpty(sessionFile) || previewSummary == null || !acknowledged.Checked) return;
            string confirmation = "请确认即将操作的设备：\n\n串口：" + Get(previewSummary, "port") + "\n目标 MAC：" + Get(previewSummary, "expected_mac") + "\n设备编号：" + Get(previewSummary, "device_id") + "\n模式：" + (Get(previewSummary, "mode") == "identity" ? "重新初始化，保留现有固件" : "完整固件与初始化") + "\n\n会先读取实际 MAC 并与目标核对，完整备份后才写入。\n会清除旧 Wi-Fi 和语音运行配置，完成后需重新配网。\n\n操作期间请勿拔掉 USB 或断电。是否开始？";
            if (MessageBox.Show(this, confirmation, "确认设备并开始烧录", MessageBoxButtons.YesNo, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2) != DialogResult.Yes) return;
            string approvedSession = sessionFile;
            SetBusy(true, "准备烧录");
            SetStatus("正在核对设备并备份，请保持 USB 连接…", false);
            stageDetail.Text = "按实际步骤显示状态。\n操作期间请保持连接。";
            AppendLog("用户已确认。开始核对硬件身份、备份和写入。");
            BridgeResult result = await RunBridge("flash", new Dictionary<string, object> { { "session_file", approvedSession }, { "execute", true } }, "complete");
            InvalidatePreview();
            if (IsVerifiedCompletion(result))
            {
                Dictionary<string, object> completed = Dict(result.Payload, "result");
                lastBackup = Get(completed, "backup_dir");
                SetBusy(false, "烧录完成");
                stageDetail.Text = "请手动重启设备。\n随后在家庭端重新蓝牙配网。";
                previewBadge.Text = "烧录完成"; previewBadge.ForeColor = Teal;
                SetStatus("完成并校验通过。请手动重启设备，再通过家庭端蓝牙重新配网。", false);
                AppendLog("备份、写入和校验完成。请手动重启设备并重新配网。");
                MessageBox.Show(this, "烧录与校验已完成。\n\n1. 手动重启设备。\n2. 在家庭端选择老人，重新进行蓝牙配网。\n3. 使用 2.4 GHz Wi-Fi，按设备提示完成确认。\n\n备份可通过“打开备份文件夹”查看。", "设备已准备好", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else
            {
                if (result.ExitCode == 0 && String.IsNullOrEmpty(result.Error)) result.Error = "引擎未确认写入与校验成功完成，必须重新检查设备状态。";
                ReportFailure(result, "烧录未完成");
                SetBusy(false, "烧录失败");
                stageDetail.Text = "保留设备连接并查看提示。\n重试前需要重新生成预览。";
            }
        }

        private static bool IsVerifiedCompletion(BridgeResult result)
        {
            return result != null && result.ExitCode == 0 && String.IsNullOrEmpty(result.Error) &&
                Get(result.Payload, "event") == "complete" && Get(Dict(result.Payload, "result"), "status") == "written_and_verified";
        }

        private void ReportFailure(BridgeResult result, string heading)
        {
            string message = String.IsNullOrEmpty(result.Error) ? "引擎未成功完成（退出码 " + result.ExitCode + "）。请检查环境、USB 连接和文件后重试。" : result.Error;
            SetStatus(heading + "：" + message, true);
            AppendLog(heading + "：" + message);
        }

        private async Task<BridgeResult> RunBridge(string command, Dictionary<string, object> request, string expectedEvent)
        {
            string pythonPath = python.Text.Trim();
            string engine = bridgePath;
            return await Task.Run(delegate {
                BridgeResult result = new BridgeResult { ExitCode = -1 };
                string requestFile = Path.Combine(Path.GetTempPath(), "echoear-request-" + Guid.NewGuid().ToString("N") + ".json");
                try
                {
                    // Request data contains paths and the public MAC only; never copy credential JSON here.
                    File.WriteAllText(requestFile, json.Serialize(request), new UTF8Encoding(false));
                    ProcessStartInfo start = new ProcessStartInfo {
                        FileName = pythonPath, Arguments = QuoteWindows("-u") + " " + QuoteWindows(engine) + " " + QuoteWindows(command) + " --request " + QuoteWindows(requestFile),
                        WorkingDirectory = Path.GetDirectoryName(engine), UseShellExecute = false, CreateNoWindow = true,
                        RedirectStandardOutput = true, RedirectStandardError = true, StandardOutputEncoding = Encoding.UTF8, StandardErrorEncoding = Encoding.UTF8
                    };
                    start.EnvironmentVariables["PYTHONIOENCODING"] = "utf-8";
                    using (Process process = new Process { StartInfo = start })
                    {
                        process.Start();
                        // Drain stderr without exposing raw dependency output that could contain credentials.
                        Task stderr = Task.Run(delegate { while (process.StandardError.ReadLine() != null) { } });
                        string line;
                        while ((line = process.StandardOutput.ReadLine()) != null)
                        {
                            if (line.Length > 1024 * 1024) { result.Error = "烧录引擎返回了过大的响应。"; continue; }
                            Dictionary<string, object> data;
                            try { data = new JavaScriptSerializer().Deserialize<Dictionary<string, object>>(line); }
                            catch { result.Error = "烧录引擎响应格式错误；原始输出已隐藏。"; continue; }
                            if (data == null) continue;
                            string kind = Get(data, "event");
                            if (kind == "phase")
                            {
                                string message = Get(data, "message");
                                string stage = Get(data, "stage");
                                Ui(delegate { SetStatus(message, false); AppendLog(message); sidebarStage.Text = StageName(stage); stageDetail.Text = message; });
                            }
                            else if (kind == expectedEvent) result.Payload = data;
                            else if (kind == "error") result.Error = Get(data, "message");
                        }
                        process.WaitForExit();
                        stderr.Wait();
                        result.ExitCode = process.ExitCode;
                        if (!String.IsNullOrEmpty(result.Error) || result.Payload == null) { result.Payload = null; if (result.ExitCode == 0) result.ExitCode = -1; }
                    }
                }
                catch { result.Error = "无法运行烧录引擎。请检查 Python 环境、程序文件以及目录读写权限。"; result.ExitCode = -1; result.Payload = null; }
                finally { try { if (File.Exists(requestFile)) File.Delete(requestFile); } catch { } }
                return result;
            });
        }

        private void Ui(Action action)
        {
            if (IsDisposed || !IsHandleCreated) return;
            try { BeginInvoke(action); } catch (InvalidOperationException) { }
        }

        private static string StageName(string stage)
        {
            switch (stage.ToLowerInvariant())
            {
                case "validating": return "检查信息";
                case "preparing": return "生成预览";
                case "ready": return "预览就绪";
                case "checking": return "核对设备";
                case "backup": return "完整备份";
                case "writing": return "写入设备";
                case "verifying": return "校验写入";
                default: return "正在处理";
            }
        }

        private static string QuoteWindows(string value)
        {
            if (value == null) value = "";
            StringBuilder result = new StringBuilder("\"");
            int backslashes = 0;
            foreach (char character in value)
            {
                if (character == '\\') { backslashes++; continue; }
                if (character == '"') { result.Append('\\', backslashes * 2 + 1); result.Append('"'); }
                else { result.Append('\\', backslashes); result.Append(character); }
                backslashes = 0;
            }
            result.Append('\\', backslashes * 2);
            result.Append('"');
            return result.ToString();
        }

        private static string Get(Dictionary<string, object> data, string key)
        {
            object value; return data != null && data.TryGetValue(key, out value) && value != null ? Convert.ToString(value, System.Globalization.CultureInfo.InvariantCulture) : "";
        }

        private static Dictionary<string, object> Dict(Dictionary<string, object> data, string key)
        {
            object value; return data != null && data.TryGetValue(key, out value) ? value as Dictionary<string, object> : null;
        }

        private static IEnumerable Items(Dictionary<string, object> data, string key)
        {
            object value; return data != null && data.TryGetValue(key, out value) && value is IEnumerable ? (IEnumerable)value : new object[0];
        }

        private Dictionary<string, object> DemoSummary()
        {
            return new Dictionary<string, object> {
                { "mode", "identity" }, { "port", "COM6" }, { "expected_mac", KnownMac }, { "device_id", "DEMO-ECHOEAR-001（演示）" }, { "model", "ECHOEAR-S3" },
                { "origin", "https://82.157.201.114" }, { "key_version", 1 }, { "reset_runtime", true }, { "firmware_version", null }, { "backup_dir", @"C:\offline-demo\current-session\backup" },
                { "regions", new object[] {
                    new Dictionary<string, object> { { "name", "ble_factory" }, { "offset", "0xe4e000" }, { "size", 24576 }, { "sha256", "c38bf520abf240ae9e0b0000000000000000000000000000000000000000000000" } },
                    new Dictionary<string, object> { { "name", "reset-runtime" }, { "offset", "0x9000" }, { "size", 24576 }, { "sha256", "d18942e3789d23fdf64c0000000000000000000000000000000000000000000000" } }
                } }
            };
        }

        internal void RenderPreview(string path)
        {
            if (!offline) throw new InvalidOperationException("Offline only");
            loading = true;
            ports.Items.Add(new PortItem { Port = "COM6", Description = "EchoEar S3 · 演示", Known = true });
            ports.SelectedIndex = 0;
            credential.Text = @"C:\Users\demo\Downloads\echoear-device.json";
            loading = false;
            ApplyPreview("offline-demo-only", DemoSummary());
            sidebarPort.Text = "串口  ·  COM6";
            sidebarStage.Text = "预览就绪";
            stageDetail.Text = "演示界面 · 未连接设备\n核对信息后再开始。";
            SetStatus("演示界面：仅展示操作流程，未读取或写入任何设备。", false);
            AppendLog("演示预览已生成。实际烧录前会核对 MAC 并完整备份。");
            ClientSize = new Size(1120, 900);
            // Native combo/grid rendering needs a visible handle. The offline-only window stays
            // off screen, never activates, and does not appear in the taskbar or run the bridge.
            ShowInTaskbar = false;
            StartPosition = FormStartPosition.Manual;
            Location = new Point(-30000, -30000);
            IntPtr ignored = Handle;
            CreateChildHandles(this);
            Show();
            PerformLayout();
            ResizeCards();
            Application.DoEvents();
            string absolute = Path.GetFullPath(path);
            Directory.CreateDirectory(Path.GetDirectoryName(absolute));
            using (Bitmap bitmap = new Bitmap(Width, Height)) { DrawToBitmap(bitmap, new Rectangle(0, 0, Width, Height)); bitmap.Save(absolute, ImageFormat.Png); }
            Hide();
        }

        protected override bool ShowWithoutActivation { get { return offline; } }

        private static void CreateChildHandles(Control parent)
        {
            foreach (Control child in parent.Controls) { child.CreateControl(); IntPtr handle = child.Handle; CreateChildHandles(child); }
        }

        internal int RunSmokeTest(string path)
        {
            List<object> checks = new List<object>();
            bool passed = true;
            Action<string, bool> check = delegate(string name, bool ok) { checks.Add(new Dictionary<string, object> { { "name", name }, { "passed", ok } }); passed &= ok; };
            check("initial_flash_disabled", !flashButton.Enabled);
            ApplyPreview("offline-session", DemoSummary());
            check("preview_requires_acknowledgement", !flashButton.Enabled);
            acknowledged.Checked = true;
            check("acknowledged_preview_enables_flash", flashButton.Enabled);
            credential.Text = "changed.json";
            check("credential_change_invalidates_preview", sessionFile == null && !flashButton.Enabled && !acknowledged.Checked);
            ApplyPreview("offline-session", DemoSummary()); acknowledged.Checked = true;
            mac.Text = "B4:3A:45:16:34:A9";
            check("mac_change_invalidates_preview", sessionFile == null && !flashButton.Enabled);
            ApplyPreview("offline-session", DemoSummary()); acknowledged.Checked = true;
            full.Checked = true;
            check("mode_change_invalidates_preview", sessionFile == null && !flashButton.Enabled);
            ApplyPreview("offline-session", DemoSummary()); acknowledged.Checked = true;
            SetBusy(true, "测试");
            check("busy_disables_actions_and_inputs", !flashButton.Enabled && !previewButton.Enabled && inputs.All(delegate(Control input) { return !input.Enabled; }));
            FormClosingEventArgs close = new FormClosingEventArgs(CloseReason.UserClosing, false);
            OnFormClosing(close);
            check("busy_blocks_window_close", close.Cancel);
            SetBusy(false, "测试完成");
            check("idle_restores_inputs", inputs.All(delegate(Control input) { return input.Enabled; }));
            InvalidatePreview();
            check("retry_requires_new_preview", !flashButton.Enabled && sessionFile == null);
            check("quotes_trailing_backslash", QuoteWindows("C:\\path with spaces\\") == "\"C:\\path with spaces\\\\\"");
            check("quotes_embedded_quote", QuoteWindows("a\"b") == "\"a\\\"b\"");
            Dictionary<string, object> verifiedResult = new Dictionary<string, object> {
                { "status", "written_and_verified" }, { "expected_mac", KnownMac }, { "backup_dir", @"C:\offline-demo\backup" },
                { "firmware_version", null }, { "firmware_action", "preserved" }, { "next_step", "reboot_and_provision" }
            };
            BridgeResult completion = new BridgeResult { ExitCode = 0, Payload = new Dictionary<string, object> { { "event", "complete" }, { "result", verifiedResult } } };
            check("real_backend_completion_status_accepted", IsVerifiedCompletion(completion));
            verifiedResult["status"] = "ok";
            check("generic_success_status_rejected", !IsVerifiedCompletion(completion));
            verifiedResult["status"] = "written_and_verified";
            completion.ExitCode = 1;
            check("nonzero_exit_rejects_complete_payload", !IsVerifiedCompletion(completion));
            completion.ExitCode = 0;
            completion.Error = "protocol_error";
            check("error_rejects_complete_payload", !IsVerifiedCompletion(completion));
            lastBackup = @"C:\offline-demo\previous-device\backup";
            ApplyPreview("new-session", DemoSummary());
            check("new_preview_replaces_previous_backup_target", lastBackup == @"C:\offline-demo\current-session\backup");
            InvalidatePreview();
            check("failed_attempt_retains_current_backup_target", lastBackup == @"C:\offline-demo\current-session\backup");
            check("bridge_stages_map_to_real_phases", StageName("writing") == "写入设备" && StageName("preparing") == "生成预览" && StageName("checking") == "核对设备" && StageName("ready") == "预览就绪" && StageName("verifying") == "校验写入");
            string absolute = Path.GetFullPath(path);
            Directory.CreateDirectory(Path.GetDirectoryName(absolute));
            File.WriteAllText(absolute, json.Serialize(new Dictionary<string, object> { { "passed", passed }, { "checks", checks }, { "hardware_accessed", false }, { "background_processes_started", 0 } }), new UTF8Encoding(false));
            return passed ? 0 : 1;
        }
    }
}