using System.IO;
using System.Collections.ObjectModel;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using Microsoft.Extensions.Options;
using SSPCTester.Logic.Models;
using SSPCTester.Logic.Report;
using SSPCTester.Logic.Storage;
using SSPCTester.UI.Services;

namespace SSPCTester.UI.ViewModels;

/// <summary>测试报告页。</summary>
public partial class ReportViewModel : ObservableObject
{
    private readonly ReportGenerator _gen;
    private readonly WordReportGenerator _wordGen;
    private readonly ReportOptions _opts;
    private readonly ProjectStore _store;
    private readonly UiLogSink _log;
    private readonly UserSettingsStore _settingsStore;

    public ObservableCollection<ReportFileDescriptor> ReportFiles { get; } = new();
    public IReadOnlyList<ReportFormatChoice> FormatChoices { get; } = new[]
    {
        new ReportFormatChoice(ReportOutputFormat.Pdf, "PDF"),
        new ReportFormatChoice(ReportOutputFormat.Word, "Word"),
        new ReportFormatChoice(ReportOutputFormat.Both, "PDF + Word")
    };

    [ObservableProperty] private Project? _project;
    [ObservableProperty] private string _lastOutputPath = "";
    [ObservableProperty] private ReportFileDescriptor? _selectedReportFile;
    [ObservableProperty] private ReportFormatChoice? _selectedFormatChoice;
    [ObservableProperty] private Uri? _previewSource;
    [ObservableProperty] private string _previewMessage = "暂无可预览的报告。";
    [ObservableProperty] private bool _hasPreview;
    [ObservableProperty] private bool _hasWordInfo;
    [ObservableProperty] private string _wordInfoText = "";
    [ObservableProperty] private string _selectedFilePath = "";

    public ReportViewModel(
        ReportGenerator gen,
        WordReportGenerator wordGen,
        IOptions<ReportOptions> opts,
        ProjectStore store,
        UiLogSink log,
        UserSettingsStore settingsStore)
    {
        _gen = gen;
        _wordGen = wordGen;
        _opts = opts.Value;
        _store = store;
        _log = log;
        _settingsStore = settingsStore;
        SelectedFormatChoice = FormatChoices.First(x => x.Format == ReportFileHelper.ParseFormat(_opts.Format));
    }

    public void SetProject(Project p)
    {
        Project = p;
        if (string.IsNullOrWhiteSpace(p.Report.FileName) ||
            string.Equals(p.Report.FileName, "report.pdf", StringComparison.OrdinalIgnoreCase))
        {
            p.Report.FileName = ReportFileHelper.DefaultTemplate;
        }

        RefreshReportFiles(selectLatest: true);
    }

    [RelayCommand]
    private async Task Generate()
    {
        if (Project == null) return;
        try
        {
            await _store.SaveAsync(Project);
            string dir = ReportDirectory(Project);
            Directory.CreateDirectory(dir);
            DateTime now = DateTime.Now;
            var format = CurrentFormat;
            string? pdfPath = null;
            string? wordPath = null;
            var curveImages = await BuildCurveImagesAsync(Project);

            if (format is ReportOutputFormat.Pdf or ReportOutputFormat.Both)
            {
                pdfPath = Path.Combine(dir, ReportFileHelper.ResolveFileName(Project, now, ".pdf"));
                _gen.CurveImages = curveImages;
                _gen.Generate(Project, pdfPath);
            }

            if (format is ReportOutputFormat.Word or ReportOutputFormat.Both)
            {
                wordPath = Path.Combine(dir, ReportFileHelper.ResolveFileName(Project, now, ".docx"));
                _wordGen.CurveImages = curveImages;
                _wordGen.Generate(Project, wordPath);
            }

            string primaryPath = pdfPath ?? wordPath!;
            ReportFileHelper.SaveInfo(BuildInfo(Project, format, now, pdfPath, wordPath), ReportFileHelper.BuildInfoPath(primaryPath));
            if (wordPath != null && !string.Equals(ReportFileHelper.BuildInfoPath(wordPath), ReportFileHelper.BuildInfoPath(primaryPath), StringComparison.OrdinalIgnoreCase))
                ReportFileHelper.SaveInfo(BuildInfo(Project, format, now, pdfPath, wordPath), ReportFileHelper.BuildInfoPath(wordPath));

            LastOutputPath = primaryPath;
            RefreshReportFiles(primaryPath);
            _log.Add(UiLogLevel.Success, "报告已生成：" + primaryPath);
        }
        catch (Exception ex)
        {
            _log.Add(UiLogLevel.Error, "生成报告失败：" + ex.Message);
        }
    }

    [RelayCommand]
    private void OpenFolder()
    {
        if (Project == null) return;
        var dir = ReportDirectory(Project);
        if (Directory.Exists(dir))
            System.Diagnostics.Process.Start("explorer.exe", dir);
    }

    [RelayCommand]
    private void RefreshReports() => RefreshReportFiles(selectLatest: true);

    [RelayCommand]
    private void OpenSelectedFile()
    {
        if (SelectedReportFile == null || !File.Exists(SelectedReportFile.FullPath)) return;
        System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(SelectedReportFile.FullPath)
        {
            UseShellExecute = true
        });
    }

    partial void OnSelectedFormatChoiceChanged(ReportFormatChoice? value)
    {
        if (value == null) return;
        _opts.Format = value.Format.ToString();
        RefreshReportFiles(selectLatest: true);
    }

    partial void OnSelectedReportFileChanged(ReportFileDescriptor? value)
    {
        if (value == null)
        {
            ClearPreview("暂无可预览的报告。");
            return;
        }

        SelectedFilePath = value.FullPath;
        if (value.IsPdf)
            LoadPreview(value.FullPath);
        else
            LoadWordInfo(value.FullPath);
    }

    public void PreviewUnavailable(string message) => ClearPreview(message);

    private void RefreshReportFiles(string? selectPath = null, bool selectLatest = false)
    {
        ReportFiles.Clear();
        var project = Project;
        if (project == null)
        {
            ClearPreview("暂无项目，无法预览报告。");
            return;
        }

        foreach (var file in ReportFileHelper.EnumerateReportFiles(ReportDirectory(project), CurrentFormat))
            ReportFiles.Add(file);

        SelectedReportFile = selectPath == null
            ? selectLatest ? DefaultSelectedReportFile() : SelectedReportFile
            : ReportFiles.FirstOrDefault(x => string.Equals(x.FullPath, selectPath, StringComparison.OrdinalIgnoreCase));

        if (SelectedReportFile == null)
            ClearPreview(CurrentFormat == ReportOutputFormat.Word
                ? "当前报告目录下暂无 Word 报告。生成报告后将在这里显示文件信息。"
                : "当前报告目录下暂无报告。生成报告后将在这里预览或显示文件信息。");
    }

    private void LoadPreview(string path)
    {
        if (!File.Exists(path))
        {
            ClearPreview("选中的报告文件不存在。");
            return;
        }

        LastOutputPath = path;
        PreviewSource = new Uri(path);
        PreviewMessage = "";
        HasPreview = true;
        var info = ReportFileHelper.LoadInfoForReport(path);
        if (!string.IsNullOrWhiteSpace(info?.WordPath))
            SetWordInfo(info, path);
        else
            HasWordInfo = false;
    }

    private void LoadWordInfo(string path)
    {
        if (!File.Exists(path))
        {
            ClearPreview("选中的 Word 报告文件不存在。");
            return;
        }

        LastOutputPath = path;
        HasPreview = false;
        PreviewSource = null;
        PreviewMessage = "";
        SetWordInfo(ReportFileHelper.LoadInfoForReport(path), path);
    }

    private void ClearPreview(string message)
    {
        HasPreview = false;
        PreviewSource = null;
        PreviewMessage = message;
        HasWordInfo = false;
        WordInfoText = "";
        SelectedFilePath = "";
    }

    private string ReportDirectory(Project project) =>
        string.IsNullOrWhiteSpace(project.FolderPath) ? _opts.SavePath : project.FolderPath;

    private ReportOutputFormat CurrentFormat => SelectedFormatChoice?.Format ?? ReportFileHelper.ParseFormat(_opts.Format);

    private ReportFileDescriptor? DefaultSelectedReportFile()
    {
        if (CurrentFormat == ReportOutputFormat.Both)
            return ReportFiles.FirstOrDefault(x => x.IsPdf) ?? ReportFiles.FirstOrDefault();
        return ReportFiles.FirstOrDefault();
    }

    private static ReportInfo BuildInfo(Project project, ReportOutputFormat format, DateTime generatedAt, string? pdfPath, string? wordPath) =>
        new()
        {
            ProjectName = project.Name,
            ProductName = project.Dut.ProductName,
            Model = project.Dut.Model,
            SerialNumber = project.Dut.SerialNumber,
            GeneratedAt = generatedAt,
            Format = format.ToString(),
            PdfPath = pdfPath,
            WordPath = wordPath,
            OverallStatus = project.OverallStatus.ToString(),
            Sections = new ReportSectionInfo
            {
                Cover = project.Report.Cover,
                Basic = project.Report.Basic,
                Curve = project.Report.Curve,
                Power = project.Report.Power,
                Protect = project.Report.Protect
            }
        };

    private void SetWordInfo(ReportInfo? info, string selectedPath)
    {
        var file = new FileInfo(selectedPath);
        string? wordPath = info?.WordPath;
        string? pdfPath = info?.PdfPath;
        var lines = new List<string>
        {
            $"文件名：{file.Name}",
            $"完整路径：{file.FullName}",
            $"文件大小：{FormatBytes(file.Length)}",
            $"修改时间：{file.LastWriteTime:yyyy-MM-dd HH:mm:ss}",
            $"格式：{(file.Extension.Equals(".docx", StringComparison.OrdinalIgnoreCase) ? "Word" : "PDF")}"
        };

        if (info != null)
        {
            lines.Add($"项目名称：{info.ProjectName}");
            lines.Add($"设备名称：{info.ProductName}");
            lines.Add($"设备型号：{info.Model}");
            lines.Add($"设备编号：{info.SerialNumber}");
            lines.Add($"生成时间：{info.GeneratedAt:yyyy-MM-dd HH:mm:ss}");
            lines.Add($"输出格式：{info.Format}");
            lines.Add($"综合判定：{info.OverallStatus}");
            lines.Add($"关联 PDF：{(string.IsNullOrWhiteSpace(pdfPath) ? "无" : File.Exists(pdfPath) ? pdfPath : "文件缺失")}");
            lines.Add($"关联 Word：{(string.IsNullOrWhiteSpace(wordPath) ? "无" : File.Exists(wordPath) ? wordPath : "文件缺失")}");
        }
        else
        {
            lines.Add("报告信息文件：未找到，已显示文件系统信息。");
        }

        WordInfoText = string.Join(Environment.NewLine, lines);
        HasWordInfo = true;
    }

    private static string FormatBytes(long bytes)
    {
        if (bytes >= 1024 * 1024) return $"{bytes / 1024d / 1024d:F2} MB";
        if (bytes >= 1024) return $"{bytes / 1024d:F1} KB";
        return $"{bytes} B";
    }

    private async Task<Dictionary<int, CurveReportImages>> BuildCurveImagesAsync(Project project)
    {
        var images = new Dictionary<int, CurveReportImages>();
        foreach (var row in project.CurveResults.OrderBy(x => x.Channel))
        {
            try
            {
                var rising = await WaveformStore.LoadAsync(project, row.RisingWaveformPath);
                var falling = await WaveformStore.LoadAsync(project, row.FallingWaveformPath);
                if (rising == null && falling == null) continue;

                images[row.Channel] = new CurveReportImages(
                    rising == null
                        ? null
                        : CurveImageRenderer.RenderRisingChannel(
                            row.Channel,
                            rising,
                            row.RisingViewStartMs ?? row.ViewStartMs,
                            row.RisingViewEndMs ?? row.ViewEndMs),
                    falling == null
                        ? null
                        : CurveImageRenderer.RenderFallingChannel(
                            row.Channel,
                            falling,
                            row.FallingViewStartMs ?? row.ViewStartMs,
                            row.FallingViewEndMs ?? row.ViewEndMs));
            }
            catch (Exception ex)
            {
                _log.Add(UiLogLevel.Warning, $"CH{row.Channel} 曲线插图生成失败：{ex.Message}");
            }
        }

        return images;
    }
}

public sealed record ReportFormatChoice(ReportOutputFormat Format, string DisplayName);