using System.Collections.ObjectModel;
using System.Windows.Input;

namespace Zcbot.WindowsNode;

internal sealed class LocalJobItemViewModel(JobDisplaySnapshot snapshot)
{
    internal JobDisplaySnapshot Snapshot { get; } = snapshot;

    public Guid JobId => Snapshot.JobId;
    public string StageText => FormatStage(Snapshot.Stage);
    public string Title => Snapshot.Title;
    public string InputFilename => Snapshot.InputFilename;
    public string ProgressText => Snapshot.Stage == "software_running"
        ? $"已执行 {FormatElapsed(DateTimeOffset.UtcNow - Snapshot.UpdatedAt)}"
        : $"{Snapshot.Progress}%";
    public string AcceptedAtText => Snapshot.AcceptedAt.LocalDateTime.ToString("MM-dd HH:mm");
    public string ShortId => Snapshot.JobId.ToString("N")[..8];
    public string Tone => Snapshot.Stage switch
    {
        "failed" or "cloud_terminal" => "error",
        "succeeded" => "success",
        "cancelled" => "neutral",
        _ => "active",
    };
    public string DetailText => string.Join("\n", [
        $"{StageText} · {Snapshot.Detail}",
        $"能力：{Snapshot.Capability}",
        $"Job ID：{Snapshot.JobId}",
        $"更新时间：{Snapshot.UpdatedAt.LocalDateTime:yyyy-MM-dd HH:mm:ss}",
    ]);

    private static string FormatElapsed(TimeSpan elapsed)
    {
        if (elapsed < TimeSpan.Zero) elapsed = TimeSpan.Zero;
        return elapsed.TotalHours >= 1
            ? $"{(int)elapsed.TotalHours}:{elapsed.Minutes:00}:{elapsed.Seconds:00}"
            : $"{elapsed.Minutes:00}:{elapsed.Seconds:00}";
    }

    private static string FormatStage(string stage) => stage switch
    {
        "accepted" => "等待处理",
        "downloading_inputs" => "下载输入",
        "ready_to_run" => "准备执行",
        "software_running" => "软件执行中",
        "uploading_outputs" => "上传结果",
        "succeeded" => "成功",
        "failed" => "失败",
        "cloud_terminal" => "云端已终止",
        "cancelled" => "已取消",
        _ => stage,
    };
}

internal sealed class JobPageViewModel : ObservableObject
{
    private readonly IJobMonitorService service;
    private LocalJobItemViewModel? selectedJob;
    private string summary = "正在读取本机任务…";

    internal JobPageViewModel(IJobMonitorService service)
    {
        this.service = service;
        RefreshCommand = new RelayCommand(Refresh);
    }

    public ObservableCollection<LocalJobItemViewModel> Jobs { get; } = [];

    public LocalJobItemViewModel? SelectedJob
    {
        get => selectedJob;
        set
        {
            if (SetProperty(ref selectedJob, value))
            {
                OnPropertyChanged(nameof(SelectedDetail));
            }
        }
    }

    public string Summary
    {
        get => summary;
        private set => SetProperty(ref summary, value);
    }

    public string SelectedDetail => SelectedJob?.DetailText
        ?? "选择任务后可查看执行阶段、更新时间和完整 Job ID。";

    public ICommand RefreshCommand { get; }

    internal void Refresh()
    {
        var selectedId = SelectedJob?.JobId;
        IReadOnlyList<JobDisplaySnapshot> snapshots;
        try
        {
            snapshots = service.ReadSnapshots();
        }
        catch (Exception exception) when (
            exception is IOException or UnauthorizedAccessException)
        {
            Summary = $"无法读取本机任务：{exception.Message}";
            return;
        }

        Jobs.Clear();
        foreach (var snapshot in snapshots)
        {
            Jobs.Add(new LocalJobItemViewModel(snapshot));
        }
        var active = snapshots.Count(item => item.IsActive);
        Summary = snapshots.Count == 0
            ? "暂无本机任务"
            : $"活动任务 {active} 个 · 最近记录 {snapshots.Count} 条";
        SelectedJob = Jobs.FirstOrDefault(item => item.JobId == selectedId)
            ?? Jobs.FirstOrDefault();
    }
}