using System.Management.Automation;

namespace Noz.PowerShell.Cmdlets;

/// Returns notes that have no incoming wikilinks — good candidates for cleanup or linking.
[Cmdlet(VerbsCommon.Get, "NozOrphans")]
[OutputType(typeof(NozNote))]
public sealed class GetNozOrphansCmdlet : NozCmdletBase
{
    [Parameter]
    public string? Topic { get; set; }

    protected override void ProcessRecord()
    {
        var notesTask = Api.GetNotesAsync();
        var graphTask = Api.GetGraphAsync();

        var notes = Run(notesTask);
        var graph = Run(graphTask);

        var targets = new HashSet<string>(graph.Edges.Select(e => e.Target));

        var orphans = notes.Where(n => !targets.Contains(n.Slug));

        if (Topic is not null)
            orphans = orphans.Where(n => string.Equals(n.Topic, Topic, StringComparison.OrdinalIgnoreCase));

        foreach (var n in orphans.OrderBy(n => n.Topic).ThenBy(n => n.Slug))
            WriteObject(NozNote.From(n));
    }
}