using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.IO;
using System.Management.Automation;
using Microsoft.PowerShell.Commands;

[EditorBrowsable(EditorBrowsableState.Never)]
public abstract class CmdletWithPathBase : PSCmdlet
{
    private string[]? _paths;

    [Parameter(
        Position = 0,
        ValueFromPipeline = true,
        ValueFromPipelineByPropertyName = true,
        ParameterSetName = "Path")]
    [SupportsWildcards]
    [ValidateNotNullOrEmpty]
    public virtual string[]? Path
    {
        get => _paths;
        set => _paths = value;
    }

    [Parameter(
        ValueFromPipelineByPropertyName = true,
        ParameterSetName = "LiteralPath")]
    [Alias("PSPath")]
    [ValidateNotNullOrEmpty]
    public virtual string[]? LiteralPath
    {
        get => _paths;
        set => _paths = value;
    }

    protected IEnumerable<string> EnumerateResolvedPaths(bool validateExists = true)
    {
        bool isLiteral = MyInvocation.BoundParameters.ContainsKey(nameof(LiteralPath));
        Collection<string> resolvedPaths;
        ProviderInfo provider;

        foreach (string path in _paths ?? [SessionState.Path.CurrentFileSystemLocation.Path])
        {
            if (isLiteral)
            {
                string resolved = SessionState.Path
                    .GetUnresolvedProviderPathFromPSPath(path, out provider, out _);

                if (!WriteErrorIfInvalidProvider(resolved, provider) &&
                    !WriteErrorIfNotExists(resolved, validateExists))
                {
                    yield return resolved;
                }

                continue;
            }

            try
            {
                resolvedPaths = GetResolvedProviderPathFromPSPath(path, out provider);
            }
            catch (Exception exception)
            {
                WriteError(new ErrorRecord(
                    exception, "ResolvePath", ErrorCategory.ObjectNotFound, path));

                continue;
            }


            foreach (string resolvedPath in resolvedPaths)
            {
                if (WriteErrorIfInvalidProvider(resolvedPath, provider))
                {
                    continue;
                }

                yield return resolvedPath;
            }
        }
    }

    private bool WriteErrorIfInvalidProvider(string path, ProviderInfo provider)
    {
        if (provider.ImplementingType == typeof(FileSystemProvider))
        {
            return false;
        }

        ArgumentException ex = new($"The resolved path '{path}' is not a FileSystem path but '{provider.Name}'.");
        WriteError(new ErrorRecord(ex, "InvalidProvider", ErrorCategory.InvalidArgument, path));
        return true;
    }

    private bool WriteErrorIfNotExists(string path, bool validateExists)
    {
        if (!validateExists)
        {
            return false;
        }

        if (File.Exists(path) || Directory.Exists(path))
        {
            return false;
        }

        ItemNotFoundException ex = new($"Cannot find path '{path}' because it does not exist.");
        WriteError(new ErrorRecord(ex, "InvalidPath", ErrorCategory.InvalidArgument, path));
        return true;
    }
}

[Cmdlet(
    VerbsDiagnostic.Test, "PathCommand",
    DefaultParameterSetName = "Path")]
public sealed class TestPathCommand : CmdletWithPathBase
{
    protected override void ProcessRecord()
    {
        foreach (string path in EnumerateResolvedPaths())
        {
            WriteObject(path);
        }
    }
}