using System.Diagnostics.CodeAnalysis;
using System.Text;

namespace Houston.Model.Documents;

/// <summary>
/// Full S3 object key of a customer document, including the customer/organization prefix.
/// </summary>
public readonly record struct DocumentKey(OrgSlug Org, DocumentType? Type, DocumentName Name)
{
    public static bool TryFromS3Key(string key, [NotNullWhen(true)] out DocumentKey? result)
    {
        result = null;

        if (key.EndsWith('/')) return false;

        var parts = key.Split('/', StringSplitOptions.RemoveEmptyEntries);

        if (parts.Contains("..")) return false;

        result = parts switch
        {
            [var org, var name] when OrgSlug.TryFromFolderName(org, out var slug)
                => new(slug.Value, null, new(name)),
            [var org, var type, var name] when OrgSlug.TryFromFolderName(org, out var slug)
                => new(slug.Value, DocumentTypeExtensions.ParseStorageFolderName(type), new(name)),
            _ => null,
        };

        return result is not null;
    }

    public override string ToString()
    {
        StringBuilder result = new();
        result.Append(Org.ToString());
        if (Type is { } type) result.Append(type.StorageFolderName).Append('/');
        result.Append(Name);
        return result.ToString();
    }
}