using System;
using System.Collections.Generic;
using System.Linq;
using StellaOps.Auth.Abstractions;

namespace StellaOps.Cartographer.Options;

/// <summary>
/// Applies Cartographer-specific defaults to <see cref="CartographerAuthorityOptions"/>.
/// </summary>
internal static class CartographerAuthorityOptionsConfigurator
{
    /// <summary>
    /// Ensures required scopes are present and duplicates are removed case-insensitively.
    /// </summary>
    /// <param name="options">Target options.</param>
    public static void ApplyDefaults(CartographerAuthorityOptions options)
    {
        ArgumentNullException.ThrowIfNull(options);

        EnsureScope(options.RequiredScopes, StellaOpsScopes.GraphRead);
        EnsureScope(options.RequiredScopes, StellaOpsScopes.GraphWrite);
    }

    private static void EnsureScope(ICollection<string> scopes, string scope)
    {
        ArgumentNullException.ThrowIfNull(scopes);
        ArgumentException.ThrowIfNullOrEmpty(scope);

        if (scopes.Any(existing => string.Equals(existing, scope, StringComparison.OrdinalIgnoreCase)))
        {
            return;
        }

        scopes.Add(scope);
    }
}