namespace SharepointToolbox.Web.Core.Models;

public record PermissionSummary(
    string Label,
    RiskLevel RiskLevel,
    int Count,
    int DistinctUsers
);

public static class PermissionSummaryBuilder
{
    private static readonly Dictionary<RiskLevel, string> Labels = new()
    {
        [RiskLevel.High]     = "High Risk",
        [RiskLevel.Medium]   = "Medium Risk",
        [RiskLevel.Low]      = "Low Risk",
        [RiskLevel.ReadOnly] = "Read Only",
    };

    public static IReadOnlyList<PermissionSummary> Build(IEnumerable<SimplifiedPermissionEntry> entries)
    {
        var grouped = entries.GroupBy(e => e.RiskLevel).ToDictionary(g => g.Key, g => g.ToList());
        return Enum.GetValues<RiskLevel>().Select(level =>
        {
            var items = grouped.GetValueOrDefault(level, new List<SimplifiedPermissionEntry>());
            var distinctUsers = items
                .SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries))
                .Select(u => u.Trim()).Where(u => u.Length > 0)
                .Distinct(StringComparer.OrdinalIgnoreCase).Count();
            return new PermissionSummary(Labels[level], level, items.Count, distinctUsers);
        }).ToList();
    }
}