using System.Text.RegularExpressions;
using PlotLine.ViewModels;

namespace PlotLine.Services;

public static class StoryIntelligenceCharacterReviewDefaults
{
    private static readonly HashSet<string> GenericFamilyReferences = CreateSet(
        "mum", "mom", "mam", "mother", "dad", "father", "brother", "sister", "grandmother", "grandfather",
        "nan", "nanny", "grandma", "grandad", "granddad", "aunt", "auntie", "uncle", "cousin");

    private static readonly Regex ContextualIndefiniteReference = new(
        @"^(one of (them|his mates|her mates|their mates|the men|the women|the boys|the girls)|his mate|her mate|their mate|his friend|her friend|their friend)$",
        RegexOptions.IgnoreCase | RegexOptions.Compiled);

    public static string DetermineAction(string? candidateName, int? proposedExistingCharacterId, string? classification = null)
    {
        if (proposedExistingCharacterId.HasValue)
        {
            return StoryIntelligenceCharacterImportActions.LinkExisting;
        }

        if (string.Equals(classification, StoryIntelligenceCharacterClassifications.GenericReference, StringComparison.OrdinalIgnoreCase)
            || string.Equals(classification, StoryIntelligenceCharacterClassifications.NonCharacter, StringComparison.OrdinalIgnoreCase)
            || IsGenericContextualReference(candidateName))
        {
            return StoryIntelligenceCharacterImportActions.Ignore;
        }

        return StoryIntelligenceCharacterImportActions.CreateNew;
    }

    public static bool IsGenericContextualReference(string? candidateName)
    {
        var normalised = Normalise(candidateName);
        if (string.IsNullOrWhiteSpace(normalised))
        {
            return false;
        }

        return GenericFamilyReferences.Contains(normalised)
            || ContextualIndefiniteReference.IsMatch(normalised);
    }

    private static string Normalise(string? value)
    {
        var cleaned = Regex.Replace(value ?? string.Empty, @"[^\p{L}\p{N}' ]+", " ");
        cleaned = cleaned.Replace("’", "'", StringComparison.Ordinal);
        return string.Join(' ', cleaned.Trim().Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries)).ToLowerInvariant();
    }

    private static HashSet<string> CreateSet(params string[] values)
        => values.Select(Normalise).ToHashSet(StringComparer.OrdinalIgnoreCase);
}