using PlotLine.Models;

namespace PlotLine.Services;

public sealed record CoreImportExistingCharacterName(int CharacterID, string Name);

public sealed class CoreImportCharacterCandidateResolutionResult
{
    public IReadOnlyList<ManuscriptScanCharacterCandidatePreview> Candidates { get; init; } = [];
    public int AutoResolvedCount { get; init; }
}

public static class CoreImportCharacterCandidateResolver
{
    public static CoreImportCharacterCandidateResolutionResult ResolveExactKnownMatches(
        IReadOnlyList<ManuscriptScanCharacterCandidatePreview> candidates,
        IReadOnlyList<CoreImportExistingCharacterName> existingNames)
    {
        var index = existingNames
            .Select(item => new { Key = CoreImportBasicLocationDetector.StableKey(item.Name), item.CharacterID })
            .Where(item => !string.IsNullOrWhiteSpace(item.Key))
            .GroupBy(item => item.Key, StringComparer.Ordinal)
            .ToDictionary(
                group => group.Key,
                group => group.Select(item => item.CharacterID).Distinct().ToList(),
                StringComparer.Ordinal);

        var resolved = 0;
        var output = candidates.Select(candidate =>
        {
            var key = CoreImportBasicLocationDetector.StableKey(candidate.Name);
            if (!string.IsNullOrWhiteSpace(key)
                && index.TryGetValue(key, out var matches)
                && matches.Count == 1)
            {
                resolved++;
                return new ManuscriptScanCharacterCandidatePreview
                {
                    TemporaryCharacterKey = candidate.TemporaryCharacterKey,
                    Name = candidate.Name,
                    MentionCount = candidate.MentionCount,
                    QualityScore = candidate.QualityScore,
                    Category = candidate.Category,
                    Reason = candidate.Reason,
                    ExistingCharacterID = matches[0],
                    IsExistingCharacterMatch = true,
                    IsAutoResolvedExistingCharacter = true,
                    SuggestedImportance = candidate.SuggestedImportance,
                    EvidenceScenes = candidate.EvidenceScenes
                };
            }

            return candidate;
        }).ToList();

        return new CoreImportCharacterCandidateResolutionResult
        {
            Candidates = output,
            AutoResolvedCount = resolved
        };
    }
}