using Omika.Diagnostics.Referential;

namespace Omika.Diagnostics.Tests.Fakes;

/// <summary>
/// Fake en mémoire de <see cref="IDiagnosticReferenceRepository"/> pour les tests sans
/// PostgreSQL. Reproduit la sémantique du repository Npgsql : normalisation TRIM+UPPER,
/// unicité (type, code), code immuable, archivage (enabled=false) sans DELETE. Les codes
/// « observés » (pour <see cref="GetUnreferencedAsync"/>) sont injectés via
/// <see cref="SeedObserved"/> (miroir du DISTINCT diagnostic_event, sans base réelle).
/// </summary>
public sealed class FakeDiagnosticReferenceRepository : IDiagnosticReferenceRepository
{
    private readonly List<DiagnosticReferenceRecord> _references = [];
    private readonly List<(string Type, string Code, long Count, DateTimeOffset LastSeen)> _observed = [];
    private long _nextId = 1;

    public IReadOnlyList<DiagnosticReferenceRecord> Seed(params DiagnosticReferenceRecord[] records)
    {
        foreach (DiagnosticReferenceRecord r in records)
        {
            if (r.Id == 0)
            {
                r.Id = _nextId++;
            }
            else
            {
                _nextId = Math.Max(_nextId, r.Id + 1);
            }

            _references.Add(r);
        }

        return _references;
    }

    public void SeedObserved(string type, string code, long count, DateTimeOffset lastSeen) =>
        _observed.Add((type, code, count, lastSeen));

    public Task<IReadOnlyList<DiagnosticReferenceRecord>> ListAsync(
        CancellationToken cancellationToken = default)
    {
        IReadOnlyList<DiagnosticReferenceRecord> ordered = _references
            .OrderBy(r => r.ReferenceType, StringComparer.Ordinal)
            .ThenBy(r => r.SortOrder)
            .ThenBy(r => r.Code, StringComparer.Ordinal)
            .ToList();
        return Task.FromResult(ordered);
    }

    public Task<DiagnosticReferenceRecord?> GetByTypeAndCodeAsync(
        string referenceType,
        string code,
        CancellationToken cancellationToken = default)
    {
        string? normalized = DiagnosticReferenceNormalization.NormalizeCode(code);
        DiagnosticReferenceRecord? found = _references.FirstOrDefault(r =>
            r.ReferenceType == referenceType && r.Code == normalized);
        return Task.FromResult(found);
    }

    public Task<DiagnosticReferenceRecord?> GetByIdAsync(
        long id,
        CancellationToken cancellationToken = default)
    {
        return Task.FromResult(_references.FirstOrDefault(r => r.Id == id));
    }

    public Task<DiagnosticReferenceRecord?> CreateAsync(
        string referenceType,
        string code,
        string label,
        string? description,
        bool enabled,
        int sortOrder,
        CancellationToken cancellationToken = default)
    {
        string? normalizedCode = DiagnosticReferenceNormalization.NormalizeCode(code);
        string? normalizedLabel = DiagnosticReferenceNormalization.NormalizeLabel(label);
        if (!DiagnosticReferenceTypes.IsSupported(referenceType) || normalizedCode is null || normalizedLabel is null)
        {
            return Task.FromResult<DiagnosticReferenceRecord?>(null);
        }

        if (_references.Any(r => r.ReferenceType == referenceType && r.Code == normalizedCode))
        {
            return Task.FromResult<DiagnosticReferenceRecord?>(null); // doublon.
        }

        DateTimeOffset now = DateTimeOffset.UtcNow;
        var record = new DiagnosticReferenceRecord
        {
            Id = _nextId++,
            ReferenceType = referenceType,
            Code = normalizedCode,
            Label = normalizedLabel,
            Description = DiagnosticReferenceNormalization.NormalizeLabel(description),
            Enabled = enabled,
            SortOrder = sortOrder,
            CreatedAtUtc = now,
            UpdatedAtUtc = now
        };
        _references.Add(record);
        return Task.FromResult<DiagnosticReferenceRecord?>(record);
    }

    public Task<bool> UpdateAsync(
        long id,
        string label,
        string? description,
        bool enabled,
        int sortOrder,
        CancellationToken cancellationToken = default)
    {
        string? normalizedLabel = DiagnosticReferenceNormalization.NormalizeLabel(label);
        DiagnosticReferenceRecord? record = _references.FirstOrDefault(r => r.Id == id);
        if (record is null || normalizedLabel is null)
        {
            return Task.FromResult(false);
        }

        record.Label = normalizedLabel;
        record.Description = DiagnosticReferenceNormalization.NormalizeLabel(description);
        record.Enabled = enabled;
        record.SortOrder = sortOrder;
        record.UpdatedAtUtc = DateTimeOffset.UtcNow;
        return Task.FromResult(true);
    }

    public Task<IReadOnlyDictionary<string, string>> GetLabelsAsync(
        string referenceType,
        CancellationToken cancellationToken = default)
    {
        var labels = new Dictionary<string, string>(StringComparer.Ordinal);
        foreach (DiagnosticReferenceRecord r in _references.Where(r => r.ReferenceType == referenceType))
        {
            labels[r.Code] = r.Label;
        }

        return Task.FromResult<IReadOnlyDictionary<string, string>>(labels);
    }

    public Task<IReadOnlyList<DiagnosticUnreferencedCode>> GetUnreferencedAsync(
        int limit,
        CancellationToken cancellationToken = default)
    {
        var result = _observed
            .Where(o => !_references.Any(r => r.ReferenceType == o.Type && r.Code == o.Code))
            .Select(o => new DiagnosticUnreferencedCode(o.Type, o.Code, o.Count, o.LastSeen))
            .OrderByDescending(x => x.ObservedCount)
            .ThenBy(x => x.ReferenceType, StringComparer.Ordinal)
            .ThenBy(x => x.Code, StringComparer.Ordinal)
            .Take(Math.Clamp(limit, 1, 200))
            .ToList();

        return Task.FromResult<IReadOnlyList<DiagnosticUnreferencedCode>>(result);
    }
}