using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json;

namespace Sozsoft.Platform.Data.Seeds;

/// <summary>
/// Component'in designer dokumanindaki (Props) Data sekmesi endpoint'lerini cozup
/// CRUD endpoint katalogu ile eslestiren ortak mantik.
/// <para>
/// Cozum kaydetme sirasinda (CustomComponentAppService) katalogu veritabanindan okur;
/// boylece <c>DataSources</c> sutunu tasarimci dokumanindan tutarli sekilde uretilir.
/// </para>
/// </summary>
public static class CustomComponentDataSourceResolver
{
    private static readonly JsonSerializerOptions JsonReadOptions = new()
    {
        PropertyNameCaseInsensitive = true
    };

    /// <summary>Eslestirmede kullanilan CRUD endpoint tanimi.</summary>
    public sealed class CrudEndpointReference
    {
        public string EntityName { get; set; } = string.Empty;
        public string Method { get; set; } = string.Empty;
        public string Path { get; set; } = string.Empty;
        public string OperationType { get; set; } = string.Empty;
    }

    /// <summary>
    /// Props icindeki <c>visualDesigner.dataSources</c> listesini okur ve her kaydi method + path
    /// ile <paramref name="endpoints"/> icinde arar. Eslesmeyen (elle yazilmis ya da custom)
    /// endpoint'ler de listede kalir; yalnizca entity/seed dosyasi alanlari bos gelir.
    /// </summary>
    public static List<CustomComponentSeedDataSourceDto> Resolve(
        string? props,
        IReadOnlyCollection<CrudEndpointReference> endpoints)
    {
        var documentSources = ParseDocumentDataSources(props);
        if (documentSources.Count == 0)
        {
            return [];
        }

        var resolved = new List<CustomComponentSeedDataSourceDto>();

        foreach (var source in documentSources)
        {
            var method = (source.Method ?? string.Empty).Trim().ToUpperInvariant();
            var url = (source.Url ?? string.Empty).Trim();
            if (url.Length == 0)
            {
                continue;
            }

            // Ayni method + path birden fazla bilesene baglanmis olabilir; tekrarlari eleriz.
            if (resolved.Exists(x => x.Method == method && string.Equals(x.Url, url, StringComparison.OrdinalIgnoreCase)))
            {
                continue;
            }

            var endpoint = endpoints.FirstOrDefault(x =>
                string.Equals(x.Method?.Trim(), method, StringComparison.OrdinalIgnoreCase) &&
                string.Equals(x.Path?.Trim(), url, StringComparison.OrdinalIgnoreCase));

            resolved.Add(new CustomComponentSeedDataSourceDto
            {
                Name = (source.Name ?? string.Empty).Trim(),
                Method = method,
                Url = url,
                ResponsePath = string.IsNullOrWhiteSpace(source.ResponsePath) ? null : source.ResponsePath.Trim(),
                EntityName = endpoint?.EntityName,
                OperationType = endpoint?.OperationType,
                SeedFile = endpoint == null
                    ? null
                    : $"{SeedPathResolver.CrudFolder}/{endpoint.EntityName}.json"
            });
        }

        return resolved;
    }

    /// <summary>Props JSON'undaki designer dokumanindan yalnizca dataSources dizisini ayiklar.</summary>
    private static List<DesignerDataSourceDto> ParseDocumentDataSources(string? props)
    {
        if (string.IsNullOrWhiteSpace(props))
        {
            return [];
        }

        try
        {
            using var document = JsonDocument.Parse(props);
            if (!document.RootElement.TryGetProperty("visualDesigner", out var designer) ||
                designer.ValueKind != JsonValueKind.Object ||
                !designer.TryGetProperty("dataSources", out var dataSources) ||
                dataSources.ValueKind != JsonValueKind.Array)
            {
                return [];
            }

            return JsonSerializer.Deserialize<List<DesignerDataSourceDto>>(dataSources.GetRawText(), JsonReadOptions) ?? [];
        }
        catch (JsonException)
        {
            return [];
        }
    }

    /// <summary>Designer dokumanindaki tek bir data source kaydi.</summary>
    private sealed class DesignerDataSourceDto
    {
        public string? Name { get; set; }
        public string? Method { get; set; }
        public string? Url { get; set; }
        public string? ResponsePath { get; set; }
    }
}