ReC/src/ReC.Application/Common/Behaviors/HeaderQueryBehavior.cs

using MediatR;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using ReC.Application.Common.Dto;
using ReC.Application.Common.Interfaces;
using System.Text.Json;

namespace ReC.Application.Common.Behaviors;

public class HeaderQueryBehavior<TRequest, TResponse>(IRecDbContext dbContext, ILogger<HeaderQueryBehavior<TRequest, TResponse>>? logger = null) : IPipelineBehavior<TRequest, TResponse>
    where TRequest : RecActionViewDto
    where TResponse : notnull
{
    public async Task<TResponse> Handle(TRequest action, RequestHandlerDelegate<TResponse> next, CancellationToken cancel)
    {
        if (action.HeaderQuery is null)
            return await next(cancel);

        var result = await dbContext.HeaderQueryResults.FromSqlRaw(action.HeaderQuery).SingleOrDefaultAsync(cancel);

        if (result?.RawHeader is null)
        {
            logger?.LogWarning("Header query did not return a result or returned a null REQUEST_HEADER. Profile ID: {ProfileId}, Action ID: {Id}", action.ProfileId, action.Id);

            return await next(cancel);
        }

        var headerDict = JsonSerializer.Deserialize<Dictionary<string, JsonElement>>(result.RawHeader);

        if(headerDict is null)
        {
            logger?.LogWarning(
                "Header JSON deserialization returned null. RawHeader: {RawHeader}, ProfileId: {ProfileId}, Id: {Id}",
                result.RawHeader, action.ProfileId, action.Id);

            return await next(cancel);
        }

        action.Headers = headerDict.ToDictionary(header => header.Key, kvp => kvp.Value.ToString());

        return await next(cancel);
    }
}