DbFirst/DbFirst.BlazorWebApp/Services/MassDataApiClient.cs

using System.Net.Http.Json;
using DbFirst.BlazorWebApp.Models;

namespace DbFirst.BlazorWebApp.Services;

public class MassDataApiClient
{
    private readonly HttpClient _httpClient;
    private const string Endpoint = "api/massdata";

    public MassDataApiClient(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }

    public async Task<int> GetCountAsync()
    {
        var result = await _httpClient.GetFromJsonAsync<int?>("api/massdata/count");
        return result ?? 0;
    }

    public async Task<List<MassDataReadDto>> GetAllAsync(int? skip, int? take)
    {
        var query = new List<string>();
        if (skip.HasValue)
        {
            query.Add($"skip={skip.Value}");
        }
        if (take.HasValue)
        {
            query.Add($"take={take.Value}");
        }

        var url = query.Count == 0 ? Endpoint : $"{Endpoint}?{string.Join("&", query)}";
        var result = await _httpClient.GetFromJsonAsync<List<MassDataReadDto>>(url);
        return result ?? new List<MassDataReadDto>();
    }

    public async Task<ApiResult<MassDataReadDto?>> UpsertAsync(MassDataWriteDto dto)
    {
        var response = await _httpClient.PostAsJsonAsync($"{Endpoint}/upsert", dto);
        if (response.IsSuccessStatusCode)
        {
            var payload = await response.Content.ReadFromJsonAsync<MassDataReadDto>();
            return ApiResult<MassDataReadDto?>.Ok(payload);
        }

        var error = await ReadErrorAsync(response);
        return ApiResult<MassDataReadDto?>.Fail(error);
    }

    private static async Task<string> ReadErrorAsync(HttpResponseMessage response)
    {
        try
        {
            var problem = await response.Content.ReadFromJsonAsync<ProblemDetailsDto>();
            if (problem != null && !string.IsNullOrWhiteSpace(problem.Title))
                return problem.Detail ?? problem.Title ?? response.ReasonPhrase ?? "Unbekannter Fehler";
        }
        catch { }

        var body = await response.Content.ReadAsStringAsync();
        if (!string.IsNullOrWhiteSpace(body))
            return body;

        return $"Fehler {(int)response.StatusCode} {response.ReasonPhrase}".Trim();
    }

    public async Task<MassDataReadDto?> GetByCustomerNameAsync(string customerName)
    {
        if (string.IsNullOrWhiteSpace(customerName))
        {
            return null;
        }

        var response = await _httpClient.GetAsync($"{Endpoint}/{Uri.EscapeDataString(customerName)}");
        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
        {
            return null;
        }

        response.EnsureSuccessStatusCode();
        return await response.Content.ReadFromJsonAsync<MassDataReadDto>();
    }
}