using System.Net;
using System.Net.Http.Json;
using System.Text.Json;
using EnvelopeGenerator.ReceiverUI.Models;
using EnvelopeGenerator.ReceiverUI.Options;
using Microsoft.Extensions.Options;

namespace EnvelopeGenerator.ReceiverUI.Services;

/// <summary>
/// Retrieves the <see cref="EnvelopeReceiverDto"/> for the authenticated receiver
/// from <c>GET api/EnvelopeReceiver/{envelopeKey}</c>.
/// </summary>
public class EnvelopeReceiverService(HttpClient http, IOptions<ApiOptions> apiOptions)
{
    private static readonly JsonSerializerOptions _jsonOptions = new(JsonSerializerDefaults.Web);

    /// <summary>
    /// Fetches the envelope receiver data for the given envelope key from the API.
    /// Throws HttpRequestException on failure with appropriate status code.
    /// </summary>
    /// <exception cref="HttpRequestException">Thrown when the API request fails.</exception>
    public async Task<EnvelopeReceiverDto?> GetAsync(string envelopeKey, CancellationToken cancel = default)
    {
        var url = $"{apiOptions.Value.BaseUrl}/api/EnvelopeReceiver/{Uri.EscapeDataString(envelopeKey)}";
        var response = await http.GetAsync(url, cancel);

        if (!response.IsSuccessStatusCode)
        {
            var statusCode = (int)response.StatusCode;
            var reasonPhrase = response.ReasonPhrase ?? "Unknown error";
            throw new HttpRequestException(
                $"Failed to load envelope receiver data. Status: {statusCode} ({reasonPhrase})",
                null,
                response.StatusCode);
        }

        return await response.Content.ReadFromJsonAsync<EnvelopeReceiverDto>(_jsonOptions, cancel);
    }
}