using ModVersionChecker.data.model;
using System;
using System.Net.Http;
using System.Text.Json;
using System.Threading.Tasks;

namespace ModVersionChecker
{
    public class ApiChecker : IVersionChecker
    {
        private static readonly HttpClient _httpClient = new HttpClient();

        public async Task<string> GetLatestVersion(Dictionary<string, string> paramsDict, SourceDef source)
        {
            if (!paramsDict.TryGetValue("url", out var url) || string.IsNullOrEmpty(url))
            {
                throw new ArgumentException("API URL required");
            }
            if (!paramsDict.TryGetValue("jsonPath", out var jsonPath) || string.IsNullOrEmpty(jsonPath))
            {
                throw new ArgumentException("jsonPath required");
            }

            var response = await _httpClient.GetAsync(url);
            if (!response.IsSuccessStatusCode)
            {
                throw new Exception($"API error: {(int)response.StatusCode} {response.ReasonPhrase}");
            }

            var body = await response.Content.ReadAsStringAsync();
            if (string.IsNullOrEmpty(body))
            {
                throw new Exception("Empty API response");
            }

            using var jsonDoc = JsonDocument.Parse(body);
            var element = jsonDoc.RootElement;

            foreach (var key in jsonPath.Split('.'))
            {
                if (!element.TryGetProperty(key, out var nextElement))
                {
                    throw new Exception($"JSON key '{key}' not found in response");
                }
                element = nextElement;
            }

            if (element.ValueKind != JsonValueKind.String)
            {
                throw new Exception($"JSON value for '{jsonPath}' is not a string");
            }

            return element.GetString()!.Trim();
        }
    }
}