using System.Text.Json;
using Serilog;

namespace Discord.API.Rest;

internal class RestClient{

    private HttpClient httpClient;

    public RestClient(string base_url, string api_key)
    {
        Log.Debug("REST: Creating new rest client. Base url: {base_url}", base_url);
        httpClient = new HttpClient(){
            BaseAddress=new Uri(base_url)
        };
        httpClient.DefaultRequestHeaders.Add("Authorization", $"Bot {api_key}");
        httpClient.DefaultRequestHeaders.Add("User-Agent", $"DiscordBot ({StaticProperties.LibraryWebsite}, {StaticProperties.LibraryVersion})");
    }

    internal RestClient(string base_url, string api_key, HttpMessageHandler msg_handler){
        Log.Debug("REST: Creating new rest client. Base url: {base_url}", base_url);
        httpClient = new HttpClient(msg_handler){
            BaseAddress=new Uri(base_url)
        };
        httpClient.DefaultRequestHeaders.Add("Authorization", $"Bot {api_key}");
        httpClient.DefaultRequestHeaders.Add("User-Agent", $"DiscordBot ({StaticProperties.LibraryWebsite}, {StaticProperties.LibraryVersion})");
    }

    public async Task<RestResponse<GetGatewayResponse>> GetGateway() =>
        await Get("gateway", s => JsonSerializer.Deserialize(s, SourceGenerationContext.Default.GetGatewayResponse));

    private async Task<RestResponse<T>> Get<T>(string url, Func<string, T> deserializer){
        try{
            HttpResponseMessage resp = await httpClient.GetAsync(url);
            if(resp.IsSuccessStatusCode){
                Log.Debug("REST: Get {url} successful, http status code: {http_code}", url, resp.StatusCode);
                return new RestSuccessResponse<T>(
                    deserializer.Invoke(await resp.Content.ReadAsStringAsync()),
                    resp.StatusCode
                );
            }else{
                RestError err = JsonSerializer.Deserialize(await resp.Content.ReadAsStringAsync(), SourceGenerationContext.Default.RestError);
                Log.Debug("REST: Get {url} returned error: HTTP: {http_code}, ERR: {err_code}; {err_msg}", url, resp.StatusCode, err.Code, err.Message);                
                return new RestErrorResponse<T>(
                    err, resp.StatusCode
                );
            }
        }catch (Exception ex){
            Log.Debug(ex, "REST: Get {url} failed.", url);
            return new RestFailResponse<T>(ex);
        }
    }

}