using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text.Json;
using System.Threading.Tasks;

namespace LibreAuth.Sdk
{
    public class LibreAuth
    {
        public string Name { get; set; }
        public string OwnerId { get; set; }
        public string Version { get; set; }
        public string Url { get; set; }
        public string SessionId { get; private set; }
        public string EncKey { get; private set; }

        private static readonly HttpClient Http = new HttpClient();

        public LibreAuth(string name, string ownerId, string version, string url)
        {
            Name = name;
            OwnerId = ownerId;
            Version = version;
            Url = url.TrimEnd('/') + "/";
        }

        public async Task<JsonDocument> InitAsync(string enckey = null)
        {
            EncKey = (enckey ?? Guid.NewGuid().ToString("N")).Substring(0, 35);
            var res = await ReqAsync(new Dictionary<string, string>
            {
                ["type"] = "init",
                ["ver"] = Version,
                ["enckey"] = EncKey,
            });
            if (!res.RootElement.GetProperty("success").GetBoolean())
                throw new Exception(res.RootElement.GetProperty("message").GetString());
            SessionId = res.RootElement.GetProperty("sessionid").GetString();
            return res;
        }

        public async Task<JsonElement> LoginAsync(string user, string pass, string hwid = "", string code = "")
        {
            return await AuthAsync(new Dictionary<string, string>
            {
                ["type"] = "login",
                ["username"] = user,
                ["pass"] = pass,
                ["hwid"] = hwid,
                ["code"] = code,
            });
        }

        public async Task<JsonElement> LicenseAsync(string key, string hwid = "")
        {
            return await AuthAsync(new Dictionary<string, string>
            {
                ["type"] = "license",
                ["key"] = key,
                ["hwid"] = hwid,
            });
        }

        public async Task<JsonElement> TokenAsync(string token, string hwid = "")
        {
            return await AuthAsync(new Dictionary<string, string>
            {
                ["type"] = "token",
                ["token"] = token,
                ["hwid"] = hwid,
            });
        }

        async Task<JsonElement> AuthAsync(Dictionary<string, string> data)
        {
            var res = await ReqAsync(data);
            if (!res.RootElement.GetProperty("success").GetBoolean())
                throw new Exception(res.RootElement.GetProperty("message").GetString());
            return res.RootElement.GetProperty("info");
        }

        async Task<JsonDocument> ReqAsync(Dictionary<string, string> data)
        {
            data["name"] = Name;
            data["ownerid"] = OwnerId;
            if (SessionId != null) data["sessionid"] = SessionId;

            var content = new FormUrlEncodedContent(data);
            var resp = await Http.PostAsync(Url, content);
            if ((int)resp.StatusCode == 429) throw new Exception("Rate limited");
            var json = await resp.Content.ReadAsStringAsync();
            return JsonDocument.Parse(json);
        }
    }
}