using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;
using Xamarin.Essentials;
using Xamarin.Forms;

namespace Pixiview.Utils
{
    public class Stores
    {
        public static readonly string PersonalFolder = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
        //public static readonly string CacheFolder = Environment.GetFolderPath(Environment.SpecialFolder.InternetCache);
        private const string imageFolder = "img-master";
        private const string thumbFolder = "img-thumb";
        private const string userFolder = "user-profile";
        private const string illustFile = "illust.json";

        public static bool NetworkAvailable
        {
            get
            {
                try
                {
                    return Connectivity.NetworkAccess == NetworkAccess.Internet
                        || Connectivity.NetworkAccess == NetworkAccess.ConstrainedInternet;
                }
                catch
                {
                    return false;
                }
            }
        }

        public static async Task<IllustData> LoadIllustData()
        {
            var file = Path.Combine(PersonalFolder, illustFile);
            string content = null;
            if (File.Exists(file))
            {
                try
                {
                    content = File.ReadAllText(file);
                }
                catch (Exception ex)
                {
                    App.DebugError("illust.load", $"failed to read file: {file}, error: {ex.Message}");
                }
            }
            if (content == null)
            {
                var response = Download(Configs.UrlIllust, headers: new[]
                {
                    ("cookie",    Configs.Cookie),
                    ("x-user-id", Configs.UserId)
                });
                if (response == null)
                {
                    return null;
                }
                using (response)
                {
                    content = await response.Content.ReadAsStringAsync();
                    try
                    {
                        File.WriteAllText(file, content, Encoding.UTF8);
                    }
                    catch (Exception ex)
                    {
                        App.DebugError("illust.save", $"failed to save illust JSON object, error: {ex.Message}");
                    }
                }
            }
            try
            {
                return JsonConvert.DeserializeObject<IllustData>(content);
            }
            catch (Exception ex)
            {
                App.DebugError("illust.load", $"failed to parse illust JSON object, error: {ex.Message}");
                return null;
            }
        }

        public static ImageSource LoadIllustImage(string url)
        {
            return LoadImage(url, imageFolder);
        }

        public static ImageSource LoadThumbnailImage(string url)
        {
            return LoadImage(url, thumbFolder);
        }

        public static ImageSource LoadUserProfileImage(string url)
        {
            return LoadImage(url, userFolder);
        }

        public static ImageSource LoadImage(string url, string folder)
        {
            var file = Path.Combine(PersonalFolder, folder, Path.GetFileName(url));
            if (!File.Exists(file))
            {
                file = DownloadImage(url, folder);
            }
            if (file != null)
            {
                return ImageSource.FromFile(file);
            }
            return null;
        }

        public static string DownloadImage(string url, string folder)
        {
            try
            {
                var directory = Path.Combine(PersonalFolder, folder);
                if (!Directory.Exists(directory))
                {
                    Directory.CreateDirectory(directory);
                }
                var file = Path.Combine(directory, Path.GetFileName(url));
                App.DebugPrint($"download, url: {url}");
                var response = Download(url);
                if (response == null)
                {
                    return null;
                }
                using (response)
                using (var fs = File.OpenWrite(file))
                {
                    response.Content.CopyToAsync(fs).Wait();
                    //if (response.Headers.Date != null)
                    //{
                    //    File.SetLastWriteTimeUtc(file, response.Headers.Date.Value.UtcDateTime);
                    //}
                }
                return file;
            }
            catch (Exception ex)
            {
                App.DebugError("image.download", ex.Message);
                return null;
            }
        }

        private static T TryCount<T>(Func<T> func, int tryCount = 3)
        {
            int tries = 0;
            while (tries < tryCount)
            {
                try
                {
                    return func();
                }
                catch (Exception ex)
                {
                    tries++;
                    System.Threading.Thread.Sleep(400);
                    App.DebugError("try.do", $"tries: {tries}, error: {ex.Message}");
                }
            }
            return default;
        }

        private static HttpResponseMessage Download(string url, string referer = null, IEnumerable<(string header, string value)> headers = null)
        {
            App.DebugPrint($"GET: {url}");
            var uri = new Uri(url);
            var handler = new HttpClientHandler
            {
                Proxy = Configs.Proxy,
                UseProxy = true
            };
            var client = new HttpClient(handler)
            {
                BaseAddress = new Uri($"{uri.Scheme}://{uri.Host}")
            };
            return TryCount(() =>
            {
                using (var request = new HttpRequestMessage(HttpMethod.Get, uri.PathAndQuery)
                {
                    Version = new Version(2, 0)
                })
                {
                    request.Headers.Referrer = referer == null ? Configs.Referer : new Uri(referer);
                    request.Headers.Add("user-agent", Configs.UserAgent);
                    if (headers != null)
                    {
                        foreach (var (header, value) in headers)
                        {
                            request.Headers.Add(header, value);
                        }
                    }
                    return client.SendAsync(request).Result;
                }
            });
        }
    }

    public static class Configs
    {
        public static readonly WebProxy Proxy = new WebProxy("router.tsanie.us", 8088);
        public static readonly Uri Referer = new Uri("https://www.pixiv.net/");

        public const int MaxThreads = 3;
        public const string UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.129 Safari/537.36";
        public const string UrlIllust = "https://www.pixiv.net/ajax/top/illust?mode=all&lang=zh";
        public const string Cookie = "first_visit_datetime_pc=2019-10-29+22%3A05%3A30; p_ab_id=2; p_ab_id_2=6;" +
            " p_ab_d_id=1155161977; a_type=0; b_type=1; d_type=2; module_orders_mypage=%5B%7B%22name%22%3A%22s" +
            "ketch_live%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22tag_follow%22%2C%22visible%22%3Atrue" +
            "%7D%2C%7B%22name%22%3A%22recommended_illusts%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22ev" +
            "eryone_new_illusts%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22following_new_illusts%22%2C%" +
            "22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22mypixiv_new_illusts%22%2C%22visible%22%3Atrue%7D%2C%7" +
            "B%22name%22%3A%22spotlight%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22fanbox%22%2C%22visib" +
            "le%22%3Atrue%7D%2C%7B%22name%22%3A%22featured_tags%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3" +
            "A%22contests%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22user_events%22%2C%22visible%22%3At" +
            "rue%7D%2C%7B%22name%22%3A%22sensei_courses%22%2C%22visible%22%3Atrue%7D%2C%7B%22name%22%3A%22boot" +
            "h_follow_items%22%2C%22visible%22%3Atrue%7D%5D; yuid_b=NgcXQWQ; login_ever=yes; c_type=31; PHPSES" +
            "SID=2603358_VHyGPeRaz7LpeoFkRsHvjXIpApCMb56a; __cfduid=d9fa2d4d1ddd30db85ebb519f9855d256158780674" +
            "7; privacy_policy_agreement=2";
        public const string UserId = "2603358";

        public static string GetThumbnailUrl(string url)
        {
            url = url.Replace("/custom-thumb/", "/img-master/");
            var index = url.LastIndexOf("_square1200.jpg");
            if (index < 0)
            {
                index = url.LastIndexOf("_custom1200.jpg");
            }
            if (index >= 0)
            {
                return url.Substring(0, index) + "_master1200.jpg";
            }
            return url;
        }
    }
}