using System;
using System.IO;
using System.Net;
using System.Threading.Tasks;
using Xamarin.Essentials;
using Xamarin.Forms;

namespace Gallery.Util
{
    public static class Store
    {
        public static readonly string PersonalFolder = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
        public static readonly string CacheFolder = FileSystem.CacheDirectory;

        private const string imageFolder = "img-original";
        private const string previewFolder = "img-preview";

        public static async Task<ImageSource> LoadRawImage(string url)
        {
            return await LoadImageAsync(url, null, PersonalFolder, imageFolder, force: true);
        }

        public static async Task<ImageSource> LoadPreviewImage(string url, bool downloading, bool force = false)
        {
            return await LoadImage(url, CacheFolder, previewFolder, downloading, force: force);
        }

        private static async Task<ImageSource> LoadImage(string url, string working, string folder, bool downloading, bool force = false)
        {
            var file = Path.Combine(working, folder, Path.GetFileName(url));
            ImageSource image;
            if (!force && File.Exists(file))
            {
                image = ImageSource.FromFile(file);
            }
            else
            {
                image = null;
            }
            if (downloading && image == null)
            {
                file = await NetHelper.DownloadImage(url, working, folder);
                if (file != null)
                {
                    return ImageSource.FromFile(file);
                }
            }
            return image;
        }

        private static async Task<ImageSource> LoadImageAsync(string url, string id, string working, string folder, bool force = false)
        {
            var file = Path.Combine(working, folder, Path.GetFileName(url));
            ImageSource image;
            if (!force && File.Exists(file))
            {
                image = ImageSource.FromFile(file);
            }
            else
            {
                image = null;
            }
            if (image == null)
            {
                file = await NetHelper.DownloadImageAsync(url, id, working, folder);
                if (file != null)
                {
                    image = ImageSource.FromFile(file);
                }
            }
            return image;
        }
    }

    public static class Config
    {
        public static readonly TimeSpan Timeout = TimeSpan.FromSeconds(30);

        public const string IsProxiedKey = "is_proxied";
        public const string ProxyHostKey = "proxy_host";
        public const string ProxyPortKey = "proxy_port";

        public const string UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36";
        public const string AcceptLanguage = "zh-cn";
        public const string AcceptImage = "image/png,image/*,*/*;q=0.8";

        public static WebProxy Proxy;
    }

    public static class Routes
    {
        public const string Gallery = "gallery";
        public const string Option = "option";
    }
}