#define WV_DEBUG

using Android.App;
using Android.OS;
using Android.Util;
using Android.Views;
using Android.Webkit;
using Java.Interop;
using Java.Lang;
using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Android;
using Android.Content;
using Android.Content.PM;
using Android.Widget;

namespace LnoidWv
{
    using JsLab.JsApi;

    // ReSharper disable once ClassNeverInstantiated.Global
    [Activity(Label = "!轻离阅", MainLauncher = true, Icon = "@drawable/icon")]
    public partial class MainActivity : Activity { }

    public class NativeFunctions : JsApiBase
    {
        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public bool PathExist(string path)
        {
            return Directory.Exists(path);
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetDirs(string path, bool full = false)
        {
            var directories = Directory.GetDirectories(path);

            var array = full
                ? directories
                : directories.Select(Path.GetFileName).ToArray();

            Array.Sort(array);

            return array;
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetPrefixes(string dataPath, Action<object> cbProcess = null)
        {
            var directories = Directory.GetDirectories(dataPath);

            Array.Sort(directories);

            var progress = cbProcess == null
                ? new Action<int>(delegate { })
                : p => cbProcess(new { Total = directories.Length, Current = p });

            return directories.Select(delegate (string prefixPath, int index)
            {
                var foo = new
                {
                    Path = prefixPath,
                    Prefix = Path.GetFileName(prefixPath)?.ToUpper(),
                    SeriesCount = Directory.GetDirectories(prefixPath).Length,
                };

                progress(index + 1);

                return foo;
            }).ToArray();
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetSeries(string prefixPath, Action<object> cbProcess = null)
        {
            var directories = Directory.GetDirectories(prefixPath);

            Array.Sort(directories);

            var progress = cbProcess == null
                ? new Action<int>(delegate { })
                : p => cbProcess(new { Total = directories.Length, Current = p });

            return directories
                .OrderBy(p => p)
                .Select((seriesPath, index) =>
                {
                    var subDirs = Directory.GetDirectories(seriesPath).OrderBy(p => p).ToArray();

                    var obj = new
                    {
                        Path = seriesPath,
                        SeriesName = File.ReadAllText(Path.Combine(seriesPath, "sname.txt")),
                        VolumeCount = subDirs.Length,
                        CoverData = subDirs
                            .Select(s => Path.Combine(s, "cover.jpg")).Where(File.Exists)
                            .Select(p => "data:image/jpeg;base64," + Convert.ToBase64String(File.ReadAllBytes(p)))
                            .FirstOrDefault()
                    };

                    progress(index + 1);

                    return obj;
                }).ToArray();
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetVolumes(string seriesPath, Action<object> cbProcess = null)
        {
            var directories = Directory.GetDirectories(seriesPath);

            Array.Sort(directories);

            var progress = cbProcess == null
                ? new Action<int>(delegate { })
                : p => cbProcess(new { Total = directories.Length, Current = p });

            return directories.OrderBy(p => p)
                .Select((volumePath, index) =>
                {
                    var b64 = Convert.ToBase64String(File.ReadAllBytes(Path.Combine(volumePath, "cover.jpg")), Base64FormattingOptions.None);

                    var obj = new
                    {
                        Path = volumePath,
                        VolumeName = File.ReadAllText(Path.Combine(volumePath, "vname.txt")),
                        ChapterCount = Directory.GetDirectories(volumePath).Length,
                        CoverData = $"data:image/jpeg;base64,{b64}",
                    };

                    progress(index + 1);

                    return obj;
                }).ToArray();
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetChapters(string volumePath, Action<object> cbProcess = null)
        {
            var directories = Directory.GetDirectories(volumePath);

            Array.Sort(directories);

            var progress = cbProcess == null
                ? new Action<int>(delegate { })
                : p => cbProcess(new { Total = directories.Length, Current = p });

            return directories
                .OrderBy(p => p)
                .Select((chapterPath, index) =>
                {
                    var pictures1 = Directory.GetFiles(chapterPath, "*.jpg");
                    var pictures2 = Directory.GetFiles(chapterPath, "*.JPG");

                    var firstBase64 = pictures1.Concat(pictures2)
                        .OrderBy(filename => filename)
                        .Select(filename => "data:image/jpeg;base64," + Convert.ToBase64String(File.ReadAllBytes(filename), Base64FormattingOptions.None))
                        .FirstOrDefault();

                    var obj = new
                    {
                        Path = chapterPath,
                        ChapterName = File.ReadAllText(Path.Combine(chapterPath, "cname.txt")),
                        FirstPicture = firstBase64
                    };

                    progress(index + 1);

                    return obj;
                }).ToArray();
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public object GetChapterContent(string chapterPath, Action<object> cbProcess = null)
        {
            var lines = File.ReadAllLines(Path.Combine(chapterPath, "ctext.txt"));

            var progress = cbProcess == null
                ? new Action<int>(delegate { })
                : p => cbProcess(new { Total = lines.Length, Current = p });


            for (var i = 0; i < lines.Length; i++)
            {
                var line = lines[i];
                if (!line.StartsWith("<img")) continue;

                var picnam = System.Web.HttpUtility.HtmlDecode(line)
                    .Replace("<img src=\"hybrid://pic?", "")
                    .Replace("\"/>", "")
                    ;

                var picabs = Path.Combine(chapterPath, picnam);
                var b64 = Convert.ToBase64String(File.ReadAllBytes(picabs), Base64FormattingOptions.None);
                lines[i] = $"<img src='data:image/jpeg;base64,{b64}' />";

                progress(i + 1);
            }
            return lines;
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public string ReadSetting()
        {
#if !Android22
            if (Android.OS.Environment.IsExternalStorageManager == false)
            {
                var uri = Android.Net.Uri.Parse("package:" + Application.Context.ApplicationInfo.PackageName);
                var intent = new Intent(Android.Provider.Settings.ActionManageAppAllFilesAccessPermission, uri);
                _mainActivity.StartActivityForResult(intent, 9527);
            }
#endif

            var localStorage = _mainActivity.Application.FilesDir.Path;
            var configFilePath = Path.Combine(localStorage, "config.json");
            return File.Exists(configFilePath)
                ? File.ReadAllText(configFilePath)
                : null;
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public void WriteSetting(string json)
        {
            var localStorage = _mainActivity.Application.FilesDir.Path;
            var configFilePath = Path.Combine(localStorage, "config.json");
            File.WriteAllText(configFilePath, json);
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public void ExitApp()
        {
            JavaSystem.Exit(0);
        }

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public void WriteLog(string content)
        {
            Log.Debug($"{_mainActivity.Application.PackageName}::JsApi::{nameof(WriteLog)}", content);
        }



        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public void CopyText(string text)
        {
            var myClipboard = (ClipboardManager)_mainActivity.GetSystemService(Context.ClipboardService);
            var myClip = ClipData.NewPlainText("text", text);
            myClipboard.PrimaryClip = myClip;
            Toast.MakeText(_mainActivity.Application, "文本已复制", ToastLength.Short).Show();
        }

        private readonly MainActivity _mainActivity;

        public NativeFunctions(MainActivity mainActivity, string jsBindName) : base(jsBindName)
        {
            _mainActivity = mainActivity;
        }

        protected override void CallJs(string code)
        {
            _mainActivity.RunOnUiThread(() => _mainActivity.CallJs(code));
        }

#if DEBUG || WV_DEBUG

        [JsApi]
        // ReSharper disable once UnusedMember.Global
        public void ReLoad()
        {
            _mainActivity.RunOnUiThread(() => _mainActivity.ReLoad());
        }

#endif
        // TODO: UI Config - GridSize(0.5x-10x) - TextSize(5-127) - UiZoom(25-500%) - TextZoom(25-500%) - PictureMode(Auto,FitW/H)
        // TODO: Fav/Continue (Chapter Entry) -> (Content Scroll Percent)
        // TODO: State S/L -- Restore on back

        // TODO: Read Zip file directly
        // TODO: Indexing for Improve load speed
        // BUG: DON'T Reload after screen rotated

        // TODO: Implement more functions to improve this app.
    }


    // ReSharper disable once ClassNeverInstantiated.Global
    public partial class MainActivity
    {
        private const string MainUrl =
        //#if DEBUG
        //            "http://192.168.23.97/main.html"
        //        //  "http://192.168.1.233/main.html"
        //        //  "http://lnoidebugserver/main.html"
        //#else
        "file:///android_asset/main.html"
        //#endif
        ;

        private const string JsBindName = "LnoidNativeFunctions";

        private WebView _view;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

#if !Android22
            if (CheckSelfPermission(Manifest.Permission.ReadExternalStorage) != Permission.Granted)
                RequestPermissions(new[] { Manifest.Permission.ReadExternalStorage }, 123321123); //  is an app-defined int constant that should be quite unique

            //var uri = Android.Net.Uri.Parse("package:" + Application.Context.ApplicationInfo.PackageName);
            //var intent = new Intent(Android.Provider.Settings.ActionManageAppAllFilesAccessPermission, uri, ApplicationContext, GetType());
            //StartActivity(intent);
#endif

            RequestWindowFeature(WindowFeatures.NoTitle);


#if DEBUG || WV_DEBUG
#if !Android22
            if (Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat)
                WebView.SetWebContentsDebuggingEnabled(true);
#else
            WebView.EnablePlatformNotifications();
#endif
#else
#if !Android22
            if (Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat)
                WebView.SetWebContentsDebuggingEnabled(false);
#endif
#endif

            _view = new WebView(this);
            _view.SetWebChromeClient(new WebChromeClient());

#pragma warning disable 618
            _view.LayoutParameters = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FillParent, ViewGroup.LayoutParams.FillParent);
#pragma warning restore 618

            _view.SetPadding(0, 0, 0, 0);

            SetContentView(_view);
            _view.SetInitialScale(100);
            _view.Settings.JavaScriptEnabled = true;

            var nativeFunctions = new NativeFunctions(this, JsBindName);
            _view.AddJavascriptInterface(nativeFunctions, JsBindName);

            _view.LoadUrl(MainUrl);
        }

        internal void CallJs(string code)
        {
            _view.LoadUrl($"javascript:{code}");
        }

        public override void OnBackPressed()
        {
            CallJs("__backButton_Pressed();");
        }

        public override bool OnKeyUp(Keycode keyCode, KeyEvent e)
        {
            if (keyCode == Keycode.Menu)
            {
                CallJs("__menuButton_Pressed();");
                return true;
            }
            return base.OnKeyUp(keyCode, e);
        }

#if WV_DEBUG
        public void ReLoad()
        {
            _view.LoadUrl(MainUrl);
        }
#endif
    }
}

// ReSharper disable once CheckNamespace
namespace JsLab.JsApi
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Reflection;

    public abstract class JsApiBase : Java.Lang.Object
    {
        private readonly string _jsBindName;
        private readonly IReadOnlyDictionary<string, JsApiMethod> _jsApiMethodDictionary;

        [AttributeUsage(AttributeTargets.Method)]
        protected sealed class JsApiAttribute : Attribute
        {
        }

        // ReSharper disable UnusedAutoPropertyAccessor.Local
        // ReSharper disable ClassNeverInstantiated.Local

        private sealed class InvokeRequestModel
        {
            public string MethodName { get; set; }
            public object[] Arguments { get; set; }
        }

        private sealed class InvokeRequestCallback
        {
            public string CallBack { get; set; }
        }

        // ReSharper restore ClassNeverInstantiated.Local
        // ReSharper restore UnusedAutoPropertyAccessor.Local

        private class JsApiMethod
        {
            public MethodInfo MethodInfo { get; }
            public IReadOnlyList<JsApiParmeter> ParameterInfos { get; }

            public JsApiMethod(MethodInfo methodInfo, IReadOnlyList<JsApiParmeter> parameterInfos)
            {
                MethodInfo = methodInfo;
                ParameterInfos = parameterInfos;
            }
        }

        private class JsApiParmeter
        {
            public string Name { get; }
            public bool IsCallback { get; }
            public JsApiParmeter(string name, bool isCallback)
            {
                Name = name;
                IsCallback = isCallback;
            }
        }

        protected JsApiBase(string jsBindName)
        {
            var myType = GetType();

            var tObjectAction = typeof(Action<object>);

            _jsApiMethodDictionary = myType.GetMethods()
                .Where(p => p.IsDefined(typeof(JsApiAttribute), true))
                .Select(p => new JsApiMethod(
                    p,
                    p.GetParameters()
                     .Select(q => new JsApiParmeter(q.Name, q.ParameterType == tObjectAction))
                     .ToArray()
                ))
                .ToDictionary(p => p.MethodInfo.Name);

            _jsBindName = jsBindName;
        }


        [Export]
#if !Android22
        [JavascriptInterface]
#endif
        // ReSharper disable once MemberCanBePrivate.Global
        public string GenerateFunctionJsonStub()
        {
            var methods = _jsApiMethodDictionary.Values.ToArray();

            // ReSharper disable once UseObjectOrCollectionInitializer
            var list = new List<string>(methods.Length);

            list.Add("$mkCallback:function(c,r){" +
                "if(typeof c!=='function') "
                + "return undefined;" +
                "if(!this.$cbIdx)"
                + "this.$cbIdx=1;" +
                "else "
                + "this.$cbIdx++;" +
                "var cbName='__cb_'+this.$cbIdx;" +
                "window[cbName]=function(d){"
                + "if(r)delete window[cbName];"
                + "c(d);" +
                "};" +
                "return cbName;" +
            "}");


            foreach (var jsApiMethod in methods)
            {
                var method = jsApiMethod.MethodInfo;
                var parameterInfos = jsApiMethod.ParameterInfos;

                var lstArgs = parameterInfos.Select((p, i) => "p" + i + "_" + p.Name).ToList();
                var argList = string.Join(",", lstArgs);

                var fnSync =
                    $"{method.Name}:function({argList})" + "{" +
                    "var arg={" + $"MethodName:'{method.Name}',Arguments:[{argList}]" + "};" +
                    "var argson=JSON.stringify(arg);" +
                    $"return JSON.parse({_jsBindName}.InvokeInterface(argson));" + "}";

                lstArgs.Insert(0, "p_callback");
                var argListAsync = string.Join(",", lstArgs);

                //Async version with callback

                var fnAsync =
                    $"{method.Name}Async:function({argListAsync})" + "{" +
                    $"if(!p_callback) throw 'callback are required.[{method.Name}Async]';" +
                     "var args=[];";

                var lstCbToDel = new List<string>(parameterInfos.Count);

                for (var i = 0; i < parameterInfos.Count; i++)
                {
                    var item = parameterInfos[i];
                    var pName = lstArgs[i + 1];// skip p_callback
                    if (item.IsCallback)
                    {
                        fnAsync +=
                            $"var cbName_{i}='undefined';" +
                            $"if(typeof {pName}!=='function')" + "{"
                            + "args.push(null);" +
                            "}else{"
                            + $"cbName_{i}=this.$mkCallback({pName},false);"
                            + $"args.push(cbName_{i});" +
                            "}";

                        lstCbToDel.Add($"cbName_{i}");
                    }
                    else
                    {
                        fnAsync += $"args.push({pName});";
                    }
                }

                fnAsync +=
                    "var cbName=this.$mkCallback(function(retr){"
                    + string.Join("", lstCbToDel.Select(p => $"delete window[{p}];"))
                    + "p_callback(retr);" +
                    "},true);" +
                    "var arg={" + $"MethodName:'{method.Name}'" + ",Arguments:args" + ",CallBack:cbName" + "};" +
                    "var argson=JSON.stringify(arg);" +
                    $"{_jsBindName}.InvokeInterfaceAsync(argson)" +
                    // cancel token handle: too lazy to implement!
                    "}";

                list.Add(fnSync);
                list.Add(fnAsync);
            }

            return "{" + string.Join(",", list) + "}";
        }

        [Export]
#if !Android22
        [JavascriptInterface]
#endif
        // ReSharper disable once UnusedMember.Global
        public string GenerateFunctionStubForEval()
        {
            var ret = $"({GenerateFunctionJsonStub()})";
            return ret;
        }

        [Export]
#if !Android22
        [JavascriptInterface]
#endif
        // ReSharper disable once UnusedMember.Global
        public void InvokeInterfaceAsync(string json)
        {
            // cancel token handle: too lazy to implement!
#if Android22
            var im = fastJSON.JSON.ToObject<InvokeRequestCallback>(json);
#else
            var im = Newtonsoft.Json.JsonConvert.DeserializeObject<InvokeRequestCallback>(json);
#endif
            Task.Factory.StartNew(() =>
            {
                var ret = InvokeInterface(json);
                var code = $"{im.CallBack}({ret})";
                CallJs(code);
            });
        }

        [Export]
#if !Android22
        [JavascriptInterface]
#endif
        // ReSharper disable once UnusedMember.Global
        // ReSharper disable once MemberCanBePrivate.Global
        public string InvokeInterface(string json)
        {
            object r;

            try
            {
#if Android22
                var im = fastJSON.JSON.ToObject<InvokeRequestModel>(json);
#else
                var im = Newtonsoft.Json.JsonConvert.DeserializeObject<InvokeRequestModel>(json);
#endif
                var method = _jsApiMethodDictionary[im.MethodName];

                for (var i = 0; i < im.Arguments.Length; i++)
                {
                    if (im.Arguments[i] == null)
                    {
                        im.Arguments[i] = Type.Missing;
                    }
                    else if (method.ParameterInfos[i].IsCallback)
                    {
                        var jsFunction = (string)im.Arguments[i];
                        im.Arguments[i] = new Action<object>(
                            o => CallJs($"{jsFunction}({Newtonsoft.Json.JsonConvert.SerializeObject(o)})"));
                    }
                }

                r = new
                {
                    Success = true,
                    Result = method.MethodInfo.Invoke(this, im.Arguments)
                };
            }
            catch (Exception ex)
            {
                r = new
                {
                    Success = false,
                    Exception = ex
                };
            }

#if Android22
            return fastJSON.JSON.ToJSON(r);
#else
            return Newtonsoft.Json.JsonConvert.SerializeObject(r);
#endif
        }

        protected abstract void CallJs(string code);
    }
}

#if Android22

namespace System.Net
{
    internal class WebUtility
    {
        public static readonly Func<string, string> HtmlEncode = Web.HttpUtility.HtmlEncode;
    }
}

#endif