using System;
using System.Collections.Generic;
using System.Linq;
using Bridge;
using Bridge.Html5;
using Bridge.Text.RegularExpressions;

namespace WebMrbc
{
	public class Mruby
	{
		public object[] preRun = new object[0];
		public object[] postRun = new object[0];

		public Mruby()
		{
			/*canvas = Document.GetElementById("canvas");

			// As a default initial behavior, pop up an alert when webgl context is lost. To make your
			// application robust, you may want to override this behavior before shipping!
			// See http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.15.2
			canvas.AddEventListener("webglcontextlost", new Action<Event>((Event e) => {
				Window.Alert("WebGL context lost. You will need to reload the page."); e.PreventDefault();
			}), false);*/
			setStatus = new Action<string>(_setStatus);
		}

		public void print(object arg)
		{
			string text;
			Array args;
			if (arg.GetType() == typeof(string))
				text = (string)arg;
			else if (arg.GetType().Is<Array>() && (args = (Array)arg).Length > 1) {
				var texts = new string[0];
				foreach (var ele in args) {
					texts.Push(ele.ToString());
				}
				text = texts.Join(" ");
			}
			else
				text = arg.ToString();

			App.WriteLine(text);
		}

		public void printErr(object arg)
		{
			string text;
			Array args;
			if (arg.GetType() == typeof(string))
				text = (string)arg;
			else if (arg.GetType().Is<Array>() && (args = (Array)arg).Length > 1) {
				var texts = new string[0];
				foreach (var ele in args) {
					texts.Push(ele.ToString());
				}
				text = texts.Join(" ");
			}
			else
				text = arg.ToString();

			App.WriteLine(text);
		}

		internal void run(string[] args)
		{
			App.Write("$ " + args.Join(" ") + "\r\n");

			var exe = (string)args.Shift();
			this["arguments"] = args;

			var onerror = Window.OnError;
			Window.OnError = new ErrorEventHandler((string message, string url, int lineNumber, int columnNumber, object error) => {
				var spinnerElement = Document.GetElementById("spinner");
				// TODO: do not warn on ok events like simulating an infinite loop or exitStatus
				setStatus("Exception thrown, see JavaScript console");
				spinnerElement.Style.Display = Display.None;
				setStatus = new Action<string>((text) => {
					if (!string.IsNullOrEmpty(text))
						printErr(new[] { "[post-exception status] " + text });
				});
				onerror(message, url, lineNumber, columnNumber, error);
				return false;
			});
			try {
				Script.Eval(exe + "(this)");
			}
			finally {
				Window.OnError = onerror;
			}
		}

		public HTMLElement canvas;
		public Action<string> setStatus;

		object _last;
		string _text;

		private void _setStatus(string text)
		{
			if (_last == null) _last = new { time = DateTime.Now.Ticks, text = "" };
			if (text == _text) return;
			_text = text;
			var progressElement = (HTMLProgressElement)Document.GetElementById("progress");
			var spinnerElement = (HTMLDivElement)Document.GetElementById("spinner");
			var m = text.Match(new Regex(@"([^(]+)\((\d+(\.\d+)?)\/(\d+)\)"));
			var now = DateTime.Now.Ticks;
			if (m != null && now - DateTime.Now.Ticks < 30) return; // if this is a progress update, skip it if too soon
			if (m != null) {
				text = m[1];
				progressElement.Value = Script.ParseInt(m[2]) * 100;
				progressElement.Max = Script.ParseInt(m[4]) * 100;
				progressElement.SetAttribute("hidden", "false");
				spinnerElement.SetAttribute("hidden", "false");
			}
			else {
				progressElement.Value = 0.0;
				progressElement.Max = 0.0;
				progressElement.SetAttribute("hidden", "true");
				if (!string.IsNullOrEmpty(text))
					spinnerElement.Style.Display = Display.None;
			}
			var statusElement = (HTMLDivElement)Document.GetElementById("status");
			statusElement.InnerHTML = text;
		}

		public int totalDependencies = 0;

		public void monitorRunDependencies(int left)
		{
			totalDependencies = System.Math.Max(totalDependencies, left);
			setStatus((left != 0) ? "Preparing... (" + (totalDependencies - left) + "/" + totalDependencies + ")" : "All downloads complete.");
		}

		[External, Name(false)]
		internal string UTF8ArrayToString(Uint8Array buf, int index)
		{
			throw new NotImplementedException();
		}

		[External]
		internal string intArrayToString(Uint8Array buf)
		{
			throw new NotImplementedException();
		}

		[External]
		internal int stringToUTF8Array(string str, Uint8Array outU8Array, int outIdx, int maxBytesToWrite)
		{
			throw new NotImplementedException();
		}

		[External]
		internal int lengthBytesUTF8(string str)
		{
			throw new NotImplementedException();
		}

		[Name(false)]
		internal Uint8Array UTF8StringToArray(string str)
		{
			var len = lengthBytesUTF8(str);
			var result = new Uint8Array(len);
			stringToUTF8Array(str, result, 0, len);
			return result;
		}

		[Script("return this.FS;")]
		internal FileSystem GetFileSystem()
		{
			return (FileSystem)this["FS"];
		}

		[External]
		internal void stdin(object data)
		{
			throw new NotImplementedException();
		}
	}
}