using System.Collections.Generic;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;
using System.Windows;
using YAMP;

namespace Wox.Plugin.Caculator
{
    public class Main : IPlugin, IPluginI18n
    {
        private static Regex regValidExpressChar = new Regex(
                        @"^(" +
                        @"ceil|floor|exp|pi|e|max|min|det|abs|log|ln|sqrt|" +
                        @"sin|cos|tan|arcsin|arccos|arctan|" +
                        @"eigval|eigvec|eig|sum|polar|plot|round|sort|real|zeta|" +
                        @"bin2dec|hex2dec|oct2dec|" +
                        @"==|~=|&&|\|\||" +
                        @"[ei]|[0-9]|[\+\-\*\/\^\., ""]|[\(\)\|\!\[\]]" +
                        @")+$", RegexOptions.Compiled);
        private static Regex regBrackets = new Regex(@"[\(\)\[\]]", RegexOptions.Compiled);
        private static ParseContext yampContext;
        private PluginInitContext context { get; set; }
        private NumberTranslator _numberTranslator;

        static Main()
        {
            yampContext = Parser.PrimaryContext;
            Parser.InteractiveMode = false;
            Parser.UseScripting = false;
        }

        public List<Result> Query(Query query)
        {
            if (query.Search.Length <= 2          // don't affect when user only input "e" or "i" keyword
                || !regValidExpressChar.IsMatch(query.Search)
                || !IsBracketComplete(query.Search)) return new List<Result>();

            try
            {
                var result = yampContext.Run(this._numberTranslator?.Translate(query.Search) ?? query.Search);
                if (result.Output != null && !string.IsNullOrEmpty(result.Result))
                {
                    string resultValue = this._numberTranslator?.TranslateBack(result.Result) ?? result.Result;
                    return new List<Result>
                    {
                        new Result
                        {
                            Title = resultValue,
                            IcoPath = "Images/calculator.png",
                            Score = 300,
                            SubTitle = "Copy this number to the clipboard",
                            Action = c =>
                            {
                                try
                                {
                                    Clipboard.SetText(resultValue);
                                    return true;
                                }
                                catch (ExternalException e)
                                {
                                    MessageBox.Show("Copy failed, please try later");
                                    return false;
                                }
                            }
                        }
                    };
                }
            }
            catch
            { }

            return new List<Result>();
        }

        private bool IsBracketComplete(string query)
        {
            var matchs = regBrackets.Matches(query);
            var leftBracketCount = 0;
            foreach (Match match in matchs)
            {
                if (match.Value == "(" || match.Value == "[")
                {
                    leftBracketCount++;
                }
                else
                {
                    leftBracketCount--;
                }
            }

            return leftBracketCount == 0;
        }

        public void Init(PluginInitContext context)
        {
            this.context = context;
            this._numberTranslator = NumberTranslator.Create(CultureInfo.CurrentCulture, CultureInfo.InvariantCulture);
        }

        public string GetTranslatedPluginTitle()
        {
            return context.API.GetTranslation("wox_plugin_caculator_plugin_name");
        }

        public string GetTranslatedPluginDescription()
        {
            return context.API.GetTranslation("wox_plugin_caculator_plugin_description");
        }
    }
}