using System;
using System.Text;
using System.Text.RegularExpressions;
using ChaosBot.Models;
using Discord;

namespace ChaosBot.Services
{
    public static class CustomCommandEmbedBuilderFacade
    {
        public static void SetDetails(EmbedBuilder embedBuilder, string customCommandContent)
        {
            StringBuilder descriptionBuilder = new StringBuilder();

            foreach (string line in customCommandContent.Split("\n"))
            {
                string prefix = "#";
                if (line.StartsWith(prefix))
                {
                    // This may require special treatment
                    string remainder = line.Substring(prefix.Length);
                    string pattern = @"^<([a-z]+)>(.+)<\/([a-z]+)>$";
                    Match match = Regex.Match(remainder, pattern);

                    // Ensure that there is some sort of match and that opening and closing tags are equal
                    if (match.Value == string.Empty || match.Groups[1] == match.Groups[3])
                    {
                        DealWithNonSpecialLine(descriptionBuilder, line);
                    }
                    else
                    {
                        string tag = match.Groups[1].Value;
                        string data = match.Groups[2].Value;
                        switch (tag)
                        {
                            case "color":
                                string colorPattern = @"^#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})";
                                Match colorMatch = Regex.Match(data, colorPattern);
                                if (colorMatch.Value == string.Empty)
                                {
                                    DealWithNonSpecialLine(descriptionBuilder, line);
                                }
                                else
                                {
                                    int r = int.Parse(colorMatch.Groups[1].Value, System.Globalization.NumberStyles.HexNumber);
                                    int g = int.Parse(colorMatch.Groups[2].Value, System.Globalization.NumberStyles.HexNumber);
                                    int b = int.Parse(colorMatch.Groups[3].Value, System.Globalization.NumberStyles.HexNumber);

                                    embedBuilder.Color = new Color(r, g, b);
                                }
                                break;
                            case "image":
                                embedBuilder.ImageUrl = data;
                                break;
                            case "title":
                                embedBuilder.Title = data;
                                break;
                            default:
                                DealWithNonSpecialLine(descriptionBuilder, line);
                                break;
                        }                        
                    }
                }
                else
                {
                    // There is definitely no special treatment
                    DealWithNonSpecialLine(descriptionBuilder, line);                    
                }
            }

            embedBuilder.Description = descriptionBuilder.ToString();
        }

        private static void DealWithNonSpecialLine(StringBuilder descriptionBuilder, string line)
        {
            // Possible todo: escape mentions or something?
            descriptionBuilder.AppendLine(line);
        }
    }
}