using Newtonsoft.Json;
using System;
using System.Collections.Generic;

namespace Oxide.Plugins
{
	[Info("Discord Message API", "bsdinis", "0.0.9")]
	class DiscordMessageAPI : CovalencePlugin
	{
		void SendDiscordMessage(string webhook, string username, string avatarUrl, string content, bool tts, List<List<object>> embeds)
		{
			if (string.IsNullOrWhiteSpace(webhook) || !IsValidUrl(webhook, out webhook))
			{
				PrintError("\nThe first argument (webhook) is not a valid URL. Unable to send Discord message!");
				return;
			}

			if (string.IsNullOrWhiteSpace(username))
			{
				PrintError("\nThe second argument (username) must not be empty. Unable to send Discord message!");
				return;
			}

			if (string.IsNullOrWhiteSpace(content) && (embeds == null || embeds.Count < 1))
			{
				PrintError("\nThe message must contain content or an embed. Unable to send an empty Discord message!");
				return;
			}

			int characters = 0;
			bool limit = false;

			if (avatarUrl == null)
			{
				avatarUrl = string.Empty;
			}
			if (content == null)
			{
				content = string.Empty;
			}

			if (username.Length > 80)
			{
				PrintWarning("\nDiscord limits the amount of characters in message's username to 80. Only the first 80 characters from the message's username will be added to the message.");
			}
			if (!IsValidUrl(avatarUrl, out avatarUrl))
			{
				PrintWarning("\nThe message's avatar URL is not a valid URL and will not be added to the message.");
			}
			if (content.Length > 2000)
			{
				PrintWarning("\nDiscord limits the amount of characters in message's content to 2000. Only the first 2000 characters from the message's content will be added to the message.");
			}

			DiscordMessage message = new DiscordMessage
			{
				username = Concatenate(username, 80),
				avatar_url = avatarUrl,
				content = Concatenate(content, 2000),
				tts = tts,
				embeds = new List<DiscordMessage.Embed>()
			};

			if (embeds != null)
			{
				for (int i = 0; i < embeds.Count; i++)
				{
					List<object> embedList = embeds[i] as List<object>;
					if (embedList == null)
					{
						PrintError($"\nUnable to read Embed[{i}].");
						continue;
					}
					if (embedList.Count < 12)
					{
						PrintError($"\nEmbed[{i}] has less than 12 objects and will not be added to the message.");
						continue;
					}

					string authorName = embedList[0] as string;
					if (authorName == null)
					{
						PrintError($"\nThe first object (author name) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string authorUrl = embedList[1] as string;
					if (authorUrl == null)
					{
						PrintError($"\nThe second object (author URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string authorIconUrl = embedList[2] as string;
					if (authorIconUrl == null)
					{
						PrintError($"\nThe third object (author icon URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string embedTitle = embedList[3] as string;
					if (embedTitle == null)
					{
						PrintError($"\nThe fourth object (embed title) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string embedURL = embedList[4] as string;
					if (embedURL == null)
					{
						PrintError($"\nThe fifth object (URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string embedDescription = embedList[5] as string;
					if (embedDescription == null)
					{
						PrintError($"\nThe sixth object (description) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					if (!(embedList[6] is int))
					{
						PrintError($"\nThe seventh object (color) from Embed[{i}] is not an int value and the whole embed will not be added to the message.");
						continue;
					}

					string thumbnailUrl = embedList[8] as string;
					if (thumbnailUrl == null)
					{
						PrintError($"\nThe nineth object (thumbnail URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string imageUrl = embedList[9] as string;
					if (imageUrl == null)
					{
						PrintError($"\nThe tenth object (image URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string footerText = embedList[10] as string;
					if (footerText == null)
					{
						PrintError($"\nThe eleventh object (footer text) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					string footerIconUrl = embedList[11] as string;
					if (footerIconUrl == null)
					{
						PrintError($"\nThe twelveth object (footer icon URL) from Embed[{i}] is not a string and the whole embed will not be added to the message.");
						continue;
					}

					DiscordMessage.Embed embed = new DiscordMessage.Embed
					{
						author = new DiscordMessage.Embed.Author
						{
							name = authorName,
							url = authorUrl,
							icon_url = authorIconUrl
						},
						title = embedTitle,
						url = embedURL,
						description = embedDescription,
						color = (int)embedList[6],
						fields = new List<DiscordMessage.Embed.Field>(),
						thumbnail = new DiscordMessage.Embed.ImageURL
						{
							url = imageUrl
						},
						image = new DiscordMessage.Embed.ImageURL
						{
							url = thumbnailUrl
						},
						footer = new DiscordMessage.Embed.Footer
						{
							text = footerText,
							icon_url = footerIconUrl
						}
					};

					List<List<object>> fields = embedList[7] as List<List<object>>;
					if (fields != null)
					{
						for (int ii = 0; ii < fields.Count; ii++)
						{
							List<object> fieldList = fields[ii] as List<object>;
							if (fieldList == null)
							{
								PrintError($"\nUnable to read Field[{ii}] from Embed[{i}].");
								continue;
							}
							if (fieldList.Count < 3)
							{
								PrintError($"\nField[{ii}] from Embed[{i}] has less than 3 objects and will not be added to the message.");
								continue;
							}

							string fieldName = fieldList[0] as string;
							if (fieldName == null)
							{
								PrintError($"\nThe first object (field name) from Field[{ii}] from Embed[{i}] is not a string and the whole field will not be added to the message.");
								continue;
							}

							string fieldValue = fieldList[1] as string;
							if (fieldValue == null)
							{
								PrintError($"\nThe second object (field value) from Field[{ii}] from Embed[{i}] is not a string and the whole field will not be added to the message.");
								continue;
							}

							if (!(fieldList[2] is bool))
							{
								PrintError($"\nThe third object (field inline) from Field[{ii}] from Embed[{i}] is not a bool and the whole field will not be added to the message.");
								continue;
							}

							if (fieldName.Length > 256)
							{
								PrintWarning($"\nDiscord limits the amount of characters in embed's field's name to 256. Only the first 256 characters from the name of Field[{ii}] from Embed[{i}] will be added to the message.");
							}
							fieldName = Concatenate(fieldName, 256);

							if (fieldValue.Length > 1024)
							{
								PrintWarning($"\nDiscord limits the amount of characters in embed's field's value to 1024. Only the first 1024 characters from the value of Field[{ii}] from Embed[{i}] will be added to the message.");
							}
							fieldValue = Concatenate(fieldValue, 1024);

							if ((characters + fieldName.Length + fieldValue.Length) > 6000)
							{
								PrintError($"\nThe message would exceed the 6000 characters limit if Field[{ii}] from Embed[{i}] is added to the message. No more fields or embeds will be added to the message.");
								limit = true;
								break;
							}

							characters += fieldName.Length;
							characters += fieldValue.Length;

							DiscordMessage.Embed.Field field = new DiscordMessage.Embed.Field
							{
								name = fieldName,
								value = fieldValue,
								inline = (bool)fieldList[2]
							};

							embed.fields.Add(field);

							if (ii < 24)
							{
								continue;
							}
							limit = true;
							PrintWarning($"\nDiscord limits the amount of fields to 25 per embed. Only the first 25 fields from Embed[{i}] will be added to the message.");
							break;
						}
					}

					DiscordMessage.Embed.Author author = embed.author;

					if (author.name.Length > 256)
					{
						PrintWarning($"\nDiscord limits the amount of characters in embed's author name to 256. Only the first 256 characters from the author name of Embed[{i}] will be added to the message.");
					}
					author.name = Concatenate(author.name, 256);
					characters += author.name.Length;

					if (!IsValidUrl(author.url, out author.url))
					{
						PrintWarning($"\nThe author URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}
					if (!IsValidUrl(author.icon_url, out author.icon_url))
					{
						PrintWarning($"\nThe author icon URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}

					if (embed.title.Length > 256)
					{
						PrintWarning($"\nDiscord limits the amount of characters in embed's title to 256. Only the first 256 characters from the title of Embed[{i}] will be added to the message.");
					}
					embed.title = Concatenate(embed.title, 256);
					characters += embed.title.Length;

					if (!IsValidUrl(embed.url, out embed.url))
					{
						PrintWarning($"\nThe URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}

					if (embed.description.Length > 4096)
					{
						PrintWarning($"\nDiscord limits the amount of characters in embed's description to 4096. Only the first 4096 characters from the description of Embed[{i}] will be added to the message.");
					}
					embed.description = Concatenate(embed.description, 4096);
					characters += embed.description.Length;

					if (!IsValidUrl(embed.thumbnail.url, out embed.thumbnail.url))
					{
						PrintWarning($"\nThe thumbnail image URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}
					if (!IsValidUrl(embed.image.url, out embed.image.url))
					{
						PrintWarning($"\nThe image URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}

					DiscordMessage.Embed.Footer footer = embed.footer;

					if (footer.text.Length > 2048)
					{
						PrintWarning($"\nDiscord limits the amount of characters in embed's footer text to 2048. Only the first 2048 characters from the footer text of Embed[{i}] will be added to the message.");
					}
					footer.text = Concatenate(footer.text, 2048);
					characters += footer.text.Length;

					if (characters > 6000)
					{
						PrintError($"\nThe message would exceed the 6000 characters limit if Embed[{i}] is added to the message. No more embeds will be added to the message.");
						limit = true;
						break;
					}

					if (!IsValidUrl(footer.icon_url, out footer.icon_url))
					{
						PrintWarning($"\nThe footer icon URL from Embed[{i}] is not a valid URL and will not be added to the message.");
					}

					message.embeds.Add(embed);

					if (i < 9)
					{
						continue;
					}
					limit = true;
					PrintWarning("\nDiscord limits the amount of embeds to 10 per message. Only the first 10 embeds will be added to the message.");
					break;
				}
			}

			webrequest.Enqueue(
				webhook,
				JsonConvert.SerializeObject(message),
				(c, r) =>
				{
					if (c == 204)
					{
						PrintWarning("Discord message " + (limit ? "embeds PARTIALLY sent to avoid exceeding the 6000 characters limit." : "successfully sent."));
					}
					else
					{
						PrintError($"Code {c}\n{JsonConvert.DeserializeObject(r)}");
					}
				},
				this,
				Core.Libraries.RequestMethod.POST,
				headers
			);
		}

		static readonly Dictionary<string, string> headers = new Dictionary<string, string>
		{
			["Content-Type"] = "application/json"
		};

		string Concatenate(string s, int i)
		{
			if (string.IsNullOrEmpty(s) || s.Length <= i)
			{
				return s;
			}
			return s.Substring(0, i);
		}

		bool IsValidUrl(string s, out string url)
		{
			url = string.Empty;
			if (string.IsNullOrWhiteSpace(s))
			{
				return true;
			}
			Uri uri;
			if (!Uri.TryCreate(s, UriKind.Absolute, out uri) || !(uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps))
			{
				return false;
			}
			url = s;
			return true;
		}

		class DiscordMessage
		{
			public string username;
			public string avatar_url;
			public string content;
			public bool tts;
			public List<Embed> embeds;

			public class Embed
			{
				public Author author;
				public string title;
				public string url;
				public string description;
				public int color;
				public List<Field> fields;
				public ImageURL thumbnail;
				public ImageURL image;
				public Footer footer;

				public class Author
				{
					public string name;
					public string url;
					public string icon_url;
				}

				public class Field
				{
					public string name;
					public string value;
					public bool inline;
				}

				public class ImageURL
				{
					public string url;
				}

				public class Footer
				{
					public string text;
					public string icon_url;
				}
			}
		}
	}
}