using System;
using System.Collections.Generic;
using ChatComponents;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.ui;
using UnityEngine;
using Color = Unity.UIWidgets.ui.Color;

namespace UIWidgetsSample
{
    public static class ChatUtils
    {
        public static string REGEX_LINK =
        @"([\w+]+\:\/\/)?([\w\d-]+\.)*[\w-]+[\.\:]\w+([\/\?\=\&\#\.]?[\w-]+)*\/?";
       
        public static string formatBytes(int size, int fractionDigits = 2)
        {
            List<string> profix = new List<string>()
            {
                
                    "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
            };
            if (size <= 0) return "0 B";
            var multiple = (log(size) / log(1024)).floor();
            
            return (size / Mathf.Pow(1024, multiple)).ToString("D3") +
                   " " + profix[multiple];
        }

        public static float log(int num)
        {
            if (num == 0)
                return float.NegativeInfinity;
            else if (num < 0)
                return Single.NaN;
            else
                return num * 1f;
        }
        

        /// Returns user avatar and name color based on the ID
        public static Color getUserAvatarNameColor(User user, List<Color> colors)
        {
            var index = user.id.GetHashCode() % colors.Count;
            return colors[0];
        }

        /// Returns user name as joined firstName and lastName
        public static string getUserName(User user) =>
            $"{user.firstName ?? ""} {user.lastName ?? ""}";

        /// Returns formatted date used as a divider between different days in the
        /// chat history
        public static string getVerboseDateTimeRepresentation(
            DateTime dateTime,
            DateTime? dateFormat = null,
            string dateLocale = null,
            DateTime? timeFormat = null
        )
        {
            var formattedDate
                = //dateFormat != null ? dateFormat.ToString().Format(dateTime) : DateTime.MMMd(dateLocale).format(dateTime);
                dateTime.ToString("MMM-dd");
            var formattedTime = //timeFormat != null ? timeFormat.format(dateTime) : DateTime.Hm(dateLocale).format(dateTime);
                    dateTime.ToString("hh:mm");
            var localDateTime = dateTime.ToLocalTime();
            var now = DateTime.Now;

            if (localDateTime.Day == now.Day &&
                localDateTime.Month == now.Month &&
                localDateTime.Year == now.Year)
                return formattedTime;

            return $"{formattedDate}, {formattedTime}";
        }

        /// Parses provided messages to chat messages (with headers and spacers) and
        /// returns them with a gallery
        public static List<object> calculateChatMessages(
            List<ChatComponents.Message> messages,
            User user,
            bool showUserNames,
            CustomDateHeaderText customDateHeaderText = null,
            DateTime? dateFormat = null,
            string dateLocale = null,
            DateTime? timeFormat = null
        )
        {
            var chatMessages = new List<object>();
            var gallery = new List<PreviewImage>();

            var shouldShowName = false;

            for (var i = messages.Count - 1; i >= 0; i--)
            {
                var isFirst = i == messages.Count - 1;
                var isLast = i == 0;
                var message = messages[i];
                var messageHasCreatedAt = message.createdAt != null;
                ChatComponents.Message nextMessage = isLast ? null : messages[i - 1];
                bool nextMessageHasCreatedAt = isLast ? true : nextMessage.createdAt != null;
                bool nextMessageSameAuthor = isLast ? false : message.author.id == nextMessage.author.id;
                bool notMyMessage = message.author.id != user.id;
                bool nextMessageDateThreshold = false;
                bool nextMessageDifferentDay = false;
                bool nextMessageInGroup = false;
                bool showName = false;

                if (showUserNames)
                {
                    var previousMessage = isFirst ? null : messages[i + 1];

                    var isFirstInGroup = notMyMessage &&
                                         (message.author.id != previousMessage?.author.id ||
                                          message.createdAt != null &&
                                          previousMessage?.createdAt != null &&
                                          (int)message.createdAt - (int)previousMessage.createdAt > 60000);

                    if (isFirstInGroup)
                    {
                        shouldShowName = false;
                        if (message.type == MessageType.text)
                            showName = true;
                        else
                            shouldShowName = true;
                    }

                    if (message.type == MessageType.text && shouldShowName)
                    {
                        showName = true;
                        shouldShowName = false;
                    }
                }

                if (messageHasCreatedAt && nextMessageHasCreatedAt)
                {
                   
                    nextMessageDateThreshold = isLast ? false : (int) nextMessage?.createdAt - (int) message.createdAt >= 900000;
                    nextMessageDifferentDay =
                        TimeSpan.FromMilliseconds(message.createdAt == null ? 0 : (int)message.createdAt).Days !=
                        TimeSpan.FromMilliseconds(nextMessage?.createdAt == null ? 0 : (int)nextMessage?.createdAt).Days;

                    nextMessageInGroup = nextMessageSameAuthor &&
                                         (int)nextMessage?.createdAt - (int)message.createdAt <= 60000;
                }

                if (isFirst && messageHasCreatedAt)
                {
                    var epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0);
                    var timeSend = epoch.AddTicks((message.createdAt == null ? 0 : (int) message.createdAt) * 1000000000);
                    chatMessages.Insert(
                        0,
                        new DateHeader(
                            customDateHeaderText != null
                                ? customDateHeaderText(
                                    new DateTime(timeSend.Year,timeSend.Month,timeSend.Day,timeSend.Hour,timeSend.Minute,timeSend.Second)
                                )
                                : getVerboseDateTimeRepresentation(
                                    new DateTime(timeSend.Year,timeSend.Month,timeSend.Day,timeSend.Hour,timeSend.Minute,timeSend.Second),//new DateTime((int) TimeSpan.FromMilliseconds(message.createdAt == null ? 0 : (int)message.createdAt).TotalMilliseconds ),//DateTime.FromFileTime(message.createdAt == null ? 0 : (int)message.createdAt),//
                                    dateFormat,
                                    dateLocale,
                                    timeFormat
                                )
                        )
                    );
                }    

                var _message =
                    new Dictionary<string, object>
                    {
                        {"message", message},
                        {"nextMessageInGroup", nextMessageInGroup},
                        {"showName", notMyMessage &&
                                     showUserNames &&
                                     showName && getUserName(message.author).isNotEmpty()
                        },
                        {"showStatus", true}
                    };
                chatMessages.Insert(0, _message);

                if (!nextMessageInGroup)
                {
                    chatMessages.Insert(
                        0,
                        new MessageSpacer(
                            12,
                            message.id
                        )
                    );
                }

                if (nextMessageDifferentDay || nextMessageDateThreshold)
                {
                    chatMessages.Insert(
                        0,
                        new DateHeader(
                            customDateHeaderText != null
                                ? customDateHeaderText(
                                    DateTime.Now)//DateTime.FromFileTime(isLast ? 0 : (int) nextMessage?.createdAt) )
                                : getVerboseDateTimeRepresentation(
                                    DateTime.Now,//DateTime.FromFileTime(isLast ? 0 : (int) nextMessage?.createdAt),
                                    dateFormat,
                                    dateLocale,
                                    timeFormat
                                )
                        )
                    );
                }

                if (message is ImageMessage)
                {
                    if (foundation_.kIsWeb)
                    {
                        if (((ImageMessage) message).uri.StartsWith("http"))
                            gallery.Add(new PreviewImage(message.id, ((ImageMessage) message).uri));
                    }

                    gallery.Add(new PreviewImage(message.id, ((ImageMessage) message).uri));
                }
            }

            var results = new List<object>(){chatMessages,gallery};
            //results.AddRange(chatMessages);
            //results.AddRange(gallery);
            return results;
        }
    }
}