using System;
using System.Collections.Generic;
using System.Text;

namespace Dfs.WayneChina.HyperPrinterHandler
{
    internal class ReceiptLineItem
    {
        /// <summary>
        /// items included in one receipt line
        /// </summary>
        public List<ReceiptColumnItem> ColumnItems = new List<ReceiptColumnItem>();

        /// <summary>
        /// text for total line that will print on receipt
        /// </summary>
        public string[] LineText { get; }
        /// <summary>
        /// Reserve several bytes at the beginning of each line, default value is zero
        /// </summary>
        private int prefixLen = 0;

        /// <summary>
        /// Reserve several bytes at the end of each line 
        /// </summary>
        private int endLen = 0;

        /// <summary>
        /// maximun length for each line, default value is 37
        /// </summary>
        private int totalLength = 37;

        private char space = ' ';

        /// <summary>
        /// 
        /// </summary>
        /// <param name="prefixLength">Reserve several bytes at the beginning of each line, default value is zero</param>
        /// <param name="remainingLength">Reserve several bytes at the end of each line , default value is zero</param>
        /// <param name="totalLength">maximun length for each line, default value is 37</param>
        public ReceiptLineItem(int prefixLength, int remainingLength, int totalLength)
        {
            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
            prefixLen = prefixLength;
            endLen = remainingLength;
            this.totalLength = totalLength;
        }

        /// <summary>
        /// Returns a list of HEX string, format for this string is as it on real receipt
        /// </summary>
        /// <returns>a list of HEX string</returns>
        public List<string> Format()
        {
            List<string> tempTexts = new List<string>();
            foreach (var ci in ColumnItems)
            {
                int lengthForEachColumn = 0;
                if (ci.colspan > 0)
                {
                    lengthForEachColumn = (int)((float)ci.colspan / GetTotalColSpanForEachLine() * (totalLength - prefixLen - endLen));
                }
                else if (ci.width > 0)
                {
                    lengthForEachColumn = (int)((float)ci.width / 100 * (totalLength - prefixLen - endLen));
                }
                byte[] b = Encoding.GetEncoding("GB2312").GetBytes(ci.Text);
                string tempCiText;
                //if the length of current column is longer than the maximun length for each column, then need to split it to serval
                //lines
                if (b.Length > lengthForEachColumn)
                {

                    int tempindex = 0;

                    int bytesToFetch = lengthForEachColumn % 2 > 0 ? lengthForEachColumn - 1 : lengthForEachColumn;

                    int splitLines = b.Length % bytesToFetch > 0
                        ? b.Length / bytesToFetch + 1
                        : b.Length / bytesToFetch;

                    for (int i = 0; i < splitLines; i++)
                    {
                        int bytesFetched = 0;
                        List<byte> tempb = new List<byte>();
                        if (i + 1 != splitLines)//not the last line
                        {
                            while (bytesFetched < bytesToFetch)
                            {
                                tempb.Add(b[tempindex++]);
                                bytesFetched++;
                            }

                            tempCiText = FormatColumnItem(Encoding.GetEncoding("GB2312").GetString(tempb.ToArray()), ci.align, lengthForEachColumn, ColumnItems.IndexOf(ci));
                            if (tempTexts.Count < i + 1)
                            {
                                tempTexts.Add(ToHexString(Encoding.GetEncoding("GB2312").GetBytes("".PadRight(lengthForEachColumn * ColumnItems.IndexOf(ci), space))));
                                tempTexts[i] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText));

                                //tempTexts.Add("".PadRight(lengthForEachColumn * ColumnItems.IndexOf(ci), space));
                                //tempTexts[i] += tempCiText;

                            }
                            else
                            {
                                tempTexts[i] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText));
                                //tempTexts[i] += tempCiText;
                            }
                        }
                        else//need to add space to make sure the legth equals to lengthForEachColumn
                        {
                            bytesToFetch = b.Length - bytesToFetch * i;
                            while (bytesFetched < bytesToFetch)
                            {
                                tempb.Add(b[tempindex++]);
                                bytesFetched++;
                            }

                            tempCiText = FormatColumnItem(Encoding.GetEncoding("GB2312").GetString(tempb.ToArray()), ci.align, lengthForEachColumn, ColumnItems.IndexOf(ci));
                            if (tempTexts.Count < i + 1)
                            {
                                tempTexts.Add(ToHexString(Encoding.GetEncoding("GB2312").GetBytes("".PadRight(lengthForEachColumn * ColumnItems.IndexOf(ci), space))));
                                tempTexts[i] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText));
                                //tempTexts.Add("".PadRight(lengthForEachColumn * ColumnItems.IndexOf(ci), space));
                                //tempTexts[i] += tempCiText;

                            }
                            else
                            {
                                tempTexts[i] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText));
                                //tempTexts[i] += tempCiText;
                            }
                        }
                    }
                }
                else
                {
                    tempCiText = FormatColumnItem(ci.Text, ci.align, lengthForEachColumn, ColumnItems.IndexOf(ci));
                    if (tempTexts.Count > 0)
                        tempTexts[0] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText));
                    //tempTexts[0] += tempCiText;
                    else
                        tempTexts.Add(ToHexString(Encoding.GetEncoding("GB2312").GetBytes(tempCiText)));
                    //tempTexts.Add(tempCiText);

                    //if there're serval lines exits, need to add space to rest columns
                    for (int i = 1; i < tempTexts.Count; i++)
                        tempTexts[i] += ToHexString(Encoding.GetEncoding("GB2312").GetBytes("".PadRight(lengthForEachColumn, space)));
                    //tempTexts[i] += "".PadRight(lengthForEachColumn, space);
                }
            }
            return tempTexts;
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="rawData">data will be formatted</param>
        /// <param name="agline">agliment, left, right or center</param>
        /// <param name="targetLength">total length of result string</param>
        /// <returns></returns>
        private string FormatColumnItem(string rawData, string agline, int targetLength, int index)
        {
            string temp = index == 0 ? "".PadRight(prefixLen, space) : string.Empty;
            if (rawData.Contains("---"))
            {
                temp += rawData.PadRight(targetLength, '-');
                return temp;
            }
            int spaceLen = targetLength - Encoding.GetEncoding("GB2312").GetBytes(rawData).Length;
            if (agline.Equals("left", StringComparison.CurrentCultureIgnoreCase))
            {
                temp += rawData.PadRight(rawData.Length + spaceLen, space);
            }
            else if (agline.Equals("right", StringComparison.CurrentCultureIgnoreCase))
            {
                temp += rawData.PadLeft(rawData.Length + spaceLen, space);
            }
            else
            {
                temp += rawData.PadLeft(spaceLen / 2 + rawData.Length, space).PadRight(rawData.Length + spaceLen, space);
            }
            return temp;
        }
        /// <summary>
        /// return total count of column spans in each line
        /// </summary>
        /// <returns></returns>
        private int GetTotalColSpanForEachLine()
        {
            var totalColSpan = 0;
            foreach (var ci in ColumnItems)
            {
                totalColSpan += ci.colspan > 0 ? ci.colspan : 0;
            }
            return totalColSpan;
        }


        private string ToHexString(byte[] sourceBytes)
        {
            string tempHexString = "";
            foreach (var b in sourceBytes)
            {
                tempHexString += System.Convert.ToString(b, 16);
            }
            return tempHexString;
        }
    }
}