using System;
using System.Collections.Generic;
using System.Text;
using static QRCoder.QRCodeGenerator;

namespace QRCoder
{
    public class AsciiQRCode : AbstractQRCode, IDisposable
    {
        /// <summary>
        /// Constructor without params to be used in COM Objects connections
        /// </summary>
        public AsciiQRCode() { }

        public AsciiQRCode(QRCodeData data) : base(data) { }

        /// <summary>
        /// Returns a strings that contains the resulting QR code as ASCII chars.
        /// </summary>
        /// <param name="repeatPerModule">Number of repeated darkColorString/whiteSpaceString per module.</param>
        /// <returns></returns>
        public string GetGraphic(int repeatPerModule)
        {
            return string.Join("\n", GetLineByLineGraphic(repeatPerModule));
        }


        /// <summary>
        /// Returns a strings that contains the resulting QR code as ASCII chars.
        /// </summary>
        /// <param name="repeatPerModule">Number of repeated darkColorString/whiteSpaceString per module.</param>
        /// <param name="darkColorString">String for use as dark color modules. In case of string make sure whiteSpaceString has the same length.</param>
        /// <param name="whiteSpaceString">String for use as white modules (whitespace). In case of string make sure darkColorString has the same length.</param>
        /// <param name="endOfLine">End of line separator. (Default: \n)</param>
        /// <returns></returns>
        public string GetGraphic(int repeatPerModule, string darkColorString, string whiteSpaceString, string endOfLine = "\n")
        {
            return string.Join(endOfLine, GetLineByLineGraphic(repeatPerModule, darkColorString, whiteSpaceString));
        }


        /// <summary>
        /// Returns an array of strings that contains each line of the resulting QR code as ASCII chars.
        /// </summary>
        /// <param name="repeatPerModule">Number of repeated darkColorString/whiteSpaceString per module.</param>
        /// <returns></returns>
        public string[] GetLineByLineGraphic(int repeatPerModule)
        {
            return GetLineByLineGraphic(repeatPerModule, "██", "  ");
        }


        /// <summary>
        /// Returns an array of strings that contains each line of the resulting QR code as ASCII chars.
        /// </summary>
        /// <param name="repeatPerModule">Number of repeated darkColorString/whiteSpaceString per module.</param>
        /// <param name="darkColorString">String for use as dark color modules. In case of string make sure whiteSpaceString has the same length.</param>
        /// <param name="whiteSpaceString">String for use as white modules (whitespace). In case of string make sure darkColorString has the same length.</param>
        /// <returns></returns>
        public string[] GetLineByLineGraphic(int repeatPerModule, string darkColorString, string whiteSpaceString)
        {
            var qrCode = new List<string>();
            //We need to adjust the repeatPerModule based on number of characters in darkColorString
            //(we assume whiteSpaceString has the same number of characters)
            //to keep the QR code as square as possible.
            var adjustmentValueForNumberOfCharacters = darkColorString.Length / 2 != 1 ? darkColorString.Length / 2 : 0;
            var verticalNumberOfRepeats = repeatPerModule + adjustmentValueForNumberOfCharacters;
            var sideLength = QrCodeData.ModuleMatrix.Count * verticalNumberOfRepeats;
            for (var y = 0; y < sideLength; y++)
            {
                bool emptyLine = true;
                var lineBuilder = new StringBuilder();

                for (var x = 0; x < QrCodeData.ModuleMatrix.Count; x++)
                {
                    var module = QrCodeData.ModuleMatrix[x][(y + verticalNumberOfRepeats) / verticalNumberOfRepeats - 1];

                    for (var i = 0; i < repeatPerModule; i++)
                    {
                        lineBuilder.Append(module ? darkColorString : whiteSpaceString);
                    }
                    if (module)
                    {
                        emptyLine = false;
                    }
                }
                if (!emptyLine)
                {
                    qrCode.Add(lineBuilder.ToString());
                }

            }
            return qrCode.ToArray();
        }
    }

    public static class AsciiQRCodeHelper
    {
        public static string GetQRCode(string plainText, int pixelsPerModule, string darkColorString, string whiteSpaceString, ECCLevel eccLevel, bool forceUtf8 = false, bool utf8BOM = false, EciMode eciMode = EciMode.Default, int requestedVersion = -1, string endOfLine = "\n")
        {
            using (var qrGenerator = new QRCodeGenerator())
            using (var qrCodeData = qrGenerator.CreateQrCode(plainText, eccLevel, forceUtf8, utf8BOM, eciMode, requestedVersion))
            using (var qrCode = new AsciiQRCode(qrCodeData))
                return qrCode.GetGraphic(pixelsPerModule, darkColorString, whiteSpaceString, endOfLine);
        }
    }
}