using System.Text;
using gppg;

namespace NewLanguage
{
    public class SourceLocation : IMerge<SourceLocation>
    {
        public int sLin; // start line
        public int sCol; // start column
        public int eLin; // end line
        public int eCol; // end column

        public string Text;

        public SourceLocation() 
        { }

        public SourceLocation(int sl, int sc, int el, int ec, string line)
        { sLin = sl; sCol = sc; eLin = el; eCol = ec; Text = line; }

        public SourceLocation Merge(SourceLocation last)
        { return new SourceLocation(this.sLin, this.sCol, last.eLin, last.eCol, this.Text); }
        
        public override string ToString()
        {
            StringBuilder locstr = new StringBuilder();
            if (sLin == eLin)
            {
                // all on one line, which will be the line
                // in Text
                locstr.Append("in \"");
                locstr.Append(Text.Substring(0, sCol));
                locstr.Append(" HERE-->");
                locstr.Append(Text.Substring(sCol, eCol - sCol));
                if (Text.Length > eCol)
                {
                    locstr.Append("<-- ");
                    locstr.Append(Text.Substring(eCol, Text.Length));
                }
                locstr.Append("\"");
            }
            else {
                // not all on one line, so we only have the end
                locstr.Append("before \"");
                locstr.Append(Text.Substring(0, eCol));
                locstr.Append("<--HERE ");
                if (Text.Length > eCol)
                {
                    locstr.Append(Text.Substring(eCol, Text.Length));
                }
                locstr.Append("\"");
            }
            locstr.AppendFormat(" (at {0},{1} - {2},{3})", sLin, sCol, eLin, eCol);
            return locstr.ToString();
        }
    }
}