namespace MySql.Data.Common
{
    using System;
    using System.Text;

    internal class SqlTokenizer
    {
        private bool ansiQuotes;
        private bool backslashEscapes;
        private int index;
        private bool inParamters;
        private string input;
        private bool inSize;
        private bool isSize;
        private bool quoted;

        public SqlTokenizer(string input)
        {
            this.input = input;
            this.index = -1;
            this.backslashEscapes = true;
        }

        public string NextToken()
        {
            char ch = '\0';
            bool flag = false;
            char ch2 = '\0';
            StringBuilder builder = new StringBuilder();
            bool flag2 = false;
            bool flag3 = false;
            this.quoted = this.isSize = false;
            while ((this.index + 1) < this.input.Length)
            {
                char ch3 = this.input[++this.index];
                if (flag)
                {
                    builder.Append(ch3);
                    flag = false;
                }
                else
                {
                    if (ch3 == ch2)
                    {
                        this.quoted = true;
                        return builder.ToString();
                    }
                    if (ch2 != '\0')
                    {
                        builder.Append(ch3);
                    }
                    else if ((((ch3 == '`') || (ch3 == '\'')) || ((ch3 == '"') && this.AnsiQuotes)) && !this.inSize)
                    {
                        ch2 = ch3;
                    }
                    else if (((ch3 == '/') && (ch == '*')) && flag2)
                    {
                        flag2 = false;
                    }
                    else if ((ch3 == '*') && (ch == '/'))
                    {
                        flag2 = true;
                        builder.Remove(builder.Length - 1, 1);
                    }
                    else if (flag2 || flag3)
                    {
                        if (flag3 && (ch3 == '\n'))
                        {
                            flag3 = false;
                        }
                    }
                    else if ((ch3 == '\\') && this.BackslashEscapes)
                    {
                        flag = true;
                        builder.Append(ch3);
                    }
                    else if (ch3 == '#')
                    {
                        flag3 = true;
                    }
                    else if ((ch3 == '-') && (ch == '-'))
                    {
                        builder.Remove(builder.Length - 1, 1);
                        flag3 = true;
                    }
                    else
                    {
                        if ((((ch3 == ',') || (ch3 == ')')) || (ch3 == '(')) && (builder.Length == 0))
                        {
                            this.inParamters = true;
                            return ch3.ToString();
                        }
                        if ((char.IsWhiteSpace(ch3) || (ch3 == '(')) || ((ch3 == ')') || ((ch3 == ',') && !this.inSize)))
                        {
                            if ((ch3 == ',') || ((ch3 == ')') && !this.inSize))
                            {
                                this.index--;
                            }
                            if ((ch3 == ')') && this.inSize)
                            {
                                this.isSize = true;
                                this.inSize = false;
                            }
                            if ((ch3 == '(') && this.inParamters)
                            {
                                this.inSize = true;
                            }
                            if (builder.Length > 0)
                            {
                                return builder.ToString();
                            }
                        }
                        else
                        {
                            builder.Append(ch3);
                        }
                    }
                }
                ch = ch3;
            }
            if (builder.Length > 0)
            {
                return builder.ToString();
            }
            return null;
        }

        public bool AnsiQuotes
        {
            get
            {
                return this.ansiQuotes;
            }
            set
            {
                this.ansiQuotes = value;
            }
        }

        public bool BackslashEscapes
        {
            get
            {
                return this.backslashEscapes;
            }
            set
            {
                this.backslashEscapes = value;
            }
        }

        public int Index
        {
            get
            {
                return this.index;
            }
        }

        public bool IsSize
        {
            get
            {
                return this.isSize;
            }
        }

        public bool Quoted
        {
            get
            {
                return this.quoted;
            }
        }
    }
}