using System.Text;

namespace CompilerDesignIFlr1
{
    internal class GrammarReader
    {
        //词法分析解决
        internal Dictionary<string, string> KeyToken { get; set; } = [];

        //此法分析解决
        internal Dictionary<string, string> SymbolToken { get; set; } = [];

        //词法分析解决
        internal Dictionary<string, string> RegexToken { get; set; } = [];

        //语法分析解决
        internal Dictionary<string, string> RegularToken { get; set; } = [];

        internal GrammarReader(string grammarFilePath)
        {
            string fileContent = File.ReadAllText(grammarFilePath);
            var dict = fileContent.PartParser();

            var tokenDict = dict["@tokens"].PartParser();
            foreach (var (key, value) in tokenDict)
            {
                if (value[1] == '!' && value[2] != '=')
                    KeyToken.Add(key, value.DeDoubleQuote().Substring(1));
                else if (value.Contains('$'))
                    RegexToken.Add(key, value.Replace("$", "").DeDoubleQuote());
                else
                    SymbolToken.Add(key, value.DeDoubleQuote());
            }
            Console.WriteLine("Key:");
            foreach (var (key, value) in KeyToken)
                Console.WriteLine($"{key}: {value}");
            Console.WriteLine("Symbol:");
            foreach (var (key, value) in SymbolToken)
                Console.WriteLine($"{key}: {value}");
            Console.WriteLine("Regex:");
            foreach (var (key, value) in RegexToken)
                Console.WriteLine($"{key}: {value}");
            foreach (var (key, value) in dict)
            {
                if (key == "@tokens")
                    continue;
                RegularToken.Add(key, value);
                Console.WriteLine(key + ": " + value);
            }
        }
    }

    file static class StringExtension
    {
        internal static Dictionary<string, string> PartParser(this string input)
        {
            Dictionary<string, string> result = [];
            input = input.Replace("\n", " ").Replace("\r", " ");
            int start = 0;
            int layer = 0;
            string key = "";
            string value = "";
            bool inQuote = false;
            for (int i = 0; i < input.Length; i++)
            {
                char c = input[i];
                switch (c)
                {
                    case '"':
                        inQuote = !inQuote;
                        break;
                    case '{':
                        if (inQuote)
                            break;
                        if (layer++ == 0)
                        {
                            key = input.Substring(start, i - start);
                            start = i + 1;
                        }
                        break;
                    case '}':
                        if (inQuote)
                            break;
                        if (layer-- == 1)
                        {
                            value = input.Substring(start, i - start);
                            result.Add(key.Trim(), value.Trim());
                            start = i + 1;
                        }
                        break;
                }
            }
            return result;
        }

        internal static string DeDoubleQuote(this string s)
        {
            StringBuilder sb = new StringBuilder();
            bool inLayer = false;
            for (int i = 0; i < s.Length; i++)
            {
                if (s[i] == '"')
                {
                    if (!inLayer)
                    {
                        inLayer = true;
                    }
                    else
                    {
                        if (sb[^1] == '\\')
                        {
                            sb[^1] = '\"';
                        }
                        else
                            inLayer = false;
                    }
                }
                else if (s[i] != ' ')
                    sb.Append(s[i]);
            }
            return sb.ToString();
        }
    }
}