using System;
using System.IO;
using System.Text;

namespace NBF
{
    public interface ICodeWriterConfig
    {
        string BlockStart { get; set; }
        string BlockEnd { get; set; }
        bool BlockFromNewLine { get; set; }
        bool UsingTabs { get; set; }
        string EndOfLine { get; set; }
    }

    public class DefCSharpCodeWriterConfig : ICodeWriterConfig
    {
        public string BlockStart { get; set; } = "{";
        public string BlockEnd { get; set; } = "}";
        public bool BlockFromNewLine { get; set; }
        public bool UsingTabs { get; set; } = true;
        public string EndOfLine { get; set; }
    }

    public class CodeWriter
    {
        private ICodeWriterConfig _config;

        private StringBuilder _stringBuilder = new StringBuilder();

        private int _nowTabCount;

        public CodeWriter()
        {
            Init();
        }

        public CodeWriter(ICodeWriterConfig config)
        {
            Init(config);
        }

        public void Write(string content)
        {
            _stringBuilder.Append(content);
        }

        public void Writeln()
        {
            _stringBuilder.Append(Environment.NewLine);
        }

        public void Writeln(string str)
        {
            _stringBuilder.Append(GetLinePrefix());
            _stringBuilder.Append(str);
            _stringBuilder.Append(Environment.NewLine);
        }

        public void StartBlock()
        {
            Writeln(_config.BlockStart);
            _nowTabCount++;
        }

        public void EndBlock()
        {
            _nowTabCount--;
            Writeln(_config.BlockEnd);
        }

        public void Save(string path)
        {
            var dirPath = Path.GetDirectoryName(path);
            if (dirPath != null && !Directory.Exists(dirPath))
            {
                Directory.CreateDirectory(dirPath);
            }

            var content = _stringBuilder.ToString();
            File.WriteAllText(path, content);
        }

        #region 内部方法

        private void Init(ICodeWriterConfig config = null)
        {
            _config = config ?? new DefCSharpCodeWriterConfig();
        }

        private string GetLinePrefix()
        {
            string ret = string.Empty;
            if (!_config.UsingTabs) return ret;
            for (var i = 0; i < _nowTabCount; i++)
            {
                ret += "\t";
            }

            return ret;
        }

        #endregion
    }
}