using GLib;

namespace Email {

  class EmailInputStream : Object {
  
    private InputStream parent;
    
    public EmailInputStream(InputStream parent) {
      this.parent = parent;
    }
    
    public  bool    eof { get; private set; default = false; }
    private uint8[] push_back = {};
    private bool    push_back_eof = false;
    
    public bool read_char(out uint8 c){
      if (push_back.length > 0) {
        c = push_back[push_back.length - 1];
        push_back.length--;
        if(push_back.length == 0) {
          eof = push_back_eof;
        }
      } else {
        if (parent.read (&c, 1, null) == 0){
          eof = true;
          return false;
        }
      }
      return true;
    }
    
    public void unread_char(uint8 c){
      if (push_back.length == 0){
        push_back_eof = eof;
        eof = false;
      }
      push_back += c;
    }
    
    public void push_back_buffer (uint8[] buffer) {
      if (buffer.length > 0 && push_back.length == 0){
        push_back_eof = eof;
        eof = false;
      }
      for(int i = buffer.length - 1; i >= 0; --i){
        push_back += buffer[i];
      }
    }
    
    public bool read_line(ref uint8[] buffer){
      uint8 c;
      uint8 CR = 0x0D;
      uint8 LF = 0x0A;
      bool crlf = false;
      buffer.resize(0);
      while (read_char(out c)) {
        //
        // CRLF management:
        //
        // ?? LF  ->  append, break
        // ?? CR  ->  append, wait for the LF
        // CR LF  ->  append, break
        // CR ??  ->  push back, break
        // ?? ??  ->  append, continue
        //
        if (c == LF) { buffer += c;    break; }
        if (crlf)    { unread_char(c); break; }
        if (c == CR) { crlf = true; }
        buffer += c;
      }
      return !eof;
    }
  
  }

}

static void main(string[] args) {
  stdout.puts("Hello\n");
}