#include "shader.h"
#include "shader_vars.h"

namespace shader {

  refcounted::~refcounted ()
  {
#if 0
    if (refcnt)
      abort ();
#endif
  }

  const char str_float  [] = "float";
  const char str_vec2   [] = "vec2";
  const char str_vec3   [] = "vec3";
  const char str_vec4   [] = "vec4";
  const char str_mat2   [] = "mat2";
  const char str_mat3   [] = "mat3";
  const char str_mat4   [] = "mat4";

  const char str_sampler_1d             [] = "sampler1D";
  const char str_sampler_1d_shadow      [] = "sampler1DShadow";
  const char str_sampler_2d             [] = "sampler2D";
  const char str_sampler_2d_shadow      [] = "sampler2DShadow";
  const char str_sampler_2d_rect        [] = "sampler2DRect";
  const char str_sampler_2d_rect_shadow [] = "sampler2DRectShadow";
  const char str_sampler_3d             [] = "sampler3D";
  const char str_sampler_3d_rect        [] = "sampler3DRect";
  const char str_sampler_cube           [] = "samplerCube";

  unsigned int var_i::next_id = 0;

  var_i::var_i (const char *typestr)
  : typestr (typestr)
  {
    //param = cgCreateParameter (cg_context, cgtype);
  }

  var_i::~var_i ()
  {
    //cgDestroyParameter (param);
  }

  temporary_i::temporary_i (const char *strtype)
  : var_i (strtype)
  {
    sprintf (name, "T%lx_%d", ((long)this >> 4) & 0xfff, ++next_id);
  }

  uniform_i::uniform_i (const char *strtype)
  : var_i (strtype), dirty (true)
  {
    sprintf (name, "U%lx_%d", ((long)this >> 4) & 0xfff, ++next_id);
  }

  fragment_string_i::~fragment_string_i ()
  {
    free (str);
  }

  ////////////////////////////////////////////////////////////////////////////

  void var_i::build_decl (ostringstream &b)
  {
    b << typestr << ' ' << name;
  }

  void uniform_i::build_decl (ostringstream &b)
  {
    b << "uniform " << typestr << ' ' << name;
  }

  void stream_i::build_decl (ostringstream &b)
  {
    b << typestr << ' ' << name;
  }

  ////////////////////////////////////////////////////////////////////////////

  void glvar_i::build (shader_builder &b)
  {
    b << name;
  }

  void var_i::build (shader_builder &b)
  {
    b << name;
  }

  void uniform_i::build (shader_builder &b)
  {
    var_i::build (b);

    if (find (b.refs.begin (), b.refs.end (), uniform (*this)) == b.refs.end ())
      b.refs.push_back (*this);
  }

  void stream_i::build (shader_builder &b)
  {
    var_i::build (b);

    if (find (b.streams.begin (), b.streams.end (), var (*this)) == b.streams.end ())
      b.streams.push_back (*this);
  }

  void temporary_i::build (shader_builder &b)
  {
    var_i::build (b);

    if (find (b.temps.begin (), b.temps.end (), var (*this)) == b.temps.end ())
      b.temps.push_back (*this);
  }

  void fragment_vector_i::build (shader_builder &b)
  {
    for (vector<fragment>::iterator i = begin (); i != end (); i++)
      (*i)->build (b);
  }

  void fragment_const_string_i::build (shader_builder &b)
  {
    b << str;
  }

  void fragment_string_i::build (shader_builder &b)
  {
    b << str;
  }

#if 0
  void statement_i::build (shader_builder &b)
  {
    b << "  ";
    fragment_vector_i::build (b);
    b << ";\n";
  }
#endif

  ////////////////////////////////////////////////////////////////////////////

  shader_object_i *cur = 0;

  shader_object_i::shader_object_i (GLenum type)
  : type (type)
  {
    id = glCreateShaderObjectARB (type);
  }

  shader_object_i::~shader_object_i ()
  {
    glDeleteObjectARB (id);
  }

  void shader_object_i::start ()
  {
    clear ();
    cur = this;
  }

  void shader_object_i::stop ()
  {
    cur = 0;
  }

  string shader_object_i::source ()
  {
    shader_builder b;
    build (b);
    ostringstream os;

    for (vector<uniform>::iterator i = b.refs.begin (); i != b.refs.end (); i++)
      {
        (*i)->build_decl (os);
        os << ";\n";
      }

    // not neccessary right now, as GLSL is rich on predefinitions
    for (vector<var>::iterator i = b.streams.begin (); i != b.streams.end (); i++)
      {
        os << "attribute ";
        (*i)->build_decl (os);
        os << ";\n";
      }

    os << "\nvoid main (void)\n{\n";

    for (vector<var>::iterator i = b.temps.begin (); i != b.temps.end (); i++)
      {
        os << "  ";
        (*i)->build_decl (os);
        os << ";\n";
      }

    os << "\n";
    os << b.source.str ();
    os << "}\n";

    return os.str ();
  }

  void shader_object_i::compile ()
  {
    string src = source ();
    const char *sptr = src.data ();
    const int slen = src.size ();

        printf ("SOURCE<%s>\n", src.c_str ());
        abort ();
    glShaderSourceARB (id, 1, &sptr, &slen);
    glCompileShaderARB (id);

    GLint compiled;
    glGetObjectParameterivARB (id, GL_OBJECT_COMPILE_STATUS_ARB, &compiled);

    if (!compiled)
      {
        char infolog[8192];
        glGetInfoLogARB (id, 8192, NULL, infolog);
        printf ("SOURCE<%s>\n", src.c_str ());
        printf ("INFOLOG<%s>\n", infolog);
        abort ();
      }
  }

  template<typename T>
  struct sl_append
  {
    T t;

    sl_append (const T &t) : t(t) { }

    void operator ()() const
    {
      cur->push_back (t);
    }
  };

  template<int length>
  struct sl_string
  {
    char str[length];

    void operator ()() const
    {
      cur->push_back (*new fragment_string_i (str));
    }
  };

  // only floats
  struct sl_float
  {
    const GLfloat c;

    sl_float (GLfloat c) : c(c) { }

    void operator ()() const
    {
      char s[64];
      sprintf (s, "%g", c);
      cur->append_string (s);
    }
  };

  template<class A, class B>
  inline sl_expr< sl_concat2<A, B> >
  concat (const A &a, const B &b)
  {
    typedef sl_concat2<A, B> expr;
    return sl_expr<expr> (expr (a, b));
  }

  template<class A, class B, class C>
  inline sl_expr< sl_concat3<A, B, C> >
  concat (const A &a, const B &b, const C &c)
  {
    typedef sl_concat3<A, B, C> expr;
    return sl_expr<expr> (expr (a, b, c));
  }

  template<class A, class B, class C, class D>
  inline sl_expr< sl_concat4<A, B, C, D> >
  concat (const A &a, const B &b, const C &c, const D &d)
  {
    typedef sl_concat4<A, B, C, D> expr;
    return sl_expr<expr> (expr (a, b, c, d));
  }

  template<typename expr>
  struct sl_convert
  {
    typedef sl_expr<expr> T;
    static inline const T &convert (const T &e)
    {
      return e;
    }
  };

  template<>
  struct sl_convert<GLfloat>
  {
    typedef sl_expr<sl_float> T;
    static inline const T convert (GLfloat f)
    {
      return sl_float (f);
    }
  };

  template<>
  struct sl_convert<vec3>
  {  
    typedef sl_expr< sl_string<256> > T;
    static inline const T convert (const vec3 &v)
    {
      sl_string<256> s;
      sprintf (s.str, "vec3 (%g, %g, %g)", v.x, v.y, v.z);
      return s;
    }
  };

  template<>
  struct sl_convert<vec4>
  {  
    typedef sl_expr< sl_string<256> > T;
    static inline const T convert (const vec4 &v)
    {
      sl_string<256> s;
      sprintf (s.str, "vec4 (%g, %g, %g, %g)", v.x, v.y, v.z, v.w);
      return s;
    }
  };

  template<>
  template<class V>
  struct sl_convert< var_ref<V> >
  {
    typedef sl_expr< sl_append< var_ref<V> > > T;
    static inline const T convert (const var_ref<V> &v)
    {
      return sl_append< var_ref<V> > (v);
    }
  };

  template<>
  struct sl_convert<glvar>
  {
    typedef sl_expr< sl_append<glvar> > T;
    static inline const T convert (const glvar &v)
    {
      return sl_append<glvar> (v);
    }
  };

  template<>
  template<const char *strtype>
  struct sl_convert< temp_ref<strtype> >
  {
    typedef sl_expr< sl_append< temp_ref<strtype> > > T;
    static inline const T convert (const temp_ref<strtype> &v)
    {
      return sl_expr< sl_append< temp_ref<strtype> > >(
               sl_append< temp_ref<strtype> > (v)
             );
    }
  };

  template<class fragment, typename expr>
  inline void sl_assign (const fragment &f, const expr &e)
  {
    cur->append_const ("  ");
    cur->append (f);
    cur->append_const (" = ");
    sl_convert<expr>::convert (e) ();
    cur->append_const (";\n");
  }

  template<class type>
  template<typename expr>
  inline const auto_lvalue_ref0<type> &auto_lvalue_ref0<type>::operator =(const expr &e) const
  {
    sl_assign (*this, e);
    return *this;
  }

  template<class type, typename arg1>
  template<typename expr>
  inline const auto_lvalue_ref1<type,arg1> &auto_lvalue_ref1<type,arg1>::operator =(const expr &e) const
  {
    sl_assign (*this, e);
    return *this;
  }

  template<const char *strtype>
  template<typename expr>
  inline const temp_ref<strtype> &temp_ref<strtype>::operator =(const expr &e) const
  {
    sl_assign (*this, e);
    return *this;
  }

  struct sl_append_const_string
  {
    fragment_const_string str;
    sl_append_const_string (const char *s)
    : str (s)
    { }

    void operator ()() const
    {
      cur->push_back (str);
    }
  };

# define SHADER_BINOP(op, str)						\
    extern const sl_append_const_string str_ ## str;				\
    template<typename A, typename B>					\
    inline const sl_expr< sl_concat3< typename sl_convert<A>::T,		\
                                      sl_append_const_string,		\
                                      typename sl_convert<B>::T > >	\
    operator op(const A &a, const B &b)					\
    {									\
      return concat (sl_convert<A>::convert (a), str_ ## str, sl_convert<B>::convert (b));	\
    }

  const sl_append_const_string str_plus  (" + "); 
  const sl_append_const_string str_minus (" - "); 
  const sl_append_const_string str_mul   (" * "); 
  const sl_append_const_string str_div   (" / "); 

  SHADER_BINOP (+, plus);
  SHADER_BINOP (-, minus);
  SHADER_BINOP (*, mul);
  SHADER_BINOP (/, div);

# undef SHADER_BINOP

  const sl_append_const_string str_rpar  (")");

  void debdebdebdebug ()//D
  {
    vertex_shader vsh;
    fragment_shader fsh;
    temp_4f t1, t2;
    sampler_2d s2d (1);

    vsh->start ();

    temp_4f lightpos;
    temp_3f wpos;

    lightpos = vec4 (10, -10, 0, 1);
    wpos = gl.model_view_matrix_inverse_transpose * vin.normal;
    vout.position = wpos;

    vsh->end ();
    vsh->compile ();
  }

}