#include <cassert>

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

namespace shader {

  refcounted::~refcounted ()
  {
#if 1
    if (refcnt)
      abort ();
#endif
  }

  void refcounted::refcnt_dec () const
  {
    if (!--refcnt)
      delete this; // quite a bit of code...
  }

  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);
  }

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

  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 gluvar_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);
    assert (id);
  }

  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 ());
    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 ();
      }
  }

  program_object::program_object ()
  {
    id = glCreateProgramObjectARB ();
    assert (id);

    glAttachObjectARB (id, vsh->id);
    glAttachObjectARB (id, fsh->id);
  }

  program_object::~program_object ()
  {
    glDeleteProgramsARB (1, &id);
  }

  void program_object::link ()
  {
    glLinkProgramARB (id);
        
    GLint linked;
    glGetObjectParameterivARB (id, GL_OBJECT_LINK_STATUS_ARB, &linked);

    if (!linked)
      {
        char infolog[8192];
        glGetInfoLogARB (id, 8192, NULL, infolog);
        printf ("LINK-INFOLOG<%s>\n", infolog);
        abort ();
      }
  }

  void sl_func0::begin () const
  {
    cur->append_string (name_par);
  }

  void sl_func0::comma () const
  {
    cur->append (str_comma);
  }

  void sl_func0::end () const
  {
    str_rpar ();
  }

  void sl_float::operator ()() const
  {
    char s[20];
    sprintf (s, "%g", c);
    cur->append_string (s);
  }

  const sl_convert< ::vec2 >::T sl_convert< ::vec2 >::convert (const ::vec2 &v)
  {
    sl_string<60> s;
    sprintf (s.str, "vec2 (%g, %g)", v.x, v.y);
    return s;
  }

  const sl_convert< ::vec3 >::T sl_convert< ::vec3 >::convert (const ::vec3 &v)
  {
    sl_string<80> s;
    sprintf (s.str, "vec3 (%g, %g, %g)", v.x, v.y, v.z);
    return s;
  }

  const sl_convert< ::vec4 >::T sl_convert< ::vec4 >::convert (const ::vec4 &v)
  {
    sl_string<100> s;
    sprintf (s.str, "vec4 (%g, %g, %g, %g)", v.x, v.y, v.z, v.w);
    return s;
  }

  const fragment_const_string str_2sp    ("  ");
  const fragment_const_string str_equal  (" = ");
  const fragment_const_string str_comma  (", ");
  const fragment_const_string str_endl   (";\n");

  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   (" / "); 
  const sl_append_const_string str_mod   (" % "); 

  const sl_append_const_string str_lpar  ("(");
  const sl_append_const_string str_rpar  (")");

  void swizzle_mask (sl_string<7> &s, int mask)
  {
    static const char channel[4] = { 'x', 'y', 'z', 'w' };

    char *str = s.str;

    *str++ = ')';
    *str++ = '.';

    while (mask)
      {
        int c = mask % 5;
        mask /= 5;

        if (c)
          *str++ = channel[c - 1];
      }

    *str++ = 0;
  }


  void debdebdebdebug ()//D
  {
    vertex_shader vsh;

    vsh->start ();

    temp_4f lightpos;
    temp_3f wpos;

    lightpos = vec4 (0, 10, 0, 1);
    wpos = xyz (gl.model_view_matrix * vin.vertex);
    vout.position = gl.model_view_matrix_inverse_transpose * vin.vertex;
    vout.tex_coord[0] = vin.tex_coord[0];
    vout.tex_coord[1] = normalize (xyz (lightpos) - wpos);
    vout.tex_coord[2] = normalize (xyzx (wpos));
    //vout.tex_coord[3] = normalize (xyz (gl.model_view_matrix_inverse_transpose) * vin.normal);
    //vout.tex_coord[4] = normalize (xyz (gl.projection_matrix_inverse_transpose) - wpos);

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

    fragment_shader fsh;

    fsh->start ();

    xyz (fout.frag_color) = noise3 (x (fin.frag_coord) * y (fin.frag_coord));

    temp_1f spec_expon;
    spec_expon = 200;

    fsh->end ();
    fsh->compile ();

    //abort ();
  }

}