#ifndef MATERIAL_H
#define MATERIAL_H

#include <vector>
#include <string>
#include <sstream>

#include "opengl.h"

#include "util.h"

namespace shader {

  using namespace std;

  const int NAMELEN = 24;

  class refcounted
  {
    template<class type> friend class ref;
    mutable int refcnt;
    void refcnt_inc () const { refcnt++; }
    void refcnt_dec () const { if (!--refcnt) delete this; };
  public:
    refcounted () : refcnt(0) { }
    virtual ~refcounted ();
  };

  template<class type>
  struct ref
  {
    type *p;

    ref ()
    {
      p = new type;
      p->refcnt_inc ();
    }

    ref (type &d)
    {
      d.refcnt_inc ();
      p = &d;
    }

    ref (const ref &r)
    {
      r.p->refcnt_inc ();
      p = r.p;
    }

    template<class type2>
    ref (const ref<type2> &r)
    {
      r.p->refcnt_inc ();
      p = r.p;
    }

    ~ref ()
    {
      p->refcnt_dec ();
    }

    ref &operator =(type &d)
    {
      d.refcnt_inc ();
      p->refcnt_dec ();
      p = &d;
      return *this;
    }

    type *operator ->() const { return p; }

    operator type &() const { return *p; }

    template<class type2>
    bool operator ==(const ref<type2> b) const
    {
      return (void *)p == (void *)b.p;
    }
  };
  
  // ref with auto-construct
  template<class type>
  struct auto_ref0 : ref<type>
  {
    auto_ref0 () : ref<type> (*new type ()) { }
  };

  template<class type, typename arg1>
  struct auto_ref1 : ref<type>
  {
    auto_ref1 (arg1 a) : ref<type> (*new type (a)) { }
  };

  extern const char str_float [];
  extern const char str_vec2  [];
  extern const char str_vec3  [];
  extern const char str_vec4  [];
  extern const char str_mat2  [];
  extern const char str_mat3  [];
  extern const char str_mat4  [];

  extern const char str_sampler_1d             [];
  extern const char str_sampler_1d_shadow      [];
  extern const char str_sampler_2d             [];
  extern const char str_sampler_2d_shadow      [];
  extern const char str_sampler_2d_rect        [];
  extern const char str_sampler_2d_rect_shadow [];
  extern const char str_sampler_3d             [];
  extern const char str_sampler_3d_rect        [];
  extern const char str_sampler_cube           [];

  typedef ref<struct var_i> var;
  typedef ref<struct uniform_i> uniform;

  struct shader_builder
  {
    vector<uniform> refs; // uniform parameters
    vector<var> temps; // temporary variables
    vector<var> streams; // varying inputs & outputs

    ostringstream source;

    template<typename type>
    shader_builder &operator <<(const type &t)
    {
      source << t;
      return *this;
    }
  };

  struct fragment_i : refcounted
  {
    virtual void build (shader_builder &b) = 0;
  };

  typedef ref<fragment_i> fragment;

  // a simple predeclared variable with unspecified type
  struct glvar_i : fragment_i
  {
    const char *name;
    void build (shader_builder &b);
    glvar_i (const char *name) : name (name) { }
  };

  typedef auto_ref1<glvar_i, const char *> glvar;

  struct var_i : fragment_i
  {
    static unsigned int next_id;

    CGparameter param;
    char name[NAMELEN];
    const char *typestr;

    void build (shader_builder &b);
    virtual void build_decl (ostringstream &b);

    var_i (CGtype cgtype, const char *typestr);
    ~var_i ();
  };

  struct uniform_i : var_i
  {
    bool dirty;

    virtual void update () = 0;

    void build (shader_builder &b);
    void build_decl (ostringstream &b);
    uniform_i (CGtype cgtype, const char *strtype);
  };

  template<int dimension, typename gltype, CGtype cgtype, const char *strtype, void (*upd)(CGparameter, const gltype *)>
  struct uniform2_i : uniform_i
  {
    gltype data[dimension];

    void update ()
    {
      if (dirty)
        {
          upd (param, data);
          dirty = false;
        }
    }

    uniform2_i () : uniform_i (cgtype, strtype) { }
  };

  template<int dimension, const char *strtype, void (*update)(CGparameter, const GLfloat *)>
  struct uniform_f_i : uniform2_i<dimension, GLfloat, CG_FLOAT, strtype, update>
  {
  };

  struct uniform_1f_i : uniform_f_i<1, str_float, cgGLSetParameter1fv> {
    void operator =(GLfloat v)
    {
      data[0] = v;
      dirty = true;
    }
  };

  struct uniform_2f_i : uniform_f_i<2, str_vec2, cgGLSetParameter2fv> { };

  struct uniform_3f_i : uniform_f_i<3, str_vec3, cgGLSetParameter3fv> {
    void operator =(const vec3 &v)
    {
      data[0] = v.x;
      data[1] = v.y;
      data[2] = v.z;
      dirty = true;
    }
  };

  struct uniform_4f_i : uniform_f_i<4, str_vec4, cgGLSetParameter4fv> {
#if 0
    void operator =(const gl::matrix &m)
    {
      memcpy (data, m.data, 16 * sizeof (GLfloat));
      dirty = true;
    }
#endif
  };

  struct uniform_matrix_2f_i : uniform_f_i< 4, str_mat2, cgGLSetMatrixParameterfc> { };
  struct uniform_matrix_3f_i : uniform_f_i< 9, str_mat3, cgGLSetMatrixParameterfc> { };
  struct uniform_matrix_4f_i : uniform_f_i<16, str_mat4, cgGLSetMatrixParameterfc> { };

  typedef ref<uniform_1f_i> uniform_1f;
  typedef ref<uniform_2f_i> uniform_2f;
  typedef ref<uniform_3f_i> uniform_3f;
  typedef ref<uniform_4f_i> uniform_4f;
  typedef ref<uniform_matrix_2f_i> uniform_matrix_2f;
  typedef ref<uniform_matrix_3f_i> uniform_matrix_3f;
  typedef ref<uniform_matrix_4f_i> uniform_matrix_4f;

  struct stream_i : var_i
  {
    void build (shader_builder &b);
    void build_decl (ostringstream &b);
    stream_i (CGtype type, const char *strtype) : var_i (type, strtype) { }
  };

  template<int dimension, GLenum gltype, CGtype cgtype, const char *strtype>
  struct varying_i : stream_i
  {
    varying_i (const char *glname)
    : stream_i (cgtype, strtype)
    {
      strcpy (name, glname);
    }

    void set (GLsizei stride, GLvoid *ptr)
    {
      cgGLSetParameterPointer (param, dimension, gltype, stride, ptr);
    }
  };

  template<int dimension, const char *strtype>
  struct varying_f_i : varying_i<dimension, GL_FLOAT, CG_FLOAT, strtype>
  {
    varying_f_i (const char *glname) : varying_i<dimension, GL_FLOAT, CG_FLOAT, strtype> (glname) { }

    void set (const gl::vertex_buffer_object &vb, GLint offset)
    {
      varying_i<dimension, GL_FLOAT, CG_FLOAT, strtype>::set (gl::format_stride (vb.format), (GLvoid *)(long)offset);
    }
  };

  struct varying_1f_i : varying_f_i<1, str_float>
  {
    varying_1f_i (const char *glname) : varying_f_i<1, str_float> (glname) { }
  };

  struct varying_2f_i : varying_f_i<2, str_vec2>
  {
    varying_2f_i (const char *glname) : varying_f_i<2, str_vec2> (glname) { }

    void set_t (const gl::vertex_buffer_object &vb)
    {
      set (vb, gl::format_offset_t (vb.format));
    }
  };

  struct varying_3f_i : varying_f_i<3, str_vec3>
  {
    varying_3f_i (const char *glname) : varying_f_i<3, str_vec3> (glname) { }

    void set_p (const gl::vertex_buffer_object &vb)
    {
      set (vb, gl::format_offset_p (vb.format));
    }

    void set_n (const gl::vertex_buffer_object &vb)
    {
      set (vb, gl::format_offset_n (vb.format));
    }
  };

  struct varying_4f_i : varying_f_i<4, str_vec4>
  {
    varying_4f_i (const char *glname) : varying_f_i<4, str_vec4> (glname) { }
  };

  typedef auto_ref1<varying_1f_i, const char *> varying_1f;
  typedef auto_ref1<varying_2f_i, const char *> varying_2f;
  typedef auto_ref1<varying_3f_i, const char *> varying_3f;
  typedef auto_ref1<varying_4f_i, const char *> varying_4f;

  extern struct vin
  {
    static varying_3f position_3f;
    static varying_4f position_4f;
    static varying_3f normal_3f;
    static varying_3f color_3f;
    static varying_4f color_4f;
    static varying_3f color2_3f;
    static varying_4f color2_4f;
    static varying_1f psize_1f;
    static varying_1f texcoord_1f[8];
    static varying_2f texcoord_2f[8];
    static varying_3f texcoord_3f[8];
    static varying_4f texcoord_4f[8];
  } vin;

  extern struct vout
  {
    // glstate builtin
    static glvar position;
    static glvar point_size;
    static glvar clip_vertex;

    // standard varying
    static glvar front_color;
    static glvar back_color;
    static glvar front_secondary_color;
    static glvar back_secondary_color;
    static glvar texcoord[8];
    static glvar fog_frag_coord;
  } vout;

  extern struct fin
  {
    // glstate builtin
    static glvar frag_coord;

    // standard varying
    static glvar color;
    static glvar secondary_color;
    static glvar texcoord[8];
    static glvar fog_frag_coord;
  } fin;

  extern struct fout
  {
    // glstate builtin
    static glvar frag_color;
    static glvar frag_depth;
    static glvar frag_data[2];
  } fout;

  // predefined globals
  extern struct gl {
    static uniform_matrix_4f model_view_matrix,
                             projection_matrix,
                             model_view_projection_matrix,
                             texture_matrix[8];
    static uniform_matrix_4f model_view_matrix_inverse,
                             projection_matrix_inverse,
                             model_view_projection_matrix_inverse,
                             texture_matrix_inverse[8];
    static uniform_matrix_4f model_view_matrix_transpose,
                             projection_matrix_transpose,
                             model_view_projection_matrix_transpose,
                             texture_matrix_transpose[8];
    static uniform_matrix_4f model_view_matrix_inverse_transpose,
                             projection_matrix_inverse_transpose,
                             model_view_projection_matrix_inverse_transpose,
                             texture_matrix_inverse_transpose[8];

    static uniform_matrix_3f normal_matrix;

    static uniform_1f normal_scale;
    static uniform_1f depth_range_near, depth_range_far, depth_range_diff;

    static uniform_4f clip_plane[2];//TODO

    // point parameters TODO

    static uniform_4f front_material_emission,
                      front_material_ambient,
                      front_material_diffuse,
                      front_material_specular,
                      front_material_shininess;
    static uniform_4f back_material_emission,
                      back_material_ambient,
                      back_material_diffuse,
                      back_material_specular,
                      back_material_shininess;

    // light source parameters TODO
    
    static uniform_4f light_model_ambient;
    static uniform_4f front_light_model_product_scene_color;
    static uniform_4f back_light_model_product_scene_color;

    // light products TODO
    // texture env and gen TODO
    // fogparameters TODO
    
    // shader output are in vout and fout
  } gl;

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

    temporary_i (CGtype cgtype, const char *strtype);
  };

  template<CGtype cgtype, const char *strtype>
  struct temp_ref : ref<temporary_i>
  {
    temp_ref ()
    : ref<temporary_i> (*new temporary_i (cgtype, strtype))
    {
    }
  };

  typedef temp_ref<CG_FLOAT, str_float> temp_1f;
  typedef temp_ref<CG_FLOAT, str_vec2>  temp_2f;
  typedef temp_ref<CG_FLOAT, str_vec3>  temp_3f;
  typedef temp_ref<CG_FLOAT, str_vec4>  temp_4f;
  typedef temp_ref<CG_FLOAT, str_mat2>  temp_matrix_2f;
  typedef temp_ref<CG_FLOAT, str_mat3>  temp_matrix_3f;
  typedef temp_ref<CG_FLOAT, str_mat4>  temp_matrix_4f;

  template<CGtype cgtype, const char *strtype>
  struct sampler_i : uniform_i
  {
    GLuint texture;

    void update ()
    {
      if (dirty)
        {
          cgGLSetTextureParameter (param, texture);
          dirty = false;
        }
    }

    void begin ()
    {
      cgGLEnableTextureParameter (texture);
    }

    sampler_i (GLuint texturename) : uniform_i (cgtype, strtype), texture (texturename) { }
  };

  struct sampler_1d_i : sampler_i<CG_SAMPLER1D, str_sampler_1d>
  {
    sampler_1d_i (GLuint texturename) : sampler_i<CG_SAMPLER1D, str_sampler_1d> (texturename) { }
  };

  struct sampler_1d_shadow_i : sampler_i<CG_SAMPLER1D, str_sampler_1d_shadow>
  {
    sampler_1d_shadow_i (GLuint texturename) : sampler_i<CG_SAMPLER1D, str_sampler_1d_shadow> (texturename) { }
  };

  struct sampler_2d_i : sampler_i<CG_SAMPLER2D, str_sampler_2d>
  {
    sampler_2d_i (GLuint texturename) : sampler_i<CG_SAMPLER2D, str_sampler_2d> (texturename) { }
  };

  struct sampler_2d_shadow_i : sampler_i<CG_SAMPLER2D, str_sampler_2d_shadow>
  {
    sampler_2d_shadow_i (GLuint texturename) : sampler_i<CG_SAMPLER2D, str_sampler_2d_shadow> (texturename) { }
  };

  struct sampler_2d_rect_i : sampler_i<CG_SAMPLERRECT, str_sampler_2d_rect>
  {
    sampler_2d_rect_i (GLuint texturename) : sampler_i<CG_SAMPLERRECT, str_sampler_2d_rect> (texturename) { }
  };

  struct sampler_2d_rect_shadow_i : sampler_i<CG_SAMPLERRECT, str_sampler_2d_rect_shadow>
  {
    sampler_2d_rect_shadow_i (GLuint texturename) : sampler_i<CG_SAMPLERRECT, str_sampler_2d_rect_shadow> (texturename) { }
  };

  struct sampler_3d_i : sampler_i<CG_SAMPLER3D, str_sampler_3d>
  {
    sampler_3d_i (GLuint texturename) : sampler_i<CG_SAMPLER3D, str_sampler_3d> (texturename) { }
  };

  struct sampler_3d_rect_i : sampler_i<CG_SAMPLER3D, str_sampler_3d_rect>
  {
    sampler_3d_rect_i (GLuint texturename) : sampler_i<CG_SAMPLER3D, str_sampler_3d_rect> (texturename) { }
  };

  struct sampler_cube_i : sampler_i<CG_SAMPLERCUBE, str_sampler_cube>
  {
    sampler_cube_i (GLuint texturename) : sampler_i<CG_SAMPLERCUBE, str_sampler_cube> (texturename) { }
  };

  typedef auto_ref1<sampler_1d_i, GLuint>             sampler_1d;
  typedef auto_ref1<sampler_1d_shadow_i, GLuint>      sampler_1d_shadow;
  typedef auto_ref1<sampler_2d_i, GLuint>             sampler_2d;
  typedef auto_ref1<sampler_2d_shadow_i, GLuint>      sampler_2d_shadow;
  typedef auto_ref1<sampler_2d_rect_i, GLuint>        sampler_2d_rect;
  typedef auto_ref1<sampler_2d_rect_shadow_i, GLuint> sampler_2d_rect_shadow;
  typedef auto_ref1<sampler_3d_i, GLuint>             sampler_3d;
  typedef auto_ref1<sampler_3d_rect_i, GLuint>        sampler_3d_rect;
  typedef auto_ref1<sampler_cube_i, GLuint>           sampler_cube;

  struct fragment_const_string_i : fragment_i
  {
    const char *str;

    void build (shader_builder &b);

    fragment_const_string_i (const char *str) : str(str) { }
  };

  struct fragment_vector_i : fragment_i, vector<fragment>
  {
    void build (shader_builder &b);

#if 0
    fragment_vector_i &operator <<(statement_i &f)
    {
      push_back (*new fragment_const_string_i ("  "));

      for (vector<fragment>::iterator i = f.begin (); i != f.end (); i++)
        push_back (*i);

      push_back (*new fragment_const_string_i (";\n"));
      return *this;
    }
#endif
  };

  typedef ref<fragment_vector_i> fragment_vector;

  struct statement_i : fragment_vector_i
  {
    void build (shader_builder &b);
  };

  struct statement : ref<statement_i>
  {
    template<class fragment_i>
    statement (ref<fragment_i> &f)
    : ref<statement_i> (*new statement_i)
    {
      p->push_back (f);
    }

    template<class fragment_i>
    const statement &operator <<(ref<fragment_i> &f) const
    {
      p->push_back (f);
      return *this;
    }

    const statement &operator <<(const char *s) const
    {
      p->push_back (*new fragment_const_string_i (s));
      return *this;
    }
  };

  struct shader_object_i : fragment_vector_i
  {
    GLenum type;
    GLuint id; // GLhandleARB, but 2.0 will use uint

    string source ();
    void compile ();

    shader_object_i (GLenum type);
    ~shader_object_i ();
  };

  template<GLenum type>
  struct shader_object : ref<shader_object_i>
  {
    shader_object ()
    : ref<shader_object_i> (*new shader_object_i (type))
    {
    }

    const statement &operator <<(const statement &f)
    {
      p->push_back (f);
      return f;
    }
  };

  typedef shader_object<GL_VERTEX_SHADER_ARB>   vertex_shader;
  typedef shader_object<GL_FRAGMENT_SHADER_ARB> fragment_shader;

  void debdebdebdebug ();//D
}

struct texture_execption
{ 
  texture_execption (string s) : msg(s) { }
  string msg; 
};

inline int power_of_two (int input)
{
  int value = 1;

  while (value < input)
    {
      value <<= 1;
    }
  return value;
}

struct material
{
  virtual void begin () = 0;
  virtual void end () = 0;
  virtual ~material ();
};

struct simple_material : material
{
  colour diffuse, specular, emission;
  GLfloat shininess;

  void begin ();
  void end ();

  simple_material () 
  : diffuse(1, 0, 1, 1)
  , specular(1, 0, 1, 1)
  , emission(1, 0, 1, 1)
  , shininess(1.)
  {
  }
};

struct texture
{
  SDL_Surface *image;
  GLuint texture_pxls;
  GLfloat texcoord[4];

  GLuint load_texture (SDL_Surface *surface, GLfloat *texcoord);

  texture(const char *f)
  {
    image = IMG_Load (f);

    if (!image) 
      throw (texture_execption ("Couldn't load " + (string) f + ": " + (string) IMG_GetError ()));

    texture_pxls = load_texture (image, (GLfloat*)&texcoord);
    if (texture_pxls == 0) 
      throw (texture_execption ("Couldn't make GL Texture, failed to create new RGB SWSurface"));
  }
};

extern CGcontext cgc;

struct xshader 
{
   CGprogram vsh, fsh;
   CGparameter lightpos;
   // mv, mvp
   CGprofile vsh_profile, fsh_profile;
   CGparameter g_Texture; // the texture parameter

   void check_cg_error (void)
   {
     CGerror err = cgGetError ();

     if (err != CG_NO_ERROR)
       {
         printf("CG error: %s\n", cgGetErrorString (err));
         exit(1);
       }
   }
   xshader (const char *vshp, const char *fshp)
   {
     vsh_profile = CG_PROFILE_ARBVP1;
     //if (cgGLIsProfileSupported (CG_PROFILE_VP30)) vsh_profile = CG_PROFILE_VP30;
     //if (cgGLIsProfileSupported (CG_PROFILE_VP40)) vsh_profile = CG_PROFILE_VP40;
     fsh_profile = CG_PROFILE_ARBFP1;
     //if (cgGLIsProfileSupported (CG_PROFILE_FP30)) fsh_profile = CG_PROFILE_FP30;
     //if (cgGLIsProfileSupported (CG_PROFILE_FP40)) fsh_profile = CG_PROFILE_FP40;

     vsh = cgCreateProgramFromFile (cgc, CG_SOURCE, vshp, vsh_profile, 0, 0);
     check_cg_error ();
     cgGLLoadProgram (vsh);
     check_cg_error ();

     fsh = cgCreateProgramFromFile (cgc, CG_SOURCE, fshp, fsh_profile, 0, 0);
     check_cg_error ();
     cgGLLoadProgram (fsh);
     check_cg_error ();

     cgGLBindProgram (vsh);
     cgGLBindProgram (fsh);

    // mv = cgGetNamedParameter (vsh, "WorldProj");
    // mvp = cgGetNamedParameter (vsh, "WorldViewProj");
     //lightpos = cgGetNamedParameter (vsh, "LightPos");
     //cgGLSetParameter4f (lightpos, 10, 10, 0, 1); //camera.p.x, camera.p.y, camera.p.z, 1);

     check_cg_error ();
   }
};

struct osama_material : material, texture, xshader {
  osama_material () 
  : xshader ("vsh.cg", "fsh.cg"), texture ("textures/osama.jpg") 
  {
     g_Texture = cgGetNamedParameter(fsh, "Texture"); // the texture cg-warper ;)
     cgGLSetTextureParameter(g_Texture, texture_pxls); // Bind the texture number 999 to g_Texture
  }

  void begin ();
  void end ();

};

void init_shaders ();
#endif