#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 = 16;

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

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

    template<class type2>
    bool operator ==(const ref<type2> b) const
    {
      return (void *)p == (void *)b.p;
    }
  };

  extern const char str_float    [];
  extern const char str_float2   [];
  extern const char str_float3   [];
  extern const char str_float4   [];
  extern const char str_float4x4 [];

  extern const char str_sampler1d   [];
  extern const char str_sampler2d   [];
  extern const char str_sampler3d   [];
  extern const char str_samplerCUBE [];
  extern const char str_samplerRECT [];

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

  struct shader_builder
  {
    struct shader_program *prog;
    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;

  struct var_i : fragment_i
  {
    static int next_name;

    CGparameter param;
    int name;
    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) : var_i (cgtype, strtype), dirty (true) { }
  };

  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_float2, cgGLSetParameter2fv> { };

  struct uniform_3f_i : uniform_f_i<3, str_float3, 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_float4, cgGLSetParameter4fv> {
    void operator =(const gl::matrix &m)
    {
      memcpy (data, m.data, 16 * sizeof (GLfloat));
      dirty = true;
    }
  };

  struct uniform_matrix_f_i : uniform_f_i<16, str_float4x4, 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_f_i> uniform_matrix_f;

  struct stream_i : var_i
  {
    char binding[16];

    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 *binding)
    : stream_i (cgtype, strtype)
    {
      strcpy (this->binding, binding);
    }

    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 *binding) : varying_i<dimension, GL_FLOAT, CG_FLOAT, strtype> (binding) { }

    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 *binding) : varying_f_i<1, str_float> (binding) { }
  };

  struct varying_2f_i : varying_f_i<2, str_float2>
  {
    varying_2f_i (const char *binding) : varying_f_i<2, str_float2> (binding) { }

    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_float3>
  {
    varying_3f_i (const char *binding) : varying_f_i<3, str_float3> (binding) { }

    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_float4>
  {
    varying_4f_i (const char *binding) : varying_f_i<4, str_float4> (binding) { }
  };

  template<class class_i>
  struct ref_varying : ref<class_i>
  {
    ref_varying (const char *binding)
    : ref<class_i> (*new class_i (binding))
    {
    }
  };

  typedef ref_varying<varying_1f_i> varying_1f;
  typedef ref_varying<varying_2f_i> varying_2f;
  typedef ref_varying<varying_3f_i> varying_3f;
  typedef ref_varying<varying_4f_i> varying_4f;

  extern struct vin
  {
    static varying_3f position_3f;
    static varying_4f position_4f;
    static varying_3f normal_3f;
    static varying_4f normal_4f;
    static varying_3f color0_3f;
    static varying_4f color0_4f;
    static varying_3f color1_3f;
    static varying_4f color1_4f;
    static varying_1f psize_1f;
    static varying_1f attr6_1f, attr7_1f;
    static varying_2f attr6_2f, attr7_2f;
    static varying_3f attr6_3f, attr7_3f;
    static varying_4f attr6_4f, attr7_4f;
    static varying_1f texcoord_1f[8];
    static varying_2f texcoord_2f[8];
    static varying_3f texcoord_3f[8];
    static varying_4f texcoord_4f[8];

    bool is (const var &r);
  } vin;

  extern struct fin
  {
    static varying_4f position_4f;
    static varying_4f color0_4f;
    static varying_4f color1_4f;
    static varying_4f texcoord_4f[8];

    bool is (const var &r);
  } fin;

  extern struct fin &vout;

  extern struct fout
  {
    static varying_4f color0_4f;
    static varying_3f color0_3f;
    static varying_4f color1_4f;
    static varying_3f color1_3f;
    static varying_1f depth_1f;

    bool is (const var &r);
  } fout;

  // predefined globals
  extern uniform_matrix_f mvp, mv, proj;

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

    temporary_i (CGtype cgtype, const char *strtype) : var_i (cgtype, 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_float2  > temp_2f;
  typedef temp_ref<CG_FLOAT, str_float3  > temp_3f;
  typedef temp_ref<CG_FLOAT, str_float4  > temp_4f;
  typedef temp_ref<CG_FLOAT, str_float4x4> temp_matrix_f;

  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 sampler1d_i : sampler_i<CG_SAMPLER1D, str_sampler1d>
  {
    sampler1d_i (GLuint texturename) : sampler_i<CG_SAMPLER1D, str_sampler1d> (texturename) { }
  };

  struct sampler2d_i : sampler_i<CG_SAMPLER2D, str_sampler2d>
  {
    sampler2d_i (GLuint texturename) : sampler_i<CG_SAMPLER2D, str_sampler2d> (texturename) { }
  };

  struct sampler3d_i : sampler_i<CG_SAMPLER3D, str_sampler3d>
  {
    sampler3d_i (GLuint texturename) : sampler_i<CG_SAMPLER3D, str_sampler3d> (texturename) { }
  };

  struct samplerCUBE_i : sampler_i<CG_SAMPLERCUBE, str_samplerCUBE>
  {
    samplerCUBE_i (GLuint texturename) : sampler_i<CG_SAMPLERCUBE, str_samplerCUBE> (texturename) { }
  };

  struct samplerRECT_i : sampler_i<CG_SAMPLERRECT, str_samplerRECT>
  {
    samplerRECT_i (GLuint texturename) : sampler_i<CG_SAMPLERRECT, str_samplerRECT> (texturename) { }
  };

  template<class sampler_i>
  struct sampler_ref : ref<sampler_i>
  {
    sampler_ref (GLuint texturename)
    : ref<sampler_i> (*new sampler_i (texturename))
    {
    }
  };

  typedef sampler_ref<sampler1d_i>   sampler1d;
  typedef sampler_ref<sampler2d_i>   sampler2d;
  typedef sampler_ref<sampler3d_i>   sampler3d;
  typedef sampler_ref<samplerCUBE_i> samplerCUBE;
  typedef sampler_ref<samplerRECT_i> samplerRECT;

  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);

    template<class fragment_i>
    fragment_vector_i &operator <<(ref<fragment_i> &f)
    {
      push_back (f);
      return *this;
    }

    template<class fragment_i>
    fragment_vector_i &operator <<(fragment_i &f)
    {
      push_back (f);
      return *this;
    }

    fragment_vector_i &operator <<(const char *s)
    {
      push_back (*new fragment_const_string_i (s));
      return *this;
    }
  };

  typedef ref<fragment_vector_i> fragment_vector;

  struct shader_program : fragment_vector_i
  {
    bool is_vertex;
    void print ();

    shader_program (bool is_vertex) : is_vertex(is_vertex) { }
  };

  struct vertex_program : shader_program
  {
    vertex_program () : shader_program (true) { }
  };

  struct fragment_program : shader_program
  {
    fragment_program () : shader_program (false) { }
  };

  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