#include <vector>
#include <deque>
#include <limits.h>
#include "../../conffile.h"
#include "shader_platform.h"

static const unsigned int glsl_max_passes = 20;

typedef void (* GLSLViewportCallback) (int source_width,   int source_height,
                                       int viewport_x,     int viewport_y,
                                       int viewport_width, int viewport_height,
                                       int *out_dst_x,     int *out_dst_y,
                                       int *out_dst_width, int *out_dst_height);

enum GLSLScaleType
{
    GLSL_NONE = 0,
    GLSL_SOURCE,
    GLSL_VIEWPORT,
    GLSL_ABSOLUTE
};

enum GLSLFilter
{
    GLSL_UNDEFINED = 0,
};

typedef struct
{
    GLint Texture;
    GLint InputSize;
    GLint TextureSize;
    GLint TexCoord;

} GLSLUniformMetrics;

typedef struct
{
    GLint Texture;
    GLint InputSize;
    GLint OutputSize;
    GLint TextureSize;

    GLint FrameCount;
    GLint FrameDirection;

    GLint TexCoord;
    GLint LUTTexCoord;
    GLint VertexCoord;

    GLint OrigTexture;
    GLint OrigInputSize;
    GLint OrigTextureSize;
    GLint OrigTexCoord;

    unsigned int max_pass;
    unsigned int max_prevpass;
    GLSLUniformMetrics Prev[7];
    GLSLUniformMetrics Pass[glsl_max_passes];
    GLSLUniformMetrics PassPrev[glsl_max_passes];
    GLint Lut[9];

} GLSLUniforms;

typedef struct
{
    char filename[PATH_MAX];
    char alias[256];
    int scale_type_x;
    int scale_type_y;
    float scale_x;
    float scale_y;
    bool fp;
    bool srgb;
    int frame_count_mod;
    unsigned int frame_count;

    GLuint program;
    GLuint vertex_shader;
    GLuint fragment_shader;
    GLuint texture;
    GLuint wrap_mode;
    GLuint fbo;
    GLuint width;
    GLuint height;
    GLuint filter;

    GLSLUniforms unif;
} GLSLPass;

typedef struct
{
    char id[256];
    char filename[PATH_MAX];
    GLuint filter;
    GLuint texture;
    GLuint wrap_mode;
    bool mipmap;
} GLSLLut;

typedef struct
{
    char name[PATH_MAX];
    char id[256];
    float min;
    float max;
    float val;
    float step;
    GLint unif[glsl_max_passes];
} GLSLParam;

typedef struct
{
    bool load_shader (char *filename);
    bool load_shader_file (char *filename);
    void render (GLuint &orig, int width, int height, int viewport_x, int viewport_y, int viewport_width, int viewport_height, GLSLViewportCallback vpcallback);
    void set_shader_vars (unsigned int pass);
    void clear_shader_vars (void);
    void strip_parameter_pragmas(char *buffer);
    GLuint compile_shader (char *program,
                           const char *aliases,
                           const char *defines,
                           GLuint type,
                           GLuint *out);
    void save (const char *filename);

    void destroy (void);
    void register_uniforms (void);

    ConfigFile conf;

    std::vector<GLSLPass> pass;
    std::vector<GLSLLut> lut;
    std::vector<GLSLParam> param;
    int max_prev_frame;
    std::deque<GLSLPass> prev_frame;
    std::vector<GLuint> vaos;

    unsigned int frame_count;
    GLuint vbo;
    GLuint prev_fbo;
    GLfloat *fa;

} GLSLShader;