#include "shader.h"

#include "render.h"
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "log.h"
#include "resources.h"
#include "stb_ds.h"
#include "timer.h"

#include "time.h"

#define SHADER_BUF 10000

static struct shader *shaders;

struct shader *MakeShader(const char *vertpath, const char *fragpath)
{
    if (arrcap(shaders) == 0)
        arrsetcap(shaders, 20);

    struct shader init = {
        .vertpath = vertpath,
        .fragpath = fragpath };
    shader_compile(&init);
    arrput(shaders, init);
    return &arrlast(shaders);
}

int shader_compile_error(GLuint shader)
{
    GLint success = 0;
    GLchar infoLog[ERROR_BUFFER] = { '\0' };

    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
    if (success) return 0;

    glGetShaderInfoLog(shader, ERROR_BUFFER, NULL, infoLog);
    YughLog(0, LOG_ERROR, "Shader compilation error.\nLog: %s", infoLog);

    return 1;
}

int shader_link_error(GLuint shader)
{
    GLint success = 0;
    GLchar infoLog[ERROR_BUFFER] = { '\0' };

    glGetProgramiv(shader, GL_LINK_STATUS, &success);
    if (success) return 0;

    glGetProgramInfoLog(shader, ERROR_BUFFER, NULL, infoLog);
    YughLog(0, LOG_ERROR, "Shader link error.\nLog: %s", infoLog);

    return 1;
}

GLuint load_shader_from_file(const char *path, int type)
{
    char spath[MAXPATH] = {'\0'};

    sprintf(spath, "%s%s", "shaders/", path);
    FILE *f = fopen(make_path(spath), "r'");
    if (!path)
        perror(spath), exit(1);

    char *buf;
    long int fsize;
    fseek(f, 0, SEEK_END);
    fsize = ftell(f);
    buf = malloc(fsize+1);
    rewind(f);
    size_t r = fread(buf, sizeof(char), fsize, f);
    buf[r] = '\0';

    fclose(f);


    GLuint id = glCreateShader(type);
    const char *code = buf;
    glShaderSource(id, 1, &code, NULL);
    glCompileShader(id);
    if (shader_compile_error(id)) {
        YughError("Error with shader %s.", path);
        return 0;
    }

    free(buf);

    return id;
}

void shader_compile(struct shader *shader)
{
    YughInfo("Making shader with %s and %s.", shader->vertpath, shader->fragpath);

    GLuint vert = load_shader_from_file(shader->vertpath, GL_VERTEX_SHADER);
    GLuint frag = load_shader_from_file(shader->fragpath, GL_FRAGMENT_SHADER);

    shader->id = glCreateProgram();
    glAttachShader(shader->id, vert);
    glAttachShader(shader->id, frag);
    glLinkProgram(shader->id);
    shader_link_error(shader->id);

    glDeleteShader(vert);
    glDeleteShader(frag);
}

void shader_use(struct shader *shader)
{
    glUseProgram(shader->id);
}

void shader_setbool(struct shader *shader, const char *name, int val)
{
    glUniform1i(glGetUniformLocation(shader->id, name), val);
}

void shader_setint(struct shader *shader, const char *name, int val)
{
    glUniform1i(glGetUniformLocation(shader->id, name), val);
}

void shader_setfloat(struct shader *shader, const char *name, float val)
{
    glUniform1f(glGetUniformLocation(shader->id, name), val);
}

void shader_setvec2(struct shader *shader, const char *name, mfloat_t val[2])
{
    glUniform2fv(glGetUniformLocation(shader->id, name), 1, val);
}

void shader_setvec3(struct shader *shader, const char *name, mfloat_t val[3])
{
    glUniform3fv(glGetUniformLocation(shader->id, name), 1, val);
}

void shader_setvec4(struct shader *shader, const char *name, mfloat_t val[4])
{
    glUniform4fv(glGetUniformLocation(shader->id, name), 1, val);
}

void shader_setmat2(struct shader *shader, const char *name, mfloat_t val[4])
{
    glUniformMatrix2fv(glGetUniformLocation(shader->id, name), 1, GL_FALSE, val);
}

void shader_setmat3(struct shader *shader, const char *name, mfloat_t val[9])
{
    glUniformMatrix3fv(glGetUniformLocation(shader->id, name), 1, GL_FALSE, val);
}

void shader_setmat4(struct shader *shader, const char *name, mfloat_t val[16])
{
    glUniformMatrix4fv(glGetUniformLocation(shader->id, name), 1, GL_FALSE, val);
}

void shader_setUBO(struct shader *shader, const char *name, unsigned int index)
{
    glUniformBlockBinding(shader->id, glGetUniformBlockIndex(shader->id, name), index);
}



void shader_compile_all()
{
    for (int i = 0; i < arrlen(shaders); i++)
        shader_compile(&shaders[i]);
}