#include "Cubed/tools/shader_tools.hpp"

#include "Cubed/tools/cubed_assert.hpp"
#include "Cubed/tools/log.hpp"

#include <filesystem>
#include <fstream>

namespace Cubed {

namespace fs = std::filesystem;

namespace Tools {

GLuint create_shader_program(const std::string& v_shader_path,
                             const std::string& f_shader_path) {

    std::string v_shader_str =
        Tools::read_shader_source(ASSETS_PATH + v_shader_path);
    std::string f_shader_str =
        Tools::read_shader_source(ASSETS_PATH + f_shader_path);
    const char* v_shader_source = v_shader_str.c_str();
    const char* f_shader_source = f_shader_str.c_str();

    GLuint v_shader = glCreateShader(GL_VERTEX_SHADER);
    GLuint f_shader = glCreateShader(GL_FRAGMENT_SHADER);

    GLint vc, fc;
    glShaderSource(v_shader, 1, &v_shader_source, NULL);
    glShaderSource(f_shader, 1, &f_shader_source, NULL);
    glCompileShader(v_shader);
    Tools::check_opengl_error();
    glGetShaderiv(v_shader, GL_COMPILE_STATUS, &vc);
    if (vc != 1) {
        Logger::error("vertex compilation failed");
        Tools::print_shader_log(v_shader);
        ASSERT(0);
    }
    glCompileShader(f_shader);
    Tools::check_opengl_error();
    glGetShaderiv(f_shader, GL_COMPILE_STATUS, &fc);
    if (fc != 1) {
        Logger::error("vertex compilation failed");
        Tools::print_shader_log(f_shader);
        ASSERT(0);
    }
    GLuint vf_program = glCreateProgram();
    glAttachShader(vf_program, v_shader);
    glAttachShader(vf_program, f_shader);
    glLinkProgram(vf_program);

    GLint linked;
    Tools::check_opengl_error();
    glGetProgramiv(vf_program, GL_LINK_STATUS, &linked);
    if (linked != 1) {
        Logger::error("linking failed");
        Tools::print_program_info(vf_program);
        ASSERT(0);
    }
    glDeleteShader(v_shader);
    glDeleteShader(f_shader);
    return vf_program;
}

void print_shader_log(GLuint shader) {
    int len = 0;
    int ch_written = 0;
    char* log;
    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &len);
    if (len > 0) {
        log = (char*)malloc(len);
        glGetShaderInfoLog(shader, len, &ch_written, log);
        Logger::info("Shader Info Log: {}", log);
        free(log);
    }
}

void print_program_info(int prog) {
    int len = 0;
    int ch_written = 0;
    char* log;
    glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &len);
    if (len > 0) {
        log = (char*)malloc(len);
        glGetProgramInfoLog(prog, len, &ch_written, log);
        Logger::info("Program Info Log: {}", log);
        free(log);
    }
}

bool check_opengl_error() {
    bool found_error = false;
    int gl_err = glGetError();
    while (gl_err != GL_NO_ERROR) {
        Logger::error("glEorr: {}", gl_err);
        found_error = true;
        gl_err = glGetError();
    }

    return found_error;
}

std::string read_shader_source(const std::string& file_path) {
    std::string content;
    std::ifstream file_stream(file_path, std::ios::in);

    if (!file_stream.is_open()) {
        Logger::error("{} not exist", file_path);
    }

    std::string line = "";
    while (!file_stream.eof()) {

        getline(file_stream, line);
        content.append(line + "\n");
    }
    file_stream.close();
    return content;
}

void delete_image_data(unsigned char* data) { SOIL_free_image_data(data); }

unsigned char* load_image_data(const std::string& tex_image_path) {
    fs::path path = ASSETS_PATH + tex_image_path;
    ASSERT_MSG(fs::is_regular_file(path), path.c_str());
    unsigned char* data = nullptr;
    int width, height, channels;
    data = SOIL_load_image(path.string().c_str(), &width, &height, &channels,
                           SOIL_LOAD_AUTO);
    ASSERT_MSG(data, "Could not load texture" + path.string());

    return data;
}

} // namespace Tools

} // namespace Cubed