#include "shader.h"

// Shader loader helper
std::string loadShaderSource(const std::string& filepath) {
    std::ifstream file(filepath);
    if (!file.is_open()) {
        std::cerr << "Failed to open shader file: " << filepath << std::endl;
        return "";
    }
    std::stringstream buffer;

    std::cout << "Loaded " << filepath << " successfully!\n";

    buffer << file.rdbuf();
    return buffer.str();
}

GLuint compileShader(GLenum type, const std::string& source) {
    GLuint shader = glCreateShader(type);
    const char* src = source.c_str();
    glShaderSource(shader, 1, &src, nullptr);
    glCompileShader(shader);

    int success;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
    if (!success) {
        char infoLog[512];
        glGetShaderInfoLog(shader, 512, nullptr, infoLog);
        std::cerr << "Shader compilation failed:\n" << infoLog << std::endl;
        exit(10);
    }
    return shader;
}

GLuint createShaderProgram(const std::string& vertexPath, const std::string& fragmentPath) {
    std::string vertexSrc = loadShaderSource(vertexPath);
    std::string fragmentSrc = loadShaderSource(fragmentPath);

    GLuint vertexShader = compileShader(GL_VERTEX_SHADER, vertexSrc);
    GLuint fragmentShader = compileShader(GL_FRAGMENT_SHADER, fragmentSrc);

    GLuint program = glCreateProgram();
    glAttachShader(program, vertexShader);
    glAttachShader(program, fragmentShader);
    glLinkProgram(program);

    int success;
    glGetProgramiv(program, GL_LINK_STATUS, &success);
    if (!success) {
        char infoLog[512];
        glGetProgramInfoLog(program, 512, nullptr, infoLog);
        std::cerr << "Shader linking failed:\n" << infoLog << std::endl;
        exit(11);
    }

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);
    return program;
}

/* GLuint createComputeProgram(const std::string& computePath) {
    std::string computeSrc = loadShaderSource(computePath);
    GLuint computeShader = compileShader(GL_COMPUTE_SHADER, computeSrc);

    GLuint program = glCreateProgram();
    glAttachShader(program, computeShader);
    glLinkProgram(program);

    int success;
    glGetProgramiv(program, GL_LINK_STATUS, &success);
    if (!success) {
        char infoLog[512];
        glGetProgramInfoLog(program, 512, nullptr, infoLog);
        std::cerr << "Compute shader linking failed:\n" << infoLog << std::endl;;
    }

    glDeleteShader(computeShader);
    return program;
} */