#include"gl_shader.hpp"
#include<sstream>
#include<fstream>

namespace acidcam {

    extern void updateError();

    ShaderProgram::ShaderProgram() : shader_id{0} {
        
    }
    
    ShaderProgram::ShaderProgram(GLuint id) : shader_id{id} {
        
    }
    
    ShaderProgram &ShaderProgram::operator=(const ShaderProgram &p) {
        shader_id = p.shader_id;
        name_ = p.name_;
        return *this;
    }
    
    int ShaderProgram::printShaderLog(GLuint shader) {
        int len = 0;
        int ch = 0;
        char *log;
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &len);
        if(len > 0) {
            log = new char [len+1];
            glGetShaderInfoLog(shader, len, &ch, log);
            std::cout << "acidcam: Shader: " << log << "\n";
            delete [] log;
        }
        return 0;
    }
    void ShaderProgram::printProgramLog(int p) {
        int len = 0;
        int ch = 0;
        char *log;
        glGetShaderiv(p, GL_INFO_LOG_LENGTH, &len);
        if(len > 0) {
            log = new char [len+1];
            glGetProgramInfoLog(p, len, &ch, log);
            std::cout << "acidcam: Program: " << log << "\n";
            delete [] log;
        }
    }
    bool ShaderProgram::checkError() {
        bool e = false;
        int glErr = glGetError();
        while(glErr != GL_NO_ERROR) {
            std::cout << "acidcam: GL Error: " << glErr << "\n";
            //std::cout << "acidcam: Error String: " << glewGetErrorString(glErr) << "\n";
            e = true;
            glErr = glGetError();
        }
        return e;
    }
    
    GLuint ShaderProgram::createProgram(const char *vshaderSource, const char *fshaderSource) {
        GLint vertCompiled;
        GLint fragCompiled;
        GLint linked;
        GLuint vShader = glCreateShader(GL_VERTEX_SHADER);
        GLuint fShader = glCreateShader(GL_FRAGMENT_SHADER);
        
        glShaderSource(vShader, 1, &vshaderSource, NULL);
        glShaderSource(fShader, 1, &fshaderSource, NULL);
        
        glCompileShader(vShader);
        checkError();
        glGetShaderiv(vShader, GL_COMPILE_STATUS, &vertCompiled);
        
        if(vertCompiled != 1) {
            std::cout << "acidcam: Error on Vertex compile\n";
            printShaderLog(vShader);
            return 0;
        }
        
        glCompileShader(fShader);
        checkError();
        
        glGetShaderiv(fShader, GL_COMPILE_STATUS, &fragCompiled);
        
        if(fragCompiled != 1) {
            std::cout << "acidcam: Error on Fragment compile\n";
            printShaderLog(fShader);
            return 0;
        }
        GLuint vfProgram = glCreateProgram();
        glAttachShader(vfProgram, vShader);
        glAttachShader(vfProgram, fShader);
        glLinkProgram(vfProgram);
        checkError();
        glGetProgramiv(vfProgram, GL_LINK_STATUS, &linked);
        if(linked != 1) {
            std::cout << "acidcam: Linking failed...\n";
            printProgramLog(vfProgram);
            return 0;
        }
        return vfProgram;
    }
    
    GLuint ShaderProgram::createProgramFromFile(const std::string &vert, const std::string &frag) {
        std::fstream v,f;
        v.open(vert, std::ios::in);
        if(!v.is_open()) {
            std::cout << "acidcam: Error could not open file: " << vert << "\n";
            acidcam::updateError();
        }
        f.open(frag, std::ios::in);
        if(!f.is_open()) {
            std::cout << "acidcam: Eror could not open file: " << frag << "\n";
            acidcam::updateError();
        }
        std::ostringstream stream1, stream2;
        stream1 << v.rdbuf();
        stream2 << f.rdbuf();
        return createProgram(stream1.str().c_str(), stream2.str().c_str());
    }
    
    bool ShaderProgram::loadProgram(const std::string &v, const std::string &f) {
        shader_id = createProgramFromFile(v,f);
        if(shader_id)
            return true;
        return false;
    }
    
    void ShaderProgram::setName(const std::string &n) {
        name_ = n;
    }
    
    void ShaderProgram::useProgram() {
        glUseProgram(shader_id);
    }
}