#include "OpenGLShaderProgram.h"

#include OPENGL_FUNCTIONS_INCLUDE
#include <QOpenGLShaderProgram>
#include <QDir>
#include "OpenGLRenderer.h"
#include "OpenGLSharedState.h"
#include "Texture2D.h"
#include "Texture3D.h"
#include "Texture4D.h"
#include "Color.h"
#include "Logs.h"

OpenGLShaderProgram::OpenGLShaderProgram(const std::string &name, OpenGLRenderer *renderer)
    : renderer(renderer), name(name) {
    program = new QOpenGLShaderProgram();
    functions = renderer->getOpenGlFunctions();
    state = new OpenGLSharedState();
    compiled = false;
}

OpenGLShaderProgram::~OpenGLShaderProgram() {
    delete program;
    delete state;
}

void OpenGLShaderProgram::addVertexSource(QString path) {
    QFile file(QString(":/shaders/%1.vert").arg(path));
    if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        source_vertex += QString(file.readAll()).toStdString();
    } else {
        Logs::error() << "Can't open vertex file " << file.fileName().toStdString() << std::endl;
    }
}

void OpenGLShaderProgram::addFragmentSource(QString path) {
    QFile file(QString(":/shaders/%1.frag").arg(path));
    if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        source_fragment += QString(file.readAll()).toStdString();
    } else {
        Logs::error() << "Can't open fragment file " << file.fileName().toStdString() << std::endl;
    }
}

void OpenGLShaderProgram::compile() {
    program->addShaderFromSourceCode(QOpenGLShader::Vertex, QString::fromStdString(source_vertex));
    program->addShaderFromSourceCode(QOpenGLShader::Fragment, QString::fromStdString(source_fragment));

    if (not program->link()) {
        Logs::warning() << "Error while compiling shader " << name << std::endl
                        << program->log().toStdString() << std::endl;
    } else if (program->log().length() > 0) {
        Logs::debug() << "Shader " << name << " compilation output:" << std::endl
                      << program->log().toStdString() << std::endl;
    }
}

void OpenGLShaderProgram::bind() {
    if (not compiled) {
        compile();
        compiled = true;
    }

    program->bind();

    int texture_unit = 0;
    renderer->getSharedState()->apply(this, texture_unit);
    state->apply(this, texture_unit);
}

void OpenGLShaderProgram::release() {
    program->release();
}

void OpenGLShaderProgram::drawTriangles(float *vertices, int triangle_count) {
    bind();

    GLuint array_vertex = program->attributeLocation("vertex");
    program->setAttributeArray(array_vertex, GL_FLOAT, vertices, 3);
    program->enableAttributeArray(array_vertex);

    functions->glDrawArrays(GL_TRIANGLES, 0, triangle_count * 3);

    program->disableAttributeArray(array_vertex);

    release();
}

void OpenGLShaderProgram::drawTriangleStrip(float *vertices, int vertex_count) {
    bind();

    GLuint array_vertex = program->attributeLocation("vertex");
    program->setAttributeArray(array_vertex, GL_FLOAT, vertices, 3);
    program->enableAttributeArray(array_vertex);

    functions->glDrawArrays(GL_TRIANGLE_STRIP, 0, vertex_count);

    program->disableAttributeArray(array_vertex);

    release();
}

void OpenGLShaderProgram::drawTrianglesUV(float *vertices, float *uv, int triangle_count) {
    bind();

    GLuint array_vertex = program->attributeLocation("vertex");
    program->setAttributeArray(array_vertex, GL_FLOAT, vertices, 3);
    program->enableAttributeArray(array_vertex);

    GLuint array_uv = program->attributeLocation("uv");
    program->setAttributeArray(array_uv, GL_FLOAT, uv, 2);
    program->enableAttributeArray(array_uv);

    functions->glDrawArrays(GL_TRIANGLES, 0, triangle_count * 3);

    program->disableAttributeArray(array_vertex);
    program->disableAttributeArray(array_uv);

    release();
}

void OpenGLShaderProgram::drawTriangleStripUV(float *vertices, float *uv, int vertex_count) {
    bind();

    GLuint array_vertex = program->attributeLocation("vertex");
    program->setAttributeArray(array_vertex, GL_FLOAT, vertices, 3);
    program->enableAttributeArray(array_vertex);

    GLuint array_uv = program->attributeLocation("uv");
    program->setAttributeArray(array_uv, GL_FLOAT, uv, 2);
    program->enableAttributeArray(array_uv);

    functions->glDrawArrays(GL_TRIANGLE_STRIP, 0, vertex_count);

    program->disableAttributeArray(array_vertex);
    program->disableAttributeArray(array_uv);

    release();
}