/**
 * \file main.cpp
 * \brief Univerxel game
 * \author Maelys Bois
 * \version 0.0.1
 *
 * Univerxel main program.
 */

#include <stdexcept>
#include <iostream>
#include <chrono>
#include <thread>

#include "render/window.hpp"
#include "render/UI.hpp"
#include "control/InputMap.hpp"
#include "control/Camera.hpp"

#include "render/Renderer.hpp"
#include "world/World.hpp"
#include "contouring/FlatBox.hpp"

#include "data/state.h"

/// Entry point
int main(int, char *[]){
    options options;
    state state;
    reports reports;

    GLFWwindow *window = createWindow(options.samples);
    if(window == NULL)
        return 1;

    glClearColor(options.renderer.clear_color.x, options.renderer.clear_color.y, options.renderer.clear_color.z, options.renderer.clear_color.w);
    glfwSwapInterval(options.target_fps < MIN_FPS);

    InputMap inputs(window);
    Camera camera(window, inputs, options.camera);

    Renderer *renderer = new Renderer(options.renderer);
    UI::setup(window);

    GLuint aimTexture = Program::loadTexture("ui/Aim", false);

    renderer->LightInvDir = glm::vec3(-0.5f, 2, -2);

    World world = World(options.world);

    do {
        const double startTime = glfwGetTime();
        { // Update
            const double partTime = glfwGetTime();
            inputs.toggle(state.capture_mouse, Input::Mouse);
            inputs.toggle(options.show_debug_menu, Input::Debug);

            camera.update(state.capture_mouse, !UI::isFocus());
            renderer->lookFrom(camera);

            state.position = camera.getPosition();
            /*look_at = world.raycast(camera.getViewRay() / scale);
            if (capture_mouse && look_at.has_value()) {
                if (inputs.isPressing(Mouse::Left))
                    world.setCube(look_at.value().first, 2, Voxel{0, 0});
                else if (inputs.isPressing(Mouse::Right))
                    world.setCube(look_at.value().first, 2, Voxel{2, 1});
            }*/
            world.update(state.position / options.voxel_size, reports.world);
            inputs.saveKeys();
            reports.main.update.push((glfwGetTime() - partTime) * 1000);
        }

        {
            const auto actions = UI::draw(options, state, reports, aimTexture);
            if (actions && UI::Actions::FPS) {
                glfwSwapInterval(options.target_fps < MIN_FPS);
            }
            if (actions && UI::Actions::FullScreen) {
                // MAYBE: real fullscreen
                if(options.fullscreen) {
                    GLFWmonitor *monitor = glfwGetPrimaryMonitor();
                    const GLFWvidmode *mode = glfwGetVideoMode(monitor);
                    glfwSetWindowMonitor(window, monitor, 0, 0, mode->width, mode->height, mode->refreshRate);
                } else {
                    glfwSetWindowMonitor(window, NULL, 0, 0, DEFAULT_WIDTH, DEFAULT_HEIGHT, GLFW_DONT_CARE);
                }
            }
            if(actions && UI::Actions::ClearColor) {
                renderer->FogColor = glm::vec3(options.renderer.clear_color.x, options.renderer.clear_color.y, options.renderer.clear_color.z);
                glClearColor(options.renderer.clear_color.x, options.renderer.clear_color.y, options.renderer.clear_color.z, options.renderer.clear_color.w);
            }
            if(actions && UI::Actions::RendererSharders) {
                renderer->reloadShaders(options.renderer.main);
            }
            if(actions && UI::Actions::RendererTextures) {
                renderer->reloadTextures(options.renderer.textures, options.renderer.mipMapLOD);
            }
            if(actions && UI::Actions::World) {
                world.setOptions(options.world);
            }
            if(actions && UI::Actions::Camera) {
                camera.setOptions(options.camera);
            }
            renderer->SkyEnable = options.renderer.skybox;
        }
        { // Rendering
            const double partTime = glfwGetTime();
            auto pass = renderer->getPass();
            pass.start();

            std::vector<std::pair<glm::mat4, Buffer *>> models;
            if(options.culling) {
                world.getModels(models, options.voxel_size, camera.getFrustum());
            } else {
                world.getModels(models, options.voxel_size);
            }
            reports.main.models_count = 0;
            reports.main.tris_count = 0;
            for (auto [model, buffer] : models) {
                reports.main.models_count++;
                reports.main.tris_count += buffer->draw(pass.setup(model));
            }
            renderer->postProcess();

            UI::render();
            reports.main.render.push((glfwGetTime() - partTime) * 1000);
        }

        { // Swap buffers
            const double partTime = glfwGetTime();
            glfwSwapBuffers(window);
            glfwPollEvents();
            reports.main.swap.push((glfwGetTime() - partTime) * 1000);
        }

        { // Wait target fps
            const double partTime = glfwGetTime();
            if(options.target_fps >= MIN_FPS && options.target_fps <= MAX_FPS) {
                while (glfwGetTime() < startTime + 1.0 / options.target_fps) {
                    std::this_thread::sleep_for(std::chrono::microseconds(100));
                }
            }
            reports.main.wait.push((glfwGetTime() - partTime) * 1000);
        }
        reports.main.fps.push(1.0 / (glfwGetTime() - startTime));
    } // Check if the ESC key was pressed or the window was closed
    while (glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS &&
           glfwWindowShouldClose(window) == 0);

    UI::unload();
    delete renderer;

    // Close OpenGL window and terminate GLFW
    glfwTerminate();

    options.save();

    return 0;
}