use std::convert::TryInto;
use glfw;
use glfw::{Action, Context, Key};
use cgmath::{Matrix4, vec3, Point3, Deg, perspective};
use cgmath::prelude::*;
const SCR_WIDTH: u32 = 1600;
const SCR_HEIGHT: u32 = 900;
const TITLE: &str = "GLFWtest";


use std::sync::mpsc::Receiver;
use std::ptr;
use std::mem;
use std::os::raw::c_void;
use std::path::Path;
use std::ffi::{CString, CStr};
mod shader;
mod model;
mod camera;
fn main() {

    let mut glfw = glfw::init(glfw::FAIL_ON_ERRORS).unwrap();

    glfw.window_hint(glfw::WindowHint::ContextVersion(3, 3));
    glfw.window_hint(glfw::WindowHint::OpenGlProfile(glfw::OpenGlProfileHint::Core));
    glfw.window_hint(glfw::WindowHint::OpenGlForwardCompat(true));
    glfw.window_hint(glfw::WindowHint::Resizable(false));
    glfw.window_hint(glfw::WindowHint::TransparentFramebuffer(true));
    glfw.window_hint(glfw::WindowHint::Decorated(false));

    let (mut window, events) = glfw.create_window(SCR_WIDTH, SCR_HEIGHT, TITLE, glfw::WindowMode::Windowed).unwrap();

    let (screen_width, screen_height) = window.get_framebuffer_size();


    window.make_current();
    window.set_key_polling(true);
    window.set_framebuffer_size_polling(true);
    window.set_cursor_pos_polling(true);
    window.set_cursor_mode(glfw::CursorMode::Disabled);


    let mut camera = camera::Camera {
        Position: Point3::new(0.0, 0.25, 1.0),
        Pitch: -20.0,
        ..camera::Camera::default()
    };

    let mut firstMouse = true;
    let mut lastX: f32 = SCR_WIDTH as f32 / 2.0;
    let mut lastY: f32 = SCR_HEIGHT as f32 / 2.0;

    // timing
    let mut deltaTime: f32; // time between current frame and last frame
    let mut lastFrame: f32 = 0.0;

    gl::load_with(|ptr| window.get_proc_address(ptr) as *const _);

    unsafe{
        gl::Enable(gl::DEPTH_TEST);
        gl::DepthFunc(gl::LESS);
        gl::Enable(gl::STENCIL_TEST);
        gl::StencilFunc(gl::NOTEQUAL, 1, 0xFF);
        gl::StencilOp(gl::KEEP, gl::KEEP, gl::REPLACE);
    };

    let (ourshader, ourModel) = unsafe {
        gl::Enable(gl::DEPTH_TEST);

        let ourShader = shader::shader::new("model");

        let ourModel = model::Model::new("resources/models/TestCarModel/CarW4.obj");

        (ourShader, ourModel)
    };



    let projection: Matrix4<f32> = perspective(Deg(45.0), SCR_WIDTH as f32/ SCR_HEIGHT as f32, 0.1, 100.0);
    println!("entering main loop");
    while !window.should_close() {
        let currentFrame = glfw.get_time() as f32;
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;

        process_events(&events, &mut firstMouse, &mut lastX, &mut lastY, &mut camera);

        processInput(&mut window, deltaTime, &mut camera);

        unsafe {
            gl::Clear(gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT | gl::STENCIL_BUFFER_BIT);
            gl::ClearColor(1.0, 1.0, 1.0, 1.0);


            ourshader.Use();
            let Projection: Matrix4<f32> = perspective(Deg(camera.Zoom), SCR_WIDTH as f32 / SCR_HEIGHT as f32, 0.1, 100.0);
            let view = camera.GetViewMatrix();
            ourshader.setMat4(&CString::new("projection").unwrap(), &projection);
            ourshader.setMat4(&CString::new("view").unwrap(), &view);


            let mut model = Matrix4::<f32>::from_translation(vec3(0.0, -0.3, 0.0));
            model = model * Matrix4::from_scale(0.2);
            ourshader.setMat4(&CString::new("model").unwrap(), &model);
            gl::StencilFunc(gl::NOTEQUAL, 1, 0xFF);
            gl::StencilMask(0x00);
            //gl::Disable(gl::DEPTH_TEST);
            ourModel.Draw(&ourshader);
            gl::Enable(gl::DEPTH_TEST);

        }


        window.swap_buffers();
        glfw.poll_events();
    }
}




 fn processInput(window: &mut glfw::Window, deltaTime: f32, camera: &mut camera::Camera) {
    if window.get_key(Key::Escape) == Action::Press {
        window.set_should_close(true)
    }

    if window.get_key(Key::W) == Action::Press {
        camera.ProcessKeyboard(camera::Camera_Movement::FORWARD, deltaTime);
    }
    if window.get_key(Key::S) == Action::Press {
        camera.ProcessKeyboard(camera::Camera_Movement::BACKWARD, deltaTime);
    }
    if window.get_key(Key::A) == Action::Press {
        camera.ProcessKeyboard(camera::Camera_Movement::LEFT, deltaTime);
    }
    if window.get_key(Key::D) == Action::Press {
        camera.ProcessKeyboard(camera::Camera_Movement::RIGHT, deltaTime);
    }
}

fn process_events(events: &Receiver<(f64, glfw::WindowEvent)>,
                  firstMouse: &mut bool,
                  lastX: &mut f32,
                  lastY: &mut f32,
                  camera: &mut camera::Camera) {
    for (_, event) in glfw::flush_messages(events) {
        match event {
            glfw::WindowEvent::FramebufferSize(width, height) => {
                // make sure the viewport matches the new window dimensions; note that width and
                // height will be significantly larger than specified on retina displays.
                unsafe { gl::Viewport(0, 0, width, height) }
            }
            glfw::WindowEvent::CursorPos(xpos, ypos) => {
                let (xpos, ypos) = (xpos as f32, ypos as f32);
                if *firstMouse {
                    *lastX = xpos;
                    *lastY = ypos;
                    *firstMouse = false;
                }

                let xoffset = xpos - *lastX;
                let yoffset = *lastY - ypos; // reversed since y-coordinates go from bottom to top

                *lastX = xpos;
                *lastY = ypos;

                camera.ProcessMouseMovement(xoffset, yoffset, true);
            }
            glfw::WindowEvent::Scroll(_xoffset, yoffset) => {
                camera.ProcessMouseScroll(yoffset as f32);
            }
            _ => {}
        }
    }
}