#include "simulation_state.h"
#include "rendering/renderer.h"
#include "core/application.h"
#include "core/window.h"
#include "core/event.h"

#include <imgui.h>
#include <GLFW/glfw3.h>

namespace Donut
{
    void SimulationState::on_enter()
    {
        DONUT_INFO("Entering Simulation State");
        m_initialized = true;
    }
    
    void SimulationState::on_exit()
    {
        DONUT_INFO("Exiting Simulation State");
    }
    
    void SimulationState::on_update(float delta_time)
    {
        
        m_engine.update_window_dimensions();
        m_engine.update_physics(delta_time);
        
        if (m_engine.get_camera().is_dragging()) 
        {
            GLFWwindow* window = static_cast<GLFWwindow*>(Application::get().get_window().get_native_window());
            double xpos, ypos;
            glfwGetCursorPos(window, &xpos, &ypos);
            m_engine.get_camera().process_orbital_mouse_move(xpos, ypos);
        }
    }
    
    void SimulationState::on_render()
    {
        if (!m_initialized) return;
        
        RenderCommand::set_clear_color(glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
        RenderCommand::clear();
        
        m_engine.generate_grid(m_engine.get_objects());
        
        glm::mat4 view = glm::lookAt(m_engine.get_camera().get_orbital_position(), m_engine.get_camera().get_target(), glm::vec3(0,1,0));
        glm::mat4 proj = glm::perspective(glm::radians(60.0f), float(m_engine.get_width())/m_engine.get_height(), 1e9f, 1e14f);
        glm::mat4 view_proj = proj * view;
        
        m_engine.draw_grid(view_proj);
        
        RenderCommand::set_viewport(0, 0, m_engine.get_width(), m_engine.get_height());
        m_engine.dispatch_compute(m_engine.get_camera());
        m_engine.draw_full_screen_quad();
    }
    
    void SimulationState::on_event(Event& event)
    {
        if (!m_initialized) return;
        
        if (event.get_event_type() == EventType::MouseButtonPressed)
        {
            MouseButtonPressedEvent& e = (MouseButtonPressedEvent&)event;
            int button = e.get_mouse_button();
            
            m_engine.get_camera().process_orbital_mouse_button(button, GLFW_PRESS, 0);
        }
        else if (event.get_event_type() == EventType::MouseButtonReleased)
        {
            MouseButtonReleasedEvent& e = (MouseButtonReleasedEvent&)event;
            int button = e.get_mouse_button();
            m_engine.get_camera().process_orbital_mouse_button(button, GLFW_RELEASE, 0);
        }
        
        if (event.get_event_type() == EventType::MouseScrolled)
        {
            MouseScrolledEvent& e = (MouseScrolledEvent&)event;
            m_engine.get_camera().process_orbital_scroll(e.get_x_offset(), e.get_y_offset());
        }
        
        if (event.get_event_type() == EventType::KeyPressed)
        {
            KeyPressedEvent& e = (KeyPressedEvent&)event;
            if (e.get_key_code() == GLFW_KEY_G)
            {
                m_engine.set_gravity(!m_engine.get_gravity());
                DONUT_INFO("Gravity turned {}", m_engine.get_gravity() ? "ON" : "OFF");
            }
        }
    }
    
    void SimulationState::on_im_ui_render()
    {
        ImGui::Begin("Simulation Controls");
        
        ImGui::Text("Black Hole Simulation");
        if (ImGui::Button("Back to Config"))
            Application::get().get_state_manager().switch_to_state("Config");

        ImGui::Separator();
        
        ImGui::Text("Simulation Info:");
        ImGui::Text("FPS: %.1f", ImGui::GetIO().Framerate);
        ImGui::Text("Frame Time: %.3f ms", 1000.0f / ImGui::GetIO().Framerate);
        ImGui::Text("Resolution: %dx%d", m_engine.get_width(), m_engine.get_height());
        ImGui::Text("Compute Resolution: %dx%d", m_engine.get_compute_width(), m_engine.get_compute_height());
        ImGui::Text("Objects: %zu", m_engine.get_objects().size());
        
        ImGui::Separator();
        
        ImGui::Text("Controls:");
        ImGui::Text("Left Mouse: Orbit camera");
        ImGui::Text("Scroll: Zoom in/out");
        ImGui::Text("G: Toggle gravity");
        ImGui::Text("Right Mouse: Enable gravity (hold)");
        
        ImGui::Separator();
        
        ImGui::Text("Physics:");
        bool gravity = m_engine.get_gravity();
        if (ImGui::Checkbox("Gravity Enabled", &gravity))
            m_engine.set_gravity(gravity);
        
        ImGui::Text("Camera:");
        ImGui::Text("Position: (%.2e, %.2e, %.2e)", 
                   m_engine.get_camera().get_orbital_position().x, 
                   m_engine.get_camera().get_orbital_position().y, 
                   m_engine.get_camera().get_orbital_position().z);
        ImGui::Text("Radius: %.2e", m_engine.get_camera().get_radius());
        ImGui::Text("Azimuth: %.2f", m_engine.get_camera().get_azimuth());
        ImGui::Text("Elevation: %.2f", m_engine.get_camera().get_elevation());
        
        ImGui::End();
    }
};