#include "Input/InputManager.h"
#include <algorithm>

namespace XCEngine {
namespace Input {

InputManager& InputManager::Get() {
    static InputManager instance;
    return instance;
}

void InputManager::Initialize(void* platformWindowHandle) {
    if (m_initialized) return;
    
    m_platformWindowHandle = platformWindowHandle;
    
    m_keyDownThisFrame.resize(256, false);
    m_keyDownLastFrame.resize(256, false);
    m_keyDown.resize(256, false);
    
    m_mouseButtonDownThisFrame.resize(5, false);
    m_mouseButtonDownLastFrame.resize(5, false);
    m_mouseButtonDown.resize(5, false);
    
    m_buttonDownThisFrame.resize(32, false);
    m_buttonDownLastFrame.resize(32, false);
    
    RegisterAxis(InputAxis("Horizontal", KeyCode::D, KeyCode::A));
    RegisterAxis(InputAxis("Vertical", KeyCode::W, KeyCode::S));
    RegisterAxis(InputAxis("Mouse X", KeyCode::None, KeyCode::None));
    RegisterAxis(InputAxis("Mouse Y", KeyCode::None, KeyCode::None));
    
    RegisterButton("Jump", KeyCode::Space);
    RegisterButton("Fire1", KeyCode::LeftCtrl);
    RegisterButton("Fire2", KeyCode::LeftAlt);
    RegisterButton("Fire3", KeyCode::LeftShift);
    
    m_initialized = true;
}

void InputManager::Shutdown() {
    if (!m_initialized) return;
    
    m_keyDownThisFrame.clear();
    m_keyDownLastFrame.clear();
    m_keyDown.clear();
    
    m_mouseButtonDownThisFrame.clear();
    m_mouseButtonDownLastFrame.clear();
    m_mouseButtonDown.clear();
    
    m_axes.clear();
    m_buttons.clear();
    m_buttonDownThisFrame.clear();
    m_buttonDownLastFrame.clear();
    
    m_platformWindowHandle = nullptr;
    m_initialized = false;
}

void InputManager::Update(float deltaTime) {
    if (!m_initialized) return;
    
    m_keyDownLastFrame = m_keyDownThisFrame;
    m_mouseButtonDownLastFrame = m_mouseButtonDownThisFrame;
    m_buttonDownLastFrame = m_buttonDownThisFrame;
    
    m_mouseDelta = Math::Vector2::Zero();
    m_mouseScrollDelta = 0.0f;
}

size_t InputManager::GetKeyIndex(KeyCode key) const {
    return static_cast<size_t>(key);
}

size_t InputManager::GetMouseButtonIndex(MouseButton button) const {
    return static_cast<size_t>(button);
}

bool InputManager::IsKeyDown(KeyCode key) const {
    if (!m_initialized) return false;
    size_t index = GetKeyIndex(key);
    if (index >= m_keyDown.size()) return false;
    return m_keyDown[index];
}

bool InputManager::IsKeyUp(KeyCode key) const {
    if (!m_initialized) return true;
    return !IsKeyDown(key);
}

bool InputManager::IsKeyPressed(KeyCode key) const {
    if (!m_initialized) return false;
    size_t index = GetKeyIndex(key);
    if (index >= m_keyDownThisFrame.size()) return false;
    return m_keyDownThisFrame[index] && !m_keyDownLastFrame[index];
}

Math::Vector2 InputManager::GetMousePosition() const {
    return m_mousePosition;
}

Math::Vector2 InputManager::GetMouseDelta() const {
    return m_mouseDelta;
}

float InputManager::GetMouseScrollDelta() const {
    return m_mouseScrollDelta;
}

bool InputManager::IsMouseButtonDown(MouseButton button) const {
    if (!m_initialized) return false;
    size_t index = GetMouseButtonIndex(button);
    if (index >= m_mouseButtonDown.size()) return false;
    return m_mouseButtonDown[index];
}

bool InputManager::IsMouseButtonUp(MouseButton button) const {
    if (!m_initialized) return true;
    return !IsMouseButtonDown(button);
}

bool InputManager::IsMouseButtonClicked(MouseButton button) const {
    if (!m_initialized) return false;
    size_t index = GetMouseButtonIndex(button);
    if (index >= m_mouseButtonDownThisFrame.size()) return false;
    return m_mouseButtonDownThisFrame[index] && !m_mouseButtonDownLastFrame[index];
}

int InputManager::GetTouchCount() const {
    return static_cast<int>(m_touches.size());
}

TouchState InputManager::GetTouch(int index) const {
    if (index >= 0 && index < static_cast<int>(m_touches.size())) {
        return m_touches[index];
    }
    return TouchState{};
}

float InputManager::GetAxis(const Containers::String& axisName) const {
    auto it = m_axes.find(axisName);
    if (it == m_axes.end()) return 0.0f;
    
    const auto& axis = it->second;
    float value = 0.0f;
    
    if (axis.GetPositiveKey() != KeyCode::None && IsKeyDown(axis.GetPositiveKey())) {
        value += 1.0f;
    }
    if (axis.GetNegativeKey() != KeyCode::None && IsKeyDown(axis.GetNegativeKey())) {
        value -= 1.0f;
    }
    
    return value;
}

float InputManager::GetAxisRaw(const Containers::String& axisName) const {
    auto it = m_axes.find(axisName);
    if (it == m_axes.end()) return 0.0f;
    
    const auto& axis = it->second;
    float value = 0.0f;
    
    if (axis.GetPositiveKey() != KeyCode::None && IsKeyPressed(axis.GetPositiveKey())) {
        value += 1.0f;
    }
    if (axis.GetNegativeKey() != KeyCode::None && IsKeyPressed(axis.GetNegativeKey())) {
        value -= 1.0f;
    }
    
    return value;
}

bool InputManager::GetButton(const Containers::String& buttonName) const {
    auto it = m_buttons.find(buttonName);
    if (it == m_buttons.end()) return false;
    return IsKeyDown(it->second);
}

bool InputManager::GetButtonDown(const Containers::String& buttonName) const {
    auto it = m_buttons.find(buttonName);
    if (it == m_buttons.end()) return false;
    return IsKeyPressed(it->second);
}

bool InputManager::GetButtonUp(const Containers::String& buttonName) const {
    auto it = m_buttons.find(buttonName);
    if (it == m_buttons.end()) return true;
    return IsKeyUp(it->second);
}

void InputManager::RegisterAxis(const InputAxis& axis) {
    m_axes[axis.GetName()] = axis;
}

void InputManager::RegisterButton(const Containers::String& name, KeyCode key) {
    m_buttons[name] = key;
}

void InputManager::ClearAxes() {
    m_axes.clear();
    m_buttons.clear();
}

void InputManager::ProcessKeyDown(KeyCode key, bool repeat) {
    if (!m_initialized) return;
    
    size_t index = GetKeyIndex(key);
    if (index >= m_keyDown.size()) return;
    
    m_keyDown[index] = true;
    m_keyDownThisFrame[index] = true;
    
    KeyEvent event;
    event.keyCode = key;
    event.type = repeat ? KeyEvent::Repeat : KeyEvent::Down;
    event.alt = false;
    event.ctrl = false;
    event.shift = false;
    event.meta = false;
    
    m_onKeyEvent.Invoke(event);
}

void InputManager::ProcessKeyUp(KeyCode key) {
    if (!m_initialized) return;
    
    size_t index = GetKeyIndex(key);
    if (index >= m_keyDown.size()) return;
    
    m_keyDown[index] = false;
    
    KeyEvent event;
    event.keyCode = key;
    event.type = KeyEvent::Up;
    event.alt = false;
    event.ctrl = false;
    event.shift = false;
    event.meta = false;
    
    m_onKeyEvent.Invoke(event);
}

void InputManager::ProcessMouseMove(int x, int y, int deltaX, int deltaY) {
    if (!m_initialized) return;
    
    m_mousePosition.x = static_cast<float>(x);
    m_mousePosition.y = static_cast<float>(y);
    m_mouseDelta.x = static_cast<float>(deltaX);
    m_mouseDelta.y = static_cast<float>(deltaY);
    
    MouseMoveEvent event;
    event.position = m_mousePosition;
    event.delta = m_mouseDelta;
    
    m_onMouseMove.Invoke(event);
}

void InputManager::ProcessMouseButton(MouseButton button, bool pressed, int x, int y) {
    if (!m_initialized) return;
    
    size_t index = GetMouseButtonIndex(button);
    if (index >= m_mouseButtonDown.size()) return;
    
    m_mouseButtonDown[index] = pressed;
    if (pressed) {
        m_mouseButtonDownThisFrame[index] = true;
    }
    
    MouseButtonEvent event;
    event.button = button;
    event.position.x = static_cast<float>(x);
    event.position.y = static_cast<float>(y);
    event.type = pressed ? MouseButtonEvent::Pressed : MouseButtonEvent::Released;
    
    m_onMouseButton.Invoke(event);
}

void InputManager::ProcessMouseWheel(float delta, int x, int y) {
    if (!m_initialized) return;
    
    m_mouseScrollDelta = delta;
    
    MouseWheelEvent event;
    event.position.x = static_cast<float>(x);
    event.position.y = static_cast<float>(y);
    event.delta = delta;
    
    m_onMouseWheel.Invoke(event);
}

void InputManager::ProcessTextInput(char c) {
    if (!m_initialized) return;
    
    TextInputEvent event;
    event.character = c;
    event.text = Containers::String(&c, 1);
    
    m_onTextInput.Invoke(event);
}

} // namespace Input
} // namespace XCEngine