// FCS Glass - src/platform/input_map.h
//
// The Win32 -> core::Key boundary. Header-only and inline so that BOTH the
// window procedure and the probe can use it: a translation table that only the
// window procedure can reach is a translation table with no test on it, and this
// is exactly the layer where a wrong mapping is invisible until a key does the
// wrong thing in a real UI.
//
// KEPT SEPARATE FROM src/core/input.h ON PURPOSE. The core module has no Windows
// dependency, so its bodies can be lifted into the portable harness by
// tools/extract_logic.py. A VK_ mapping cannot be lifted, so it lives here and is
// probed on the Windows side instead.

#ifndef FCS_PLATFORM_INPUT_MAP_H
#define FCS_PLATFORM_INPUT_MAP_H

#include <windows.h>

#include "core/input.h"

namespace fcs {
namespace platform {

// VK_* -> core::Key. Returns Key::None for anything the core layer does not
// reason about, which is the overwhelming majority of the keyboard: the point of
// a small enum is that the common keys are named and the rest are absent, not
// that all 256 virtual keys are modelled.
inline core::Key KeyFromVk(int vk) {
  switch (vk) {
    case VK_TAB:     return core::Key::Tab;
    case VK_ESCAPE:  return core::Key::Escape;
    case VK_RETURN:  return core::Key::Enter;   // Enter, NOT the numeric-keypad one
    case VK_SPACE:   return core::Key::Space;
    case VK_LEFT:    return core::Key::Left;
    case VK_RIGHT:   return core::Key::Right;
    case VK_UP:      return core::Key::Up;
    case VK_DOWN:    return core::Key::Down;
    default:         return core::Key::None;
  }
}

// Maps a VK_*BUTTON code to a button index, or -1. NOT for mouse-message wParams:
// WM_xBUTTONDOWN/UP carry MK_* flags (MK_MBUTTON is 0x10, VK_MBUTTON is 0x04, and any
// held modifier changes the value), so feeding wParam here drops presses and releases.
// Use ButtonFromMessage for the window procedure. (Review P3-01.)
inline int ButtonFromVk(int vk) {
  switch (vk) {
    case VK_LBUTTON: return 0;
    case VK_RBUTTON: return 1;
    case VK_MBUTTON: return 2;
    default:         return -1;
  }
}

// Mouse button index for a mouse MESSAGE (left 0, right 1, middle 2), or -1 if it is not
// a button message. The result never depends on wParam. The indices are the core layer's
// bit positions and must not be reordered independently of it.
inline int ButtonFromMessage(UINT msg) {
  switch (msg) {
    case WM_LBUTTONDOWN: case WM_LBUTTONUP: return 0;
    case WM_RBUTTONDOWN: case WM_RBUTTONUP: return 1;
    case WM_MBUTTONDOWN: case WM_MBUTTONUP: return 2;
    default:                                return -1;
  }
}

}  // namespace platform
}  // namespace fcs

#endif  // FCS_PLATFORM_INPUT_MAP_H