// Skill keys cast their combat-art slot.
//
// The game casts one art with the right mouse button: the one in the
// "selected" art slot, which is always slot 0 now (src/mods/skillbar.cpp).
// Slot 0's key presses the right mouse button; the keys of slots 1-6 first
// make their slot the selected one. The button is pressed by posting
// WM_RBUTTONDOWN to the game window, so the game handles it exactly like a
// real right-click at the cursor (UI hit tests, target under the cursor,
// cEvent_creature 0x105), and released with the key: holding the key is
// holding the button. While no skill key is held, slot 0 is selected again
// (checked every engine tick, which also covers saves loaded with another
// selection).

#include "mods/skillkeys.h"

#include <atomic>

#include <windows.h>

#include "game/engine/events.h"
#include "mods/skillbar.h"

namespace mods::skillkeys {
namespace {

// The game window, if it has the focus (it does while a skill key is used).
HWND GameWindow() {
    HWND window = GetForegroundWindow();
    DWORD process = 0;
    if (!window || !GetWindowThreadProcessId(window, &process) || process != GetCurrentProcessId()) {
        return nullptr;
    }
    return window;
}

LPARAM CursorClientPos(HWND window) {
    POINT cursor = {};
    GetCursorPos(&cursor);
    ScreenToClient(window, &cursor);
    return MAKELPARAM(cursor.x, cursor.y);
}

// The key holding the right mouse button down, and the window it was pressed
// in. Set on the window thread, read by the engine tick.
std::atomic<int> g_heldKey{0};
HWND g_window = nullptr;

void OnTick(uint8_t*) {
    if (!g_heldKey.load() && mods::skillbar::SelectedSkillSlot() != 0) {
        mods::skillbar::SelectSkillSlot(0);
    }
}

struct Registration {
    Registration() { game::OnEngineTick(&OnTick); }
} g_registration;

} // namespace

void KeyPressed(unsigned slot, int vk) {
    if (g_heldKey.load() || !mods::skillbar::SkillSlotHasArt(slot)) {
        return;
    }
    HWND window = GameWindow();
    if (!window) {
        return;
    }
    g_window = window;
    g_heldKey = vk;  // before selecting: the tick leaves the selection alone
    if (slot != 0) {
        mods::skillbar::SelectSkillSlot(slot);
    }
    PostMessageW(window, WM_RBUTTONDOWN, MK_RBUTTON, CursorClientPos(window));
}

bool KeyHeld() {
    return g_heldKey.load() != 0;
}

void KeyReleased(int vk) {
    if (g_heldKey.load() != vk) {
        return;
    }
    PostMessageW(g_window, WM_RBUTTONUP, 0, CursorClientPos(g_window));
    g_heldKey = 0;
}

} // namespace mods::skillkeys