// Potion counts on the potion slots of the bottom bar.
//
// Request (2026-10-17): the potion selector always shows how many potions of
// each kind the hero carries (only when there are any).
//
// The bar shows 5 potion kinds: cUI_Taskbar2::RenderPotionSlots (0x6e39e0)
// draws control k-1 (embedded at +0x258, stride 0xbc) when
// cInventoryEntry::GetPotionRef(k) finds a potion of kind k, else the empty
// control behind it (+0x3ac). GetPotionRef walks the inventory grid and asks
// ItemPotionKind for each item's kind; the count here does the same and adds
// up the potion stacks (itemstack.cpp).
//
// Their tooltips (game::PotionTooltipText, set on the slots by the taskbar,
// 0x6e6060; shown as "\dFFFFFF80Heiltrank \wFFFFFFFF[SPC]") name the key
// bound to the kind (mods/input.cpp) instead of the game's own, which is
// switched off; no key part while unbound.

#include <cstdint>
#include <cwchar>
#include <string>

#include "game/engine/items.h"
#include "game/engine/objects.h"
#include "game/ui/text.h"
#include "game/ui/texts.h"
#include "mods/input.h"
#include "mods/itemstack.h"
#include "mods/skillslots.h"
#include "re/hook.h"

namespace mods::potioncounts {
namespace {

// cUI_Taskbar2 fields.
constexpr size_t kInventoryIndex = 0x158;  // u16: the hero's inventory
constexpr size_t kPotionSlots = 0x258;     // game::kPotionKinds embedded controls
constexpr size_t kPotionSlotSize = 0xbc;

constexpr uint16_t kCountFont = 1;  // as the art cooldown labels (skillbar.cpp)
constexpr uint32_t kCountColor = 0xffffffff;
constexpr int kCountInset = 3;  // from the slot's bottom-right corner

void RenderCounts(uint8_t* taskbar, void* renderer) {
    const uint8_t* inventory =
        skillslots::Inventory(*reinterpret_cast<const uint16_t*>(taskbar + kInventoryIndex));
    if (!inventory || !game::GetPlayerHero()) {
        return;
    }
    unsigned counts[game::kPotionKinds + 1] = {};
    game::ForEachGridItem(inventory, [&](uint32_t id) {
        const int kind = game::PotionKindOf(id);
        if (kind >= 1 && kind <= game::kPotionKinds) {
            counts[kind] += itemstack::StackCount(id);
        }
    });
    const int lineHeight = game::FontLineHeight(kCountFont);
    for (int kind = 1; kind <= game::kPotionKinds; ++kind) {
        if (counts[kind] == 0) {
            continue;
        }
        game::UiRect rect = game::ControlScreenRect(taskbar + kPotionSlots + (kind - 1) * kPotionSlotSize);
        rect.y += rect.h - lineHeight - kCountInset;
        rect.w = static_cast<int16_t>(rect.w - kCountInset);
        wchar_t text[8];
        swprintf_s(text, L"%u", counts[kind]);
        game::DrawText(renderer, kCountFont, rect, text, kCountColor, game::kTextRight);
    }
}

// The game's tooltip with its "[key]" end replaced by the bound key's.
std::wstring TooltipWithKey(uint32_t text, int vk) {
    std::wstring tooltip = game::ShownText(text);
    if (const size_t key = tooltip.rfind(L'['); key != std::wstring::npos && tooltip.back() == L']') {
        tooltip.erase(key);
    }
    if (vk) {
        tooltip += L"[" + input::KeyLabel(vk) + L"]";
    }
    return tooltip;
}

void UpdateTooltips() {
    for (int kind = 1; kind <= game::kPotionKinds; ++kind) {
        if (const uint32_t text = game::PotionTooltipText(kind)) {
            game::SetTextOverride(text, TooltipWithKey(text, input::PotionKey(kind)));
        }
    }
}

} // namespace
} // namespace mods::potioncounts

// cUI_Taskbar2::RenderPotionSlots (0x6e39e0, ret 4): then the counts.
void __fastcall UiTaskbar_RenderPotionSlots(void* self, void* edx, void* renderer);
RE_HOOK(0x006e39e0, UiTaskbar_RenderPotionSlots);
void __fastcall UiTaskbar_RenderPotionSlots(void* self, void* edx, void* renderer) {
    UiTaskbar_RenderPotionSlots_original(self, edx, renderer);
    if (self) {
        mods::potioncounts::RenderCounts(static_cast<uint8_t*>(self), renderer);
        mods::potioncounts::UpdateTooltips();
    }
}