Support dynamic base currency

README.md

@@ -17,17 +17,18 @@ An automated Telegram bot designed to help gamers find the lowest prices for Pla
 - **Global Search:** Compare prices across multiple regions (TR, US, UA, PL, etc.) in one click
 - **Price Tracking:** Subscribe to your favorite games
 - **Smart Notifications:** Get alerts when prices drop or a sale starts
-- **Currency Conversion:** View all prices in your local currency
+- **Currency Conversion:** View all prices converted to your preferred currency (USD by default)
 
 ### Commands
 
-| Command              | Description                                                      |
-|----------------------|------------------------------------------------------------------|
-| `/start`             | Welcome message                                                  |
-| `/add_region`        | Search and add a PS Store region to track                        |
-| `/my_regions`        | Manage your tracked regions                                      |
-| `/search`            | Search for a game and compare prices across your tracked regions |
-| `/my_subscriptions`  | View your subscribed games with current prices                   |
+| Command             | Description                                                      |
+|---------------------|------------------------------------------------------------------|
+| `/start`            | Welcome message                                                  |
+| `/currency`         | View or change your display currency                             |
+| `/add_region`       | Search and add a PS Store region to track                        |
+| `/my_regions`       | Manage your tracked regions                                      |
+| `/search`           | Search for a game and compare prices across your tracked regions |
+| `/my_subscriptions` | View your subscribed games with current prices                   |
 
 ---
 
@@ -151,9 +152,10 @@ Migrations run automatically before `bot` and `worker` start.
 
 ## Documentation
 
-| Document                                             | Description                                                 |
-|------------------------------------------------------|-------------------------------------------------------------|
-| [`worker/README.md`](worker/README.md)               | Worker jobs: price check, notifications, aggregation window |
-| [`db/models/README.md`](db/models/README.md)         | Database schema: tables, relationships, key constraints     |
-| [`deploy/vector/README.md`](deploy/vector/README.md) | Vector alerting pipeline: sources, transforms, metrics      |
-| [`research/README.md`](research/README.md)           | PS Store search grouping research                           |
+| Document                                             | Description                                                  |
+|------------------------------------------------------|--------------------------------------------------------------|
+| [`worker/README.md`](worker/README.md)               | Worker jobs: price check, notifications, aggregation window  |
+| [`db/models/README.md`](db/models/README.md)         | Database schema: tables, relationships, key constraints      |
+| [`services/README.md`](services/README.md)           | Services: currency conversion logic, exchange rates, display |
+| [`deploy/vector/README.md`](deploy/vector/README.md) | Vector alerting pipeline: sources, transforms, metrics       |
+| [`research/README.md`](research/README.md)           | PS Store search grouping research                            |

bot/formatters.py

@@ -1,5 +1,4 @@
-
-from services.currency import PS_CURRENCY_MAP, convert_to_usd
+from services.currency import DEFAULT_BASE_CURRENCY, PS_CURRENCY_MAP, PS_ISO_TO_SYMBOL, convert
 from services.ps_store import GameInfo, RegionPrice
 
 TYPE_EMOJI = {
@@ -27,27 +26,39 @@ def _format_price(amount: float, currency: str) -> str:
     return f"{currency}{sep}{amount:.2f}"
 
 
-def _usd_by_locale(
+def _base_by_locale(
     prices: dict[str, RegionPrice],
     rates: dict[str, float] | None,
+    base_currency: str,
 ) -> dict[str, float | None]:
     result = {}
     for locale, rp in prices.items():
         if rp.price is not None and rp.currency is not None and rates is not None:
-            result[locale] = convert_to_usd(rp.price, rp.currency, rates)
+            result[locale] = convert(rp.price, rp.currency, base_currency, rates)
         else:
             result[locale] = None
     return result
 
 
+def _base_str(base_value: float | None, base_currency: str, region_iso: str) -> str:
+    if base_value is None or region_iso == base_currency:
+        return ""
+    symbol = PS_ISO_TO_SYMBOL.get(base_currency, base_currency)
+    sep = " " if symbol.isalpha() else ""
+    if base_value == int(base_value):
+        return f" ({symbol}{sep}{int(base_value)})"
+    return f" ({symbol}{sep}{base_value:.2f})"
+
+
 def _price_line(
     prices: dict[str, RegionPrice],
     rates: dict[str, float] | None,
+    base_currency: str = DEFAULT_BASE_CURRENCY,
 ) -> str:
-    usd_map = _usd_by_locale(prices, rates)
+    base_map = _base_by_locale(prices, rates, base_currency)
     cheapest = min(
-        (loc for loc, usd in usd_map.items() if usd is not None),
-        key=lambda loc: usd_map[loc],
+        (loc for loc, val in base_map.items() if val is not None),
+        key=lambda loc: base_map[loc],
         default=None,
     )
 
@@ -58,12 +69,12 @@ def _price_line(
             parts.append(f"{flag} N/A")
             continue
 
-        usd = usd_map.get(locale)
+        base_val = base_map.get(locale)
         iso = PS_CURRENCY_MAP.get(rp.currency, rp.currency)
-        usd_str = f" (${usd:.2f})" if usd is not None and iso != "USD" else ""
+        base_suffix = _base_str(base_val, base_currency, iso)
         strike = f"<s>{_format_price(rp.base_price, rp.currency)}</s> " if rp.base_price is not None else ""
         discount_str = f" {rp.discount_text}" if rp.discount_text else ""
-        price_label = f"{strike}{_format_price(rp.price, rp.currency)}{discount_str}{usd_str}"
+        price_label = f"{strike}{_format_price(rp.price, rp.currency)}{discount_str}{base_suffix}"
         text = f"{flag} {price_label}"
 
         if locale == cheapest and cheapest is not None and len(prices) > 1:
@@ -84,11 +95,12 @@ def _card_price_lines(
     prices: dict[str, RegionPrice],
     rates: dict[str, float] | None,
     old_prices: dict[str, float] | None = None,
+    base_currency: str = DEFAULT_BASE_CURRENCY,
 ) -> list[str]:
-    usd_map = _usd_by_locale(prices, rates)
+    base_map = _base_by_locale(prices, rates, base_currency)
     cheapest = min(
-        (loc for loc, usd in usd_map.items() if usd is not None),
-        key=lambda loc: usd_map[loc],
+        (loc for loc, val in base_map.items() if val is not None),
+        key=lambda loc: base_map[loc],
         default=None,
     )
 
@@ -99,12 +111,12 @@ def _card_price_lines(
             lines.append(f"{flag} N/A")
             continue
 
-        usd = usd_map.get(locale)
+        base_val = base_map.get(locale)
         iso = PS_CURRENCY_MAP.get(rp.currency, rp.currency)
-        usd_str = f" (${usd:.2f})" if usd is not None and iso != "USD" else ""
+        base_suffix = _base_str(base_val, base_currency, iso)
         strike = f"<s>{_format_price(rp.base_price, rp.currency)}</s> " if rp.base_price is not None else ""
         discount_str = f" {rp.discount_text}" if rp.discount_text else ""
-        price_label = f"{strike}{_format_price(rp.price, rp.currency)}{discount_str}{usd_str}"
+        price_label = f"{strike}{_format_price(rp.price, rp.currency)}{discount_str}{base_suffix}"
 
         url = f"https://store.playstation.com/{locale}/product/{rp.ps_id}"
         is_cheapest = locale == cheapest and cheapest is not None and len(prices) > 1
@@ -115,14 +127,12 @@ def _card_price_lines(
 
         old_price = (old_prices or {}).get(locale)
         if old_price is not None and old_price != rp.price:
-            # Skip when the game is on sale and old_price == base_price:
-            # the strikethrough base_price in the card already shows the pre-sale price.
             if rp.base_price is None or abs(rp.base_price - old_price) > 0.001:
-                old_usd = convert_to_usd(old_price, rp.currency, rates) if rates else None
+                old_base = convert(old_price, rp.currency, base_currency, rates) if rates else None
                 old_iso = PS_CURRENCY_MAP.get(rp.currency, rp.currency)
-                old_usd_str = f" (${old_usd:.2f})" if old_usd is not None and old_iso != "USD" else ""
+                old_base_suffix = _base_str(old_base, base_currency, old_iso)
                 arrow = "↓" if rp.price < old_price else "↑"
-                text += f"  {arrow} <s>{_format_price(old_price, rp.currency)}{old_usd_str}</s>"
+                text += f"  {arrow} <s>{_format_price(old_price, rp.currency)}{old_base_suffix}</s>"
 
         lines.append(text)
 
@@ -135,6 +145,7 @@ def format_game_list(
     games: list[GameInfo],
     prices: list[dict[str, RegionPrice]],
     rates: dict[str, float] | None = None,
+    base_currency: str = DEFAULT_BASE_CURRENCY,
 ) -> str:
     if not games:
         return "Nothing found. Try a different query."
@@ -143,7 +154,7 @@ def format_game_list(
     for game, game_prices in zip(games, prices):
         lines = _game_header(game)
         if game_prices:
-            lines.append(_price_line(game_prices, rates))
+            lines.append(_price_line(game_prices, rates, base_currency))
         cards.append("\n".join(lines))
 
     return f"{title}\n\n" + "\n\n".join(cards) + f"\n\n{footer}"
@@ -166,11 +177,12 @@ def format_game_card(
     old_prices: dict[str, float] | None = None,
     title: str = "",
     footer: str = "",
+    base_currency: str = DEFAULT_BASE_CURRENCY,
 ) -> str:
     lines = _game_header(game)
     if prices:
         lines.append("\nPrices by region:")
-        lines.extend(_card_price_lines(prices, rates, old_prices))
+        lines.extend(_card_price_lines(prices, rates, old_prices, base_currency))
         offer_end = _offer_end_line(prices)
         if offer_end:
             lines.append(f"\nOffer ends:\n<b>{offer_end}</b>")

bot/handlers/__init__.py

@@ -1,9 +1,10 @@
 from aiogram import Router
 
-from bot.handlers import regions, search, start, subscriptions
+from bot.handlers import currency, regions, search, start, subscriptions
 
 router = Router()
 router.include_router(start.router)
+router.include_router(currency.router)
 router.include_router(regions.router)
 router.include_router(search.router)
 router.include_router(subscriptions.router)

bot/handlers/currency.py

@@ -0,0 +1,65 @@
+from aiogram import F, Router
+from aiogram.filters import Command
+from aiogram.types import CallbackQuery, Message
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from bot.keyboards.inline import currency_suggestions_keyboard
+from services.currency import DEFAULT_BASE_CURRENCY, PS_ISO_TO_SYMBOL, find_currency_suggestions, get_rates
+from services.user import get_or_create_user
+
+router = Router()
+
+
+def _currency_label(iso: str) -> str:
+    symbol = PS_ISO_TO_SYMBOL.get(iso, iso)
+    return f"{iso} ({symbol})" if symbol != iso else iso
+
+
+async def _set_currency(iso: str, user, session: AsyncSession) -> str:
+    user.preferred_currency = iso
+    await session.commit()
+    return f"Display currency set to <b>{_currency_label(iso)}</b>."
+
+
+@router.message(Command("currency"))
+async def cmd_currency(message: Message, session: AsyncSession) -> None:
+    user = await get_or_create_user(session, message.from_user.id, message.from_user.username)
+
+    arg = message.text.partition(" ")[2].strip().upper()
+
+    if not arg:
+        current = user.preferred_currency or DEFAULT_BASE_CURRENCY
+        await message.answer(
+            f"Your current display currency: <b>{_currency_label(current)}</b>\n\n"
+            f"To change it, use:\n<code>/currency EUR</code>\n\n"
+            f"Any ISO 4217 currency code is accepted (e.g. SGD, HKD, MYR)."
+        )
+        return
+
+    rates = await get_rates()
+
+    if arg in rates or arg == "USD":
+        await message.answer(await _set_currency(arg, user, session))
+        return
+
+    suggestions = find_currency_suggestions(arg, rates)
+    if not suggestions:
+        await message.answer(
+            f"<b>{arg}</b> is not a recognised currency code and no similar codes were found.\n"
+            "Use a valid ISO 4217 code like EUR, GBP, SGD, HKD, etc."
+        )
+        return
+
+    await message.answer(
+        f"<b>{arg}</b> not found. Did you mean:",
+        reply_markup=currency_suggestions_keyboard(suggestions),
+    )
+
+
+@router.callback_query(F.data.startswith("currency_select:"))
+async def on_currency_select(callback: CallbackQuery, session: AsyncSession) -> None:
+    iso = callback.data.split(":", 1)[1]
+    user = await get_or_create_user(session, callback.from_user.id, callback.from_user.username)
+    text = await _set_currency(iso, user, session)
+    await callback.message.edit_text(text)
+    await callback.answer()

bot/handlers/search.py

@@ -9,7 +9,7 @@
 from bot.formatters import format_game_card, format_game_list
 from bot.keyboards.inline import search_results_keyboard, subscribe_keyboard, unsubscribe_keyboard
 from bot.states.subscription import SearchForm
-from services.currency import get_rates
+from services.currency import DEFAULT_BASE_CURRENCY, get_rates
 from services.ps_store import GameInfo, RegionPrice, best_ps_id, get_game_info, search_games
 from services.region import get_user_regions
 from services.subscription import is_subscribed
@@ -181,8 +181,10 @@ async def _do_search(message: Message, state: FSMContext, session: AsyncSession,
         for key in visible_keys
     ]
 
+    base_currency = user.preferred_currency or DEFAULT_BASE_CURRENCY
+
     await state.set_state(SearchForm.showing_results)
-    await state.update_data(entries=entries, rates=rates)
+    await state.update_data(entries=entries, rates=rates, base_currency=base_currency)
 
     hidden = len(all_games) - len(games)
     footer = "Want to track prices in more regions?\nAdd a new one: /add_region"
@@ -196,6 +198,7 @@ async def _do_search(message: Message, state: FSMContext, session: AsyncSession,
         games=games,
         prices=[by_key[k] for k in visible_keys],
         rates=rates,
+        base_currency=base_currency,
     )
     await message.answer(text, reply_markup=search_results_keyboard(games))
 
@@ -227,6 +230,7 @@ async def on_game_select(callback: CallbackQuery, state: FSMContext, session: As
     data = await state.get_data()
     entries = data.get("entries", [])
     rates = data.get("rates")
+    base_currency = data.get("base_currency", DEFAULT_BASE_CURRENCY)
 
     index = int(callback.data.split(":", 1)[1])
     if index >= len(entries):
@@ -261,6 +265,7 @@ async def on_game_select(callback: CallbackQuery, state: FSMContext, session: As
         prices,
         rates,
         footer="Want to track prices in more regions?\nAdd a new one: /add_region",
+        base_currency=base_currency,
     )
     game_id = await is_subscribed(session, callback.from_user.id, game.composite_key, game.ps_id_suffix)
     keyboard = unsubscribe_keyboard(game_id) if game_id else subscribe_keyboard(index)

bot/handlers/start.py

@@ -14,5 +14,8 @@ async def cmd_start(message: Message, session: AsyncSession) -> None:
     await session.commit()
     await message.answer(
         "Hi! I'm PriceStation — I track prices in the PS Store.\n\n"
-        "Use /add_region to choose the regions you want to follow."
+        "/currency — set your display currency\n"
+        "/add_region — choose regions to follow\n"
+        "/search — find a game and subscribe to price drops\n"
+        "/my_subscriptions — manage your subscriptions"
     )

bot/handlers/subscriptions.py

@@ -8,7 +8,7 @@
 from bot.keyboards.inline import subscriptions_list_keyboard
 from bot.metrics import bot_handler_errors
 from bot.states.subscription import SearchForm
-from services.currency import get_rates
+from services.currency import DEFAULT_BASE_CURRENCY, get_rates
 from services.ps_store import GameInfo, RegionPrice
 from services.subscription import get_user_subscriptions_page, subscribe_to_game, unsubscribe_from_game
 from services.user import get_or_create_user
@@ -86,7 +86,8 @@ async def _build_subs_page(
     page: int,
 ) -> tuple[str, InlineKeyboardMarkup] | None:
     """Return (text, keyboard) for the given page, or None if no subscriptions."""
-    await get_or_create_user(session, telegram_id, username)
+    user = await get_or_create_user(session, telegram_id, username)
+    base_currency = user.preferred_currency or DEFAULT_BASE_CURRENCY
 
     total, page_items = await get_user_subscriptions_page(
         session, telegram_id, page, _SUBS_PAGE_SIZE
@@ -106,14 +107,15 @@ async def _build_subs_page(
         for gi, prices in page_items
     ]
     await state.set_state(SearchForm.showing_results)
-    await state.update_data(entries=entries, rates=rates)
+    await state.update_data(entries=entries, rates=rates, base_currency=base_currency)
 
     text = format_game_list(
         title=f"Your subscriptions ({total} total):",
         footer="Prices may be slightly outdated.",
         games=games,
         prices=[prices for _, prices in page_items],
         rates=rates,
+        base_currency=base_currency,
     )
     return text, subscriptions_list_keyboard(games, page, total_pages)
 

bot/keyboards/inline.py

@@ -76,6 +76,14 @@ def subscriptions_list_keyboard(
     return builder.as_markup()
 
 
+def currency_suggestions_keyboard(suggestions: list[tuple[str, str]]) -> InlineKeyboardMarkup:
+    builder = InlineKeyboardBuilder()
+    for iso, name in suggestions:
+        builder.button(text=f"{iso} — {name}", callback_data=f"currency_select:{iso}")
+    builder.adjust(1)
+    return builder.as_markup()
+
+
 def cancel_keyboard() -> InlineKeyboardMarkup:
     builder = InlineKeyboardBuilder()
     builder.button(text="Cancel", callback_data="cancel")