feat: Hand ranking API

Hand ranking API with a health check root endpoint and rank endpoint.

3 files changed, 63 insertions, 4 deletions

diff --git a/poker/api.py b/poker/api.py
new file mode 100644
index 0000000..9faa89b
--- /dev/null
+++ b/poker/api.py
@@ -0,0 +1,56 @@
+from fastapi import Body, FastAPI
+from loguru import logger
+
+from poker.constants import Suit, Value
+from poker.models import Card, Hand
+from poker.rank import rank_hand
+
+app = FastAPI()
+
+_CARD_PATTERN = r"\s".join(5 * ["(2|3|4|5|6|7|8|9|10|J|K|Q|A)[CDHS]"])
+_SUIT_MAP = {
+    "C": Suit.CLUBS,
+    "D": Suit.DIAMONDS,
+    "H": Suit.HEARTS,
+    "S": Suit.SPADES,
+}
+_VALUE_MAP = {
+    "2": Value.TWO,
+    "3": Value.THREE,
+    "4": Value.FOUR,
+    "5": Value.FIVE,
+    "6": Value.SIX,
+    "7": Value.SEVEN,
+    "8": Value.EIGHT,
+    "9": Value.NINE,
+    "10": Value.TEN,
+    "J": Value.JACK,
+    "Q": Value.QUEEN,
+    "K": Value.KING,
+    "A": Value.ACE,
+}
+
+
+@app.get("/")
+async def health_check() -> str:
+    """Health check endpoint."""
+    return "OK"
+
+
+@app.post("/rank")
+def rank(body: str = Body(regex=_CARD_PATTERN, example="2H 3D 5S 10C KD")) -> str:
+    """Rank hand.
+
+    TODO: Improve error response.
+    """
+    logger.info(f"Input hand: {body}")
+    cards = [
+        Card(suit=_SUIT_MAP[card[-1]], value=_VALUE_MAP[card[:-1]])
+        for card in body.split()
+    ]
+
+    ranked_hand = rank_hand(Hand(cards=cards))
+
+    logger.info(f"Hand rank: {ranked_hand.rank}")
+
+    return ranked_hand.description
diff --git a/poker/constants.py b/poker/constants.py
index e0a7348..6402ef7 100644
--- a/poker/constants.py
+++ b/poker/constants.py
@@ -17,6 +17,11 @@ class Rank(IntEnum):
     PAIR = 9
     HIGH_CARD = 10
 
+    def __str__(self) -> str:
+        """Return string representation."""
+        out: str = self.name.lower().replace("_", " ").title()
+        return out
+
 
 class Suit(AutoName):
     """Card suit enum."""
@@ -46,7 +51,7 @@ class Value(IntEnum):
 
     def __str__(self) -> str:
         """Return string representation."""
-        if self.value in [1, 11, 12, 13]:
+        if self.value in [1, 11, 12, 13, 14]:
             out: str = self.name.lower()
         else:
             out = str(self.value)
diff --git a/poker/rank/hands.py b/poker/rank/hands.py
index 6a81af5..a622f87 100644
--- a/poker/rank/hands.py
+++ b/poker/rank/hands.py
@@ -162,7 +162,7 @@ def rank_hand(hand: Hand) -> RankedHand:
     for rank, func in _FUNCTIONS.items():
         result = func(hand)
         if result:
-            out = RankedHand(
+            return RankedHand(
                 cards=hand.cards,
                 rank=rank,
                 description=DESCRIPTIONS[rank].format(**result),
@@ -170,5 +170,3 @@ def rank_hand(hand: Hand) -> RankedHand:
 
     if out is None:
         raise ValueError("No rank found.")
-
-    return out