Merge pull request #663 from lnbits/lnurlp/float_fiat_amount

lnurlp: support for floating point fiat values

lnbits/extensions/lnurlp/crud.py

@@ -9,6 +9,12 @@ async def create_pay_link(data: CreatePayLinkData, wallet_id: str) -> PayLink:
 
     returning = "" if db.type == SQLITE else "RETURNING ID"
     method = db.execute if db.type == SQLITE else db.fetchone
+    # database only allows int4 entries for min and max. For fiat currencies,
+    # we multiply by data.fiat_base_multiplier (usually 100) to save the value in cents.
+    if data.currency and data.fiat_base_multiplier:
+        data.min *= data.fiat_base_multiplier
+        data.max *= data.fiat_base_multiplier
+
     result = await (method)(
         f"""
         INSERT INTO lnurlp.pay_links (
@@ -22,9 +28,10 @@ async def create_pay_link(data: CreatePayLinkData, wallet_id: str) -> PayLink:
             success_text,
             success_url,
             comment_chars,
-            currency
+            currency,
+            fiat_base_multiplier
         )
-        VALUES (?, ?, ?, ?, 0, 0, ?, ?, ?, ?, ?)
+        VALUES (?, ?, ?, ?, 0, 0, ?, ?, ?, ?, ?, ?)
         {returning}
         """,
         (
@@ -37,6 +44,7 @@ async def create_pay_link(data: CreatePayLinkData, wallet_id: str) -> PayLink:
             data.success_url,
             data.comment_chars,
             data.currency,
+            data.fiat_base_multiplier,
         ),
     )
     if db.type == SQLITE:

lnbits/extensions/lnurlp/lnurl.py

@@ -29,11 +29,15 @@ async def api_lnurl_response(request: Request, link_id):
             status_code=HTTPStatus.NOT_FOUND, detail="Pay link does not exist."
         )
 
-    rate = await get_fiat_rate_satoshis(link.currency) if link.currency else 1
+    rate = (
+        await get_fiat_rate_satoshis(link.currency) / link.fiat_base_multiplier
+        if link.currency
+        else 1
+    )
 
     resp = LnurlPayResponse(
         callback=request.url_for("lnurlp.api_lnurl_callback", link_id=link.id),
-        min_sendable=math.ceil(link.min * rate) * 1000,
+        min_sendable=round(link.min * rate) * 1000,
         max_sendable=round(link.max * rate) * 1000,
         metadata=link.lnurlpay_metadata,
     )

lnbits/extensions/lnurlp/migrations.py

@@ -50,3 +50,13 @@ async def m003_min_max_comment_fiat(db):
     await db.execute("ALTER TABLE lnurlp.pay_links ADD COLUMN max INTEGER;")
     await db.execute("UPDATE lnurlp.pay_links SET max = min;")
     await db.execute("DROP TABLE lnurlp.invoices")
+
+
+async def m004_fiat_base_multiplier(db):
+    """
+    Store the multiplier for fiat prices. We store the price in cents and
+    remember to multiply by 100 when we use it to convert to Dollars.
+    """
+    await db.execute(
+        "ALTER TABLE lnurlp.pay_links ADD COLUMN fiat_base_multiplier INTEGER DEFAULT 1;"
+    )

lnbits/extensions/lnurlp/models.py

@@ -11,20 +11,21 @@ from pydantic import BaseModel
 
 class CreatePayLinkData(BaseModel):
     description: str
-    min: int = Query(0.01, ge=0.01)
-    max: int = Query(0.01, ge=0.01)
+    min: float = Query(1, ge=0.01)
+    max: float = Query(1, ge=0.01)
     currency: str = Query(None)
     comment_chars: int = Query(0, ge=0, lt=800)
     webhook_url: str = Query(None)
     success_text: str = Query(None)
     success_url: str = Query(None)
+    fiat_base_multiplier: int = Query(100, ge=1)
 
 
 class PayLink(BaseModel):
     id: int
     wallet: str
     description: str
-    min: int
+    min: float
     served_meta: int
     served_pr: int
     webhook_url: Optional[str]
@@ -32,11 +33,15 @@ class PayLink(BaseModel):
     success_url: Optional[str]
     currency: Optional[str]
     comment_chars: int
-    max: int
+    max: float
+    fiat_base_multiplier: int
 
     @classmethod
     def from_row(cls, row: Row) -> "PayLink":
         data = dict(row)
+        if data["currency"] and data["fiat_base_multiplier"]:
+            data["min"] /= data["fiat_base_multiplier"]
+            data["max"] /= data["fiat_base_multiplier"]
         return cls(**data)
 
     def lnurl(self, req: Request) -> str:

lnbits/extensions/lnurlp/views_api.py

@@ -76,10 +76,6 @@ async def api_link_create_or_update(
     link_id=None,
     wallet: WalletTypeInfo = Depends(get_key_type),
 ):
-    if data.min < 1:
-        raise HTTPException(
-            detail="Min must be more than 1.", status_code=HTTPStatus.BAD_REQUEST
-        )
 
     if data.min > data.max:
         raise HTTPException(
@@ -87,7 +83,7 @@ async def api_link_create_or_update(
         )
 
     if data.currency == None and (
-        round(data.min) != data.min or round(data.max) != data.max
+        round(data.min) != data.min or round(data.max) != data.max or data.min < 1
     ):
         raise HTTPException(
             detail="Must use full satoshis.", status_code=HTTPStatus.BAD_REQUEST