Add dashboard endpoint

backend/app/routers/me_v1.py

@@ -1,6 +1,8 @@
+from datetime import UTC, datetime, timedelta
 from uuid import UUID
 from fastapi import APIRouter, HTTPException
 from fastapi.params import Depends
+from sqlalchemy import select
 from sqlalchemy.orm import Session as DbSession
 
 from app.database import get_db
@@ -10,6 +12,9 @@ from app.schemas.user import PasswordUpdate, UserUpdate, User
 from app.security.jwt_bearer import JWTBearer
 from app.services import session_service, user_service
 from app.util.errors import InvalidStateError, NotFoundError
+from app.schemas.dashboard import DashboardResponse, DashboardStats
+from app.models.transaction import Transaction as DbTransaction
+from app.schemas.transaction import TransactionStatus
 
 router = APIRouter(prefix="/me", tags=["Me (v1)"])
 
@@ -109,3 +114,74 @@ async def delete_user_session(
     except NotFoundError:
         raise HTTPException(status_code=404, detail="session_not_found")
     return list()
+
+@router.get(path="/dashboard", response_model=DashboardResponse)
+async def get_dashboard(
+    db: DbSession = Depends(get_db),
+    token: AccessToken = Depends(JWTBearer()),
+):
+    """
+    Get dashboard information for the currently authenticated user.
+    """
+    # Currently ongoing transaction
+    stmt_current_transaction = select(DbTransaction).where(DbTransaction.user_id == token.subject).where(DbTransaction.status == TransactionStatus.ONGOING)
+    current_transaction = db.execute(stmt_current_transaction).scalars().first()
+
+    # Common base query
+    stmt_base = select(DbTransaction).where(DbTransaction.user_id == token.subject).where( DbTransaction.status == TransactionStatus.ENDED).order_by(DbTransaction.ended_at.desc())
+
+    # 5 most recent transactions
+    stmt_transactions_recent = stmt_base.limit(5)
+    recent_transactions = db.execute(stmt_transactions_recent).scalars().all()
+
+    # Calculate beginning of the current and previous month
+    current_date = datetime.now(UTC).replace(hour=0, minute=0, second=0, microsecond=0, tzinfo=None)
+
+    beginning_current_month = current_date.replace(day=1)
+
+    beginning_previous_month = beginning_current_month.replace(
+        year=(beginning_current_month.year - 1 if beginning_current_month.month == 1 else beginning_current_month.year),
+        month=(12 if beginning_current_month.month == 1 else beginning_current_month.month - 1)
+    )
+
+    # Transactions for total calculations
+    stmt_transactions = stmt_base.where(DbTransaction.ended_at >= beginning_previous_month)
+    transactions = db.execute(stmt_transactions).scalars().all()
+
+    # Current month totals
+    count = 0
+    energy_total = 0
+    cost_total = 0
+
+    # Previous month totals
+    count_previous = 0
+    energy_total_previous = 0
+    cost_total_previous = 0
+
+    # Calculate totals
+    for trans in transactions:
+        trans_energy = trans.meter_end - trans.meter_start
+        trans_cost = trans_energy * trans.price
+        if trans.ended_at >= beginning_current_month:
+            # Current month
+            energy_total += trans_energy
+            cost_total += trans_cost
+            count += 1
+        else:
+            # Previous month
+            energy_total_previous += trans_energy
+            cost_total_previous += trans_cost
+            count_previous += 1
+    
+    return DashboardResponse(
+        stats=DashboardStats(
+            transaction_count=count,
+            transaction_count_previous=count_previous,
+            transaction_energy_total=energy_total,
+            transaction_energy_total_previous=energy_total_previous,
+            transaction_cost_total=cost_total,
+            transaction_cost_total_previous=cost_total_previous
+        ),
+        current_transaction=current_transaction,
+        recent_transactions=recent_transactions
+    )

backend/app/schemas/chargepoint.py

@@ -8,6 +8,8 @@ from app.schemas.connector import Connector
 
 from ocpp.v201.enums import ResetEnumType, ResetStatusEnumType
 
+from app.util.encoders import decimal_encoder
+
 class ChargePointBase(BaseModel):
     identity: str
     is_active: bool
@@ -32,6 +34,7 @@ class ChargePoint(ChargePointBase):
 
     class Config:
         from_attributes = True
+        json_encoders = {Decimal: decimal_encoder}
 
 class ChargePointPassword(BaseModel):
     password: str

backend/app/schemas/chargepoint_variable.py

@@ -4,6 +4,8 @@ from uuid import UUID
 from pydantic import BaseModel
 import enum
 
+from app.util.encoders import decimal_encoder
+
 class AttributeType(enum.Enum):
     ACTUAL = "Actual"
     TARGET = "Target"
@@ -52,6 +54,7 @@ class ChargepointVariable(BaseModel):
 
     class Config:
         from_attributes = True
+        json_encoders = {Decimal: decimal_encoder}
 
 class ChargepointVariableUpdate(BaseModel):
     value: str

backend/app/schemas/dashboard.py

@@ -0,0 +1,25 @@
+from decimal import Decimal
+from typing import Optional
+from pydantic import BaseModel
+
+from app.schemas.transaction import Transaction
+from app.util.encoders import decimal_encoder
+
+class DashboardStats(BaseModel):
+    transaction_count: int
+    transaction_count_previous: int
+    transaction_energy_total: Decimal
+    transaction_energy_total_previous: Decimal
+    transaction_cost_total: Decimal
+    transaction_cost_total_previous: Decimal
+
+    class Config:
+        json_encoders = {Decimal: decimal_encoder}
+
+class DashboardResponse(BaseModel):
+    stats: DashboardStats
+    current_transaction: Optional[Transaction] = None
+    recent_transactions: list[Transaction]
+
+    class Config:
+        json_encoders = {Decimal: decimal_encoder}

backend/app/schemas/meter_value.py

@@ -5,6 +5,8 @@ from typing import Optional
 from uuid import UUID
 from pydantic import BaseModel
 
+from app.util.encoders import decimal_encoder
+
 class PhaseType(enum.Enum):
     L1 = "L1"
     L2 = "L2"
@@ -55,3 +57,4 @@ class MeterValue(BaseModel):
 
     class Config:
         from_attributes = True
+        json_encoders = {Decimal: decimal_encoder}

backend/app/schemas/session.py

@@ -8,4 +8,5 @@ class Session(BaseModel):
     name: str
     last_used: datetime
 
-    model_config = {"from_attributes": True}
+    class Config:
+        from_attributes = True

backend/app/schemas/transaction.py

@@ -5,6 +5,8 @@ from typing import Optional
 from uuid import UUID
 from pydantic import BaseModel
 
+from app.util.encoders import decimal_encoder
+
 class TransactionStatus(enum.Enum):
     ONGOING = "ongoing"
     ENDED = "ended"
@@ -50,6 +52,7 @@ class Transaction(BaseModel):
 
     class Config:
         from_attributes = True
+        json_encoders = {Decimal: decimal_encoder}
 
 class RemoteTransactionStartStopResponse(BaseModel):
     status: RemoteTransactionStartStopStatus

backend/app/util/encoders.py

@@ -0,0 +1,22 @@
+from decimal import Decimal
+from typing import Union
+
+def decimal_encoder(dec_value: Decimal) -> Union[int, float]:
+    """Encodes a Decimal as int of there's no exponent, otherwise float.
+
+    This is useful when we use ConstrainedDecimal to represent Numeric(x,0)
+    where a integer (but not int typed) is used. Encoding this as a float
+    results in failed round-tripping between encode and parse.
+    Our Id type is a prime example of this.
+
+    >>> decimal_encoder(Decimal("1.0"))
+    1.0
+
+    >>> decimal_encoder(Decimal("1"))
+    1
+    """
+    exponent = dec_value.as_tuple().exponent
+    if isinstance(exponent, int) and exponent >= 0:
+        return int(dec_value)
+    else:
+        return float(dec_value)