from pydantic import BaseModel
from typing import List, Optional

class UsageStats(BaseModel):
    total_runs: int
    total_tokens: int
    total_input_tokens: int
    total_output_tokens: int
    total_cost: float

class UsageByEntity(BaseModel):
    entity_id: Optional[str] = None
    stats: UsageStats

class FinancialReport(BaseModel):
    summary: UsageStats
    by_user: Optional[List[UsageByEntity]] = None
    by_project: Optional[List[UsageByEntity]] = None