import json
from sqlalchemy.orm import Session
from . import models, schemas
import uuid
from datetime import datetime

def get_user(db: Session, user_id: str):
    return db.query(models.User).filter(models.User.id == user_id).first()

def get_users(db: Session):
    return db.query(models.User).all()

def create_user(db: Session, user: schemas.UserAccount):
    db_user = models.User(
        id=user.id,
        name=user.name,
        department=user.department,
        medical_allowance=user.medical_allowance
    )
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    return db_user

def get_claims(db: Session):
    return db.query(models.Claim).all()

def create_claim(db: Session, claim: schemas.ClaimSubmission, user_id: str):
    # Calculate amount claimed (payout)
    user = get_user(db, user_id)
    if not user:
        return None
        
    spent_amount = claim.amount_spent
    remaining = user.medical_allowance
    amount_claimed = min(spent_amount, remaining)
    
    # Update User Balance
    user.medical_allowance -= amount_claimed
    
    # Create DB model
    db_claim = models.Claim(
        id=str(uuid.uuid4()),
        timestamp=datetime.now().isoformat(),
        user_id=user_id,
        amount_spent=spent_amount,
        amount_claimed=amount_claimed,
        provider_name=claim.provider_name,
        visit_date=claim.visit_date,
        treatment_type=claim.treatment_type,
        cost_center=claim.cost_center,
        declaration_signed=claim.declaration_signed,
        extraction_data=json.dumps(claim.extraction_data.model_dump()) if claim.extraction_data else None
    )
    db.add(db_claim)
    db.commit()
    db.refresh(db_claim)
    return db_claim

def delete_claim(db: Session, claim_id: str):
    db_claim = db.query(models.Claim).filter(models.Claim.id == claim_id).first()
    if db_claim:
        # Refund user allowance
        user = get_user(db, db_claim.user_id)
        if user:
            user.medical_allowance += db_claim.amount_claimed
            
        db.delete(db_claim)
        db.commit()
        return True
    return False

def to_pydantic_claim(db_claim: models.Claim) -> schemas.ClaimRecord:
    ext_data = None
    if db_claim.extraction_data:
        try:
            ext_data = schemas.ExtractionResponse(**json.loads(db_claim.extraction_data))
        except:
            pass
            
    return schemas.ClaimRecord(
        id=db_claim.id,
        timestamp=db_claim.timestamp,
        submitted_by=db_claim.owner.name if db_claim.owner else "Unknown",
        department=db_claim.owner.department if db_claim.owner else "Unknown",
        amount_spent=db_claim.amount_spent,
        amount_claimed=db_claim.amount_claimed,
        provider_name=db_claim.provider_name,
        visit_date=db_claim.visit_date,
        treatment_type=db_claim.treatment_type,
        cost_center=db_claim.cost_center,
        declaration_signed=db_claim.declaration_signed,
        extraction_data=ext_data
    )

def seed_demo_user(db: Session):
    user_id = "demo-user-123"
    db_user = get_user(db, user_id)
    if not db_user:
        db_user = models.User(
            id=user_id,
            name="Demo User",
            department="Operations",
            medical_allowance=5000.0
        )
        db.add(db_user)
        db.commit()
        db.refresh(db_user)
    return db_user