from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session
from typing import List
from datetime import date, datetime

from app.core.database import get_db
from app.core.security import decode_access_token
from app.models.user import User
from app.models.habit import Habit, HabitCompletion
from app.schemas.habit import HabitCreate, HabitResponse, HabitCompletionCreate

router = APIRouter(prefix="/habits", tags=["habits"])
security = HTTPBearer()

def get_current_user_id(credentials: HTTPAuthorizationCredentials = Depends(security)) -> str:
    """Extrai user_id do token JWT"""
    token = credentials.credentials
    payload = decode_access_token(token)
    if not payload:
        raise HTTPException(status_code=401, detail="Token inválido")
    return payload.get("sub")

@router.post("/", response_model=HabitResponse, status_code=status.HTTP_201_CREATED)
async def create_habit(
    habit_data: HabitCreate,
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Criar novo hábito"""
    new_habit = Habit(
        user_id=user_id,
        name=habit_data.name,
        description=habit_data.description,
        frequency_type=habit_data.frequency_type,
        target_count=habit_data.target_count,
        reminder_time=habit_data.reminder_time,
        start_date=habit_data.start_date or date.today()
    )
    
    db.add(new_habit)
    db.commit()
    db.refresh(new_habit)
    
    return new_habit

@router.get("/", response_model=List[HabitResponse])
async def list_habits(
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Listar todos os hábitos do usuário"""
    habits = db.query(Habit).filter(
        Habit.user_id == user_id,
        Habit.is_active == True
    ).all()
    
    return habits

@router.post("/{habit_id}/complete", status_code=status.HTTP_201_CREATED)
async def complete_habit(
    habit_id: str,
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Marcar hábito como completo para hoje"""
    # Verificar se já completou hoje
    today = date.today()
    existing = db.query(HabitCompletion).filter(
        HabitCompletion.habit_id == habit_id,
        HabitCompletion.user_id == user_id,
        HabitCompletion.completion_date == today
    ).first()
    
    if existing:
        raise HTTPException(status_code=400, detail="Hábito já completado hoje")
    
    # Criar completion
    completion = HabitCompletion(
        habit_id=habit_id,
        user_id=user_id,
        completion_date=today,
        completion_time=datetime.now().time()
    )
    
    db.add(completion)
    db.commit()
    
    return {"message": "Hábito completado!", "date": today}

@router.delete("/{habit_id}/complete")
async def uncomplete_habit(
    habit_id: str,
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Desmarcar hábito de hoje"""
    today = date.today()
    completion = db.query(HabitCompletion).filter(
        HabitCompletion.habit_id == habit_id,
        HabitCompletion.user_id == user_id,
        HabitCompletion.completion_date == today
    ).first()
    
    if not completion:
        raise HTTPException(status_code=404, detail="Completion não encontrado")
    
    db.delete(completion)
    db.commit()
    
    return {"message": "Completion removido"}

@router.get("/stats")
async def get_habit_stats(
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Estatísticas de hábitos"""
    from sqlalchemy import func
    
    total_habits = db.query(func.count(Habit.id)).filter(
        Habit.user_id == user_id,
        Habit.is_active == True
    ).scalar()
    
    completed_today = db.query(func.count(HabitCompletion.id)).filter(
        HabitCompletion.user_id == user_id,
        HabitCompletion.completion_date == date.today()
    ).scalar()
    
    return {
        "total_habits": total_habits,
        "completed_today": completed_today,
        "pending_today": total_habits - completed_today
    }

@router.delete("/{habit_id}")
async def delete_habit(
    habit_id: str,
    user_id: str = Depends(get_current_user_id),
    db: Session = Depends(get_db)
):
    """Deletar hábito"""
    habit = db.query(Habit).filter(
        Habit.id == habit_id,
        Habit.user_id == user_id
    ).first()
    
    if not habit:
        raise HTTPException(status_code=404, detail="Hábito não encontrado")
    
    db.delete(habit)
    db.commit()
    
    return {"message": "Hábito deletado"}