from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy.orm import Session
from typing import List, Optional, Dict, Any
from datetime import datetime

from app import crud
from app.models.todo import PriorityEnum as ModelPriorityEnum
from app.schemas.todo import Todo, TodoCreate, TodoUpdate, PriorityEnum
from app.db.base import get_db

router = APIRouter()


@router.get("/", response_model=List[Todo])
def read_todos(
    skip: int = 0,
    limit: int = 100,
    category: Optional[str] = None,
    priority: Optional[PriorityEnum] = None,
    completed: Optional[bool] = None,
    due_before: Optional[datetime] = None,
    due_after: Optional[datetime] = None,
    sort_by: str = "created_at",
    sort_desc: bool = True,
    db: Session = Depends(get_db)
):
    """
    Get all todos with filtering options:
    - Filter by category
    - Filter by priority level
    - Filter by completion status
    - Filter by due date (before/after)
    - Sort by any field
    - Pagination
    """
    todos = crud.get_todos(
        db=db,
        skip=skip,
        limit=limit,
        category=category,
        priority=priority.value if priority else None,
        completed=completed,
        due_before=due_before,
        due_after=due_after,
        sort_by=sort_by,
        sort_desc=sort_desc
    )
    return todos


@router.post("/", response_model=Todo, status_code=status.HTTP_201_CREATED)
def create_todo(todo: TodoCreate, db: Session = Depends(get_db)):
    """Create a new todo item with extended fields"""
    return crud.create_todo(db=db, todo=todo)


@router.get("/stats", response_model=Dict[str, Any])
def get_todo_stats(db: Session = Depends(get_db)):
    """Get statistics about todos"""
    return crud.get_todo_stats(db=db)


@router.get("/{todo_id}", response_model=Todo)
def read_todo(todo_id: int, db: Session = Depends(get_db)):
    """Get a specific todo by ID"""
    db_todo = crud.get_todo(db, todo_id=todo_id)
    if db_todo is None:
        raise HTTPException(status_code=404, detail="Todo not found")
    return db_todo


@router.put("/{todo_id}", response_model=Todo)
def update_todo(todo_id: int, todo: TodoUpdate, db: Session = Depends(get_db)):
    """Update a todo with new values including category, priority and due date"""
    db_todo = crud.update_todo(db=db, todo_id=todo_id, todo=todo)
    if db_todo is None:
        raise HTTPException(status_code=404, detail="Todo not found")
    return db_todo


@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_todo(todo_id: int, db: Session = Depends(get_db)):
    """Delete a todo by ID"""
    success = crud.delete_todo(db=db, todo_id=todo_id)
    if not success:
        raise HTTPException(status_code=404, detail="Todo not found")
    return None