import sqlite3
from typing import List

from fastapi import APIRouter, HTTPException, status

from app.database import Database
from app.schemas import Todo, TodoCreate, TodoUpdate


router = APIRouter(prefix="/todos", tags=["todos"])


def row_to_todo(row: sqlite3.Row) -> Todo:
    return Todo(id=row["id"], title=row["title"], done=bool(row["done"]))


@router.get("", response_model=List[Todo])
def list_todos(db: Database) -> List[Todo]:
    rows = db.execute("SELECT id, title, done FROM todos ORDER BY id").fetchall()
    return [row_to_todo(row) for row in rows]


@router.post("", response_model=Todo, status_code=status.HTTP_201_CREATED)
def create_todo(payload: TodoCreate, db: Database) -> Todo:
    cursor = db.execute(
        "INSERT INTO todos (title, done) VALUES (?, ?)",
        (payload.title, 0),
    )
    db.commit()
    return Todo(id=cursor.lastrowid, title=payload.title, done=False)


@router.get("/{todo_id}", response_model=Todo)
def get_todo(todo_id: int, db: Database) -> Todo:
    row = db.execute(
        "SELECT id, title, done FROM todos WHERE id = ?",
        (todo_id,),
    ).fetchone()
    if row is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found")
    return row_to_todo(row)


@router.patch("/{todo_id}", response_model=Todo)
def update_todo(todo_id: int, payload: TodoUpdate, db: Database) -> Todo:
    todo = get_todo(todo_id, db)
    updates = payload.model_dump(exclude_unset=True)

    if not updates:
        return todo

    title = updates.get("title", todo.title)
    done = updates.get("done", todo.done)
    db.execute(
        "UPDATE todos SET title = ?, done = ? WHERE id = ?",
        (title, int(done), todo_id),
    )
    db.commit()

    return get_todo(todo_id, db)


@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_todo(todo_id: int, db: Database) -> None:
    cursor = db.execute("DELETE FROM todos WHERE id = ?", (todo_id,))
    db.commit()
    if cursor.rowcount == 0:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Todo not found")