from typing import Optional, Sequence
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import select, delete
from sqlalchemy.ext.asyncio import AsyncSession
from app.schemas.posts import PostCreate, PostRead
from app.db_engine import get_async_session
from app.models.posts import Post


router = APIRouter(
    prefix="/posts",
    tags=["posts"],
    responses={404: {"description": "Not found"}},
)


@router.get("/")
async def get_posts(
    page: int = Query(1, ge=1),
    page_size: int = Query(10, ge=1, le=100),
    db: AsyncSession = Depends(get_async_session),
):
    offset = (page - 1) * page_size

    stmt = select(Post).order_by(Post.id).offset(offset).limit(page_size)

    result = await db.execute(stmt)
    posts: Sequence[Post] = result.scalars().all()

    return posts


@router.get("/{id}", response_model=PostRead)
async def get_post(id: int, db: AsyncSession = Depends(get_async_session)):
    post = await db.get(Post, id)
    if post is None:
        raise HTTPException(status_code=404, detail="Post not found")
    else:
        return post


@router.post("/", response_model=PostRead)
async def create_post(
    title: str,
    content: str,
    images: Optional[str] = None,
    db: AsyncSession = Depends(get_async_session),
) -> Post:
    try:
        post = PostCreate(title=title, content=content, images=images)
    except ValueError as e:
        raise HTTPException(status_code=422, detail=str(e))
    new_post = Post(title=post.title, content=post.content, images=post.images)
    db.add(new_post)
    await db.commit()
    await db.refresh(new_post)
    return new_post


@router.put("/{id}")
async def update_post(
    id: int,
    db: AsyncSession = Depends(get_async_session),
    title: Optional[str] = None,
    content: Optional[str] = None,
    images: Optional[str] = None,
):
    s = select(Post).where(Post.id == id)
    result = await db.execute(s)
    post = result.scalars().first()

    if post is None:
        raise HTTPException(status_code=404, detail="Post not found")

    if title is not None:
        post.title = title  # type: ignore
    if content is not None:
        post.content = content  # type: ignore
    if images is not None:
        post.images = images  # type: ignore

    await db.commit()
    return post


@router.delete("/{id}")
async def delete_post(id: int, db: AsyncSession = Depends(get_async_session)):
    s = delete(Post).where(Post.id == id)
    await db.execute(s)
    await db.commit()
    return {"message": "Post deleted"}