from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session
from typing import List
import uuid

from database import get_db
from models import Post as PostModel
from schemas import Post, CreatePostRequest, UpdatePostRequest, Error

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


@router.get("", response_model=List[Post])
def get_posts(db: Session = Depends(get_db)):
    """모든 게시물 조회"""
    posts = db.query(PostModel).all()
    result = []
    for post in posts:
        result.append({
            "id": post.id,
            "username": post.username,
            "content": post.content,
            "createdAt": post.created_at,
            "updatedAt": post.updated_at,
            "likesCount": len(post.likes),
            "commentsCount": len(post.comments)
        })
    return result


@router.post("", response_model=Post, status_code=status.HTTP_201_CREATED)
def create_post(post_request: CreatePostRequest, db: Session = Depends(get_db)):
    """새 게시물 생성"""
    post_id = f"post-{uuid.uuid4()}"
    new_post = PostModel(
        id=post_id,
        username=post_request.username,
        content=post_request.content
    )
    db.add(new_post)
    db.commit()
    db.refresh(new_post)
    
    return {
        "id": new_post.id,
        "username": new_post.username,
        "content": new_post.content,
        "createdAt": new_post.created_at,
        "updatedAt": new_post.updated_at,
        "likesCount": 0,
        "commentsCount": 0
    }


@router.get("/{postId}", response_model=Post)
def get_post_by_id(postId: str, db: Session = Depends(get_db)):
    """특정 게시물 조회"""
    post = db.query(PostModel).filter(PostModel.id == postId).first()
    if not post:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail={"message": "리소스를 찾을 수 없습니다", "details": "지정된 ID의 게시물이 존재하지 않습니다"}
        )
    
    return {
        "id": post.id,
        "username": post.username,
        "content": post.content,
        "createdAt": post.created_at,
        "updatedAt": post.updated_at,
        "likesCount": len(post.likes),
        "commentsCount": len(post.comments)
    }


@router.patch("/{postId}", response_model=Post)
def update_post(postId: str, post_request: UpdatePostRequest, db: Session = Depends(get_db)):
    """게시물 업데이트"""
    post = db.query(PostModel).filter(PostModel.id == postId).first()
    if not post:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail={"message": "리소스를 찾을 수 없습니다", "details": "지정된 ID의 게시물이 존재하지 않습니다"}
        )
    
    post.username = post_request.username
    post.content = post_request.content
    db.commit()
    db.refresh(post)
    
    return {
        "id": post.id,
        "username": post.username,
        "content": post.content,
        "createdAt": post.created_at,
        "updatedAt": post.updated_at,
        "likesCount": len(post.likes),
        "commentsCount": len(post.comments)
    }


@router.delete("/{postId}", status_code=status.HTTP_204_NO_CONTENT)
def delete_post(postId: str, db: Session = Depends(get_db)):
    """게시물 삭제"""
    post = db.query(PostModel).filter(PostModel.id == postId).first()
    if not post:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail={"message": "리소스를 찾을 수 없습니다", "details": "지정된 ID의 게시물이 존재하지 않습니다"}
        )
    
    db.delete(post)
    db.commit()
    return None