from fastapi import FastAPI, HTTPException, Depends
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from . import schemas, database, models, auth
from passlib.context import CryptContext
import logging

app = FastAPI(
    title="Task Service",
    root_path="/task",
    docs_url="/docs",
    openapi_url="/openapi.json"
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

@app.on_event("startup")
async def startup():
    await database.init_db()

async def get_db():
    async with database.AsyncSessionLocal() as session:
        yield session

@app.get("/")
def root():
    return {
        "service": "task",
        "message": "Task service is running"
    }

@app.post("/tasks/", response_model=schemas.Task)
async def create_task(task: schemas.TaskCreate, db: AsyncSession = Depends(get_db), current_user: dict = Depends(auth.get_current_user)):
    logger.info(f"Creating task for user: {current_user['username']}, title: {task.title}")
    stmt = select(models.Task).where(models.Task.title == task.title, models.Task.username == task.username)
    result = await db.execute(stmt)
    if result.scalars().first():
        raise HTTPException(status_code=400, detail="Task with this title already exists for the user")
    db_task = models.Task(title=task.title, description=task.description, username=task.username)
    db.add(db_task)
    await db.commit()
    await db.refresh(db_task)
    logger.info(f"Task created with ID: {db_task.id}")
    return db_task

@app.get("/tasks/", response_model=list[schemas.Task])
async def get_tasks(db: AsyncSession = Depends(get_db), current_user: dict = Depends(auth.get_current_user)):
    stmt = select(models.Task).where(models.Task.username == current_user['username'])
    result = await db.execute(stmt)
    return result.scalars().all()

@app.get("/tasks/{task_id}", response_model=schemas.Task)
async def get_task(task_id: int, db: AsyncSession = Depends(get_db), current_user: dict = Depends(auth.get_current_user)):
    stmt = select(models.Task).where(models.Task.id == task_id, models.Task.username == current_user['username'])
    result = await db.execute(stmt)
    task = result.scalars().first()
    if not task:
        raise HTTPException(status_code=404, detail="Task not found")
    return task

@app.put("/tasks/{task_id}", response_model=schemas.Task)
async def update_task(task_id: int, task_update: schemas.TaskCreate, db: AsyncSession = Depends(get_db), current_user: dict = Depends(auth.get_current_user)):
    stmt = select(models.Task).where(models.Task.id == task_id, models.Task.username == current_user['username'])
    result = await db.execute(stmt)
    db_task = result.scalars().first()
    if not db_task:
        raise HTTPException(status_code=404, detail="Task not found")
    db_task.title = task_update.title
    db_task.description = task_update.description
    await db.commit()
    await db.refresh(db_task)
    return db_task

@app.delete("/tasks/{task_id}", status_code=204)
async def delete_task(task_id: int, db: AsyncSession = Depends(get_db), current_user: dict = Depends(auth.get_current_user)):
    stmt = select(models.Task).where(models.Task.id == task_id, models.Task.username == current_user['username'])
    result = await db.execute(stmt)
    db_task = result.scalars().first()
    if not db_task:
        raise HTTPException(status_code=404, detail="Task not found")
    await db.delete(db_task)
    await db.commit()
    return {
        "message": "Task deleted."
    }