from fastapi import FastAPI, Depends, HTTPException, status
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy.orm import Session
from typing import List
import uuid

from . import models, schemas, auth, database
from .database import engine, get_db

models.Base.metadata.create_all(bind=engine)

app = FastAPI(title="Dashy API")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"], # In production, specify your frontend URL
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.post("/token", response_model=schemas.Token)
async def login_for_access_token(form_data: schemas.UserCreate, db: Session = Depends(get_db)):
    user = db.query(models.User).filter(models.User.id == form_data.id).first()
    if not user or not auth.verify_password(form_data.password, user.password_hash):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    access_token = auth.create_access_token(data={"sub": user.id})
    return {"access_token": access_token, "token_type": "bearer"}

@app.get("/users", response_model=List[schemas.User])
def read_users(db: Session = Depends(get_db)):
    return db.query(models.User).all()

@app.get("/tasks", response_model=List[schemas.Task])
def read_tasks(db: Session = Depends(get_db)):
    return db.query(models.Task).all()

@app.post("/tasks", response_model=schemas.Task)
def create_task(task: schemas.TaskCreate, db: Session = Depends(get_db)):
    task_id = task.id or f"t_{uuid.uuid4().hex[:8]}"
    db_task = models.Task(
        id=task_id,
        title=task.title,
        description=task.description,
        assignee_id=task.assignee_id,
        added_by=task.added_by,
        priority=task.priority,
        source=task.source,
        status=task.status,
        due_at=task.due_at,
        reminder_at=task.reminder_at
    )
    db.add(db_task)
    
    for tag_name in task.tags:
        tag = db.query(models.Tag).filter(models.Tag.tag == tag_name).first()
        if not tag:
            tag = models.Tag(tag=tag_name)
            db.add(tag)
        db_task.tags.append(tag)
    
    db.commit()
    db.refresh(db_task)
    return db_task

@app.patch("/tasks/{task_id}", response_model=schemas.Task)
def update_task(task_id: str, task_update: schemas.TaskUpdate, db: Session = Depends(get_db)):
    db_task = db.query(models.Task).filter(models.Task.id == task_id).first()
    if not db_task:
        raise HTTPException(status_code=404, detail="Task not found")
    
    update_data = task_update.dict(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_task, key, value)
    
    db.commit()
    db.refresh(db_task)
    return db_task

@app.get("/audit", response_model=List[schemas.AuditLog])
def read_audit(db: Session = Depends(get_db)):
    return db.query(models.AuditLog).order_by(models.AuditLog.at.desc()).all()

@app.post("/audit", response_model=schemas.AuditLog)
def create_audit(audit: schemas.AuditLogBase, db: Session = Depends(get_db)):
    audit_id = f"a_{uuid.uuid4().hex[:8]}"
    db_audit = models.AuditLog(
        id=audit_id,
        actor=audit.actor,
        action=audit.action,
        summary=audit.summary,
        target=audit.target
    )
    db.add(db_audit)
    db.commit()
    db.refresh(db_audit)
    return db_audit