from datetime import datetime, timezone
from fastapi import APIRouter, Request, Form, HTTPException
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.templating import Jinja2Templates
from sqlalchemy import select

from app.models.base import async_session
from app.models.user import User
from app.auth import hash_password, verify_password, create_session

router = APIRouter()
templates = Jinja2Templates(directory="app/templates")


@router.get("/login", response_class=HTMLResponse)
async def login_page(request: Request):
    return templates.TemplateResponse("login.html", {"request": request})


@router.post("/login")
async def login(request: Request, username: str = Form(), password: str = Form()):
    async with async_session() as session:
        result = await session.execute(select(User).where(User.username == username))
        user = result.scalar_one_or_none()
        if not user or not verify_password(password, user.password_hash):
            return templates.TemplateResponse(
                "login.html",
                {"request": request, "error": "Invalid username or password"},
            )
        token = await create_session(user.id)

    resp = RedirectResponse(url="/dashboard", status_code=303)
    resp.set_cookie(key="session_token", value=token, httponly=True, max_age=86400 * 30)
    return resp


@router.get("/register", response_class=HTMLResponse)
async def register_page(request: Request):
    return templates.TemplateResponse("register.html", {"request": request})


@router.post("/register")
async def register(
    request: Request,
    username: str = Form(),
    password: str = Form(),
    display_name: str = Form(default=""),
):
    async with async_session() as session:
        result = await session.execute(select(User).where(User.username == username))
        if result.scalar_one_or_none():
            return templates.TemplateResponse(
                "register.html",
                {"request": request, "error": "Username already taken"},
            )
        user = User(
            username=username,
            password_hash=hash_password(password),
            display_name=display_name or username,
            created_at=datetime.now(timezone.utc).isoformat(),
        )
        session.add(user)
        await session.commit()
        await session.refresh(user)
        token = await create_session(user.id)

    resp = RedirectResponse(url="/dashboard", status_code=303)
    resp.set_cookie(key="session_token", value=token, httponly=True, max_age=86400 * 30)
    return resp


@router.get("/logout")
async def logout():
    resp = RedirectResponse(url="/login", status_code=303)
    resp.delete_cookie("session_token")
    return resp