"""Authentication routes for the federation app.

Owns magic link login/logout + OAuth2 authorization server endpoint.
Account pages (newsletters, widget pages) have moved to the account app.
"""
from __future__ import annotations

import secrets
from datetime import datetime, timezone, timedelta

from quart import (
    Blueprint,
    request,
    redirect,
    url_for,
    session as qsession,
    g,
    current_app,
)
from sqlalchemy import select
from sqlalchemy.exc import SQLAlchemyError

from shared.db.session import get_session
from shared.models import User
from shared.models.oauth_code import OAuthCode
from shared.infrastructure.urls import federation_url, app_url
from shared.infrastructure.cart_identity import current_cart_identity
from shared.events import emit_activity

from .services import (
    pop_login_redirect_target,
    store_login_redirect_target,
    send_magic_email,
    find_or_create_user,
    create_magic_link,
    validate_magic_link,
    validate_email,
)

SESSION_USER_KEY = "uid"

ALLOWED_CLIENTS = {"blog", "market", "cart", "events", "account"}


async def _render_social_auth_page(component: str, title: str, **kwargs) -> str:
    """Render an auth page with social layout — replaces sx_components helpers."""
    from shared.sx.helpers import sx_call
    from shared.sx.page import get_template_context
    from sxc.pages.utils import _social_page
    ctx = await get_template_context()
    content = sx_call(component, **{k: v for k, v in kwargs.items() if v})
    return await _social_page(ctx, None, content=content, title=title)


def register(url_prefix="/auth"):
    auth_bp = Blueprint("auth", __name__, url_prefix=url_prefix)

    # --- OAuth2 authorize endpoint -------------------------------------------

    @auth_bp.get("/oauth/authorize")
    @auth_bp.get("/oauth/authorize/")
    async def oauth_authorize():
        client_id = request.args.get("client_id", "")
        redirect_uri = request.args.get("redirect_uri", "")
        state = request.args.get("state", "")

        if client_id not in ALLOWED_CLIENTS:
            return "Invalid client_id", 400

        expected_redirect = app_url(client_id, "/auth/callback")
        if redirect_uri != expected_redirect:
            return "Invalid redirect_uri", 400

        # Not logged in — bounce to magic link login, then back here
        if not g.get("user"):
            # Preserve the full authorize URL so we return here after login
            authorize_path = request.full_path  # includes query string
            store_login_redirect_target()
            return redirect(url_for("auth.login_form", next=authorize_path))

        # Logged in — issue authorization code
        code = secrets.token_urlsafe(48)
        now = datetime.now(timezone.utc)
        expires = now + timedelta(minutes=5)

        async with get_session() as s:
            async with s.begin():
                oauth_code = OAuthCode(
                    code=code,
                    user_id=g.user.id,
                    client_id=client_id,
                    redirect_uri=redirect_uri,
                    expires_at=expires,
                )
                s.add(oauth_code)

        sep = "&" if "?" in redirect_uri else "?"
        return redirect(f"{redirect_uri}{sep}code={code}&state={state}")

    # --- Magic link login flow -----------------------------------------------

    @auth_bp.get("/login/")
    async def login_form():
        store_login_redirect_target()
        cross_cart_sid = request.args.get("cart_sid")
        if cross_cart_sid:
            qsession["cart_sid"] = cross_cart_sid
        if g.get("user"):
            # If there's a pending redirect (e.g. OAuth authorize), follow it
            redirect_url = pop_login_redirect_target()
            return redirect(redirect_url)
        return await _render_social_auth_page("account-login-content", "Login \u2014 Rose Ash")

    @auth_bp.post("/start/")
    async def start_login():
        form = await request.form
        email_input = form.get("email") or ""

        is_valid, email = validate_email(email_input)
        if not is_valid:
            return await _render_social_auth_page(
                "account-login-content", "Login \u2014 Rose Ash",
                error="Please enter a valid email address.", email=email_input,
            ), 400

        user = await find_or_create_user(g.s, email)
        token, expires = await create_magic_link(g.s, user.id)

        from shared.utils import host_url
        magic_url = host_url(url_for("auth.magic", token=token))

        email_error = None
        try:
            await send_magic_email(email, magic_url)
        except Exception as e:
            current_app.logger.error("EMAIL SEND FAILED: %r", e)
            email_error = (
                "We couldn't send the email automatically. "
                "Please try again in a moment."
            )

        return await _render_social_auth_page(
            "account-check-email-content", "Check your email \u2014 Rose Ash",
            email=email, email_error=email_error,
        )

    @auth_bp.get("/magic/<token>/")
    async def magic(token: str):
        now = datetime.now(timezone.utc)
        user_id: int | None = None

        try:
            async with get_session() as s:
                async with s.begin():
                    user, error = await validate_magic_link(s, token)

                    if error:
                        return await _render_social_auth_page(
                            "account-login-content", "Login \u2014 Rose Ash",
                            error=error,
                        ), 400
                    user_id = user.id

        except Exception:
            return await _render_social_auth_page(
                "account-login-content", "Login \u2014 Rose Ash",
                error="Could not sign you in right now. Please try again.",
            ), 502

        assert user_id is not None

        ident = current_cart_identity()
        anon_session_id = ident.get("session_id")

        try:
            async with get_session() as s:
                async with s.begin():
                    u2 = await s.get(User, user_id)
                    if u2:
                        u2.last_login_at = now
                    if anon_session_id:
                        await emit_activity(
                            s,
                            activity_type="rose:Login",
                            actor_uri="internal:system",
                            object_type="Person",
                            object_data={
                                "user_id": user_id,
                                "session_id": anon_session_id,
                            },
                        )
        except SQLAlchemyError:
            current_app.logger.exception(
                "[auth] non-fatal DB update for user_id=%s", user_id
            )

        qsession[SESSION_USER_KEY] = user_id

        redirect_url = pop_login_redirect_target()
        resp = redirect(redirect_url, 303)
        resp.set_cookie(
            "sso_hint", "1",
            domain=".rose-ash.com", max_age=30 * 24 * 3600,
            secure=True, samesite="Lax", httponly=True,
        )
        return resp

    @auth_bp.post("/logout/")
    async def logout():
        qsession.pop(SESSION_USER_KEY, None)
        resp = redirect(federation_url("/"))
        resp.delete_cookie("sso_hint", domain=".rose-ash.com", path="/")
        return resp

    @auth_bp.get("/clear/")
    async def clear():
        """One-time migration helper: clear all session cookies."""
        qsession.clear()
        resp = redirect(federation_url("/"))
        resp.delete_cookie("blog_session", domain=".rose-ash.com", path="/")
        resp.delete_cookie("sso_hint", domain=".rose-ash.com", path="/")
        return resp

    @auth_bp.get("/sso-logout/")
    async def sso_logout():
        """SSO logout: clear federation session + sso_hint, redirect to blog."""
        qsession.pop(SESSION_USER_KEY, None)
        from shared.infrastructure.urls import blog_url
        resp = redirect(blog_url("/"))
        resp.delete_cookie("sso_hint", domain=".rose-ash.com", path="/")
        return resp

    return auth_bp
