"""The signed-in user's own account (milestone 490): the time zone every
page writes its times in. Any role reaches it, for themselves only."""
from __future__ import annotations

from itertools import groupby

from quart import Blueprint, abort, current_app, redirect, render_template, request, session

from steward.auth.middleware import require_role
from steward.core import formatting
from steward.models.users import User, UserRole

account_bp = Blueprint("account", __name__, url_prefix="/account")

_SOURCES = {"local": "a Steward password", "ldap": "LDAP", "oidc": "single sign-on"}


def _zones_by_region() -> list[tuple[str, list[str]]]:
    """The Account page's choices: UTC alone, then every zone under its
    region ('America', 'Europe', …)."""
    named = [z for z in formatting.zone_names() if "/" in z]
    return [("", ["UTC"])] + [(region, list(zones)) for region, zones
                              in groupby(named, key=lambda z: z.split("/", 1)[0])]


async def _me(db) -> User:
    # A share link opens widgets read-only; it has no account.
    user_id = session.get("user_id")
    if not user_id:
        abort(403)
    user = await db.get(User, user_id)
    if user is None:
        abort(403)
    return user


@account_bp.get("/")
@require_role(UserRole.viewer)
async def account(error: str | None = None, status: int = 200):
    async with current_app.db_sessionmaker() as db:
        user = await _me(db)
    tz = formatting.zone(user.time_zone)
    return await render_template(
        "account/index.html", user=user, source=_SOURCES.get(user.auth_source, user.auth_source),
        zone_name=user.time_zone or "UTC", zone_label=formatting.tz_label(tz),
        zones=_zones_by_region(), error=error), status


@account_bp.post("/")
@require_role(UserRole.viewer)
async def account_save():
    from steward.core.audit import log_audit
    name = ((await request.form).get("time_zone") or "").strip()
    if name not in formatting.zone_names():
        return await account(f"{name or 'That'} is not a time zone Steward knows.", 400)
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            user = await _me(db)
            before = user.time_zone
            user.time_zone = name
    session["tz"] = name
    if before != name:
        await log_audit(current_app, user.id, user.username, "account.time_zone",
                        detail={"time_zone": name, "was": before or "UTC"})
    return redirect("/account/")


@account_bp.post("/time-zone/adopt")
@require_role(UserRole.viewer)
async def adopt_time_zone():
    """The browser's zone, saved for an account that has none yet: base.html
    sends it once, on the first page after a sign-in without one. A zone set
    on the Account page is never replaced. Answers whether it was saved."""
    name = ((await request.get_json(silent=True)) or {}).get("time_zone") or ""
    if name not in formatting.zone_names():
        return {"adopted": False}, 400
    async with current_app.db_sessionmaker() as db:
        async with db.begin():
            user = await _me(db)
            if user.time_zone is not None:
                return {"adopted": False}
            user.time_zone = name
    session["tz"] = name
    return {"adopted": True}