"""Calendar widget: merged-event agenda/week/month view into the
widget's own region -- the widget-system analogue of routers/device.py's
old _render_calendar_mode/_advance_calendar_mode/_back_calendar_mode.

render() builds directly at whatever target box it's asked for --
calendar_render.py's layout math picks from discrete size tiers (see
its own _size_tier) rather than always laying out at full panel size and
resizing after the fact, so a small placed calendar widget gets an
actually-legible small-size layout instead of a shrunk-down full-size
one.

"Photo inlay" (calendar mode's old half-and-half photo split) has no
widget-system equivalent -- place an independent photo widget alongside
instead; arbitrary placement is strictly more flexible than one fixed
split ever was."""

from __future__ import annotations

from PIL import Image
from sqlalchemy.orm import Session

from zoneinfo import ZoneInfo

from ..calendar_render import _build
from ..db import widget_locked
from ..models import CalendarWidgetConfig, Frame, Widget
from ..routers.common import (
    get_or_refresh_calendar_events_for_widget,
    get_or_refresh_weather_for_widget,
)

ACTION_LABELS = {"advance": "Next period", "back": "Previous period"}


def render(db: Session, frame: Frame, widget: Widget, target_w: int, target_h: int,
          is_normal_wake: bool = True) -> Image.Image:
    """is_normal_wake=True (an ordinary /frame/image GET, not a button
    press) resets browse_offset back to "today" if it had drifted --
    mirrors the old _render_calendar_mode's identical behavior. A button
    press explicitly moved the browse position on purpose, so it passes
    is_normal_wake=False to render its own already-updated offset instead
    of immediately snapping back to 0."""
    if is_normal_wake:
        with widget_locked(db, frame.id, widget.id) as (_, _, locked_cfg):
            if locked_cfg.browse_offset != 0:
                locked_cfg.browse_offset = 0

    cfg = db.get(CalendarWidgetConfig, widget.id)
    events, fetch_summary = get_or_refresh_calendar_events_for_widget(db, frame, widget)
    weather_cities = get_or_refresh_weather_for_widget(db, frame, widget) if cfg.weather_enabled else None

    if cfg.render_style == "modern":
        # Local import: html_render pulls in Playwright, a real headless-
        # Chromium dependency -- every other widget type, and this one's
        # own classic path, should never pay for it.
        from .. import calendar_html_render

        tz = ZoneInfo(frame.timezone) if frame.timezone else ZoneInfo("UTC")
        return calendar_html_render.build(
            events, cfg.view, cfg.browse_offset, target_w, target_h, tz, cfg.week_start, frame.palette_rgb,
            weather_cities, cfg.weather_units, cfg.week_days, cfg.week_layout, cfg.week_start_offset,
            frame.theme,
        )

    return _build(
        events, view=cfg.view, browse_offset=cfg.browse_offset, target_w=target_w, target_h=target_h,
        timezone=frame.timezone, fetch_summary=fetch_summary, week_start=cfg.week_start,
        palette_rgb=frame.palette_rgb, weather_cities=weather_cities, weather_units=cfg.weather_units,
        week_days=cfg.week_days, week_layout=cfg.week_layout,
        week_start_offset=cfg.week_start_offset,
    )


def _advance(db: Session, frame: Frame, widget: Widget) -> None:
    with widget_locked(db, frame.id, widget.id) as (_, _, cfg):
        cfg.browse_offset += 1


def _back(db: Session, frame: Frame, widget: Widget) -> None:
    with widget_locked(db, frame.id, widget.id) as (_, _, cfg):
        cfg.browse_offset -= 1


ACTIONS = {"advance": _advance, "back": _back}