"""The per-frame HTML pages: Photos (/frames/{id}), Configuration,
Calendar, and Stats tabs, all inside the sidebar app shell. Data loading
happens client-side against /api/frames/{id}/... (routers/api_frames.py);
these routes just authorize and render the scaffold."""

from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, Request
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.templating import Jinja2Templates
from sqlalchemy import select
from sqlalchemy.orm import Session

from ..auth import can_view_frame, current_user
from ..calendar_render import CALENDAR_VIEW_LABELS
from ..db import get_db
from ..image_pipeline import (
    DEFAULT_PALETTE_RGB,
    DISPLAY_MODE_LABELS,
    PALETTE_LABELS,
    palette_to_hex,
)
from ..models import Frame, FrameCalendar, User, UserFrame
from ..quiet_hours import ALL_TIMEZONES
from .common import shell_context

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


def _frame_page(request: Request, db: Session, frame_id: int, template: str, tab: str, **extra):
    user = current_user(request, db)
    if user is None:
        return RedirectResponse(f"/login?next=/frames/{frame_id}", status_code=303)
    frame = db.get(Frame, frame_id)
    if frame is None or not can_view_frame(db, user, frame):
        raise HTTPException(404, "No such frame")
    ctx = shell_context(request, db, user, active_frame=frame)
    ctx.update({"frame": frame, "active_tab": tab, **extra})
    return templates.TemplateResponse(template, ctx)


@router.get("/frames/{frame_id}", response_class=HTMLResponse)
def frame_photos_page(frame_id: int, request: Request, db: Session = Depends(get_db)):
    return _frame_page(
        request, db, frame_id, "frame_photos.html", "photos",
        display_mode_labels=DISPLAY_MODE_LABELS,
    )


def _user_available_calendars(user: User) -> list[dict]:
    """This user's full set of calendars available to add to any frame:
    the single ICS subscription (if set) plus every CalDAV calendar last
    discovered from Settings' "Discover calendars" button. Doesn't hit
    the network -- reads the cached list a user refreshes themselves."""
    calendars = []
    if user.calendar_ics_url:
        calendars.append({"key": "ics", "label": "My calendar (ICS)"})
    for c in (user.calendar_caldav_calendars or []):
        calendars.append({"key": f"caldav:{c['href']}", "label": c.get("display_name") or "Calendar"})
    return calendars


def _calendar_users_for_frame(db: Session, frame_id: int, viewer_id: int | None) -> list[dict]:
    """Per-linked-user calendar list for the Calendar tab's "Included
    calendars" section. The viewer's own row lists EVERY calendar they
    have available, each with a full add/remove toggle; every other
    linked user's row lists ONLY the calendars they've already included
    (mute-only for the viewer -- see api_frames.py's api_calendar_select:
    only a calendar's owner may turn it on, but anyone linked to the
    frame may turn one off)."""
    users = db.execute(
        select(User).join(UserFrame, UserFrame.user_id == User.id)
        .where(UserFrame.frame_id == frame_id).order_by(User.username)
    ).scalars().all()
    included_by_user: dict[int, list[FrameCalendar]] = {}
    for fc in db.execute(select(FrameCalendar).where(FrameCalendar.frame_id == frame_id)).scalars().all():
        included_by_user.setdefault(fc.user_id, []).append(fc)

    result = []
    for u in users:
        is_self = u.id == viewer_id
        if is_self:
            own_rows = {fc.calendar_key: fc for fc in included_by_user.get(u.id, [])}
            calendars = [
                {**c, "included": own_rows[c["key"]].included if c["key"] in own_rows else False,
                 "color_index": own_rows[c["key"]].color_index if c["key"] in own_rows else None}
                for c in _user_available_calendars(u)
            ]
        else:
            calendars = [
                {"key": fc.calendar_key, "label": fc.calendar_label, "included": True}
                for fc in included_by_user.get(u.id, []) if fc.included
            ]
        result.append({
            "user_id": u.id, "display_name": u.display_name or u.username,
            "is_self": is_self, "calendars": calendars,
        })
    return result


def _tasks_source_info(db: Session, frame: Frame) -> dict | None:
    """Whose CalDAV calendar this frame's week-view task list currently
    pulls from, and its label -- for showing "using <name>'s Chores
    list" to everyone linked, not just whoever set it. None if no
    source is configured."""
    if not frame.calendar_tasks_user_id or not frame.calendar_tasks_calendar_key:
        return None
    user = db.get(User, frame.calendar_tasks_user_id)
    if user is None:
        return None
    label = frame.calendar_tasks_calendar_key
    for c in (user.calendar_caldav_calendars or []):
        if f"caldav:{c['href']}" == frame.calendar_tasks_calendar_key:
            label = c.get("display_name") or label
            break
    return {"user_id": user.id, "display_name": user.display_name or user.username, "label": label}


@router.get("/frames/{frame_id}/config", response_class=HTMLResponse)
def frame_config_page(frame_id: int, request: Request, db: Session = Depends(get_db)):
    return _frame_page(
        request, db, frame_id, "frame_config.html", "config",
        timezones=ALL_TIMEZONES,
        palette_labels=PALETTE_LABELS,
        default_palette_rgb=DEFAULT_PALETTE_RGB,
        palette_to_hex=palette_to_hex,
    )


WEEK_START_LABELS = {0: "Monday", 1: "Tuesday", 2: "Wednesday", 3: "Thursday",
                     4: "Friday", 5: "Saturday", 6: "Sunday"}


@router.get("/frames/{frame_id}/calendar", response_class=HTMLResponse)
def frame_calendar_page(frame_id: int, request: Request, db: Session = Depends(get_db)):
    viewer = current_user(request, db)
    frame = db.get(Frame, frame_id)
    viewer_task_calendars = []
    if viewer is not None and frame is not None and can_view_frame(db, viewer, frame):
        viewer_task_calendars = [c for c in _user_available_calendars(viewer) if c["key"].startswith("caldav:")]
    return _frame_page(
        request, db, frame_id, "frame_calendar.html", "calendar",
        calendar_views=CALENDAR_VIEW_LABELS,
        calendar_users=_calendar_users_for_frame(db, frame_id, viewer.id if viewer else None),
        week_start_labels=WEEK_START_LABELS,
        calendar_color_labels=PALETTE_LABELS,
        default_palette_rgb=DEFAULT_PALETTE_RGB,
        palette_to_hex=palette_to_hex,
        viewer_task_calendars=viewer_task_calendars,
        tasks_source=_tasks_source_info(db, frame) if frame is not None else None,
    )


@router.get("/frames/{frame_id}/stats", response_class=HTMLResponse)
def frame_stats_page(frame_id: int, request: Request, db: Session = Depends(get_db)):
    return _frame_page(request, db, frame_id, "frame_stats.html", "stats")