"""ESPresso Frame server: pulls photos from Immich, pre-processes them for
the panel, and serves the ESP32 a ready-to-display frame."""

from __future__ import annotations

import io
import logging
import random

import httpx
from fastapi import FastAPI, Form, HTTPException, Request
from fastapi.responses import HTMLResponse, Response
from fastapi.templating import Jinja2Templates
from PIL import Image

from . import config
from .image_pipeline import render_frame
from .immich_client import ImmichClient

logger = logging.getLogger(__name__)

app = FastAPI(title="ESPresso Frame Server")
templates = Jinja2Templates(directory="app/templates")

MIN_REFRESH_INTERVAL_S = 60
MAX_REFRESH_INTERVAL_S = 86400


@app.get("/health")
def health() -> dict:
    return {"status": "ok"}


@app.get("/frame/config")
def frame_config():
    """Device-facing settings, polled by the frame alongside its
    reachability check. Always returns 200 with current settings
    (defaults if nothing's been saved yet) -- no Immich-configured gate,
    since this doubles as the "is the server up" signal."""
    cfg = config.load()
    return {"refresh_interval_s": cfg.refresh_interval_s}


@app.get("/", response_class=HTMLResponse)
def index(request: Request):
    cfg = config.load()
    return templates.TemplateResponse("index.html", {"request": request, "cfg": cfg})


@app.get("/api/albums")
def api_albums():
    cfg = config.load()
    if not cfg.immich_url or not cfg.immich_api_key:
        raise HTTPException(400, "Immich URL/API key not configured yet")
    try:
        albums = ImmichClient(cfg.immich_url, cfg.immich_api_key).list_albums()
    except httpx.HTTPError as e:
        raise HTTPException(502, f"Could not reach Immich at {cfg.immich_url}: {e}") from e
    return [{"id": a["id"], "name": a["albumName"], "count": a.get("assetCount", 0)} for a in albums]


@app.post("/api/config")
def api_config_save(
    album_id: str = Form(""),
    order: str = Form("sequential"),
    refresh_interval_s: int = Form(3600),
    smart_crop_faces: bool = Form(True),
):
    # Immich URL/API key are env-var only (IMMICH_URL/IMMICH_API_KEY, see
    # docker-compose.yml.example) -- config.load() already applies them,
    # and this handler doesn't touch cfg.immich_url/immich_api_key at all,
    # so there's nothing here that could overwrite or clear them.
    cfg = config.load()
    if album_id != cfg.album_id:
        cfg.cursor = 0  # restart from the top of a newly selected album
    cfg.album_id = album_id
    cfg.order = order if order in ("sequential", "shuffle") else "sequential"
    cfg.refresh_interval_s = max(MIN_REFRESH_INTERVAL_S, min(MAX_REFRESH_INTERVAL_S, refresh_interval_s))
    cfg.smart_crop_faces = smart_crop_faces
    config.save(cfg)
    return {"status": "saved"}


@app.get("/frame/image")
def frame_image():
    cfg = config.load()
    if not cfg.immich_url or not cfg.immich_api_key:
        raise HTTPException(400, "Immich URL/API key not configured yet")
    if not cfg.album_id:
        raise HTTPException(400, "No album configured yet")

    client = ImmichClient(cfg.immich_url, cfg.immich_api_key)
    try:
        assets = client.list_album_assets(cfg.album_id)
    except httpx.HTTPError as e:
        raise HTTPException(502, f"Could not reach Immich at {cfg.immich_url}: {e}") from e

    if not assets:
        raise HTTPException(404, "Album has no photos")

    if cfg.order == "shuffle":
        asset = random.choice(assets)
    else:
        index = cfg.cursor % len(assets)
        asset = assets[index]
        cfg.cursor = (index + 1) % len(assets)
        config.save(cfg)

    try:
        jpeg_bytes = client.download_asset_preview(asset["id"])
    except httpx.HTTPError as e:
        raise HTTPException(502, f"Could not download asset from Immich: {e}") from e

    faces = None
    if cfg.smart_crop_faces:
        try:
            faces = client.get_asset_faces(asset["id"])
        except httpx.HTTPError as e:
            # A faces lookup hiccup shouldn't block showing a photo at
            # all -- just fall back to a plain center-crop this cycle.
            logger.warning("Could not fetch faces for asset %s: %s", asset["id"], e)

    source = Image.open(io.BytesIO(jpeg_bytes))
    frame_bytes = render_frame(source, faces=faces)

    return Response(content=frame_bytes, media_type="application/octet-stream")