"""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 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

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


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


@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(
    immich_url: str = Form(""),
    immich_api_key: str = Form(""),
    album_id: str = Form(""),
    order: str = Form("sequential"),
):
    cfg = config.load()
    cfg.immich_url = immich_url.strip()
    cfg.immich_api_key = immich_api_key.strip()
    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"
    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

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

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