import re
from pathlib import Path

from flask import Blueprint, current_app, redirect, render_template, request
from app.immich import ImmichClient
from app.state import TripState, Photo, load_state, save_state

bp = Blueprint("albums", __name__)


def _sanitise_slug(s: str) -> str:
    s = s.strip().lower()
    s = re.sub(r'[^a-z0-9-]+', '-', s)
    return s.strip('-')


def _client():
    return ImmichClient(current_app.config["IMMICH_URL"],
                        current_app.config["IMMICH_API_KEY"])


@bp.get("/")
def index():
    try:
        albums = _client().list_albums()
        error = None
    except ConnectionError as e:
        albums = []
        error = str(e)
    state_dir = Path(current_app.config["STATE_DIR"])
    for album in albums:
        album["has_state"] = (state_dir / f"{album['id']}.json").exists()
    return render_template("phase1.html", albums=albums, error=error,
                           current_phase="", album_id=None,
                           phase_stale=[], notes_content="")


@bp.post("/select")
def select():
    album_ids = request.form.getlist("album_ids[]")
    grav_trip_slug = _sanitise_slug(request.form["grav_trip_slug"])
    start_over = request.form.get("start_over") == "1"

    if len(album_ids) == 1:
        primary_id = album_ids[0]
    else:
        primary_id = "__merged__" + "_".join(sorted(album_ids))

    existing = load_state(primary_id, current_app)
    if existing and not start_over:
        return redirect(f"/{existing.phase}?album_id={primary_id}")

    # Fetch and merge assets, deduplicating by asset ID
    all_assets = {}
    album_name_parts = []
    for aid in album_ids:
        album = _client().get_album(aid)
        album_name_parts.append(album["albumName"])
        for asset in album["assets"]:
            if asset["id"] not in all_assets:
                all_assets[asset["id"]] = asset

    photos = [
        Photo(id=a["id"], original_filename=a["originalFileName"],
              local_datetime=a["localDateTime"])
        for a in sorted(all_assets.values(), key=lambda x: x["localDateTime"])
    ]
    for i, p in enumerate(photos):
        p.order = i

    state = TripState(
        album_id=primary_id,
        album_name=", ".join(album_name_parts),
        grav_trip_slug=grav_trip_slug,
        photos=photos,
    )
    save_state(state, current_app)
    return redirect(f"/triage?album_id={primary_id}")