// Pin one venue shell onto a look.
//
// The same shell-swap in three places: the filmstrip's `venueSel`, the venue
// gallery's venue picker, and the app's `?venueSel=`. Only the shell is
// forced — module/name/archetype. The VenueSpec population stays the census
// one (counts overlap between archetypes), so this is what makes a pinned
// preview the exact image the app reproduces, rather than a nearby one.

import { venues } from './registry.js';

/**
 * Force `look.venue` to render as the named venue.
 *
 * @param {object} look  LookSpec from generateLook (mutated in place)
 * @param {string} name  venue name, e.g. 'Ride'
 * @param {object} [opts]
 * @param {number} [opts.seed]  seed for a from-scratch spec (default 1)
 * @param {boolean} [opts.buildIfMissing]  build a neutral spec when the
 *   census produced no venue at all (the venue gallery does; the filmstrip
 *   keeps the no-venue video instead)
 * @returns {boolean} true when a venue is pinned afterwards
 */
export function pinVenueShell(look, name, { seed = 1, buildIfMissing = false } = {}) {
    if (!name || !look) return false;
    const picked = venues.find((v) => v.name === name);
    if (!picked) throw new Error(`unknown venue "${name}"`);
    if (!look.venue) {
        if (!buildIfMissing) return false;
        look.venue = {
            archetype: picked.archetype, name: picked.name, seed,
            shell: { kind: picked.archetype }, projection: { kind: 'screen' },
            population: { kind: 'scatter', count: 5, spread: 0.7, jitter: 0.25 },
            paletteMap: [0, 1, 2, 3],
            perSection: (look.sections || []).map(
                () => ({ light: 0.7, fog: 0.35, popMul: 0.65, reachMul: 0.85 })),
            venue: true, readsDepth: false, module: picked,
        };
        return true;
    }
    look.venue.module = picked;
    look.venue.name = picked.name;
    look.venue.archetype = picked.archetype;
    return true;
}