/**
 * Pure builders for the Publish preview confirmation screen.
 * Resolves taxonomy ids → display names; never invents fields beyond the slab.
 */
import { decodeName } from '../decodeName';
import type { PhotoRow, Slab, Taxonomy, TaxAttribute, TaxCategory, TaxTag } from '../../api/slabs';

export interface PreviewPhoto {
  id: string;
  url: string;
  role: 'calibration' | 'overlay' | 'batch';
  /** Leftmost (seq order) = Woo cover. */
  primary: boolean;
}

export interface PreviewFact {
  label: string;
  value: string;
}

export interface PublishPreviewModel {
  photos: PreviewPhoto[];
  sku: string;
  title: string;
  price: string;
  facts: PreviewFact[];
  shortDescription: string;
  description: string;
}

const fmt1 = (v: number) => {
  const s = v.toFixed(1);
  return s.endsWith('.0') ? s.slice(0, -2) : s;
};
const fmt2 = (v: number) => v.toFixed(2);

function catName(cats: TaxCategory[], id: number | null | undefined): string {
  if (id == null) return '—';
  const c = cats.find((x) => x.id === id);
  return c ? decodeName(c.name) : `#${id}`;
}

function termName(attrs: TaxAttribute[], id: number | null | undefined): string {
  if (id == null) return '—';
  for (const a of attrs) {
    const t = a.terms.find((x) => x.id === id);
    if (t) return decodeName(t.name);
  }
  return `#${id}`;
}

function attrTermsByName(attrs: TaxAttribute[], name: string): { id: number; name: string }[] {
  const attr = attrs.find((a) => a.name.toLowerCase() === name.toLowerCase());
  return (attr?.terms ?? []).map((t) => ({ id: t.id, name: decodeName(t.name) }));
}

function namesForIds(
  ids: number[],
  lookup: (id: number) => string | null,
): string {
  if (!ids.length) return '—';
  return ids.map((id) => lookup(id) ?? `#${id}`).join(', ');
}

function tagName(tags: TaxTag[], id: number): string | null {
  const t = tags.find((x) => x.id === id);
  return t ? decodeName(t.name) : null;
}

/** Widths as "min–max (avg)" inches, matching Review dims language. */
export function formatWidths(slab: Pick<Slab, 'width_min_in' | 'width_max_in' | 'width_avg_in'>): string {
  return `${fmt1(slab.width_min_in)}–${fmt1(slab.width_max_in)}″ (avg ${fmt1(slab.width_avg_in)}″)`;
}

export function buildPublishPreviewModel(
  slab: Slab,
  tax: Taxonomy | null,
  photos: PhotoRow[],
  urlFor: (photoId: string, kind: 'original' | 'processed') => string,
): PublishPreviewModel {
  const cats = tax?.categories ?? [];
  const attrs = tax?.attributes ?? [];
  const tags = tax?.tags ?? [];

  const figureTerms = attrTermsByName(attrs, 'figure');
  const figureLookup = (id: number) => {
    const t = figureTerms.find((x) => x.id === id);
    return t ? t.name : null;
  };

  const ordered = [...photos].sort((a, b) => a.seq - b.seq);
  const previewPhotos: PreviewPhoto[] = ordered.map((p, i) => ({
    id: p.id,
    url: urlFor(p.id, p.has_processed ? 'processed' : 'original'),
    role: p.role ?? 'batch',
    primary: i === 0,
  }));

  const woodNames = namesForIds(slab.wood_category_ids ?? [], (id) => {
    const c = cats.find((x) => x.id === id);
    return c ? decodeName(c.name) : null;
  });

  const facts: PreviewFact[] = [
    { label: 'Species', value: catName(cats, slab.species_id) },
    { label: 'Wood categories', value: woodNames },
    { label: 'Edge', value: termName(attrs, slab.edge_type_term_id) },
    {
      label: 'Figure',
      value: namesForIds(slab.figure_term_ids ?? [], figureLookup),
    },
    { label: 'Grade', value: termName(attrs, slab.grade_term_id) },
    { label: 'Moisture', value: termName(attrs, slab.moisture_term_id) },
    {
      label: 'Features',
      value: namesForIds(slab.feat_tag_ids ?? [], (id) => tagName(tags, id)),
    },
    { label: 'Length', value: `${fmt1(slab.length_in)}″` },
    { label: 'Widths', value: formatWidths(slab) },
    { label: 'Thickness', value: `${fmt1(slab.thickness_in)}″` },
    { label: 'Bdft', value: fmt2(slab.bdft) },
  ];

  return {
    photos: previewPhotos,
    sku: slab.sku || '—',
    title: slab.title || '—',
    price: slab.price != null ? `$${slab.price.toFixed(2)}` : '—',
    facts,
    shortDescription: (slab.short_description ?? '').trim() || '—',
    description: (slab.description ?? '').trim() || '—',
  };
}