import { NextResponse } from 'next/server'
import { getCatalog } from '@/lib/catalog-cache'
import { readOverrides } from '@/lib/overrides'
import type { CatalogItem } from '@/data/mock-catalog'

function applyOverrides(items: CatalogItem[]): CatalogItem[] {
  const overrides = readOverrides()

  return items
    .map((item) => {
      const ov = overrides[item.id]
      if (!ov) return item
      return {
        ...item,
        featured:       ov.featured              ?? item.featured,
        category:       ov.categoryOverride      ?? item.category,
        categoryLabel:  ov.categoryLabelOverride ?? item.categoryLabel,
        categories:     ov.categoryOverride
          ? [ov.categoryOverride,      ...(item.categories     ?? [item.category]).slice(1)]
          : (item.categories     ?? [item.category]),
        categoryLabels: ov.categoryLabelOverride
          ? [ov.categoryLabelOverride, ...(item.categoryLabels ?? [item.categoryLabel]).slice(1)]
          : (item.categoryLabels ?? [item.categoryLabel]),
        showColors:    ov.showColors     != null ? ov.showColors : item.showColors,
        colorMin:      ov.colorMin       ?? item.colorMin,
        colorMax:      ov.colorMax       !== undefined ? ov.colorMax : item.colorMax,
        chromeSurchargePerColor: ov.chromeSurchargePerColor ?? item.chromeSurchargePerColor,
        disabledColors: ov.disabledColors?.length ? ov.disabledColors : item.disabledColors,
        quantityUnit:  ov.quantityUnit ?? item.quantityUnit,
        description:   ov.descriptionOverride   ?? item.description,
        variations:    item.variations
          .filter((v) => !(ov.hiddenVariationIds ?? []).includes(v.id)),
        modifiers:     item.modifiers
          .filter((m) => !(ov.hiddenModifierIds ?? []).includes(m.id))
          .map((m) => {
            const minOverride = ov.modifierMinSelected?.[m.id]
            return minOverride !== undefined ? { ...m, minSelected: minOverride } : m
          }),
      }
    })
    .filter((item) => !(overrides[item.id]?.hidden))
    .sort((a, b) => {
      const featDiff = (b.featured ? 1 : 0) - (a.featured ? 1 : 0)
      if (featDiff !== 0) return featDiff
      const aOrder = overrides[a.id]?.sortOrder ?? 0
      const bOrder = overrides[b.id]?.sortOrder ?? 0
      return aOrder - bOrder
    })
}

export async function GET() {
  try {
    const { items: rawItems } = await getCatalog()
    const items = applyOverrides(rawItems)
    return NextResponse.json({ items, source: 'square' })
  } catch (err) {
    console.error('[catalog] error:', err)
    return NextResponse.json({ items: [], source: 'error' }, { status: 500 })
  }
}