import { t } from '@/i18n'
import type { MediaItem } from '@/composables/useMedia'
import { formatDimensions, formatSize } from '@/lib/mediaFormat'

export interface DuplicateGroup {
	hash: string
	copies: MediaItem[]
	suggested: MediaItem
	header: string
}

function byAge(first: MediaItem, second: MediaItem) {
	return Date.parse(first.created_at) - Date.parse(second.created_at) || first.id - second.id
}

function byPreference(first: MediaItem, second: MediaItem) {
	return second.used_in - first.used_in || byAge(first, second)
}

export function groupHeader(copies: MediaItem[]) {
	const [first] = copies
	return t('{0} identical images · {1} each · {2}', [
		copies.length,
		formatSize(first!.size),
		formatDimensions(first!.width, first!.height),
	])
}

export function groupDuplicates(items: MediaItem[]): DuplicateGroup[] {
	const byHash = new Map<string, MediaItem[]>()
	for (const item of items) {
		byHash.set(item.sha256, [...(byHash.get(item.sha256) ?? []), item])
	}
	return [...byHash.entries()]
		.filter(([, copies]) => copies.length > 1)
		.map(([hash, copies]) => {
			const sorted = [...copies].sort(byPreference)
			return {
				hash,
				copies: sorted,
				suggested: sorted[0]!,
				get header() {
					return groupHeader(sorted)
				},
			}
		})
		.sort((first, second) => byAge(first.suggested, second.suggested))
}

export function mergeArticleCount(copies: MediaItem[], keepId: number) {
	return copies
		.filter((copy) => copy.id !== keepId)
		.reduce((total, copy) => total + copy.used_in, 0)
}