export const ITEM_STATUS = Object.freeze({
	PENDING: 'pending',
	PICKED: 'picked',
	PARTIAL: 'partial',
	SKIPPED: 'skipped'
})

export function createItemStates(items) {
	return items.reduce((states, item) => {
		states[item.id] = ITEM_STATUS.PENDING
		return states
	}, {})
}

export function getPickSummary(items, states) {
	const summary = {
		total: items.length,
		picked: 0,
		partial: 0,
		skipped: 0,
		pending: 0
	}

	items.forEach((item) => {
		const status = states[item.id] || ITEM_STATUS.PENDING
		summary[status] += 1
	})

	summary.processed = summary.picked + summary.partial + summary.skipped
	summary.progress = summary.total
		? Math.round(summary.processed / summary.total * 100)
		: 0
	summary.canSubmit = summary.total > 0 && (
		summary.pending === 0 || summary.picked > 0 || summary.partial > 0
	)
	summary.buttonText = '提交拣货完成'

	return summary
}

export function submitStates(items, states) {
	const nextStates = { ...states }
	const autoSkippedIds = []

	items.forEach((item) => {
		const status = nextStates[item.id] || ITEM_STATUS.PENDING
		if (status === ITEM_STATUS.PENDING) {
			nextStates[item.id] = ITEM_STATUS.SKIPPED
			autoSkippedIds.push(item.id)
		}
	})

	return {
		states: nextStates,
		autoSkippedIds
	}
}

export function classifyScan(items, states, scanCode) {
	const item = items.find((entry) => entry.sku === scanCode) || null
	if (!item) return { type: 'unknown', item: null }

	const status = states[item.id] || ITEM_STATUS.PENDING
	if (status === ITEM_STATUS.PENDING) return { type: 'pending', item }

	return { type: 'processed', item, status }
}