import { createBoxes } from '@/data/demo-data.js'
import { createItemStates } from '@/utils/picking-state.js'
import { stableTaskIdentity, stableTaskIdentityKey } from '@/utils/task-identity.js'

function clone(value) {
	return JSON.parse(JSON.stringify(value))
}

function createInitialState() {
	const boxes = createBoxes()
	return {
		boxes,
		currentBoxIndex: 0,
		itemStates: createItemStates(boxes[0].items),
		partialQuantities: {}, scannedBoxCodes: {}, boxDrafts: {}, completedBoxes: {}, scanValue: '', scanHistory: []
	}
}

let state = createInitialState()

const STORAGE_PREFIX = 'pda-picking-draft'

function storageAvailable() {
	return typeof uni !== 'undefined' && typeof uni.getStorageSync === 'function' && typeof uni.setStorageSync === 'function'
}

export function getPickingDraftKey(identity = {}) {
	const identityKey = stableTaskIdentityKey(identity)
	return identityKey ? `${STORAGE_PREFIX}:${identityKey}` : ''
}

function draftPayload(nextState, identity) {
	const value = stableTaskIdentity(identity)
	return {
		operatorId: value.operatorId,
		taskId: value.taskId,
		loadingPlanId: value.loadingPlanId,
		containerBookingId: value.containerBookingId,
		warehouseId: identity.warehouseId ?? null,
		currentBoxIndex: nextState.currentBoxIndex,
		itemStates: nextState.itemStates,
		partialQuantities: nextState.partialQuantities,
		scannedBoxCodes: nextState.scannedBoxCodes,
		boxDrafts: nextState.boxDrafts,
		completedBoxes: nextState.completedBoxes,
		scanHistory: nextState.scanHistory,
		updatedAt: new Date().toISOString()
	}
}

export function getPickingSession() {
	return clone(state)
}

export function savePickingSession(nextState, identity = {}) {
	state = clone(nextState)
	const key = getPickingDraftKey(identity)
	if (key && storageAvailable()) uni.setStorageSync(key, draftPayload(state, identity))
}

export function restorePickingSession(identity = {}) {
	const key = getPickingDraftKey(identity)
	if (!key || !storageAvailable()) return null
	const saved = uni.getStorageSync(key)
	const expected = stableTaskIdentity(identity)
	if (!saved || saved.operatorId !== expected.operatorId || saved.taskId !== expected.taskId || saved.loadingPlanId !== expected.loadingPlanId || saved.containerBookingId !== expected.containerBookingId) return null
	const restored = { ...state, ...clone(saved) }
	delete restored.operatorId
	delete restored.taskId
	delete restored.loadingPlanId
	delete restored.containerBookingId
	delete restored.warehouseId
	delete restored.updatedAt
	state = restored
	return clone(state)
}

export function clearPickingDraft(identity = {}) {
	const key = getPickingDraftKey(identity)
	if (key && typeof uni !== 'undefined' && typeof uni.removeStorageSync === 'function') uni.removeStorageSync(key)
}

export function resetPickingSession() {
	state = createInitialState()
}

export function getPickingOverview() {
	const completedCount = Object.values(state.completedBoxes).filter(Boolean).length
	return { boxes: clone(state.boxes), completedBoxes: { ...state.completedBoxes }, completedCount, pendingBoxCount: state.boxes.length - completedCount }
}