export const COMPLETION_PHASE = Object.freeze({
	READY: 'READY',
	SUBMITTING: 'SUBMITTING',
	RECONCILING: 'RECONCILING',
	PROCESSING: 'PROCESSING',
	FAILED: 'FAILED',
	COMPLETED: 'COMPLETED'
})

const PROCESSING_STATUSES = new Set(['COMPLETING', 'PROCESSING'])
const COMPLETED_STATUSES = new Set(['COMPLETED'])
const FAILED_STATUSES = new Set(['COMPLETION_FAILED'])

function normalizedStatus(value) {
	return String(value || '').trim().toUpperCase()
}

/**
 * Resolve already-normalized task/command facts into a UI phase. DTO field
 * extraction deliberately stays outside this module until the backend schema
 * is frozen.
 */
export function resolveCompletionPhase({ taskStatus, commandStatus, submitting = false, reconciling = false } = {}) {
	if (reconciling) return COMPLETION_PHASE.RECONCILING
	if (submitting) return COMPLETION_PHASE.SUBMITTING
	const statuses = [taskStatus, commandStatus].map(normalizedStatus)
	if (statuses.some((status) => COMPLETED_STATUSES.has(status))) return COMPLETION_PHASE.COMPLETED
	if (statuses.some((status) => FAILED_STATUSES.has(status))) return COMPLETION_PHASE.FAILED
	if (statuses.some((status) => PROCESSING_STATUSES.has(status))) return COMPLETION_PHASE.PROCESSING
	return COMPLETION_PHASE.READY
}

export function completionPresentation(phase, failureStage = '') {
	if (phase === COMPLETION_PHASE.SUBMITTING) return { label: '正在提交', action: '', blocked: true }
	if (phase === COMPLETION_PHASE.RECONCILING) return { label: '正在确认提交结果', action: '', blocked: true }
	if (phase === COMPLETION_PHASE.PROCESSING) return { label: '完成处理中', action: '', blocked: true }
	if (phase === COMPLETION_PHASE.COMPLETED) return { label: '装柜已完成', action: '', blocked: true }
	if (phase === COMPLETION_PHASE.FAILED) {
		return { label: failureStage ? `完成失败：${failureStage}` : '完成失败', action: '重试完成', blocked: true, retryable: true }
	}
	return { label: '待确认装柜', action: '确认装柜完成', blocked: false }
}

export function shouldReconcileCompletion(error = {}) {
	const code = normalizedStatus(error.code || error.errCode)
	return Boolean(error.network || error.timeout || code === 'TIMEOUT' || code === 'REQUEST_TIMEOUT')
}

/** 受理后立即查询真实任务，串行短轮询只等待终态，不重发完成命令。 */
export async function observeLoadingCompletion({ initialTask, readTask, isActive, onTask,
	intervalMs = 250, maxWaitMs = 10000, now = Date.now,
	wait = (delay) => new Promise((resolve) => setTimeout(resolve, delay)) }) {
	const started = now()
	let task = initialTask
	const phase = () => resolveCompletionPhase({ taskStatus: task?.taskStatus || task?.workflowStatus,
		commandStatus: task?.completionCommand?.status || task?.commandStatus })
	while (phase() === COMPLETION_PHASE.PROCESSING && isActive() && now() - started < maxWaitMs) {
		const latest = await readTask()
		if (!isActive()) return null
		if (!latest) throw new Error('服务端未返回装柜完成状态，请刷新任务')
		task = latest
		onTask(task)
		if (phase() !== COMPLETION_PHASE.PROCESSING) break
		const remaining = maxWaitMs - (now() - started)
		if (remaining > 0) await wait(Math.min(intervalMs, remaining))
	}
	return isActive() ? task : null
}

/**
 * A retry keeps the original operationId and the exact accepted request facts.
 * expectedTaskVersion participates in requestHash and must not be refreshed.
 */
export function refreshCompletionAttempt(previousAttempt = {}, latestFacts = {}) {
	if (!previousAttempt.operationId) throw new Error('缺少原完成操作标识，不能安全重试')
	const expectedTaskVersion = previousAttempt.expectedTaskVersion
	if (expectedTaskVersion === null || expectedTaskVersion === undefined) throw new Error('缺少服务端最新任务版本，不能安全重试')
	return {
		...previousAttempt,
		...latestFacts,
		operationId: previousAttempt.operationId,
		expectedTaskVersion: Number(expectedTaskVersion)
	}
}