export interface ProgressValue {
	current: number
	total: number
	secondary?: ProgressValue | null
}

export interface ProgressSnapshot {
	phase: string
	progress?: ProgressValue | null
	parallel?: {
		phase: string
		current: number
		total: number
	} | null
}

export interface ProgressTextSnapshot extends ProgressSnapshot {
	status: string
	details?: { type: string; step?: string } | null
	summary: {
		files_completed: number
		files_total?: number | null
		bytes_downloaded: number
		bytes_total?: number | null
	}
}

export type InstallProgressTextSource =
	| { type: 'required_files' | 'phase' }
	| { type: 'bytes' | 'items'; current: number; total: number }

export function effectiveInstallProgress(
	snapshot: ProgressSnapshot,
): ProgressValue | null | undefined {
	if (snapshot.phase === 'downloading_content' && snapshot.progress?.secondary) {
		return snapshot.progress.secondary
	}

	return snapshot.progress
}

export function effectiveParallelProgress(
	snapshot: ProgressSnapshot,
): ProgressValue | null | undefined {
	if (!snapshot.parallel) return null
	return {
		current: snapshot.parallel.current,
		total: snapshot.parallel.total,
	}
}

export function hasDeterminateInstallProgress(
	progress: ProgressValue | null | undefined,
): progress is ProgressValue {
	return (
		progress != null &&
		Number.isFinite(progress.current) &&
		Number.isFinite(progress.total) &&
		progress.current >= 0 &&
		progress.total > 0
	)
}

export function installProgressFraction(snapshot: ProgressSnapshot): number | null {
	const progress = effectiveInstallProgress(snapshot)
	if (!hasDeterminateInstallProgress(progress)) return null

	return Math.max(0, Math.min(1, progress.current / progress.total))
}

export function installProgressTextSource(
	snapshot: ProgressTextSnapshot,
): InstallProgressTextSource {
	if (snapshot.status === 'waiting_for_user') return { type: 'required_files' }

	const isContentDownload = snapshot.phase === 'downloading_content'
	const isByteDownload =
		snapshot.phase === 'downloading_pack_file' ||
		snapshot.phase === 'downloading_minecraft' ||
		(snapshot.phase === 'preparing_java' &&
			snapshot.details?.type === 'java' &&
			snapshot.details.step === 'downloading')
	const progress = effectiveInstallProgress(snapshot)
	if (hasDeterminateInstallProgress(progress)) {
		if (isContentDownload) {
			return {
				type: snapshot.progress?.secondary ? 'bytes' : 'items',
				current: progress.current,
				total: progress.total,
			}
		}
		if (isByteDownload) {
			return { type: 'bytes', current: progress.current, total: progress.total }
		}
	}

	if (snapshot.progress != null) return { type: 'phase' }

	if ((isContentDownload || isByteDownload) && snapshot.summary.bytes_total) {
		return {
			type: 'bytes',
			current: snapshot.summary.bytes_downloaded,
			total: snapshot.summary.bytes_total,
		}
	}
	if (isContentDownload && snapshot.summary.files_total) {
		return {
			type: 'items',
			current: snapshot.summary.files_completed,
			total: snapshot.summary.files_total,
		}
	}

	return { type: 'phase' }
}