import type { TalkingHeadProject, TalkingHeadSnapshot } from "./contracts.ts";

export interface MediaTimelineOperationInput {
	kind: "timeline";
	segments: Array<{
		id: string;
		sourcePath: string;
		sourceStartSeconds: number;
		sourceEndSeconds: number;
	}>;
	overlays: Array<{
		id: string;
		sourcePath: string;
		outputStartSeconds: number;
		outputEndSeconds: number;
		sourceStartSeconds?: number;
		fit: "cover" | "contain";
		audio: "keep-primary";
	}>;
	musicTrack?: {
		sourcePath: string;
		sourceStartSeconds: number;
		sourceEndSeconds: number;
		outputStartSeconds: number;
		outputEndSeconds: number;
		playback: "trim" | "loop";
		fadeInSeconds: number;
		fadeOutSeconds: number;
		ducking: "dialogue-sidechain";
		mix: {
			method: "ebu-r128-dialogue-relative";
			dialogueAnalysisPath: string;
			musicAnalysisPath: string;
			targetMusicBelowDialogueLu: number;
			maxTruePeakDbtp: number;
		};
	};
}

function seconds(milliseconds: number): number {
	return milliseconds / 1_000;
}

export function toMediaTimelineOperation(
	project: TalkingHeadProject,
	snapshot: TalkingHeadSnapshot,
	options: { allowDraft?: boolean } = {},
): MediaTimelineOperationInput {
	if (snapshot.editorialStatus !== "content-reviewed" && !options.allowDraft) {
		throw new Error("A-roll has not completed full editorial review; use an explicitly labeled preview or submit an editorial plan");
	}
	return {
		kind: "timeline",
		segments: snapshot.aroll.map((segment) => ({
			id: segment.id,
			sourcePath: project.source.path,
			sourceStartSeconds: seconds(segment.sourceStartMs),
			sourceEndSeconds: seconds(segment.sourceEndMs),
		})),
		overlays: snapshot.broll.map((placement) => ({
			id: placement.id,
			sourcePath: placement.assetPath,
			outputStartSeconds: seconds(placement.outputStartMs),
			outputEndSeconds: seconds(placement.outputEndMs),
			...(placement.assetStartMs === undefined ? {} : { sourceStartSeconds: seconds(placement.assetStartMs) }),
			fit: placement.fit,
			audio: placement.audio,
		})),
		...(snapshot.bgm ? {
			musicTrack: {
				sourcePath: snapshot.bgm.assetPath,
				sourceStartSeconds: seconds(snapshot.bgm.sourceStartMs),
				sourceEndSeconds: seconds(snapshot.bgm.sourceEndMs),
				outputStartSeconds: seconds(snapshot.bgm.outputStartMs),
				outputEndSeconds: seconds(snapshot.bgm.outputEndMs),
				playback: snapshot.bgm.playback,
				fadeInSeconds: seconds(snapshot.bgm.fadeInMs),
				fadeOutSeconds: seconds(snapshot.bgm.fadeOutMs),
				ducking: snapshot.bgm.ducking,
				mix: {
					method: snapshot.bgm.mix.method,
					dialogueAnalysisPath: snapshot.bgm.mix.dialogueAnalysisPath,
					musicAnalysisPath: snapshot.bgm.mix.musicAnalysisPath,
					targetMusicBelowDialogueLu: snapshot.bgm.mix.targetMusicBelowDialogueLu,
					maxTruePeakDbtp: snapshot.bgm.mix.maxTruePeakDbtp,
				},
			},
		} : {}),
	};
}

export function timelineDelivery(project: TalkingHeadProject, snapshot: TalkingHeadSnapshot): {
	editorialStatus: NonNullable<TalkingHeadSnapshot["editorialStatus"]>;
	listeningStatus: "pending";
	mediaOperation?: MediaTimelineOperationInput;
	previewMediaOperation?: MediaTimelineOperationInput;
} {
	const operation = toMediaTimelineOperation(project, snapshot, { allowDraft: true });
	return {
		editorialStatus: snapshot.editorialStatus ?? "draft",
		listeningStatus: "pending" as const,
		...(snapshot.editorialStatus === "content-reviewed" ? { mediaOperation: operation } : { previewMediaOperation: operation }),
	};
}