import { ANATOMY_FACE, CHAPTER_FACE } from "#configuration/constants/vocabulary.constants";
import type { ReferenceContent, ReferenceTarget } from "#types/reference.types";
import { chapterOf, payloadOfHref } from "#domain/converters/reference.converter";
import { ANCHOR_PREFIX } from "#configuration/constants/document.constants";
import { loadPayload } from "#core/loaders/payload.loader";
import { loadReferences } from "#assets/reference.generated";

const fragmentOf = function fragmentOf(href: string): string {
    return href.slice(href.indexOf(ANCHOR_PREFIX) + ANCHOR_PREFIX.length);
};

const loadContent = async function loadContent(
    target: ReferenceTarget,
    href: string,
): Promise<ReferenceContent | null> {
    if (target.face === CHAPTER_FACE) {
        const chapter = chapterOf(await loadPayload(payloadOfHref(href)), fragmentOf(href));
        return chapter === null ? null : { chapter, kind: "chapter" };
    }
    if (target.face === ANATOMY_FACE) {
        const { anatomyReference } = await import("#domain/loaders/anatomy.loader");
        const record = anatomyReference(fragmentOf(href));
        return record === null ? null : { kind: "record", record };
    }
    const index = await loadReferences(target.face);
    const record = index?.[target.ref];
    return record === undefined ? null : { kind: "record", record };
};

export const loadReference = async function loadReference(
    target: ReferenceTarget,
    href: string,
): Promise<ReferenceContent | null> {
    const content = await loadContent(target, href);
    if (content === null) {
        return null;
    }
    const { withEvidence } = await import("#domain/loaders/evidence.loader");
    return withEvidence(target, content);
};