import type { BobbinContext, XrpcRequestInit } from "./client";
import type { Nsid } from "@atcute/lexicons/syntax";
import { INVALID_HANDLE, type MiniDoc } from "./identity";
import { jsonPost } from "./_request";
import { didFromUri, rkeyFromUri } from "./uri";

// payload types, also the keys payloads land under in the data sidecar
export const TYPE_COUNT = "sh.tangled.query.enrichResponse#count";
export const TYPE_VIEWER = "sh.tangled.query.enrichResponse#viewer";
export const TYPE_MINIDOC = "blue.microcosm.identity.resolveMiniDoc";

export type PayloadType = typeof TYPE_COUNT | typeof TYPE_VIEWER | typeof TYPE_MINIDOC;

export type RecordPath = string & {};
export type EnvelopePath = ".repo" | ".collection" | ".rkey" | ".";
export type LinkSource = `${Nsid}:${RecordPath | EnvelopePath}`;

// a descriptor is also the key its payload reads back under, so the readers
// take the whole descriptor, a request and its reads can't drift apart
export interface LinkDescriptor<T extends PayloadType = PayloadType> {
	source: LinkSource;
	type: T;
	targets?: RecordPath[];
}

export type CountDescriptor = LinkDescriptor<typeof TYPE_COUNT>;
export type ViewerDescriptor = LinkDescriptor<typeof TYPE_VIEWER>;
export type DocDescriptor = LinkDescriptor<typeof TYPE_MINIDOC>;

// data[ref][source][type] = payload, payload shape depends on the type
export type Sidecar = Record<string, Record<string, Record<string, unknown>>>;

export interface Enriched<O> {
	output: O;
	data: Sidecar;
}

export interface EnrichRequest {
	xrpc: string;
	params?: Record<string, unknown>;
	enrich: LinkDescriptor[];
	viewer?: string;
}

export const target = <T extends PayloadType>(
	descriptor: LinkDescriptor<T>,
	targets: RecordPath[]
): LinkDescriptor<T> => ({ ...descriptor, targets });

export const targetAll = <T extends PayloadType>(
	descriptors: LinkDescriptor<T>[],
	targets: RecordPath[]
): LinkDescriptor<T>[] => descriptors.map((descriptor) => target(descriptor, targets));

// bobbin rejects viewer payloads with no viewer, so a logged-out request drops
// them here instead of at every call site
export const enrich = <O>(
	ctx: BobbinContext,
	req: EnrichRequest,
	init?: XrpcRequestInit
): Promise<Enriched<O>> =>
	jsonPost<Enriched<O>>(
		ctx,
		"sh.tangled.query.enrichResponse",
		{
			...req,
			enrich: req.viewer
				? req.enrich
				: req.enrich.filter((descriptor) => descriptor.type !== TYPE_VIEWER)
		},
		init
	);

const payloadOf = (
	data: Sidecar,
	ref: string | undefined,
	{ source, type }: LinkDescriptor
): unknown => (ref !== undefined ? data[ref]?.[source]?.[type] : undefined);

export const countOf = (data: Sidecar, ref: string | undefined, of: CountDescriptor): number =>
	(payloadOf(data, ref, of) as number | undefined) ?? 0;

// undefined means no viewer or inapplicable descriptor, null means no matching record
export const viewerUriOf = (
	data: Sidecar,
	ref: string | undefined,
	of: ViewerDescriptor
): string | null | undefined => payloadOf(data, ref, of) as string | null | undefined;

export const viewerRkeyOf = (
	data: Sidecar,
	ref: string | undefined,
	of: ViewerDescriptor
): string | null | undefined => {
	const uri = viewerUriOf(data, ref, of);
	return uri ? rkeyFromUri(uri) : uri;
};

export const miniDocOf = (
	data: Sidecar,
	did: string | undefined,
	of: DocDescriptor
): MiniDoc | undefined => payloadOf(data, did, of) as MiniDoc | undefined;

export const handleOf = (data: Sidecar, did: string | undefined, of: DocDescriptor): string =>
	miniDocOf(data, did, of)?.handle ?? INVALID_HANDLE;

export const authorOf = (
	data: Sidecar,
	uri: string,
	of: DocDescriptor
): { did: string; handle: string } => {
	const did = didFromUri(uri);
	return { did, handle: handleOf(data, did, of) };
};