import { error } from "@sveltejs/kit";
import { createBobbinClient, type BobbinContext } from "#lib/api/client.ts";
import {
	branches as knotMirrorBranches,
	blob as knotMirrorBlob,
	blobRawUrl as knotMirrorBlobRawUrl,
	languages as knotMirrorLanguages,
	getRef as knotMirrorGetRef,
	tags as knotMirrorTags,
	tree as knotMirrorTree,
	listCommitsByRef
} from "#lib/api/knotmirror.ts";
import type { Did } from "@atcute/lexicons";
import type { GitInfo } from "#lib/api/records.ts";
import type { Fetch } from "#lib/fetch.ts";

export interface GitServiceConfig {
	bobbinUrl: string;
}

export interface GitTarget {
	ctx: BobbinContext;
	repo: Did;
}

export const knotMirrorTarget = (
	config: GitServiceConfig,
	repo: { repoDid: string },
	fetch: Fetch
): GitTarget => ({
	// git json (diffs, trees) carries no handles and can run to megabytes, so the ssr
	// diff cap has to see it stream
	ctx: createBobbinClient({ serviceUrl: config.bobbinUrl, fetch, normalizeHandles: false }),
	repo: repo.repoDid as Did
});

export const hasGit = <R extends { git?: GitInfo }>(repo: R): repo is R & { git: GitInfo } =>
	repo.git !== undefined;

export const requireGit = <R extends { git?: GitInfo }>(repo: R): R & { git: GitInfo } => {
	if (!hasGit(repo)) error(404, "This repository doesn't support git");
	return repo;
};

export const gitTarget = (
	config: GitServiceConfig,
	repo: { uri: string; repoDid?: string },
	fetch: Fetch
): GitTarget => {
	if (!repo.repoDid) error(404, "This repository has not been indexed yet");
	return knotMirrorTarget(config, { repoDid: repo.repoDid }, fetch);
};

export const tree = (target: GitTarget, params: { ref: string; path?: string }) =>
	knotMirrorTree(target.ctx, { repo: target.repo, ...params });

export const log = (target: GitTarget, params: { ref: string; limit: number; skip?: number }) =>
	listCommitsByRef(target.ctx, {
		repo: target.repo,
		ranges: [params.ref],
		limit: params.limit,
		skip: params.skip
	});

export const branch = (target: GitTarget, name: string) =>
	knotMirrorGetRef(target.ctx, { repo: target.repo, ref: name });

export const branches = (target: GitTarget, limit: number, cursor?: string) =>
	knotMirrorBranches(target.ctx, { repo: target.repo, limit, cursor });

export const tags = (target: GitTarget, limit: number, cursor?: string) =>
	knotMirrorTags(target.ctx, { repo: target.repo, limit, cursor });

export const tag = (target: GitTarget, name: string) =>
	knotMirrorGetRef(target.ctx, { repo: target.repo, ref: `refs/tags/${name}` });

export const languages = (target: GitTarget, ref: string) =>
	knotMirrorLanguages(target.ctx, { repo: target.repo, ref });

export const blob = (target: GitTarget, params: { ref: string; path: string }, maxBytes: number) =>
	knotMirrorBlob(target.ctx, { repo: target.repo, ...params }, maxBytes);

export const blobRawUrl = (
	target: GitTarget,
	params: { ref: string; path: string; download?: boolean }
): string => knotMirrorBlobRawUrl(target.ctx.serviceUrl, { repo: target.repo, ...params });