export type TechLogServingContract = Readonly<{
  schemaVersion: 1;
  publicSpaPaths: readonly string[];
  studioPathPrefix: "/studio";
  studioSpaPathPatterns: readonly string[];
  notFound: Readonly<{
    status: 404;
    contentType: "text/plain;charset=UTF-8";
    body: "Not Found";
  }>;
}>;

type ServingContractInput = Readonly<{
  publicRecords: readonly Readonly<{
    path: string;
    topicSlug: string;
  }>[];
  projects: readonly Readonly<{ slug: string }>[];
  releases: readonly Readonly<{ path: string }>[];
}>;

const staticPublicPaths = Object.freeze([
  "/",
  "/explore",
  "/explore/cases",
  "/explore/questions",
  "/explore/references",
  "/profile",
  "/projects",
  "/releases",
  "/search",
]);

const studioSpaPathPatterns = Object.freeze([
  "^/studio$",
  // The Asset Library is a first-class Studio route (TECH_LOG_STUDIO_ASSETS in
  // the route contract) but was never listed here, so a hard navigation or a
  // reload of /studio/assets was served the in-shell Studio 404 -- the screen
  // was only reachable by client-side navigation from another Studio page.
  "^/studio/assets$",
  "^/studio/documents$",
  "^/studio/documents/new$",
  "^/studio/documents/[^/]+/(edit|validation|preview|publish)$",
  "^/studio/publications$",
  "^/studio/publications/[^/]+/preview$",
]);

function asciiCompare(left: string, right: string): number {
  return left < right ? -1 : left > right ? 1 : 0;
}

export function createTechLogServingContract({
  publicRecords,
  projects,
  releases,
}: ServingContractInput): TechLogServingContract {
  const publicSpaPaths = new Set(staticPublicPaths);
  for (const record of publicRecords) {
    publicSpaPaths.add(record.path);
    publicSpaPaths.add(`/topics/${record.topicSlug}`);
  }
  for (const project of projects) {
    const projectPath = `/projects/${project.slug}`;
    publicSpaPaths.add(projectPath);
    publicSpaPaths.add(`${projectPath}/activity`);
    publicSpaPaths.add(`${projectPath}/decisions`);
    publicSpaPaths.add(`${projectPath}/records`);
  }
  for (const release of releases) publicSpaPaths.add(release.path);

  return Object.freeze({
    schemaVersion: 1,
    publicSpaPaths: Object.freeze([...publicSpaPaths].sort(asciiCompare)),
    studioPathPrefix: "/studio",
    studioSpaPathPatterns,
    notFound: Object.freeze({
      status: 404,
      contentType: "text/plain;charset=UTF-8",
      body: "Not Found",
    }),
  });
}