import type {
  EnvironmentProject,
  EnvironmentThreadShell,
} from "@t3tools/client-runtime/state/shell";
import * as Arr from "effect/Array";
import * as Order from "effect/Order";

import { groupProjectsByRepository } from "../../lib/repositoryGroups";

export interface ThreadNavigationGroup {
  readonly key: string;
  readonly title: string;
  readonly threads: ReadonlyArray<EnvironmentThreadShell>;
}

const threadActivityOrder = Order.mapInput(
  Order.Struct({
    activityAt: Order.flip(Order.Number),
    title: Order.String,
  }),
  (thread: EnvironmentThreadShell) => ({
    activityAt: new Date(thread.updatedAt ?? thread.createdAt).getTime(),
    title: thread.title,
  }),
);

export function buildThreadNavigationGroups(input: {
  readonly projects: ReadonlyArray<EnvironmentProject>;
  readonly threads: ReadonlyArray<EnvironmentThreadShell>;
  readonly searchQuery?: string;
}): ReadonlyArray<ThreadNavigationGroup> {
  const query = input.searchQuery?.trim().toLocaleLowerCase() ?? "";
  const activeThreads = input.threads.filter((thread) => thread.archivedAt === null);

  return groupProjectsByRepository({ ...input, threads: activeThreads }).flatMap((group) => {
    const threads = Arr.sort(
      group.projects.flatMap((projectGroup) => projectGroup.threads),
      threadActivityOrder,
    );
    const title = group.projects[0]?.project.title ?? group.title;
    const groupMatches =
      query.length === 0 ||
      title.toLocaleLowerCase().includes(query) ||
      group.title.toLocaleLowerCase().includes(query) ||
      group.projects.some((projectGroup) =>
        projectGroup.project.title.toLocaleLowerCase().includes(query),
      );
    const matchingThreads = groupMatches
      ? threads
      : threads.filter((thread) => thread.title.toLocaleLowerCase().includes(query));

    if (query.length > 0 && matchingThreads.length === 0) {
      return [];
    }

    return [
      {
        key: group.key,
        title,
        threads: matchingThreads,
      },
    ];
  });
}