import { readdirSync } from "node:fs";
import { join } from "node:path";
import type { FastifyInstance } from "fastify";
import type { PiModel } from "../pi/list-models.js";
import { isPrincipalContext, requirePermission } from "../auth/authorization.js";

export type ListModelsFn = () => Promise<PiModel[]>;

/**
 * List YAML workspace configs found in <harnessDir>/workspaces/*.yaml.
 * Returns [{name, file}] — no database credentials or secrets.
 */
export function listWorkspaces(harnessDir: string): { name: string; file: string }[] {
  const dir = join(harnessDir, "workspaces");
  let entries: string[];
  try {
    entries = readdirSync(dir);
  } catch {
    return [];
  }
  return entries
    .filter((f) => f.endsWith(".yaml") || f.endsWith(".yml"))
    .map((f) => ({ name: f.replace(/\.ya?ml$/, ""), file: f }));
}

export function metaRoutes(
  app: FastifyInstance,
  deps: { harnessDir: string; listModels?: ListModelsFn },
): void {
  app.get("/models", async (request, reply) => {
    if (!isPrincipalContext(requirePermission(request, reply, "session.use"))) return reply;
    const fn = deps.listModels ?? (async () => []);
    try {
      return { models: await fn() };
    } catch (error) {
      app.log.warn({
        component: "pi-model-list",
        errorType: error instanceof Error ? error.name : typeof error,
      }, "Pi model listing failed");
      // Graceful fallback: Pi may not be running; don't crash the server.
      return { models: [] as PiModel[] };
    }
  });
}