import { copyFile, mkdir, readdir } from "node:fs/promises";
import { join, relative, resolve } from "node:path";
import type { Feature, RouteHandler } from "@stc/contracts";
import { serveMedia } from "@stc/core";
import { assertAllowedPath, importRoots, OUTSIDE } from "./roots";
import { coverCacheDir, coursesDir, exists, isPlainId, managedCourse, saveManifest, type Deps } from "./context";

export const KINDS = ["packt-video", "code-repo", "pdf-deck", "video-folder"] as const;
const OPTION_KEYS = ["title", "courseId", "attachTo", "media", "transcribe"] as const;
const COVER_NAME = /^[A-Za-z0-9][A-Za-z0-9._-]*\.jpg$/;
const GIT_URL = /^(https?:\/\/|ssh:\/\/|git@)\S+$/;

const json = (body: unknown, status = 200) => Response.json(body, { status });

export function importRoutes(deps: () => Deps): Feature["routes"] {
  /** Imports read arbitrary server paths, so every route needs the owner role. */
  const owner = (h: RouteHandler): RouteHandler => (req, rc) => {
    if (!rc.user) return json({ error: "Sign in required" }, 401);
    if (!rc.user.roles.includes("owner")) return json({ error: "Only the owner can import" }, 403);
    return h(req, rc);
  };

  return {
    "/api/import/info": {
      GET: owner(() => {
        const d = deps();
        const dir = coursesDir(d);
        const served = d.ctx.config.courseDirs.some((c) => resolve(c) === dir);
        return json({ transcribe: Boolean(d.transcribeUrl), coursesDir: dir, coursesDirServed: served, importRoots: importRoots(d) });
      }),
    },
    "/api/import/jobs": {
      GET: owner(async () => {
        const jobs = (await deps().ctx.jobs.list()).filter((j) => j.kind.startsWith("import."));
        return json(jobs);
      }),
      POST: owner(async (req) => {
        const d = deps();
        let body: any;
        try { body = await req.json(); } catch { return json({ error: "Body must be JSON" }, 400); }
        const kind = String(body?.kind ?? "");
        const options: Record<string, unknown> = {};
        for (const k of OPTION_KEYS) if (body?.options?.[k] !== undefined && body.options[k] !== "") options[k] = body.options[k];
        if (kind === "transcribe") {
          if (!d.transcribeUrl) return json({ error: "STC_TRANSCRIBE_URL is not set" }, 409);
          if (typeof options.courseId !== "string") return json({ error: "courseId is required" }, 400);
          return json({ id: await d.ctx.jobs.enqueue("import.transcribe", { courseId: options.courseId }) }, 202);
        }
        if (!(KINDS as readonly string[]).includes(kind)) return json({ error: `kind must be one of ${KINDS.join(", ")}` }, 400);
        const path = typeof body?.path === "string" ? body.path.trim() : "";
        if (!path) return json({ error: "path is required" }, 400);
        const isGit = kind === "code-repo" && GIT_URL.test(path);
        if (!isGit) {
          if (!path.startsWith("/")) return json({ error: "Use an absolute path" }, 400);
          try { await assertAllowedPath(d, path); } catch { return json({ error: OUTSIDE }, 400); }
        }
        if ((kind === "code-repo" || kind === "pdf-deck") && typeof options.courseId !== "string") return json({ error: "courseId is required" }, 400);
        if (kind === "pdf-deck" && typeof options.attachTo !== "string") return json({ error: "attachTo is required" }, 400);
        return json({ id: await d.ctx.jobs.enqueue(`import.${kind}`, { kind, path, options }) }, 202);
      }),
    },
    "/api/import/courses": {
      GET: owner(() => {
        const d = deps();
        const base = coursesDir(d);
        const out = d.ctx.courses.list()
          .filter((c) => c.manifest && !relative(base, c.root).startsWith(".."))
          .map((c) => ({
            id: c.id, title: c.manifest!.title,
            modules: c.manifest!.modules.map((m) => ({ id: m.id, title: m.title, lessons: m.lessons.map((l) => ({ id: l.id, title: l.title })) })),
          }));
        return json(out);
      }),
    },
    "/api/import/covers/:courseId": {
      GET: owner(async (_req, rc) => {
        const d = deps();
        const id = rc.params.courseId!;
        if (!isPlainId(id)) return json({ error: "Invalid course id" }, 400);
        const c = d.ctx.courses.get(id);
        const names = (await readdir(coverCacheDir(d, id)).catch(() => [] as string[])).filter((n) => COVER_NAME.test(n)).sort();
        return json({ current: c?.manifest?.cover ?? null, candidates: names });
      }),
      POST: owner(async (req, rc) => {
        const d = deps();
        let body: any;
        try { body = await req.json(); } catch { return json({ error: "Body must be JSON" }, 400); }
        const name = String(body?.name ?? "");
        if (!COVER_NAME.test(name)) return json({ error: "Invalid candidate name" }, 400);
        if (!isPlainId(rc.params.courseId!)) return json({ error: "Invalid course id" }, 400);
        const src = join(coverCacheDir(d, rc.params.courseId!), name);
        if (!(await exists(src))) return json({ error: "No such candidate" }, 404);
        let course;
        try { course = await managedCourse(d, rc.params.courseId); } catch (e) { return json({ error: (e as Error).message }, 404); }
        await mkdir(join(course.dir, "media"), { recursive: true });
        await copyFile(src, join(course.dir, "media", "cover.jpg"));
        course.manifest.cover = "media/cover.jpg";
        await saveManifest(course.dir, course.manifest);
        await d.ctx.courses.reload(course.id);
        return json({ cover: "media/cover.jpg" });
      }),
    },
    "/api/import/covers/:courseId/:name": {
      GET: owner(async (req, rc) => {
        const name = rc.params.name!;
        if (!COVER_NAME.test(name)) return new Response("Not found", { status: 404 });
        if (!isPlainId(rc.params.courseId!)) return new Response("Not found", { status: 404 });
        const file = join(coverCacheDir(deps(), rc.params.courseId!), name);
        if (!(await exists(file))) return new Response("Not found", { status: 404 });
        return serveMedia(req, file);
      }),
    },
  };
}