import { NextResponse } from "next/server";
import { getPaths } from "yt-dlp-transcript-common/lib/paths";
import { readChannelConfig } from "yt-dlp-transcript-common/controller/channels";
import { bulkRelocateChannelMediaAction } from "../../../channels/bulkStorageActions";
import { previewRelocationAction } from "../../../channels/[slug]/storageActions";
import {
  OpsInputError,
  ops,
  optBool,
  optString,
  queueResponse,
  reqSlugs,
} from "../_lib";

export const dynamic = "force-dynamic";

// POST { slugs: string[], locationId?: string, root?: string, dryRun?: boolean }
//   -> { ok: true, queued, skipped }
//
// THE DESTINATION IS A LOCATION ID WHEREVER POSSIBLE — the root is resolved on
// the server from settings.storage.locations, so a caller holding a stale root
// cannot aim a batch somewhere a re-point has moved. `root` is the one-off
// escape hatch the panel also offers. A skip is not a failure: every slug that
// did not queue comes back with the same sentence the bulk bar shows.
//
// `dryRun: true` (release 19, A4) is the Storage panel's preview per channel
// (previewRelocationAction) and starts nothing: { ok, dryRun, previews:
// [{slug, preview} | {slug, error}] } — the bytes to copy and both sides'
// free space. As on the panel, a preview of a CLASSIC channel (its big files
// still real files in data/) first tiers it in place — same-disk renames into
// its own media/, the step every move's preflight takes (release 17's ruling);
// no byte leaves the corpus disk.
export async function POST(request: Request) {
  return ops(request, ["slugs", "locationId", "root", "dryRun"], async (body) => {
    const slugs = reqSlugs(body, "slugs");
    const locationId = optString(body, "locationId");
    const root = optString(body, "root");
    const dryRun = optBool(body, "dryRun") === true;
    if ((locationId ? 1 : 0) + (root ? 1 : 0) !== 1) {
      throw new OpsInputError(
        'send exactly one of "locationId" (a location configured on /storage) or "root" (an absolute path)',
      );
    }
    const dest = locationId
      ? ({ kind: "location", locationId } as const)
      : ({ kind: "custom", root: root as string } as const);
    if (dryRun) {
      const previews = [];
      for (const slug of slugs) {
        // The bulk move's own skip for a slug with no channel: the panel's
        // preview is only ever asked about a channel that exists, and a
        // zero-byte preview of a typo is the silent success this layer refuses.
        if (!(await readChannelConfig(getPaths(), slug))) {
          previews.push({ slug, error: "channel not found" });
          continue;
        }
        const res = await previewRelocationAction(slug, dest);
        previews.push(res.ok ? { slug, preview: res.preview } : { slug, error: res.error });
      }
      return NextResponse.json({ ok: true, dryRun: true, previews });
    }
    return queueResponse(await bulkRelocateChannelMediaAction(slugs, dest));
  });
}