import { getPaths } from "yt-dlp-transcript-common/lib/paths";
import { readChannelConfig } from "yt-dlp-transcript-common/controller/channels";
import {
  applyChannelFormPatch,
  channelConfigToFormData,
  validateChannelFormPatch,
} from "../../../channels/components/channelConfigToForm";
import {
  setChannelExclusionsAction,
  updateChannelAction,
} from "../../../channels/actions";
import {
  actionResponse,
  OpsInputError,
  ops,
  optBool,
  readSiteMemberships,
  reqSlug,
} from "../_lib";

export const dynamic = "force-dynamic";

// POST {
//   slug: string,
//   patch?: { <Configure-form field>: string|number|boolean|null },
//   sites?: [{ siteId, groupId? | newGroupName? }],
//   excludeFromBuild?: boolean,
//   excludeFromCleanup?: boolean,
// }
// — at least one of patch / sites / excludeFromBuild / excludeFromCleanup.
//
// The patch keys are the FORM's field names, not ChannelConfig's, because the
// form is what validates them: `downloadFilterInclude` / `downloadFilterExclude`
// rather than a `downloadFilter` object, `ytdlpExtraArgs` as a string or an
// array of lines. See channelConfigToForm.ts for why the patch is laid over the
// channel's current form representation instead of being written directly.
//
// `""` (or null) clears a field, exactly as clearing the input does.
//
// `sites` is the Configure form's Sites section: the WHOLE membership set, so
// a site left out is left, and `[]` takes the channel off every site. It rides
// the same save as the patch, as it does in the form.
//
// The two exclusions are the /channels rack's build and cleanup toggles, set
// to a value rather than flipped, since a caller cannot see the switch.
export async function POST(request: Request) {
  return ops(
    request,
    ["slug", "patch", "sites", "excludeFromBuild", "excludeFromCleanup"],
    async (body) => {
      const slug = reqSlug(body, "slug");
      const patch = body.patch;
      if (
        patch !== undefined &&
        (typeof patch !== "object" || patch === null || Array.isArray(patch))
      ) {
        throw new OpsInputError('"patch" must be a JSON object');
      }
      const sites = readSiteMemberships(body);
      const excludeFromBuild = optBool(body, "excludeFromBuild");
      const excludeFromCleanup = optBool(body, "excludeFromCleanup");
      if (
        patch === undefined &&
        sites === undefined &&
        excludeFromBuild === undefined &&
        excludeFromCleanup === undefined
      ) {
        throw new OpsInputError(
          'nothing to change — give "patch", "sites", "excludeFromBuild" or "excludeFromCleanup"',
        );
      }
      // KEYS FIRST, CHANNEL SECOND. A misspelled field is a fact about the
      // request; reporting "channel not found" for it would hide the real error.
      if (patch !== undefined) {
        try {
          validateChannelFormPatch(patch as Record<string, unknown>);
        } catch (e) {
          throw new OpsInputError((e as Error).message);
        }
      }
      const paths = getPaths();
      const existing = await readChannelConfig(paths, slug);
      if (!existing) throw new OpsInputError(`Channel "${slug}" not found`);
      if (patch !== undefined || sites !== undefined) {
        const fd = channelConfigToFormData(existing);
        if (patch !== undefined) {
          applyChannelFormPatch(fd, patch as Record<string, unknown>);
        }
        if (sites !== undefined) {
          fd.set("siteMembershipsJson", JSON.stringify(sites));
        }
        const saved = await updateChannelAction(slug, undefined, fd);
        if (saved?.error) return actionResponse(saved);
      }
      return actionResponse(
        await setChannelExclusionsAction(slug, {
          excludeFromBuild,
          excludeFromCleanup,
        }),
      );
    },
  );
}