import { NextResponse } from "next/server";
import {
  STORED_CHANNEL_TIERS,
  PRIORITY_OPERATIONS,
  type PriorityOperation,
  type StoredChannelTier,
} from "yt-dlp-transcript-common/lib/channelPriority";
import {
  applyChannelPriorityPresetAction,
  setChannelOperationTierAction,
  setChannelTierAction,
} from "../../../channels/actions";
import {
  actionResponse,
  OpsInputError,
  ops,
  optString,
  reqSlugs,
} from "../_lib";

export const dynamic = "force-dynamic";

// POST { slugs: string[], tier?: "normal"|"low"|"paused"|null, operation?: one
//        of sync|transcription|download|digest|backfill, preset?: "sync-only"|"clear" }
//
// Three named gestures, one route, because they are one gesture in the UI: the
// /channels deck's tier control. `operation` present pins that operation's
// override (null clears it back to the base tier); absent sets the BASE tier.
// `preset` is the deck's two shortcuts and takes no tier.
export async function POST(request: Request) {
  return ops(
    request,
    ["slugs", "tier", "operation", "preset"],
    async (body) => {
      const slugs = reqSlugs(body, "slugs");
      const preset = optString(body, "preset");
      if (preset !== undefined) {
        if (preset !== "sync-only" && preset !== "clear") {
          throw new OpsInputError('"preset" must be "sync-only" or "clear"');
        }
        return actionResponse(
          await applyChannelPriorityPresetAction(slugs, preset),
        );
      }
      const rawTier = body.tier;
      if (rawTier !== null && typeof rawTier !== "string") {
        throw new OpsInputError(
          `"tier" must be one of ${STORED_CHANNEL_TIERS.join(", ")} (or null with an "operation", to clear the override)`,
        );
      }
      if (
        rawTier !== null &&
        !(STORED_CHANNEL_TIERS as readonly string[]).includes(rawTier)
      ) {
        throw new OpsInputError(
          `"tier" must be one of ${STORED_CHANNEL_TIERS.join(", ")}`,
        );
      }
      const operation = optString(body, "operation");
      if (operation !== undefined) {
        if (!(PRIORITY_OPERATIONS as readonly string[]).includes(operation)) {
          throw new OpsInputError(
            `"operation" must be one of ${PRIORITY_OPERATIONS.join(", ")}`,
          );
        }
        return actionResponse(
          await setChannelOperationTierAction(
            slugs,
            operation as PriorityOperation,
            rawTier as StoredChannelTier | null,
          ),
        );
      }
      if (rawTier === null) {
        throw new OpsInputError(
          'a null "tier" clears an operation override — name an "operation", or send a stored tier',
        );
      }
      return actionResponse(
        await setChannelTierAction(slugs, rawTier as StoredChannelTier),
      );
    },
  );
}

export function GET() {
  return NextResponse.json(
    { ok: false, error: "POST only" },
    { status: 405 },
  );
}