// Transport-agnostic Parallel search normalization shared by the paid REST
// provider (`parallel`) and the free Search MCP provider (`parallel-free`).
// Both transports return the same v1 result shape, so query/result handling
// lives here instead of being copied into each runtime.
import {
  buildSearchCacheKey,
  resolveSiteName,
  wrapWebContent,
} from "openclaw/plugin-sdk/provider-web-search";
import { normalizeOptionalString } from "openclaw/plugin-sdk/string-coerce-runtime";
import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";

// Internal-only bounds (the model-facing tool schema declares its own copies).
const PARALLEL_MAX_SEARCH_COUNT = 40;
// Parallel v1 Search caps each search_queries entry at 200 chars, the objective
// field at 5000, and accepts up to 5 search queries. See
// https://docs.parallel.ai/search/best-practices.
const PARALLEL_MAX_SEARCH_QUERY_CHARS = 200;
const PARALLEL_MAX_OBJECTIVE_CHARS = 5000;
const PARALLEL_MAX_SEARCH_QUERIES = 5;
// Paid v1 REST accepts session ids up to 1000 chars, but the free Search MCP
// `tools/list` schema caps session_id at 100. Each runtime passes its own limit
// (and advertises it in the tool schema) so callers never send an out-of-contract id.
export const PARALLEL_SESSION_ID_MAX_LENGTH = 1000;
export const PARALLEL_FREE_SESSION_ID_MAX_LENGTH = 100;
const PARALLEL_CLIENT_MODEL_MAX_LENGTH = 100;

export type ParallelSearchResult = {
  title?: unknown;
  url?: unknown;
  publish_date?: unknown;
  excerpts?: unknown;
};

export type ParallelSearchResponse = {
  search_id?: unknown;
  session_id?: unknown;
  results?: unknown;
  warnings?: unknown;
  usage?: unknown;
};

export function resolveParallelSearchCount(value: number): number {
  return Math.max(1, Math.min(PARALLEL_MAX_SEARCH_COUNT, Math.floor(value)));
}

export function normalizeParallelSessionId(
  value: string | undefined,
  maxLength: number,
): string | undefined {
  const trimmed = normalizeOptionalString(value);
  return trimmed && trimmed.length <= maxLength ? trimmed : undefined;
}

export function normalizeParallelObjective(value: string | undefined): string | undefined {
  const trimmed = normalizeOptionalString(value);
  if (!trimmed) {
    return undefined;
  }
  return trimmed.length <= PARALLEL_MAX_OBJECTIVE_CHARS
    ? trimmed
    : truncateUtf16Safe(trimmed, PARALLEL_MAX_OBJECTIVE_CHARS);
}

export function normalizeParallelClientModel(value: string | undefined): string | undefined {
  const trimmed = normalizeOptionalString(value);
  if (!trimmed) {
    return undefined;
  }
  return trimmed.length <= PARALLEL_CLIENT_MODEL_MAX_LENGTH
    ? trimmed
    : truncateUtf16Safe(trimmed, PARALLEL_CLIENT_MODEL_MAX_LENGTH);
}

// Parallel's API caps each entry at 200 chars and accepts up to 5 queries. We
// trim, drop empties/duplicates, truncate over-long entries to the API's hard
// limit, and cap to the API's maximum so a malformed call from the model
// doesn't 422 the request. See https://docs.parallel.ai/search/best-practices.
export function normalizeParallelSearchQueries(value: unknown): string[] {
  const candidates = Array.isArray(value) ? value : [];
  const seen = new Set<string>();
  const out: string[] = [];
  for (const entry of candidates) {
    if (typeof entry !== "string") {
      continue;
    }
    const trimmed = entry.trim();
    if (!trimmed) {
      continue;
    }
    const capped =
      trimmed.length <= PARALLEL_MAX_SEARCH_QUERY_CHARS
        ? trimmed
        : truncateUtf16Safe(trimmed, PARALLEL_MAX_SEARCH_QUERY_CHARS);
    if (seen.has(capped)) {
      continue;
    }
    seen.add(capped);
    out.push(capped);
    if (out.length === PARALLEL_MAX_SEARCH_QUERIES) {
      break;
    }
  }
  return out;
}

export function invalidSearchQueriesPayload() {
  return {
    error: "invalid_search_queries",
    message:
      "search_queries must be a non-empty array of keyword strings (max 5, max 200 chars each). See https://docs.parallel.ai/search/best-practices.",
    docs: "https://docs.openclaw.ai/tools/parallel-search",
  };
}

export function normalizeParallelResults(payload: unknown): ParallelSearchResult[] {
  if (!payload || typeof payload !== "object") {
    return [];
  }
  const results = (payload as ParallelSearchResponse).results;
  if (!Array.isArray(results)) {
    return [];
  }
  return results.filter((entry): entry is ParallelSearchResult =>
    Boolean(entry && typeof entry === "object" && !Array.isArray(entry)),
  );
}

/** Maps a Parallel v1 response into wrapped `web_search` result entries. */
export function mapParallelResults(response: ParallelSearchResponse): Record<string, unknown>[] {
  return normalizeParallelResults(response).map((entry) => {
    const title = typeof entry.title === "string" ? entry.title : "";
    const url = typeof entry.url === "string" ? entry.url : "";
    const published =
      typeof entry.publish_date === "string" && entry.publish_date ? entry.publish_date : undefined;
    const excerpts = Array.isArray(entry.excerpts)
      ? entry.excerpts
          .filter((e): e is string => typeof e === "string")
          .map((e) => wrapWebContent(e, "web_search"))
      : [];
    const description = excerpts.join("\n\n");
    return Object.assign(
      {
        title: title ? wrapWebContent(title, "web_search") : "",
        url,
        description,
        siteName: resolveSiteName(url) || undefined,
      },
      published ? { published } : {},
      excerpts.length > 0 ? { excerpts } : {},
    );
  });
}

/**
 * Drops a Parallel-generated `sessionId` before caching. Identical queries from
 * unrelated tasks would otherwise share that id; caller-supplied session ids are
 * part of the cache key, so a cache hit only ever returns the matching id.
 */
export function stripParallelGeneratedSessionId(
  payload: Record<string, unknown>,
): Record<string, unknown> {
  if (!("sessionId" in payload)) {
    return payload;
  }
  const { sessionId: _omitted, ...rest } = payload;
  void _omitted;
  return rest;
}

export function buildParallelCacheKey(params: {
  endpoint: string;
  objective?: string;
  searchQueries: readonly string[];
  count: number;
  sessionId?: string;
  clientModel?: string;
}): string {
  return buildSearchCacheKey([
    "parallel",
    // The transport endpoint (REST URL or the free MCP URL) partitions paid-REST
    // vs free-MCP and REST endpoint overrides so transports never share cached
    // payloads.
    params.endpoint,
    params.objective,
    // Join with a NUL delimiter (can't appear in normalized queries) so distinct
    // arrays like ["ab","c"] and ["a","bc"] don't collide on the same cache key.
    params.searchQueries.join("\u0000"),
    params.count,
    // Different Parallel sessions can return different ranked excerpts for the
    // same query set, so partition cached payloads by caller-provided session.
    params.sessionId,
    // Parallel tailors defaults/optimizations to client_model per its docs, so
    // partition cached payloads by it; otherwise two models hitting the same
    // query inside the cache TTL would silently share ranked excerpts.
    params.clientModel,
  ]);
}