// search-analytics.ts — sends events to Intelligent Search Events API
const ACCOUNT_NAME = "mystore";
const EVENTS_URL = `https://sp.vtex.com/event-api/v1/${ACCOUNT_NAME}/event`;

interface SearchEvent {
  type: "search.query" | "search.click" | "search.add_to_cart";
  text: string;
  misspelled: boolean;
  match: number;
  operator: string;
  locale: string;
  agent: string;
  url: string;
  products?: Array<{ productId: string; position: number }>;
}

export async function sendSearchEvent(event: SearchEvent): Promise<void> {
  try {
    await fetch(EVENTS_URL, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(event),
      keepalive: true, // ensures event is sent even during navigation
    });
  } catch (error) {
    // Analytics failures should not break the UI
    console.warn("Failed to send search event:", error);
  }
}

// Usage: call after rendering search results
function onSearchResultsRendered(query: string, products: Product[]): void {
  sendSearchEvent({
    type: "search.query",
    text: query,
    misspelled: false,
    match: products.length,
    operator: "and",
    locale: "en-US",
    agent: "my-headless-store",
    url: window.location.href,
    products: products.map((p, i) => ({
      productId: p.productId,
      position: i + 1,
    })),
  });
}

// Search works but NO analytics events are sent — search ranking degrades
async function searchProducts(query: string): Promise<Product[]> {
  const response = await fetch(
    `https://mystore.vtexcommercestable.com.br/api/io/_v/api/intelligent-search/product_search/?query=${query}&locale=en-US`
  );
  const data = await response.json();
  return data.products;
  // Missing: no call to sendSearchEvent() — Intelligent Search cannot learn
}

// Properly manages operator/fuzzy across pagination
interface SearchState {
  query: string;
  page: number;
  count: number;
  locale: string;
  facets?: string;
  operator: string | null; // null for first page, then persisted
  fuzzy: string | null;    // null for first page, then persisted
}

async function searchProducts(state: SearchState): Promise<SearchResponse> {
  const { query, page, count, locale, facets = "", operator, fuzzy } = state;

  const params = new URLSearchParams({
    query,
    locale,
    page: String(page),
    count: String(count),
  });

  // Only add operator/fuzzy if this is not the first page
  if (operator !== null) params.set("operator", operator);
  if (fuzzy !== null) params.set("fuzzy", fuzzy);

  const baseUrl = `https://${ACCOUNT}.vtexcommercestable.com.br`;
  const facetPath = facets ? `/${facets}` : "";
  const url = `${baseUrl}/api/io/_v/api/intelligent-search/product_search${facetPath}?${params}`;

  const response = await fetch(url);
  const data = await response.json();

  // Store operator/fuzzy from response for next page
  if (page === 0) {
    state.operator = data.operator;
    state.fuzzy = data.fuzzy;
  }

  return data;
}

// Usage: first page
const state: SearchState = {
  query: "running shoes",
  page: 0,
  count: 24,
  locale: "en-US",
  operator: null, // API will decide
  fuzzy: null,    // API will decide
};

const firstPage = await searchProducts(state);

// Usage: subsequent pages
state.page = 1;
const secondPage = await searchProducts(state); // reuses operator/fuzzy

// Using fixed operator/fuzzy values — causes bad results
async function searchProducts(query: string, page: number): Promise<SearchResponse> {
  const params = new URLSearchParams({
    query,
    locale: "en-US",
    page: String(page),
    count: "24",
    operator: "or", // WRONG: fixed value instead of API-provided
    fuzzy: "0",     // WRONG: fixed value instead of API-provided
  });

  const response = await fetch(
    `https://mystore.vtexcommercestable.com.br/api/io/_v/api/intelligent-search/product_search/?${params}`
  );
  return response.json();
}

// Or forgetting operator/fuzzy entirely on subsequent pages
async function searchProductsPage2(query: string): Promise<SearchResponse> {
  const params = new URLSearchParams({
    query,
    locale: "en-US",
    page: "1", // WRONG: no operator/fuzzy from first page
    count: "24",
  });
  // ...
}

// Frontend — calls Intelligent Search directly (no BFF needed)
const VTEX_SEARCH_BASE = `https://${ACCOUNT}.vtexcommercestable.com.br/api/io/_v/api/intelligent-search`;

export async function getAutocomplete(term: string, locale: string): Promise<AutocompleteResponse> {
  const params = new URLSearchParams({ query: term, locale });
  const response = await fetch(`${VTEX_SEARCH_BASE}/autocomplete_suggestions?${params}`);
  return response.json();
}

export async function getTopSearches(locale: string): Promise<TopSearchesResponse> {
  const params = new URLSearchParams({ locale });
  const response = await fetch(`${VTEX_SEARCH_BASE}/top_searches?${params}`);
  return response.json();
}

export async function getFacets(facetPath: string, query: string, locale: string): Promise<FacetsResponse> {
  const params = new URLSearchParams({ query, locale });
  const response = await fetch(`${VTEX_SEARCH_BASE}/facets/${facetPath}?${params}`);
  return response.json();
}

// BFF proxy for Intelligent Search — unnecessary overhead
// server/routes/search.ts
router.get("/api/bff/search", async (req, res) => {
  const { query, from, to, locale } = req.query;
  // This just forwards to VTEX with no added value
  const response = await fetch(
    `https://mystore.vtexcommercestable.com.br/api/io/_v/api/intelligent-search/product_search/?query=${query}&from=${from}&to=${to}&locale=${locale}`
  );
  const data = await response.json();
  res.json(data); // Added latency for no benefit
});

Frontend (Browser)
    │
    ├── GET /api/io/_v/api/intelligent-search/product_search/...
    │   └── Returns: products, pagination info, operator, fuzzy
    │
    ├── GET /api/io/_v/api/intelligent-search/facets/...
    │   └── Returns: available filters with counts
    │
    ├── GET /api/io/_v/api/intelligent-search/autocomplete_suggestions?query=...
    │   └── Returns: suggested terms + suggested products
    │
    └── POST https://sp.vtex.com/event-api/v1/{account}/event
        └── Sends: search impressions, clicks, add-to-cart events

// lib/intelligent-search-client.ts
const ACCOUNT = "mystore";
const ENVIRONMENT = "vtexcommercestable";
const BASE_URL = `https://${ACCOUNT}.${ENVIRONMENT}.com.br/api/io/_v/api/intelligent-search`;

interface ProductSearchParams {
  query?: string;
  page: number;
  count?: number;
  locale: string;
  facets?: string;
  sort?: "price:asc" | "price:desc" | "orders:desc" | "name:asc" | "name:desc" | "release:desc" | "discount:desc";
  hideUnavailableItems?: boolean;
  operator?: string | null;
  fuzzy?: string | null;
  // Optional parameters
  simulationBehavior?: "default" | "skip" | "only1P";
}

interface ProductSearchResponse {
  products: Product[];
  recordsFiltered: number;
  // Pagination info
  pagination: {
    count: number;
    current: { index: number };
    before: Array<{ index: number }>;
    after: Array<{ index: number }>;
    perPage: number;
    next: { index: number } | null;
    previous: { index: number } | null;
    first: { index: number };
    last: { index: number };
  };
  // Search metadata to persist for next pages
  operator: string;
  fuzzy: string;
  // Spelling correction info
  correction?: {
    misspelled: boolean;
    text: string;
    correction: string;
  };
  // Search behavior
  translated: boolean;
  locale: string;
  query: string;
}

export async function productSearch(params: ProductSearchParams): Promise<ProductSearchResponse> {
  const { facets = "", operator, fuzzy, ...queryParams } = params;
  const searchParams = new URLSearchParams();

  if (queryParams.query) searchParams.set("query", queryParams.query);
  searchParams.set("page", String(queryParams.page));
  searchParams.set("locale", queryParams.locale);
  if (queryParams.count) searchParams.set("count", String(queryParams.count));
  if (queryParams.sort) searchParams.set("sort", queryParams.sort);
  if (queryParams.hideUnavailableItems) searchParams.set("hideUnavailableItems", "true");
  if (queryParams.simulationBehavior) searchParams.set("simulationBehavior", queryParams.simulationBehavior);
  
  // Only add operator/fuzzy if not null (i.e., not first page)
  if (operator !== null && operator !== undefined) searchParams.set("operator", operator);
  if (fuzzy !== null && fuzzy !== undefined) searchParams.set("fuzzy", fuzzy);

  const facetPath = facets ? `/${facets}` : "";
  const url = `${BASE_URL}/product_search${facetPath}?${searchParams}`;

  const response = await fetch(url);
  if (!response.ok) {
    throw new Error(`Search failed: ${response.status}`);
  }
  return response.json();
}

// lib/facets.ts
export async function getFacets(
  facetPath: string,
  query: string,
  locale: string
): Promise<FacetsResponse> {
  const params = new URLSearchParams({ query, locale });
  const url = `${BASE_URL}/facets/${facetPath}?${params}`;

  const response = await fetch(url);
  if (!response.ok) {
    throw new Error(`Facets fetch failed: ${response.status}`);
  }
  return response.json();
}

// Build facet path from selected filters
export function buildFacetPath(selectedFilters: Record<string, string[]>): string {
  const parts: string[] = [];
  for (const [key, values] of Object.entries(selectedFilters)) {
    for (const value of values) {
      parts.push(`${key}/${value}`);
    }
  }
  return parts.join("/");
}

// lib/autocomplete.ts
export function createDebouncedAutocomplete(delayMs: number = 300) {
  let timeoutId: ReturnType<typeof setTimeout> | null = null;

  return function debouncedAutocomplete(
    query: string,
    locale: string,
    callback: (suggestions: AutocompleteResponse) => void
  ): void {
    if (timeoutId) clearTimeout(timeoutId);

    if (query.length < 2) {
      callback({ searches: [] });
      return;
    }

    timeoutId = setTimeout(async () => {
      const params = new URLSearchParams({ query, locale });
      const response = await fetch(`${BASE_URL}/autocomplete_suggestions?${params}`);
      const suggestions = await response.json();
      callback(suggestions);
    }, delayMs);
  };
}

// search-page.ts — framework-agnostic search orchestration
import { productSearch } from "./lib/intelligent-search-client";
import { getFacets, buildFacetPath } from "./lib/facets";
import { createDebouncedAutocomplete } from "./lib/autocomplete";
import { sendSearchEvent } from "./search-analytics";

interface SearchState {
  query: string;
  page: number;
  count: number;
  locale: string;
  selectedFilters: Record<string, string[]>;
  operator: string | null;
  fuzzy: string | null;
  results: ProductSearchResponse | null;
  facets: FacetsResponse | null;
}

const state: SearchState = {
  query: "",
  page: 0,
  count: 24,
  locale: "en-US",
  selectedFilters: {},
  operator: null, // API decides on first page
  fuzzy: null,    // API decides on first page
  results: null,
  facets: null,
};

async function executeSearch(): Promise<void> {
  const facetPath = buildFacetPath(state.selectedFilters);

  const [searchResults, facetResults] = await Promise.all([
    productSearch({
      query: state.query,
      page: state.page,
      count: state.count,
      locale: state.locale,
      facets: facetPath,
      operator: state.operator,
      fuzzy: state.fuzzy,
    }),
    getFacets(facetPath, state.query, state.locale),
  ]);

  // Store operator/fuzzy from first page for subsequent pages
  if (state.page === 0) {
    state.operator = searchResults.operator;
    state.fuzzy = searchResults.fuzzy;
  }

  state.results = searchResults;
  state.facets = facetResults;

  // Send analytics event after results are rendered
  sendSearchEvent({
    type: "search.query",
    text: state.query,
    misspelled: searchResults.correction?.misspelled ?? false,
    match: searchResults.recordsFiltered,
    operator: searchResults.operator,
    locale: state.locale,
    agent: "my-headless-store",
    url: window.location.href,
    products: searchResults.products.map((p, i) => ({
      productId: p.productId,
      position: state.page * searchResults.products.length + i + 1,
    })),
  });
}

// Handle product click from search results — send click event
function onProductClick(productId: string, position: number): void {
  sendSearchEvent({
    type: "search.click",
    text: state.query,
    misspelled: false,
    match: state.results?.recordsFiltered ?? 0,
    operator: state.results?.operator ?? "and",
    locale: state.locale,
    agent: "my-headless-store",
    url: window.location.href,
    products: [{ productId, position }],
  });
}

// Handle page change
function goToPage(newPage: number): void {
  state.page = newPage;
  executeSearch(); // reuses operator/fuzzy from first page
}

// Handle new search (reset pagination state)
function newSearch(query: string): void {
  state.query = query;
  state.page = 0;
  state.operator = null; // reset for new search
  state.fuzzy = null;    // reset for new search
  executeSearch();
}