export type PageType =
  | "homepage"
  | "category"
  | "product"
  | "search"
  | "cart"
  | "other";

export interface PageContext {
  page_link: string;
  page_type: PageType;
  h1: string;
}

function detectPageType(): PageType {
  if (typeof window === "undefined" || typeof document === "undefined") {
    return "other";
  }

  const url = window.location.href.toLowerCase();
  const path = window.location.pathname.toLowerCase();
  const bodyClasses = document.body.className.toLowerCase();

  // Homepage detection
  if (
    path === "/" ||
    path === "" ||
    bodyClasses.includes("home") ||
    bodyClasses.includes("front-page")
  ) {
    return "homepage";
  }

  // Cart detection
  if (
    path.includes("/cart") ||
    path.includes("/basket") ||
    bodyClasses.includes("woocommerce-cart")
  ) {
    return "cart";
  }

  // Checkout detection - map to cart since API doesn't have checkout
  if (
    path.includes("/checkout") ||
    bodyClasses.includes("woocommerce-checkout")
  ) {
    return "cart";
  }

  // Search detection
  if (
    path.includes("/search") ||
    url.includes("?s=") ||
    url.includes("?q=") ||
    bodyClasses.includes("search-results") ||
    bodyClasses.includes("search")
  ) {
    return "search";
  }

  // Product page detection
  if (
    path.includes("/product/") ||
    path.includes("/products/") ||
    bodyClasses.includes("single-product") ||
    bodyClasses.includes("product-template") ||
    document.querySelector("[data-product-id]") ||
    document.querySelector(".product-single") ||
    document.querySelector("form.cart")
  ) {
    return "product";
  }

  // Category detection
  if (
    path.includes("/category/") ||
    path.includes("/collection/") ||
    path.includes("/collections/") ||
    path.includes("/product-category/") ||
    path.includes("/shop/") ||
    bodyClasses.includes("archive") ||
    bodyClasses.includes("tax-product_cat") ||
    bodyClasses.includes("post-type-archive-product") ||
    bodyClasses.includes("collection-template")
  ) {
    return "category";
  }

  return "other";
}

function getPageH1(): string {
  if (typeof document === "undefined") {
    return "";
  }

  const h1 = document.querySelector("h1");
  return h1?.textContent?.trim() || document.title || "";
}

export function getPageContext(): PageContext {
  return {
    page_link: typeof window !== "undefined" ? window.location.href : "",
    page_type: detectPageType(),
    h1: getPageH1(),
  };
}

/**
 * Builds a context string to prepend to user messages
 * This provides the AI with page context for better responses
 * Format is LLM-friendly with clear markers and only includes available data
 */
export function buildPageContextString(): string {
  const context = getPageContext();

  // Build context parts, only including fields that have meaningful values
  const parts: string[] = [];

  if (context.page_type && context.page_type !== "other") {
    parts.push(`page_type: ${context.page_type}`);
  }

  if (context.h1) {
    parts.push(`page_title: ${context.h1}`);
  }

  if (context.page_link) {
    parts.push(`url: ${context.page_link}`);
  }

  // If no meaningful context, return empty string
  if (parts.length === 0) {
    return "";
  }

  return `[USER_PAGE_CONTEXT: ${parts.join(" | ")}]\n\n`;
}