import { format, formatDistanceToNow } from "date-fns";

export function formatDateTime(iso: string | null | undefined): string {
  if (!iso) return "—";
  return format(new Date(iso), "MMM d, yyyy h:mm a");
}

export function formatRelative(iso: string | null | undefined): string {
  if (!iso) return "—";
  return formatDistanceToNow(new Date(iso), { addSuffix: true });
}

/**
 * NinjaPear's funding fields (`total_raised`, a round's `amount`) come back
 * as raw numeric strings (e.g. "500000000"), with no currency formatting.
 * Turns that into "$500,000,000"; leaves already-formatted or non-numeric
 * values (e.g. "$1M", "Undisclosed") untouched.
 */
export function formatMoney(value: string): string {
  const trimmed = value.trim();
  if (!trimmed || !/^\d+(\.\d+)?$/.test(trimmed)) return trimmed;
  const amount = Number(trimmed);
  if (!Number.isFinite(amount)) return trimmed;
  return `$${amount.toLocaleString("en-US")}`;
}

/**
 * NinjaPear's competitor/customer `name` fields sometimes come back as a
 * bare URL (e.g. "https://squareup.com") rather than a company name. Turns
 * that into something readable; leaves already-clean names untouched.
 */
export function companyNameFromUrl(value: string): string {
  const trimmed = value.trim();
  const withoutProtocol = trimmed.replace(/^https?:\/\//i, "").replace(/^www\./i, "");
  if (!withoutProtocol.includes(".")) return trimmed;

  const label = withoutProtocol.split("/")[0]?.split(".")[0];
  if (!label) return trimmed;
  return label.charAt(0).toUpperCase() + label.slice(1).toLowerCase();
}

const ENRICHMENT_REASON_LABELS: Record<string, string> = {
  product_overlap: "Similar products",
  organic_keyword_overlap: "Overlapping search keywords",
};

/** Turns a NinjaPear competitor-match slug (e.g. "product_overlap") into a
 * human-readable label; unrecognized slugs still read as words. */
export function formatEnrichmentReason(reason: string): string {
  const known = ENRICHMENT_REASON_LABELS[reason];
  if (known) return known;
  return reason
    .split("_")
    .filter(Boolean)
    .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
    .join(" ");
}

/** Light heuristics to turn a raw exception string from an enrichment
 * section failure into a short, non-technical summary. */
export function summarizeEnrichmentError(raw: string): string {
  const firstLine = raw.split("\n")[0]?.trim() ?? raw;
  if (/^\d+ validation errors?/i.test(firstLine)) {
    return "The data returned didn't match the expected format.";
  }
  if (/404 not found/i.test(raw)) {
    return "The requested data wasn't found.";
  }
  if (/timed? ?out/i.test(raw)) {
    return "The request timed out.";
  }
  if (/\b5\d\d\b/.test(raw) && /error/i.test(raw)) {
    return "The data provider returned a server error.";
  }
  return firstLine.length > 100 ? `${firstLine.slice(0, 100)}…` : firstLine;
}