frontend/src/lib/csv.ts

import { HAZARD_LABEL, type Cluster } from "./api";

export function clustersToCsv(clusters: Cluster[]): string {
  const header = [
    "rank",
    "cluster_id",
    "hazard_type",
    "severity",
    "report_count",
    "status",
    "lat",
    "lon",
    "first_seen",
    "last_seen",
  ];
  const rows = clusters.map((c, i) => [
    i + 1,
    c.id,
    HAZARD_LABEL[c.hazard_type],
    c.severity,
    c.report_count,
    c.status,
    c.centroid_lat.toFixed(6),
    c.centroid_lon.toFixed(6),
    c.first_seen,
    c.last_seen,
  ]);
  return [header, ...rows]
    .map((r) => r.map((v) => `"${String(v).replace(/"/g, '""')}"`).join(","))
    .join("\n");
}

export function downloadCsv(filename: string, csv: string): void {
  const blob = new Blob([csv], { type: "text/csv;charset=utf-8;" });
  const url = URL.createObjectURL(blob);
  const a = document.createElement("a");
  a.href = url;
  a.download = filename;
  a.click();
  URL.revokeObjectURL(url);
}