/**
 * Web upload validator. Builds on the shared media classifier so the
 * web upload action and the bot's send path agree on which delivery
 * kind a file gets routed to (image / video / audio / document).
 *
 * Policy: never reject on format alone. If a JPEG-tagged HEIC photo
 * gets uploaded, route it through the document path so the recipient
 * still gets the file (just without an inline preview). Only reject
 * on size — image/video/audio inline limits are tighter than the
 * 100 MB document cap, so the validator picks the cap based on the
 * RESOLVED delivery kind, not the original mime category.
 */
export {
  classifyMediaKind,
  isUnsupportedImageMime,
  isSupportedVideoMime,
  isSupportedAudioMime,
  resolveDeliveryKind,
  sniffUnsupportedImage,
  sniffUnsupportedVideo,
  WA_LIMITS,
  WA_MAX_BYTES,
  type WaMediaKind,
} from "@cmbot/shared";

import {
  resolveDeliveryKind as _resolve,
  WA_LIMITS as _WA_LIMITS,
  type WaMediaKind as _WaMediaKind,
} from "@cmbot/shared";

const KB = 1024;
const MB = 1024 * 1024;

export type WaSizeCheck =
  | { ok: true; kind: _WaMediaKind; limitBytes: number }
  | { ok: false; kind: _WaMediaKind; limitBytes: number; error: string };

/**
 * Validate an uploaded file. Returns the resolved delivery kind and
 * the cap regardless of pass/fail. The optional `bytes` arg lets the
 * caller pass the buffered payload so iOS-Safari-style mime spoofs
 * (HEIC labelled image/jpeg, .mov labelled video/mp4) get caught and
 * routed to the document path.
 */
export function validateForWhatsApp(
  mimeType: string,
  sizeBytes: number,
  bytes?: Uint8Array,
): WaSizeCheck {
  const kind = _resolve(mimeType, bytes);
  const limitBytes = _WA_LIMITS[kind];
  if (sizeBytes <= 0) {
    return { ok: false, kind, limitBytes, error: "Empty file" };
  }
  if (sizeBytes > limitBytes) {
    return {
      ok: false,
      kind,
      limitBytes,
      error: `${labelFor(kind)} too large (${formatBytes(sizeBytes)} > ${formatBytes(limitBytes)} limit on WhatsApp)`,
    };
  }
  return { ok: true, kind, limitBytes };
}

function labelFor(kind: _WaMediaKind): string {
  switch (kind) {
    case "image":
      return "Image";
    case "video":
      return "Video";
    case "audio":
      return "Audio";
    case "document":
      return "Document";
    case "sticker":
      return "Sticker";
  }
}

/** Render a byte count with a sensible WhatsApp-style unit. */
export function formatBytes(n: number): string {
  if (n < KB) return `${n} B`;
  if (n < MB) return `${(n / KB).toFixed(0)} KB`;
  return `${(n / MB).toFixed(1)} MB`;
}