import type { GenerateConfig } from "@/lib/card-gen/id-config";
import { savePreset, type CardPreset } from "@/lib/card-gen/local-store";

export type ServerPresetMeta = {
  id: string;
  name: string;
  config: GenerateConfig;
  imageName: string;
  hasImage: boolean;
  fontName: string | null;
  hasFont: boolean;
  createdAt: number;
  updatedAt: number;
};

async function readError(res: Response): Promise<string> {
  const body = (await res.json().catch(() => null)) as { error?: string } | null;
  return body?.error || `Request failed (${res.status})`;
}

export async function fetchServerPresetList(): Promise<ServerPresetMeta[]> {
  const res = await fetch("/api/founders-card/presets", { cache: "no-store" });
  if (!res.ok) throw new Error(await readError(res));
  const body = (await res.json()) as { presets?: ServerPresetMeta[] };
  return Array.isArray(body.presets) ? body.presets : [];
}

async function fileFromEndpoint(
  url: string,
  fallbackName: string,
): Promise<File | null> {
  const res = await fetch(url, { cache: "no-store" });
  if (!res.ok) return null;
  const blob = await res.blob();
  if (blob.size === 0) return null;
  const name =
    /filename="([^"]+)"/i.exec(res.headers.get("content-disposition") ?? "")?.[1] ??
    fallbackName;
  return new File([blob], name, {
    type: blob.type || "application/octet-stream",
  });
}

export async function fetchServerPresets(): Promise<CardPreset[]> {
  const list = await fetchServerPresetList();
  const out: CardPreset[] = [];
  for (const meta of list) {
    const image = meta.hasImage
      ? await fileFromEndpoint(
          `/api/founders-card/presets/${meta.id}/image`,
          meta.imageName || "base.png",
        )
      : null;
    const font = meta.hasFont
      ? await fileFromEndpoint(
          `/api/founders-card/presets/${meta.id}/font`,
          meta.fontName || "custom.ttf",
        )
      : null;
    out.push({
      id: meta.id,
      name: meta.name,
      config: meta.config,
      image,
      font,
      createdAt: meta.createdAt,
      updatedAt: meta.updatedAt,
    });
  }
  return out;
}

export async function pushPresetToServer(input: {
  id?: string;
  name: string;
  config: GenerateConfig;
  image: File | null;
  font: File | null;
}): Promise<ServerPresetMeta> {
  const fd = new FormData();
  fd.append("name", input.name);
  fd.append("config", JSON.stringify(input.config));
  if (input.id) fd.append("id", input.id);
  if (input.image) fd.append("image", input.image);
  if (input.font) fd.append("font", input.font);
  if (!input.font) fd.append("clearFont", "1");
  const res = await fetch("/api/founders-card/presets", {
    method: "POST",
    body: fd,
  });
  if (!res.ok) throw new Error(await readError(res));
  return (await res.json()) as ServerPresetMeta;
}

export async function deleteServerPreset(id: string): Promise<void> {
  const res = await fetch(`/api/founders-card/presets/${id}`, {
    method: "DELETE",
  });
  if (!res.ok && res.status !== 404) throw new Error(await readError(res));
}

export async function cacheServerPresetsLocally(
  presets: CardPreset[],
): Promise<void> {
  for (const preset of presets) {
    await savePreset({
      id: preset.id,
      name: preset.name,
      config: preset.config,
      image: preset.image,
      font: preset.font,
    });
  }
}