/**
 * Publish a markdown note as an AT Protocol record.
 *
 * - Strips links to unpublished notes (keeps just the link text)
 * - Uploads local images as blobs and replaces paths with CIDs
 * - Creates the space.litenote.note record
 */

import { resolve, dirname } from "path";

interface BlobRef {
  $type: "blob";
  ref: { $link: string };
  mimeType: string;
  size: number;
}

interface ImageEntry {
  image: BlobRef;
  alt: string;
}

interface PublishOptions {
  /** PDS host, e.g. "https://bsky.social" */
  pdsHost: string;
  /** Author DID */
  did: string;
  /** Auth token for XRPC calls */
  accessJwt: string;
  /** Note title */
  title: string;
  /** Raw markdown content */
  content: string;
  /** Base directory for resolving relative image paths */
  baseDir: string;
  /** Predicate that returns true if a link target is an unpublished note */
  isUnpublishedLink?: (href: string) => boolean;
}

const MIME_TYPES: Record<string, string> = {
  ".png": "image/png",
  ".jpg": "image/jpeg",
  ".jpeg": "image/jpeg",
  ".gif": "image/gif",
  ".webp": "image/webp",
  ".svg": "image/svg+xml",
  ".avif": "image/avif",
};

/**
 * Strip markdown links where the href points to an unpublished note.
 * `[text](unpublished-ref)` → `text`
 */
export function stripUnpublishedLinks(
  markdown: string,
  isUnpublished: (href: string) => boolean,
): string {
  // Match [text](href) but not ![alt](src) (images start with !)
  return markdown.replace(
    /(?<!!)\[([^\]]*)\]\(([^)]+)\)/g,
    (match, text, href) => {
      if (isUnpublished(href)) {
        return text;
      }
      return match;
    },
  );
}

/**
 * Extract local image references from markdown.
 * Returns matches for `![alt](path)` where path is not a URL.
 */
export function extractLocalImages(
  markdown: string,
): Array<{ full: string; alt: string; path: string }> {
  const results: Array<{ full: string; alt: string; path: string }> = [];
  const regex = /!\[([^\]]*)\]\(([^)]+)\)/g;
  let m: RegExpExecArray | null;
  while ((m = regex.exec(markdown)) !== null) {
    const [full, alt, path] = m;
    // Skip URLs
    if (/^https?:\/\//i.test(path)) continue;
    results.push({ full, alt, path });
  }
  return results;
}

function getMimeType(filePath: string): string {
  const ext = filePath.toLowerCase().match(/\.[^.]+$/)?.[0] ?? "";
  return MIME_TYPES[ext] ?? "application/octet-stream";
}

async function uploadBlob(
  pdsHost: string,
  accessJwt: string,
  filePath: string,
): Promise<BlobRef> {
  const file = Bun.file(filePath);
  const bytes = await file.arrayBuffer();
  const mimeType = getMimeType(filePath);

  const res = await fetch(`${pdsHost}/xrpc/com.atproto.repo.uploadBlob`, {
    method: "POST",
    headers: {
      "Content-Type": mimeType,
      Authorization: `Bearer ${accessJwt}`,
    },
    body: bytes,
  });

  if (!res.ok) {
    const text = await res.text();
    throw new Error(`uploadBlob failed (${res.status}): ${text}`);
  }

  const data = (await res.json()) as { blob: BlobRef };
  return data.blob;
}

export async function publish(opts: PublishOptions) {
  const { pdsHost, did, accessJwt, title, baseDir } = opts;
  let content = opts.content;

  // 1. Strip links to unpublished notes
  if (opts.isUnpublishedLink) {
    content = stripUnpublishedLinks(content, opts.isUnpublishedLink);
  }

  // 2. Extract & upload local images
  const localImages = extractLocalImages(content);
  const images: ImageEntry[] = [];

  for (const img of localImages) {
    const absPath = resolve(baseDir, img.path);
    const blob = await uploadBlob(pdsHost, accessJwt, absPath);
    const cid = blob.ref.$link;

    // Replace the local path with the CID in markdown
    content = content.replace(img.full, `![${img.alt}](${cid})`);

    images.push({ image: blob, alt: img.alt });
  }

  // 3. Create the record
  const now = new Date().toISOString();
  const record: Record<string, unknown> = {
    $type: "space.litenote.note",
    title,
    content,
    publishedAt: now,
    createdAt: now,
  };

  if (images.length > 0) {
    record.images = images;
  }

  const res = await fetch(
    `${pdsHost}/xrpc/com.atproto.repo.createRecord`,
    {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${accessJwt}`,
      },
      body: JSON.stringify({
        repo: did,
        collection: "space.litenote.note",
        record,
      }),
    },
  );

  if (!res.ok) {
    const text = await res.text();
    throw new Error(`createRecord failed (${res.status}): ${text}`);
  }

  return (await res.json()) as { uri: string; cid: string };
}