import { runCommand } from "./process";

/**
 * Extract a .rm file (which is a zip archive) to a temporary directory.
 * Returns the path to the extraction directory.
 */
export async function extractRmFile(rmPath: string, outputDir: string): Promise<string> {
  // .rm files are zip archives
  const { code, stderr } = await runCommand("unzip", ["-o", rmPath, "-d", outputDir]);
  if (code !== 0) {
    throw new Error(`Failed to extract .rm file: ${stderr}`);
  }
  return outputDir;
}

/**
 * List the contents of the extracted .rm archive.
 */
export async function listRmContents(extractedDir: string): Promise<string[]> {
  const { stdout, code, stderr } = await runCommand("find", [extractedDir, "-type", "f"]);
  if (code !== 0) {
    throw new Error(`Failed to list .rm contents: ${stderr}`);
  }
  return stdout.trim().split("\n").filter(Boolean);
}

/**
 * Check if a document is a notebook (handwritten) or a PDF/ebook.
 * On reMarkable v3.x, notebooks have .rm page files and no content.pdf.
 * Falls back to rendering a test page if ambiguous.
 */
export async function isNotebook(extractedDir: string): Promise<boolean> {
  const contents = await listRmContents(extractedDir);
  // Notebooks have .rm page files and no embedded PDF content
  const hasRmPages = contents.some((f) => f.endsWith(".rm") && !f.endsWith(".zip"));
  const hasContentPdf = contents.some((f) => f.endsWith("content.pdf") || f.endsWith(".pdf"));

  // Clear case
  if (hasRmPages && !hasContentPdf) return true;
  if (!hasRmPages || hasContentPdf) return false;

  // Ambiguous: try to render a page
  const pageFiles = contents.filter((f) => f.endsWith(".rm") && !f.endsWith(".zip"));
  if (pageFiles.length === 0) return false;

  try {
    // Try rendering the first page
    const { code } = await runCommand("file", [pageFiles[0]]);
    // If file command succeeds and identifies it as data, assume notebook
    return code === 0;
  } catch {
    return false;
  }
}

/**
 * Get the list of page .rm files from an extracted notebook.
 * Returns basenames only.
 * Recursively searches for .rm files (not just root).
 */
export async function getPageFiles(extractedDir: string): Promise<string[]> {
  const contents = await listRmContents(extractedDir);
  return contents.filter((f) => f.endsWith(".rm") && !f.endsWith(".zip")).sort();
}