const fs = require("fs");
const path = require("path");

// Directory containing the content files
const CONTENT_DIR = "./content";

// Fields to transfer
const FIELDS = [
  "Date",
  "Categories",
  "Affiliatelink",
  "Autopublish",
  "Autopublishdate",
  "Tags",
];

// Function to process a single German file
function processFile(deFilePath) {
  const enFilePath = deFilePath.replace(".de.md", ".en.md");
  let firstChange = true;

  if (!fs.existsSync(enFilePath)) {
    console.log(`Skipping ${deFilePath} as no corresponding EN file found.`);
    return;
  }

  console.log(`Processing ${deFilePath} and ${enFilePath}`);

  // Read file contents
  const deContent = fs.readFileSync(deFilePath, "utf-8");
  const enContent = fs.readFileSync(enFilePath, "utf-8");

  // Split content into blocks
  const deBlocks = deContent.split("----").map((block) => block.trim());
  let updatedDeBlocks = [];
  let updatedEnContent = enContent;

  for (const block of deBlocks) {
    if (!block) continue; // Skip empty blocks

    let isFieldTransferred = false;

    for (const field of FIELDS) {
      const fieldRegex = new RegExp(`^${field}:\\s*(.+)$`, "m");
      const match = block.match(fieldRegex);

      if (match) {
        const value = match[1];
        console.log(
          `Extracted value for ${field} in ${deFilePath}: '${value}'`,
        );

        // Update or append the field in the EN file
        const enFieldRegex = new RegExp(`^${field}:`, "m");
        if (updatedEnContent.match(enFieldRegex)) {
          updatedEnContent = updatedEnContent.replace(
            enFieldRegex,
            `${field}: ${value}`,
          );
        } else {
          if (firstChange) {
            updatedEnContent += `\n\n----\n\n${field}: ${value}\n`;
            firstChange = false;
          } else {
            updatedEnContent += `\n----\n\n${field}: ${value}\n`;
          }
        }

        isFieldTransferred = true;
      }
    }

    // Keep blocks that do not contain transferred fields
    if (!isFieldTransferred) {
      updatedDeBlocks.push(block);
    }
  }

  // Remove empty blocks and reassemble the German file
  const newDeContent = updatedDeBlocks.filter(Boolean).join("\n\n----\n\n");

  // Write the updated content back to the files
  fs.writeFileSync(deFilePath, newDeContent.trim() + "\n");
  fs.writeFileSync(enFilePath, updatedEnContent.trim() + "\n");

  console.log(`Updated ${deFilePath} and ${enFilePath}`);
}

// Recursive function to find and process all `.de.md` files
function processDirectory(directory) {
  console.log("-------- Process:", directory);
  const entries = fs.readdirSync(directory, { withFileTypes: true });

  for (const entry of entries) {
    const fullPath = path.join(directory, entry.name);

    if (entry.isDirectory()) {
      processDirectory(fullPath);
    } else if (entry.isFile() && fullPath.endsWith(".de.md")) {
      processFile(fullPath);
    }
  }
}

// Start processing
processDirectory(CONTENT_DIR);

console.log("Field transfer and cleanup complete.");