const fs = require("fs").promises;
const path = require("path");
const config = require("../config");

class AttachmentHandler {
  constructor() {
    this.attachmentsDir = path.join(__dirname, "..", "attachments");
  }

  async getAttachments() {
    if (!config.attachments.enabled || config.attachments.files.length === 0) {
      return [];
    }

    const attachments = [];

    for (const filename of config.attachments.files) {
      try {
        const filePath = path.join(this.attachmentsDir, filename);

        // Check if file exists
        await fs.access(filePath);

        // Get file stats for size validation
        const stats = await fs.stat(filePath);

        // Skip files larger than 10MB to avoid email size issues
        if (stats.size > 10 * 1024 * 1024) {
          console.warn(`Skipping ${filename}: File too large (>10MB)`);
          continue;
        }

        attachments.push({
          filename: filename,
          path: filePath,
        });
      } catch (error) {
        console.warn(`Unable to attach ${filename}: ${error.message}`);
      }
    }

    return attachments;
  }

  // Helper to validate attachment types
  isValidFileType(filename) {
    const validExtensions = [
      ".pdf",
      ".doc",
      ".docx",
      ".txt",
      ".jpg",
      ".jpeg",
      ".png",
      ".gif",
    ];
    const ext = path.extname(filename).toLowerCase();
    return validExtensions.includes(ext);
  }

  // Get list of available attachments for logging
  async listAvailableFiles() {
    try {
      const files = await fs.readdir(this.attachmentsDir);
      return files.filter((file) => this.isValidFileType(file));
    } catch (error) {
      return [];
    }
  }
}

module.exports = new AttachmentHandler();