// src/integrations/serviceChannel/attachments.js
import scAxios from './client.js';
import axios from 'axios';
import { extname } from 'node:path';
import { logger } from '../../utils/logger.js';

const mimeTypes = {
  '.pdf': 'application/pdf',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.png': 'image/png',
  '.gif': 'image/gif',
  '.doc': 'application/msword',
  '.docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  '.xls': 'application/vnd.ms-excel',
  '.xlsx': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
  '.txt': 'text/plain',
};

function getContentTypeFromFilename(filename) {
  if (!filename) return 'application/octet-stream';
  const ext = extname(filename).toLowerCase();
  return mimeTypes[ext] || 'application/octet-stream';
}

// ──────────────────────────────────────────────
// Download single attachment by ID
// ──────────────────────────────────────────────
export async function downloadAttachmentById(workOrderId, attachmentId) {
  const start = Date.now();
  logger('servicechannel:attachment', `Downloading attachment ${attachmentId} from WO ${workOrderId}`);

  try {
    // First get metadata (to get Uri + Name)
    const metaRes = await scAxios.get(`/odata/workorders(${workOrderId})/attachments`, {
      params: { $filter: `Id eq ${attachmentId}` },
    });

    const atts = metaRes.data.value || [];
    if (atts.length === 0) {
      throw new Error(`Attachment ${attachmentId} not found on WO ${workOrderId}`);
    }

    const att = atts[0];
    if (!att.Uri) {
      throw new Error(`No download URI for attachment ${attachmentId}`);
    }

    let fileName = att.Name || `attachment_${attachmentId}`;
    if (att.Name && !extname(att.Name)) {
      fileName += '.bin';
    }

    // Download the actual file
    const fileRes = await axios.get(att.Uri, { responseType: 'arraybuffer' });

    logger('servicechannel:attachment', 
      `Successfully downloaded ${fileName} (${Date.now() - start} ms)`);

    return {
      success: true,
      fileName,
      buffer: Buffer.from(fileRes.data),
      contentType: getContentTypeFromFilename(fileName),
      isInvoiceCopy: !!att.IsInvoiceDigitalCopy,
      metadata: att,
    };
  } catch (err) {
    const msg = err.response
      ? `${err.response?.status || 'unknown'} – ${err.message}`
      : err.message;

    logger('servicechannel:attachment', 
      `Failed to download attachment ${attachmentId} from WO ${workOrderId}: ${msg}`, 'error');

    throw new Error(`Download failed for WO ${workOrderId} / Att ${attachmentId}: ${msg}`);
  }
}

// ──────────────────────────────────────────────
// Attachment Functions
// ──────────────────────────────────────────────

export async function listWorkOrderAttachments(workOrderId) {
  logger('servicechannel:client', `Listing attachments for work order ${workOrderId}`);

  try {
    const response = await scAxios.get(`/workorders/${workOrderId}/attachments`);
    const attachments = response.data?.value || response.data?.Attachments || response.data || [];

    logger('servicechannel:client', `Found ${attachments.length} attachments for WO ${workOrderId}`);
    return attachments;
  } catch (err) {
    logger('servicechannel:client', `Failed to list attachments for WO ${workOrderId}: ${err.message}`, 'error');
    return [];
  }
}

export async function getWorkOrderAttachments(woId) {
  logger('servicechannel:client', `Fetching attachments for work order ${woId}`);

  try {
    const response = await scAxios.get(`/workorders/${woId}/attachments`);
    const attachments = response.data?.value || response.data?.Attachments || response.data || [];

    logger('servicechannel:client', `Found ${attachments.length} attachments for WO ${woId}`);

    return attachments.map(att => ({
      id: att.Id || att.AttachmentId,
      fileName: att.FileName || att.Name || att.OriginalFileName || 'attachment',
      fileType: att.ContentType || att.MimeType || 'application/octet-stream',
      fileSize: att.FileSize ? `${(att.FileSize / 1024).toFixed(1)} KB` : 'Unknown size',
      uploadedDate: att.CreatedDateTime || att.UploadedOn || att.DateCreated
        ? new Date(att.CreatedDateTime || att.UploadedOn || att.DateCreated).toLocaleString('en-US')
        : 'Unknown',
      downloadUrl: att.DownloadUrl || att.Url || null
    }));
  } catch (err) {
    logger('servicechannel:client', `Error fetching attachments for WO ${woId}: ${err.message}`, 'error');
    return [];
  }
}