import axios from "axios";
import apiClient from '@/lib/api/axios-instance';
import { createHeaders } from '@/lib/api';
import { API_BASE_URL } from "@/config";

// Create API_URL from API_BASE_URL
const API_URL = `${API_BASE_URL}/api`;

export interface Attachment {
  attachmentId: number;
  fileName: string;
  fileType: string;
  filePath: string;
  entityType: string;
  entityId: number;
  description?: string;
  createdAt?: string;
  createdBy?: string;
}

export interface AttachmentCreateRequest {
  attachmentId: number;
  fileName: string;
  fileType: string;
  filePath: string;
  entityType: string;
  entityId: number;
  description?: string;
  _IFormFile: File;
}

export interface DownloadResult {
  blob: Blob;
  fileName: string;
  contentType: string;
}

export interface DownloadProgressCallback {
  (progress: number, totalSize: number): void;
}

export const attachmentApi = {
  getAll: async (): Promise<Attachment[]> => {
    try {
      const response = await apiClient.get(`${API_URL}/Attachments`);
      return response.data;
    } catch (error) {
      console.error("Error fetching all attachments:", error);
      throw error;
    }
  },

  getById: async (id: number): Promise<Attachment> => {
    try {
      const response = await apiClient.get(`${API_URL}/Attachments/${id}`);
      return response.data;
    } catch (error) {
      console.error(`Error fetching attachment with ID ${id}:`, error);
      throw error;
    }
  },

  getByEntityTypeAndId: async (entityType: string, entityId: number): Promise<Attachment[]> => {
    try {
      const response = await apiClient.get(`${API_URL}/Attachments/${entityType}/${entityId}`);
      return response.data;
    } catch (error) {
      console.error(`Error fetching attachments for ${entityType} with ID ${entityId}:`, error);
      throw error;
    }
  },

  delete: async (id: number): Promise<boolean> => {
    try {
      const response = await apiClient.delete(`${API_URL}/Attachments/${id}`);
      return response.status === 200;
    } catch (error) {
      console.error(`Error deleting attachment with ID ${id}:`, error);
      throw error;
    }
  },

  upload: async (data: FormData): Promise<Attachment> => {
    try {
      const response = await apiClient.post(`${API_URL}/Attachments/uploadfile`, data, {
        headers: {
          'Content-Type': undefined,
        },
      });
      return response.data;
    } catch (error) {
      console.error("Error uploading attachment:", error);
      throw error;
    }
  },
  
  download: async (id: number, onProgress?: DownloadProgressCallback): Promise<DownloadResult> => {
    try {
      // First get the attachment info to determine the correct filename
      const attachmentInfo = await attachmentApi.getById(id);
      
      // Download the file with the blob response type
      const response = await apiClient.get(`${API_URL}/Attachments/download/${id}`, {
        responseType: 'blob',
      });
      
      // Extract content type from headers or use default
      const contentType = response.headers['content-type'] || 
                          attachmentInfo.fileType || 
                          'application/octet-stream';
      
      // Extract filename from Content-Disposition header if available
      const contentDisposition = response.headers['content-disposition'] || '';
      
      let fileName = attachmentInfo.fileName;
      
      // Try to extract filename from Content-Disposition header
      const filenameMatch = contentDisposition.match(/filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/);
      if (filenameMatch && filenameMatch[1]) {
        const extractedName = filenameMatch[1].replace(/['"]/g, '');
        if (extractedName) {
          fileName = extractedName;
        }
      }
      
      console.log(`Downloaded file: ${fileName}, content-type: ${contentType}, size: ${response.data.size} bytes`);
      
      return {
        blob: response.data,
        fileName,
        contentType
      };
    } catch (error) {
      console.error(`Error downloading attachment with ID ${id}:`, error);
      throw error;
    }
  },
  
  // Method to directly trigger a file download
  downloadAndSave: async (id: number, onProgress?: DownloadProgressCallback): Promise<void> => {
    try {
      const result = await attachmentApi.download(id, onProgress);
      
      // Create a URL for the blob
      const url = window.URL.createObjectURL(result.blob);
      
      // Create a download link
      const link = document.createElement('a');
      link.href = url;
      link.download = result.fileName;
      
      // Add to document, click and remove
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
      
      // Release the object URL
      window.URL.revokeObjectURL(url);
      
      console.log(`File "${result.fileName}" downloaded successfully`);
    } catch (error) {
      console.error(`Error downloading and saving attachment with ID ${id}:`, error);
      throw error;
    }
  },
  
  // Method to get a temporary view URL for an attachment
  getViewUrl: async (id: number): Promise<string> => {
    try {
      // Get attachment info to check file type
      const attachment = await attachmentApi.getById(id);
      const fileType = attachment.fileType.toLowerCase();
      
      // Check if it's a viewable file type
      const isViewableType = 
        fileType.includes('image') || 
        fileType.includes('pdf') || 
        fileType.includes('text') || 
        fileType.includes('html') ||
        fileType.includes('.jpg') ||
        fileType.includes('.jpeg') ||
        fileType.includes('.png') ||
        fileType.includes('.gif') ||
        fileType.includes('.webp') ||
        fileType.includes('.pdf') ||
        fileType.includes('.txt') ||
        fileType.includes('.html');
      
      if (!isViewableType) {
        throw new Error(`File type ${fileType} is not supported for preview`);
      }
      
      // Download the file as a blob and create a URL
      const result = await attachmentApi.download(id);
      const url = window.URL.createObjectURL(result.blob);
      
      return url;
    } catch (error) {
      console.error(`Error creating view URL for attachment with ID ${id}:`, error);
      throw error;
    }
  },
  
  // Check if file is viewable
  isViewable: (attachment: Attachment): boolean => {
    const fileType = attachment.fileType.toLowerCase();
    const fileName = attachment.fileName.toLowerCase();
    
    // Check if it's a viewable file type
    return (
      fileType.includes('image') || 
      fileType.includes('pdf') || 
      fileType.includes('text') || 
      fileType.includes('html') ||
      fileName.endsWith('.jpg') ||
      fileName.endsWith('.jpeg') ||
      fileName.endsWith('.png') ||
      fileName.endsWith('.gif') ||
      fileName.endsWith('.webp') ||
      fileName.endsWith('.pdf') ||
      fileName.endsWith('.txt') ||
      fileName.endsWith('.html')
    );
  }
};