kent_logistics_app/lib/screens/chat_file_viewer.dart

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:photo_view/photo_view.dart';
import 'package:video_player/video_player.dart';
import 'package:chewie/chewie.dart';
import 'package:flutter_pdfview/flutter_pdfview.dart';
import 'package:path_provider/path_provider.dart';
import 'package:dio/dio.dart';

class ChatFileViewer {
  /// Entry point used by chat screen
  static void open(
      BuildContext context, {
        required String url,
        required String fileType,
      }) {
    if (fileType.startsWith('image/')) {
      _openImage(context, url);
    } else if (fileType.startsWith('video/')) {
      _openVideo(context, url);
    } else if (fileType == 'application/pdf') {
      _openPdf(context, url);
    } else {
      _downloadFile(context, url);
    }
  }

  // ===========================
  // IMAGE VIEWER
  // ===========================
  static void _openImage(BuildContext context, String url) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => Scaffold(
          backgroundColor: Colors.black,
          appBar: AppBar(backgroundColor: Colors.black),
          body: PhotoView(
            imageProvider: NetworkImage(url),
          ),
        ),
      ),
    );
  }

  // ===========================
  // VIDEO VIEWER
  // ===========================
  static void _openVideo(BuildContext context, String url) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => _VideoPlayerPage(url: url),
      ),
    );
  }

  // ===========================
  // PDF VIEWER
  // ===========================
  static Future<void> _openPdf(
      BuildContext context, String url) async {
    final dir = await getTemporaryDirectory();
    final path = "${dir.path}/chat.pdf";

    await Dio().download(url, path);

    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => Scaffold(
          appBar: AppBar(title: const Text("PDF")),
          body: PDFView(filePath: path),
        ),
      ),
    );
  }

  // ===========================
  // FILE DOWNLOAD
  // ===========================
  static Future<void> _downloadFile(
      BuildContext context, String url) async {
    final dir = await getExternalStorageDirectory();
    final fileName = url.split('/').last;
    final path = "${dir!.path}/$fileName";

    await Dio().download(url, path);

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text("File downloaded: $fileName")),
    );
  }
}

// ===========================
// VIDEO PLAYER WIDGET
// ===========================
class _VideoPlayerPage extends StatefulWidget {
  final String url;
  const _VideoPlayerPage({required this.url});

  @override
  State<_VideoPlayerPage> createState() => _VideoPlayerPageState();
}

class _VideoPlayerPageState extends State<_VideoPlayerPage> {
  late VideoPlayerController _videoController;
  ChewieController? _chewieController;

  @override
  void initState() {
    super.initState();

    _videoController = VideoPlayerController.network(widget.url)
      ..initialize().then((_) {
        setState(() {
          _chewieController = ChewieController(
            videoPlayerController: _videoController,
            autoPlay: true,
            looping: false,
          );
        });
      });
  }

  @override
  void dispose() {
    _videoController.dispose();
    _chewieController?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("Video")),
      body: Center(
        child: _chewieController == null
            ? const CircularProgressIndicator()
            : Chewie(controller: _chewieController!),
      ),
    );
  }
}