import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:go_router/go_router.dart';
import 'package:qpay/screens/gateway/gateway_controller.dart';
import 'package:webview_flutter/webview_flutter.dart';

class GatewayScreen extends StatefulWidget {
  const GatewayScreen({super.key});

  @override
  State<GatewayScreen> createState() => _GatewayScreenState();
}

class _GatewayScreenState extends State<GatewayScreen> {
  late WebViewController _webViewController;
  late GatewayController controller;
  late String url;

  bool integrationStarted = false;

  @override
  void initState() {
    super.initState();
    controller = GatewayController(context);
    url = controller.transactionController.model.receiptData?['targetUrl'];
    _initWebView(url);

    bool simulate = bool.parse(dotenv.env['SIMULATE_PAYMENT_SUCCESS']!);
    if(simulate) {
      sleep(Duration(seconds: 10));
      String targetUrl = url.replaceAll("/pay/", "/receipt/");
      _webViewController.loadRequest(Uri.parse(targetUrl));
    }
  }

  void _initWebView(String url) {
    _webViewController =
        WebViewController()
          ..setJavaScriptMode(JavaScriptMode.unrestricted)
          ..setNavigationDelegate(
            NavigationDelegate(
              onProgress: (int progress) {
                // Update loading bar.
              },
              onPageStarted: (String url) {
                controller.startLoading();
              },
              onPageFinished: (String url) {
                controller.finishLoading();
              },
              onHttpError: (HttpResponseError error) {},
              onWebResourceError: (WebResourceError error) {},
              onUrlChange: (UrlChange url) async {
                print("URL Changed to ${url.url!}");

                if(url.url!.contains("/checkout/receipt/")){
                  if(integrationStarted) {
                    return;
                  }

                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(
                      content: Text("Payment was successful, please wait while we process your order."),
                      behavior: SnackBarBehavior.floating,
                      backgroundColor: Colors.black87,
                      duration: const Duration(seconds: 10),
                    ),
                  );

                  setState(() {
                    integrationStarted = true;
                  });

                  WidgetsBinding.instance.addPostFrameCallback((_) {
                    context.go('/integration');
                  });
                }
              }
            ),
          )
          ..loadRequest(Uri.parse(url));
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Complete your payment'),
        leading:
            context.canPop()
                ? IconButton(
                  onPressed: () {
                    context.pop();
                  },
                  icon: const Icon(Icons.arrow_back),
                )
                : SizedBox.shrink(),
      ),
      body: ListenableBuilder(
        listenable: controller,
        builder: (context, child) {
          if (controller.model.status == 'SUCCESS') {
            WidgetsBinding.instance.addPostFrameCallback((_) {
              context.go('/integration');
            });
          }
          return controller.model.isLoading
              ? const Center(child: CircularProgressIndicator(strokeWidth: 5))
              : WebViewWidget(controller: _webViewController);
        },
      ),
    );
  }
}