import "package:auto_route/auto_route.dart";
import "package:flutter/material.dart";
import "package:flutter_riverpod/flutter_riverpod.dart";
import "package:mobile_scanner/mobile_scanner.dart";

import "package:smol_mail/data/providers/providers.dart";
import "package:smol_mail/presentation/app_widget.dart";
import "package:smol_mail/presentation/theme/app_colors.dart";
import "package:smol_mail/shared/utils/snackbar.dart";
import "package:smol_mail/smol/errors.dart";
import "package:smol_mail/smol/link.dart";

/// The §8 strong path: a self-certifying smol:// address is pasted, scanned
/// or deep-linked in, and the user confirms before its key is bound. A
/// routed dialog page rather than showDialog, so auto_route's platform-link
/// handling — which pops pageless top routes — leaves it standing. The QR
/// icon swaps the text field for a camera view; a scanned URI only fills
/// the field, the Import tap is still what binds the key.
@RoutePage()
class ImportContactDialogScreen extends ConsumerStatefulWidget {
  final String? prefill;

  const ImportContactDialogScreen({super.key, this.prefill});

  @override
  ConsumerState<ImportContactDialogScreen> createState() =>
      ImportContactDialogScreenState();
}

class ImportContactDialogScreenState
    extends ConsumerState<ImportContactDialogScreen> {
  late final controller = TextEditingController(text: widget.prefill ?? "");
  bool scanning = false;
  MobileScannerController? _scanner;

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

  void _toggleScan() {
    setState(() {
      _scanner?.dispose();
      _scanner =
          scanning ? null : MobileScannerController(formats: [BarcodeFormat.qrCode]);
      scanning = !scanning;
    });
  }

  // Only a URI fumi accepts fills the field; anything else the camera sees
  // is not for this dialog, so scanning simply continues.
  void _onDetect(BarcodeCapture capture) {
    if (!scanning) return;
    for (final barcode in capture.barcodes) {
      final raw = barcode.rawValue?.trim();
      if (raw != null && parseSmolLink(raw) != null) {
        controller.text = raw;
        _toggleScan();
        return;
      }
    }
  }

  void _import() {
    final text = controller.text;
    if (text.trim().isEmpty) return;
    try {
      ref.read(clientProvider).importContact(text);
      ref.read(revisionProvider.notifier).bump();
      rootScaffoldMessengerKey.currentState?.showSnackBar(
        const SnackBar(content: Text("contact imported (verified key)")),
      );
      AutoRouter.of(context).pop();
    } on SmolError catch (err) {
      showErrorSnackBar(context, err.message);
    }
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      backgroundColor: Theme.of(context).extension<AppColors>()!.cardFill,
      title: const Text("Import contact"),
      content: scanning
          ? SizedBox(
              height: 220,
              width: double.maxFinite,
              child: ClipRRect(
                borderRadius: BorderRadius.circular(12),
                child: MobileScanner(
                  controller: _scanner!,
                  onDetect: _onDetect,
                  errorBuilder: (context, error) => Center(
                    child: Padding(
                      padding: const EdgeInsets.all(12),
                      child: Text(
                        error.errorCode.name,
                        style: Theme.of(context).textTheme.labelSmall,
                        textAlign: TextAlign.center,
                      ),
                    ),
                  ),
                ),
              ),
            )
          : TextField(
              controller: controller,
              autofocus: true,
              onSubmitted: (_) => _import(),
              decoration: InputDecoration(
                hintText: "smol://user@host/key",
                filled: true,
                fillColor: Theme.of(context).colorScheme.surface,
              ),
            ),
      actions: [
        IconButton(
          tooltip: scanning ? "Type the address" : "Scan a QR code",
          onPressed: _toggleScan,
          icon: Icon(scanning ? Icons.keyboard : Icons.qr_code_scanner),
        ),
        TextButton(
          onPressed: _import,
          child: const Text("Import"),
        ),
      ],
    );
  }
}