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

import "package:smol_mail/data/providers/providers.dart";
import "package:smol_mail/shared/utils/format.dart";
import "package:smol_mail/shared/utils/snackbar.dart";
import "package:smol_mail/smol/errors.dart";
import "package:smol_mail/smol/proto.dart";

/// The full key, the address to hand out, and any key this one replaced —
/// the row can only afford a fingerprint, and §8 turns on the user being able
/// to inspect exactly what changed.
@RoutePage()
class ContactDetailScreen extends ConsumerStatefulWidget {
  final String address;

  const ContactDetailScreen({super.key, required this.address});

  @override
  ConsumerState<ContactDetailScreen> createState() =>
      _ContactDetailScreenState();
}

class _ContactDetailScreenState extends ConsumerState<ContactDetailScreen> {
  bool resolving = false;
  bool tokenBusy = false;

  // §5.8: admitting or withdrawing a contact's accept token pushes the
  // change to the server right away, since it only takes effect once the
  // server holds the changed set.
  Future<void> _toggleAccepted(bool currentlyAccepted) async {
    final client = ref.read(clientProvider);
    setState(() => tokenBusy = true);
    try {
      if (currentlyAccepted) {
        await client.blockContact(widget.address);
      } else {
        await client.acceptContact(widget.address);
      }
      ref.read(revisionProvider.notifier).bump();
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(currentlyAccepted
              ? "${widget.address} blocked; their mail now lands in requests"
              : "${widget.address} accepted; their mail now lands in your main tier")),
        );
      }
    } on SmolError catch (err) {
      if (mounted) showErrorSnackBar(context, err.message);
    } finally {
      if (mounted) setState(() => tokenBusy = false);
    }
  }

  Future<void> _reResolve() async {
    final client = ref.read(clientProvider);
    setState(() => resolving = true);
    try {
      final outcome = await client.refreshContact(widget.address);
      ref.read(revisionProvider.notifier).bump();
      if (mounted) {
        // A rotation or an unexplained key change is §8 material; it stays
        // until dismissed and stands out like any other warning.
        if (outcome.warn) {
          showErrorSnackBar(context, outcome.message,
              duration: const Duration(days: 1));
        } else {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(content: Text(outcome.message)),
          );
        }
      }
    } on SmolError catch (err) {
      if (mounted) {
        showErrorSnackBar(context, err.message);
      }
    } finally {
      if (mounted) setState(() => resolving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    ref.watch(revisionProvider);
    final store = ref.read(storeProvider);
    final contact = store.contact(widget.address);
    final accepted = store.accepted(widget.address);
    final isAccepted = accepted != null && accepted.active;

    return Scaffold(
      appBar: AppBar(title: Text(widget.address)),
      body: contact == null
          ? Center(
              child: Text("no such contact",
                  style: Theme.of(context).textTheme.labelSmall))
          : ListView(
              padding: const EdgeInsets.all(20),
              children: [
                _chip(context, contact.verified
                    ? "verified key"
                    : "key pinned on first use"),
                const SizedBox(height: 20),
                Text(
                  "Accept token (SPEC.md §5.8)",
                  style: Theme.of(context).textTheme.titleMedium,
                ),
                const SizedBox(height: 5),
                Text(
                  isAccepted
                      ? "This contact's mail lands in your main tier."
                      : "This contact's mail lands in requests until accepted.",
                  style: Theme.of(context).textTheme.labelSmall,
                ),
                const SizedBox(height: 10),
                tokenBusy
                    ? const Center(child: CircularProgressIndicator())
                    : TextButton.icon(
                        onPressed: () => _toggleAccepted(isAccepted),
                        icon: Icon(isAccepted ? Icons.block : Icons.check_circle_outline,
                            size: 18),
                        label: Text(isAccepted ? "Block" : "Accept"),
                      ),
                const SizedBox(height: 20),
                const Divider(height: 1),
                const SizedBox(height: 20),
                _field(context, "fingerprint", fingerprint(contact.key)),
                _field(context, "public key", b32encode(contact.key)),
                Row(
                    children: [
                      Expanded(
                        child: _field(
                            context,
                            "address",
                            parseAddress(widget.address)
                                .uri(contact.key)),
                      ),
                      IconButton(
                        icon: const Icon(Icons.copy, size: 18),
                        onPressed: () => copyText(
                            context,
                            parseAddress(widget.address).uri(contact.key)),
                      ),
                    ],
                  ),
                if (contact.history.isNotEmpty) ...[
                  const SizedBox(height: 30),
                  Text("previous keys (${contact.history.length})",
                      style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 5),
                  Text(
                    "Replaced by a signed rotation chain (SPEC.md §7). Mail signed with these "
                    "was sent before the change; rotation is not revocation, so a stolen key "
                    "can still rotate onward.",
                    style: Theme.of(context).textTheme.labelSmall,
                  ),
                  const SizedBox(height: 10),
                  for (final entry in contact.history)
                    Padding(
                      padding: const EdgeInsets.symmetric(vertical: 6),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(fingerprint(entry.key)),
                          Text(b32encode(entry.key),
                              style: Theme.of(context).textTheme.labelSmall),
                          Text(
                            "replaced ${formatTime(entry.until ~/ 1000)}",
                            style: Theme.of(context).textTheme.labelSmall,
                          ),
                        ],
                      ),
                    ),
                ],
                const SizedBox(height: 30),
                resolving
                    ? const Center(child: CircularProgressIndicator())
                    : TextButton.icon(
                        onPressed: _reResolve,
                        icon: const Icon(Icons.refresh, size: 18),
                        label: const Text("Re-resolve"),
                      ),
              ],
            ),
    );
  }

  Widget _chip(BuildContext context, String text) => Container(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
        decoration: BoxDecoration(
          border: Border.all(color: Theme.of(context).primaryColor),
          borderRadius: BorderRadius.circular(10),
        ),
        child: Text(
          text,
          style: Theme.of(context)
              .textTheme
              .labelSmall!
              .copyWith(color: Theme.of(context).primaryColor),
        ),
      );

  Widget _field(BuildContext context, String label, String value) => Padding(
        padding: const EdgeInsets.symmetric(vertical: 4),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(label, style: Theme.of(context).textTheme.labelSmall),
            SelectableText(value, style: Theme.of(context).textTheme.bodySmall),
          ],
        ),
      );
}