// End-to-end against a live server: register an address, send sealed mail to
// ourselves, fetch it back, exercise the accept-token round trip (§5.8)
// between the requests and main tiers, restore onto a second store, and
// check the server is drained afterwards. Skips when nothing listens on
// 127.0.0.1:1961, so `devbox run test` does not depend on a server.
//
// The server key is pinned directly: on this machine the bunshin.service
// static key is a documented, operator-supplied value — exactly the trusted
// channel SPEC.md §4 asks a pin to come from.

import "dart:io";
import "dart:math";
import "dart:typed_data";

import "package:flutter_test/flutter_test.dart";
import "package:hive_flutter/hive_flutter.dart";

import "package:smol_mail/smol/address.dart";
import "package:smol_mail/smol/client.dart";
import "package:smol_mail/smol/errors.dart";
import "package:smol_mail/smol/store.dart";
import "package:smol_mail/smol/ui.dart";

const host = "127.0.0.1";
const port = 1961;
const serverKey = "lm2gqd7e5q67xq3isc5hx6jfj2q7a7xvq4l7trctxipudujovmgq";

Uint8List randomBytes(int n) =>
    Uint8List.fromList(List.generate(n, (_) => Random.secure().nextInt(256)));

Future<bool> serverUp() async {
  try {
    final probe = await Socket.connect(host, port,
        timeout: const Duration(seconds: 2));
    probe.destroy();
    return true;
  } catch (_) {
    return false;
  }
}

Future<SmolStore> freshStore(String tag, String dir) => SmolStore.open(
    dbPath: "$dir/$tag.db", stateBox: "$tag-state", readBox: "$tag-read");

void main() {
  test("register, send to self, fetch, unseal, drain", () async {
    if (!await serverUp()) {
      markTestSkipped("no server on $host:$port");
      return;
    }
    final dir = await Directory.systemTemp.createTemp("smol-e2e");
    Hive.init(dir.path);
    final store = await freshStore("main", dir.path);
    final client = SmolClient(store);

    final warnings = <String>[];
    client.onWarning = warnings.add;

    await client.createIdentity();
    final me = client.identity!;
    final user = "e2e${hex(randomBytes(4))}";
    final address = parseAddress("$user@$host");
    store.pinServer(host, serverKey, port);

    await client.registerAccount(address.short);
    expect(client.accountAddress()!.short, address.short);

    await client.send(address.short, "hello e2e", "sealed and signed");
    await client.send(address.short, "second", "another sealed envelope");

    final summary = await client.fetch();
    expect(summary.stored, 2);
    expect(summary.rejected, isEmpty);

    // §5.8: we have not accepted ourselves as a correspondent yet, so this
    // unsolicited self-mail lands in the requests tier, not the main one.
    expect(store.listMessages("inbox"), isEmpty);
    final requests = store.listMessages("requests");
    expect(requests.length, 2);
    final subjects = requests.map((m) => client.describe(m).subject).toSet();
    expect(subjects, {"hello e2e", "second"});
    final hello = requests
        .firstWhere((m) => client.describe(m).subject == "hello e2e");
    final opened = client.describe(hello);
    expect(opened.error, isNull);
    // fumi's describe splits the trailing newline into the frontmatter
    // parse, so the body arrives trimmed.
    expect(opened.body, "sealed and signed");
    expect(opened.sender, me.publicKey);

    // The server must be drained: everything that verified was acknowledged.
    final again = await client.fetch();
    expect(again.stored, 0);

    // Accept ourselves as a correspondent (§5.8): the change is pushed to
    // the server right away. This next message carries our own Accept field,
    // but no MAC yet, so it still lands in requests.
    await client.acceptContact(address.short);
    await client.send(address.short, "third", "still unsolicited");
    expect((await client.fetch()).stored, 1);
    expect(store.listMessages("requests").length, 3);
    expect(store.listMessages("inbox"), isEmpty);

    // Having now learned our own token, the next one carries a matching MAC
    // and reaches the main tier.
    await client.send(address.short, "fourth", "now accepted");
    expect((await client.fetch()).stored, 1);
    final mainTier = store.listMessages("inbox");
    expect(mainTier.length, 1);
    expect(client.describe(mainTier.single).subject, "fourth");

    // The sent copy is sealed to ourselves and readable (§5.6).
    final sent = store.listMessages("sent");
    expect(sent.length, 4);
    expect(client.describe(sent.first).error, isNull);

    // A restored seed can rebind the address without REGISTER; the address
    // must resolve to this identity's key.
    final recalled = await client.recallAccount(address.short);
    expect(recalled.short, address.short);
    expect(
        () => client.recallAccount("nobody@$host"), throwsA(isA<SmolError>()));

    // Restore on a second device: same master, fresh store, no pin. Unpinned
    // recall is refused; re-registering a taken name is refused; recall with
    // the operator-supplied key then binds the account without REGISTER.
    final secondStore = await freshStore("second", dir.path);
    final secondDevice = SmolClient(secondStore);
    secondStore.restoreMaster(store.master()!, 0);
    await expectLater(
        secondDevice.recallAccount(address.short), throwsA(isA<SmolError>()));
    secondStore.pinServer(host, serverKey, port);
    await expectLater(
        secondDevice.registerAccount(address.short), throwsA(isA<SmolError>()));
    final bound = await secondDevice.recallAccount(address.short);
    expect(bound.short, address.short);
    expect(secondDevice.accountAddress()!.user, user);

    // Re-resolving our own address finds the same key and says so quietly.
    final outcome = await client.refreshContact(address.short);
    expect(outcome.warn, isFalse);
    expect(outcome.message, contains("key unchanged"));
    expect(store.contact(address.short)!.history, isEmpty);
  }, timeout: const Timeout(Duration(minutes: 2)));

  test("leave mail on server keeps mail until deleted, with dedupe on refetch",
      () async {
    if (!await serverUp()) {
      markTestSkipped("no server on $host:$port");
      return;
    }
    final dir = await Directory.systemTemp.createTemp("smol-e2e-keep");
    Hive.init(dir.path);
    final store = await freshStore("keep", dir.path);
    final client = SmolClient(store);

    await client.createIdentity();
    final user = "e2ekeep${hex(randomBytes(4))}";
    final address = parseAddress("$user@$host");
    store.pinServer(host, serverKey, port);
    await client.registerAccount(address.short);

    await store.setLeaveOnServer(true);
    await client.send(address.short, "kept", "stays on the server until deleted");

    final first = await client.fetch();
    expect(first.stored, 1);
    final record = store.listMessages("requests").single;
    expect(record.keptOnServer, isTrue);
    expect(client.describe(record).subject, "kept");

    // Re-paging from scratch must not duplicate it locally (the seen-id
    // dedupe), even though the server still has it (nothing was deleted).
    final second = await client.fetch(reset: true);
    expect(second.stored, 0);
    expect(store.listMessages("requests").length, 1);

    // Deleting removes it locally and from the server too: a further full
    // re-page after deletion comes back empty rather than resurrecting it.
    await client.deleteMessage("requests", record);
    expect(store.listMessages("requests"), isEmpty);
    final third = await client.fetch(reset: true);
    expect(third.stored, 0);
    expect(store.listMessages("requests"), isEmpty);
  }, timeout: const Timeout(Duration(minutes: 2)));
}