import { useQuery } from "@tanstack/react-query";
import { useRouter } from "expo-router";
import React, { useEffect, useRef } from "react";
import { Text, View } from "react-native";
import { useApp } from "../../src/app-context";
import { AppHeader } from "../../src/components/AppHeader";
import { ChatScreenHeader } from "../../src/components/ChatScreenHeader";
import { GuestAuthGate } from "../../src/components/GuestAuthGate";
import { ScreenShell } from "../../src/components/ScreenShell";
import {
  bindPendingFileIntent,
  bindPendingTextIntent,
  loadPendingTextIntent,
  pendingDialogKey,
} from "../../src/pending-intent";
import { dialogApi } from "../../src/services";
import { ErrorNotice, Loading, styles } from "../../src/ui";
import { spacing } from "../../src/theme";

export default function DialogsScreen() {
  const app = useApp();
  const router = useRouter();
  const requestKey = useRef(pendingDialogKey() ?? crypto.randomUUID());
  const chat = useQuery({
    queryKey: ["current-dialog", requestKey.current],
    queryFn: () => dialogApi.create(requestKey.current),
    enabled: app.authStatus === "authenticated",
  });

  useEffect(() => {
    if (chat.data) {
      const intent = loadPendingTextIntent();
      if (intent && !intent.dialogId) bindPendingTextIntent(intent, chat.data.dialog_id);
      bindPendingFileIntent(chat.data.dialog_id);
      router.replace(`/dialogs/${chat.data.dialog_id}`);
    }
  }, [chat.data, router]);

  if (app.authStatus !== "authenticated") {
    return (
      <ScreenShell>
        <ChatScreenHeader title="Чат" subtitle="Требуется вход" />
        <GuestAuthGate
          icon="message-circle"
          title="Чат доступен после входа"
          description="Авторизуйтесь, чтобы переписываться с оператором и получать ответы."
        />
      </ScreenShell>
    );
  }

  return (
    <ScreenShell>
      <AppHeader />
      <View style={{ flex: 1, padding: spacing.lg, justifyContent: "center" }}>
        <Text accessibilityRole="header" style={styles.title}>Открываем чат…</Text>
        {chat.isLoading && <Loading />}
        {chat.error && <ErrorNotice error={chat.error} retry={() => void chat.refetch()} />}
      </View>
    </ScreenShell>
  );
}