import { voicesForLocale } from "@rakazo/core";
import { useFocusEffect } from "expo-router";
import { useCallback, useState } from "react";
import { ActivityIndicator, Pressable, ScrollView, StyleSheet, Text, View } from "react-native";
import { SafeAreaView } from "react-native-safe-area-context";
import { NativeSymbol } from "../components/native-symbol";
import { rpc } from "../lib/api";
import { mobileTokens } from "../lib/appearance";
import { useI18n } from "../lib/i18n";
import { native, useThemedStyles } from "../lib/native";
import {
  alignVoiceWithLocale,
  KOKORO_LOCAL_TOKEN,
  LOCAL_VOICE_PROVIDER,
  speakText,
} from "../lib/voice";

type VoiceCredential = {
  id: string;
  provider: string;
  voiceId: string;
};
type VoiceInfo = { id: string; label: string; description?: string };

export default function VoiceSettings() {
  const styles = useThemedStyles(createVoiceStyles);
  const { locale, t } = useI18n();
  const [connected, setConnected] = useState(false);
  const [voices, setVoices] = useState<VoiceInfo[]>([]);
  const [voiceId, setVoiceId] = useState("");
  const [loading, setLoading] = useState(true);
  const [pending, setPending] = useState<"connect" | "disconnect" | "voice" | null>(null);
  const [playing, setPlaying] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);

  const load = useCallback(async () => {
    await alignVoiceWithLocale(locale).catch(() => undefined);
    const credentials = await rpc<VoiceCredential[]>("voice/credentials");
    const cred = credentials.find((entry) => entry.provider === LOCAL_VOICE_PROVIDER);
    setConnected(Boolean(cred));
    setVoiceId(cred?.voiceId ?? "");
    if (cred) {
      const listed = await rpc<VoiceInfo[]>("voice/voices", { provider: LOCAL_VOICE_PROVIDER });
      setVoices(voicesForLocale(listed, locale));
    } else {
      setVoices([]);
    }
  }, [locale]);

  useFocusEffect(
    useCallback(() => {
      setLoading(true);
      void load()
        .catch((err: unknown) =>
          setError(err instanceof Error ? err.message : t("Could not load voice settings")),
        )
        .finally(() => setLoading(false));
    }, [load]),
  );

  async function connect() {
    setPending("connect");
    setError(null);
    try {
      await rpc("voice/connect", { provider: LOCAL_VOICE_PROVIDER, apiKey: KOKORO_LOCAL_TOKEN });
      await load();
    } catch (err) {
      setError(err instanceof Error ? err.message : t("Could not connect"));
    } finally {
      setPending(null);
    }
  }

  async function disconnect() {
    setPending("disconnect");
    setError(null);
    try {
      await rpc("voice/disconnect", { provider: LOCAL_VOICE_PROVIDER });
      await load();
    } catch (err) {
      setError(err instanceof Error ? err.message : t("Could not disconnect"));
    } finally {
      setPending(null);
    }
  }

  async function chooseVoice(nextVoiceId: string) {
    setVoiceId(nextVoiceId);
    setPending("voice");
    setError(null);
    try {
      await rpc("voice/setVoice", { voiceId: nextVoiceId, provider: LOCAL_VOICE_PROVIDER });
    } catch (err) {
      setError(err instanceof Error ? err.message : t("Could not save that voice"));
      await load().catch(() => undefined);
    } finally {
      setPending(null);
    }
  }

  async function playVoice(voice: VoiceInfo) {
    setPlaying(voice.id);
    setError(null);
    try {
      await speakText(t("Hi, this is how I'll sound when I read replies out loud."), {
        voiceId: voice.id,
      });
    } catch (err) {
      setError(err instanceof Error ? err.message : t("Could not play a sample"));
    } finally {
      setPlaying((current) => (current === voice.id ? null : current));
    }
  }

  const busy = pending !== null;

  return (
    <SafeAreaView edges={["bottom"]} style={styles.screen}>
      <ScrollView contentContainerStyle={styles.content}>
        {loading ? <ActivityIndicator color={native.secondaryLabel} /> : null}
        {error ? <Text style={styles.error}>{error}</Text> : null}
        {!loading && !connected ? (
          <Pressable
            disabled={busy}
            onPress={() => void connect()}
            style={[styles.button, busy && styles.disabled]}
          >
            <Text style={styles.buttonLabel}>{t("Connect")}</Text>
          </Pressable>
        ) : null}
        {voices.length ? (
          <ScrollView
            horizontal
            accessibilityRole="radiogroup"
            showsHorizontalScrollIndicator={false}
            snapToInterval={CARD_WIDTH + CARD_GAP}
            decelerationRate="fast"
            style={styles.carousel}
            contentContainerStyle={styles.carouselContent}
          >
            {voices.map((voice) => {
              const active = voiceId === voice.id;
              return (
                <Pressable
                  key={voice.id}
                  accessibilityRole="radio"
                  accessibilityState={{ checked: active, disabled: busy }}
                  disabled={busy}
                  onPress={() => void chooseVoice(voice.id)}
                  style={[styles.card, active && styles.cardActive]}
                >
                  <View style={styles.cardHeader}>
                    <Text numberOfLines={1} style={styles.cardTitle}>
                      {voice.label}
                    </Text>
                    <Pressable
                      accessibilityRole="button"
                      accessibilityLabel={t("Play {name}", { name: voice.label })}
                      disabled={playing !== null}
                      hitSlop={8}
                      onPress={() => void playVoice(voice)}
                      style={styles.play}
                    >
                      {playing === voice.id ? (
                        <ActivityIndicator size="small" color={native.secondaryLabel} />
                      ) : (
                        <NativeSymbol ios="play.fill" android="play" size={14} />
                      )}
                    </Pressable>
                  </View>
                  {voice.description ? (
                    <Text style={styles.cardMeta}>{voice.description}</Text>
                  ) : null}
                </Pressable>
              );
            })}
          </ScrollView>
        ) : null}
        {connected ? (
          <Pressable
            disabled={busy}
            onPress={() => void disconnect()}
            style={[styles.secondary, busy && styles.disabled]}
          >
            <Text style={styles.secondaryLabel}>
              {pending === "disconnect" ? t("Disconnecting…") : t("Disconnect")}
            </Text>
          </Pressable>
        ) : null}
      </ScrollView>
    </SafeAreaView>
  );
}

const CARD_WIDTH = 160;
const CARD_GAP = 12;

function createVoiceStyles() {
  const tokens = mobileTokens();
  return StyleSheet.create({
    screen: { flex: 1, backgroundColor: native.page },
    content: { paddingVertical: 20, gap: 10 },
    error: { color: tokens.destructive, marginBottom: 8, marginHorizontal: 20 },
    carousel: { flexGrow: 0 },
    carouselContent: { paddingHorizontal: 20, gap: CARD_GAP },
    card: {
      width: CARD_WIDTH,
      borderRadius: 14,
      borderWidth: 1,
      borderColor: tokens.border,
      paddingHorizontal: 14,
      paddingVertical: 12,
      backgroundColor: tokens.card,
    },
    cardActive: { borderColor: tokens.primary, borderWidth: 2, backgroundColor: tokens.muted },
    cardHeader: { flexDirection: "row", alignItems: "center", justifyContent: "space-between" },
    cardTitle: { flexShrink: 1, color: native.label, fontSize: 16, fontWeight: "600" },
    cardMeta: { color: native.tertiaryLabel, marginTop: 4, fontSize: 13 },
    play: {
      width: 30,
      height: 30,
      borderRadius: 15,
      alignItems: "center",
      justifyContent: "center",
      backgroundColor: tokens.muted,
    },
    button: {
      marginHorizontal: 20,
      backgroundColor: tokens.primary,
      borderRadius: 12,
      paddingVertical: 12,
      alignItems: "center",
    },
    disabled: { opacity: 0.4 },
    buttonLabel: { color: tokens.primaryForeground, fontWeight: "600" },
    secondary: { marginTop: 16, alignItems: "center" },
    secondaryLabel: { color: native.secondaryLabel, fontSize: 15 },
  });
}