import { useState, useEffect } from "react";

type VoiceMode = "text" | "voice_input" | "full_voice";

interface UseVoiceModeReturn {
  mode: VoiceMode;
  setMode: (next: VoiceMode) => Promise<void>;
  isLoading: boolean;
}

export function useVoiceMode(): UseVoiceModeReturn {
  const [mode, setModeState] = useState<VoiceMode>("text");
  const [isLoading, setIsLoading] = useState(true);

  // Load current voiceMode from nexus-settings on mount
  useEffect(() => {
    let cancelled = false;

    const load = async () => {
      try {
        const res = await fetch("/api/nexus/settings", {
          credentials: "include",
        });

        if (res.ok && !cancelled) {
          const data = (await res.json()) as { voiceMode?: string };
          const raw = data.voiceMode;
          if (raw === "voice_input" || raw === "full_voice" || raw === "text") {
            setModeState(raw as VoiceMode);
          }
        }
      } catch (err) {
        console.error("[useVoiceMode] Failed to load settings:", err);
      } finally {
        if (!cancelled) {
          setIsLoading(false);
        }
      }
    };

    load();
    return () => {
      cancelled = true;
    };
  }, []);

  const setMode = async (next: VoiceMode): Promise<void> => {
    const previous = mode;
    // Optimistic update
    setModeState(next);

    try {
      const res = await fetch("/api/nexus/settings", {
        method: "PATCH",
        credentials: "include",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ voiceMode: next }),
      });

      if (!res.ok) {
        throw new Error(`PATCH /api/nexus/settings returned ${res.status}`);
      }
    } catch (err) {
      console.error("[useVoiceMode] Failed to update voiceMode:", err);
      // Revert on error
      setModeState(previous);
    }
  };

  return { mode, setMode, isLoading };
}