import { useState, useCallback, useEffect } from "react";
import { fetchCodexUsage } from "@/lib/api/codexApi";
import { loadCodexAuth, saveCodexAuth, clearCodexAuth } from "@/lib/storage";
import { pickAndReadCodexAuth } from "@/lib/fileReader";
import type { CodexUsageResponse, CodexAuth } from "@/types/codex";

type Status = "idle" | "loading" | "success" | "error";

export function useCodexUsage() {
  const [auth, setAuth] = useState<CodexAuth | null>(null);
  const [usage, setUsage] = useState<CodexUsageResponse | null>(null);
  const [status, setStatus] = useState<Status>("idle");
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    loadCodexAuth().then((stored) => {
      if (stored) setAuth(stored);
    });
  }, []);

  const importAuthFile = useCallback(async () => {
    try {
      const parsed = await pickAndReadCodexAuth();
      await saveCodexAuth(parsed);
      setAuth(parsed);
      setError(null);
    } catch (e: unknown) {
      const msg = e instanceof Error ? e.message : "UNKNOWN_ERROR";
      if (msg !== "PICKER_CANCELLED") setError(msg);
    }
  }, []);

  const refresh = useCallback(async () => {
    if (!auth) return;
    setStatus("loading");
    setError(null);
    try {
      const data = await fetchCodexUsage(auth);
      setUsage(data);
      setStatus("success");
    } catch (e: unknown) {
      const msg = e instanceof Error ? e.message : "UNKNOWN_ERROR";
      setError(msg);
      setStatus("error");
      if (msg === "TOKEN_EXPIRED") {
        await clearCodexAuth();
        setAuth(null);
      }
    }
  }, [auth]);

  useEffect(() => {
    if (auth) void refresh();
  }, [auth]);

  const clearAuth = useCallback(async () => {
    await clearCodexAuth();
    setAuth(null);
    setUsage(null);
    setStatus("idle");
    setError(null);
  }, []);

  return { auth, usage, status, error, importAuthFile, refresh, clearAuth };
}