/**
 * AI 模拟面试 hook：拉取面试配置 + 开始面试。
 */
import { useCallback, useState } from 'react';
import { fetchAIInterviewData, startInterview } from '../api';
import type { AIInterviewData, InterviewMode, InterviewQuestionTypeCode, InterviewSession } from '../types';
import { useAsyncData } from './useAsyncData';

export function useAIInterview() {
  const fetcher = useCallback(() => fetchAIInterviewData(), []);
  const { data, loading, error, refresh } = useAsyncData<AIInterviewData>(fetcher);

  /** 本地交互状态：模式 / 题型 / 专项 */
  const [mode, setMode] = useState<InterviewMode | null>(null);
  const [questionTypes, setQuestionTypes] = useState<InterviewQuestionTypeCode[]>([]);
  const [specials, setSpecials] = useState<string[]>([]);
  const [starting, setStarting] = useState(false);

  const resolvedMode = mode ?? data?.mode ?? 'full';
  const resolvedTypes = questionTypes.length
    ? questionTypes
    : (data?.questionTypes.filter((t) => t.selected).map((t) => t.id) ?? []);
  const resolvedSpecials = specials.length
    ? specials
    : (data?.specials.filter((s) => s.selected).map((s) => s.id) ?? []);

  const toggleQuestionType = useCallback((id: InterviewQuestionTypeCode) => {
    setQuestionTypes((prev) => {
      const base =
        prev.length > 0
          ? prev
          : ([] as InterviewQuestionTypeCode[]);
      return base.includes(id) ? base.filter((t) => t !== id) : [...base, id];
    });
  }, []);

  const toggleSpecial = useCallback((id: string) => {
    setSpecials((prev) => (prev.includes(id) ? prev.filter((s) => s !== id) : [...prev, id]));
  }, []);

  const start = useCallback(async (): Promise<InterviewSession> => {
    setStarting(true);
    try {
      return await startInterview();
    } finally {
      setStarting(false);
    }
  }, []);

  return {
    data: data ?? null,
    loading,
    error,
    refresh,
    mode: resolvedMode,
    setMode,
    questionTypes: resolvedTypes,
    toggleQuestionType,
    specials: resolvedSpecials,
    toggleSpecial,
    start,
    starting,
  };
}