// src/hooks/useHFValidators.ts
import { useMemo, useRef, useState } from 'react';
import { fetchHFModel, fetchHFDataset } from '../services/hf';

const debounce = (fn: (...args: any[]) => void, ms = 350) => {
  let t: any;
  return (...args: any[]) => {
    clearTimeout(t);
    t = setTimeout(() => fn(...args), ms);
  };
};

export function useHFModelValidator() {
  const cache = useRef<Map<string, any>>(new Map());
  const [loading, setLoading] = useState(false);
  const [result, setResult] = useState<any>(null);

  const validate = useMemo(
    () =>
      debounce(async (modelId: string, expected: 'language' | 'scorer') => {
        if (!modelId?.includes('/')) {
          setResult(null);
          return;
        }
        if (cache.current.has(modelId)) {
          setResult(cache.current.get(modelId));
          return;
        }
        setLoading(true);
        try {
          const info = await fetchHFModel(modelId);
          const id: string = info.id?.toLowerCase() ?? '';
          const tags: string[] = info.tags ?? [];
          let actual: string | undefined = info.pipeline_tag;

          if (!actual) {
            if (id.includes('t5') || tags.includes('text2text-generation')) actual = 'text2text-generation';
            else if (tags.includes('text-generation')) actual = 'text-generation';
            else if (tags.includes('text-classification')) actual = 'text-classification';
          }

          const ok =
            expected === 'language'
              ? ['text-generation', 'text2text-generation'].includes(actual || '')
              : actual === 'text-classification';

          const payload = ok
            ? {
                isValid: true,
                modelInfo: {
                  id: info.id,
                  downloads: info.downloads ?? 0,
                  pipeline_tag: actual,
                  tags,
                  author: info.id?.split('/')?.[0] ?? 'unknown',
                  modelName: info.id?.split('/')?.[1] ?? info.id,
                },
              }
            : {
                isValid: false,
                error:
                  expected === 'language'
                    ? `Model task should be text-generation or text2text-generation, but is ${actual || 'Unknown'}」`
                    : `Model task should be text-classification, but is${actual || 'Unknown'}」`,
              };

          cache.current.set(modelId, payload);
          setResult(payload);
        } catch (e: any) {
          setResult({ isValid: false, error: e?.message || 'Error when valiating model' });
        } finally {
          setLoading(false);
        }
      }),
    []
  );

  return { loading, result, validate };
}

export function useHFDatasetValidator() {
  const cache = useRef<Map<string, any>>(new Map());
  const [loading, setLoading] = useState(false);
  const [result, setResult] = useState<any>(null);

  const validate = useMemo(
    () =>
      debounce(async (datasetId: string) => {
        if (!datasetId?.includes('/')) {
          setResult(null);
          return;
        }
        if (cache.current.has(datasetId)) {
          setResult(cache.current.get(datasetId));
          return;
        }
        const valid = /^[a-zA-Z0-9._-]+\/[a-zA-Z0-9._-]+$/.test(datasetId);
        if (!valid) {
          setResult({ isValid: false, error: 'Incorrect Dataset ID Format' });
          return;
        }
        setLoading(true);
        try {
          const info = await fetchHFDataset(datasetId);
          const payload = {
            isValid: true,
            datasetInfo: {
              id: info.id,
              author: info.id?.split('/')?.[0] ?? 'unknown',
              datasetName: info.id?.split('/')?.[1] ?? info.id,
              downloads: info.downloads ?? 0,
              tags: info.tags ?? [],
              description: info.description ?? 'No Description',
              task_categories: info.task_categories ?? [],
            },
          };
          cache.current.set(datasetId, payload);
          setResult(payload);
        } catch (e: any) {
          setResult({ isValid: false, error: e?.message || 'An error occurred while validating the dataset' });
        } finally {
          setLoading(false);
        }
      }),
    []
  );

  return { loading, result, validate };
}