import React, { useMemo } from 'react';
import { Text, TextStyle, StyleProp } from 'react-native';

interface HighlightTextProps {
  text: string;
  keyword: string;
  style?: StyleProp<TextStyle>;
  highlightStyle?: StyleProp<TextStyle>;
}

const HighlightText: React.FC<HighlightTextProps> = ({ text, keyword, style, highlightStyle }) => {
  const parts = useMemo(() => {
    if (!text || !keyword) return [{ text, highlight: false }];

    const result: Array<{ text: string; highlight: boolean }> = [];
    const lowerText = text.toLowerCase();
    const lowerKeyword = keyword.toLowerCase();
    let lastIndex = 0;

    let searchFrom = 0;
    while (searchFrom < lowerText.length) {
      const index = lowerText.indexOf(lowerKeyword, searchFrom);
      if (index === -1) break;

      if (index > lastIndex) {
        result.push({ text: text.substring(lastIndex, index), highlight: false });
      }
      result.push({ text: text.substring(index, index + keyword.length), highlight: true });
      lastIndex = index + keyword.length;
      searchFrom = lastIndex;
    }

    if (lastIndex < text.length) {
      result.push({ text: text.substring(lastIndex), highlight: false });
    }

    return result.length > 0 ? result : [{ text, highlight: false }];
  }, [text, keyword]);

  return (
    <Text style={style}>
      {parts.map((part, i) =>
        part.highlight ? (
          <Text key={i} style={highlightStyle}>{part.text}</Text>
        ) : (
          <Text key={i}>{part.text}</Text>
        )
      )}
    </Text>
  );
};

export default HighlightText;