ReadabilityAnalyzer.ts•3.74 kB
/**
* ReadabilityAnalyzer - Calculate readability metrics (Flesch-Kincaid, etc.)
*/
import { WritingStorage } from "../storage/WritingStorage.js";
export interface ReadabilityMetrics {
file: string;
fleschReadingEase: number;
fleschKincaidGradeLevel: number;
averageWordsPerSentence: number;
averageSyllablesPerWord: number;
totalWords: number;
totalSentences: number;
readingLevel: "elementary" | "middle-school" | "high-school" | "college" | "advanced";
}
export class ReadabilityAnalyzer {
constructor(private storage: WritingStorage) {}
async analyzeReadability(filePath?: string): Promise<ReadabilityMetrics[]> {
const files = filePath
? [await this.storage.getFile(filePath)]
: await this.storage.getAllFiles();
const validFiles = files.filter((f) => f !== null);
const results: ReadabilityMetrics[] = [];
for (const file of validFiles) {
const metrics = this.calculateMetrics(file.content, file.file_path);
results.push(metrics);
}
return results;
}
private calculateMetrics(content: string, filePath: string): ReadabilityMetrics {
// Remove markdown syntax
const cleanText = this.stripMarkdown(content);
const sentences = this.countSentences(cleanText);
const words = this.countWords(cleanText);
const syllables = this.countSyllables(cleanText);
const avgWordsPerSentence = sentences > 0 ? words / sentences : 0;
const avgSyllablesPerWord = words > 0 ? syllables / words : 0;
// Flesch Reading Ease: 206.835 - 1.015(words/sentences) - 84.6(syllables/words)
const fleschReadingEase =
206.835 - 1.015 * avgWordsPerSentence - 84.6 * avgSyllablesPerWord;
// Flesch-Kincaid Grade Level: 0.39(words/sentences) + 11.8(syllables/words) - 15.59
const fleschKincaidGradeLevel =
0.39 * avgWordsPerSentence + 11.8 * avgSyllablesPerWord - 15.59;
return {
file: filePath,
fleschReadingEase: Math.max(0, Math.min(100, fleschReadingEase)),
fleschKincaidGradeLevel: Math.max(0, fleschKincaidGradeLevel),
averageWordsPerSentence: avgWordsPerSentence,
averageSyllablesPerWord: avgSyllablesPerWord,
totalWords: words,
totalSentences: sentences,
readingLevel: this.getReadingLevel(fleschKincaidGradeLevel),
};
}
private stripMarkdown(content: string): string {
return content
.replace(/^#+\s+/gm, "") // Remove headers
.replace(/\[([^\]]+)\]\([^)]+\)/g, "$1") // Links
.replace(/[*_~`]/g, "") // Emphasis
.replace(/^[->]\s+/gm, "") // Lists
.replace(/```[\s\S]*?```/g, "") // Code blocks
.replace(/`[^`]+`/g, ""); // Inline code
}
private countSentences(text: string): number {
const sentences = text.match(/[.!?]+/g);
return sentences ? sentences.length : 1;
}
private countWords(text: string): number {
const words = text.match(/\b\w+\b/g);
return words ? words.length : 0;
}
private countSyllables(text: string): number {
const words = text.match(/\b\w+\b/g) || [];
return words.reduce((total, word) => total + this.syllablesInWord(word), 0);
}
private syllablesInWord(word: string): number {
word = word.toLowerCase();
if (word.length <= 3) {return 1;}
const vowels = word.match(/[aeiouy]+/g);
let count = vowels ? vowels.length : 1;
// Adjust for silent 'e'
if (word.endsWith("e")) {count--;}
return Math.max(1, count);
}
private getReadingLevel(gradeLevel: number): ReadabilityMetrics["readingLevel"] {
if (gradeLevel < 6) {return "elementary";}
if (gradeLevel < 9) {return "middle-school";}
if (gradeLevel < 13) {return "high-school";}
if (gradeLevel < 16) {return "college";}
return "advanced";
}
}