/**
* Compact Formatter
*
* Formats observations in a compact, token-efficient format.
*/
import type { Observation, Summary } from '../types/index.js';
export interface CompactFormatterOptions {
maxNarrativeLength?: number;
includeFacts?: boolean;
includeConcepts?: boolean;
includeFiles?: boolean;
separator?: string;
}
export class CompactFormatter {
private options: CompactFormatterOptions;
constructor(options: CompactFormatterOptions = {}) {
this.options = {
maxNarrativeLength: 200,
includeFacts: true,
includeConcepts: true,
includeFiles: false,
separator: ' | ',
...options,
};
}
/**
* Format a single observation
*/
formatObservation(obs: Observation): string {
const parts: string[] = [];
// Type and title
parts.push(`[${obs.type.toUpperCase()}] ${obs.title}`);
// Truncated narrative
if (obs.narrative) {
const narrative = this.truncate(obs.narrative, this.options.maxNarrativeLength!);
parts.push(narrative);
}
// Facts (condensed)
if (this.options.includeFacts && obs.facts) {
const facts = this.parseArray(obs.facts);
if (facts.length > 0) {
parts.push(`Facts: ${facts.slice(0, 3).join('; ')}`);
}
}
// Concepts
if (this.options.includeConcepts && obs.concepts) {
const concepts = this.parseArray(obs.concepts);
if (concepts.length > 0) {
parts.push(`[${concepts.join(', ')}]`);
}
}
// Files
if (this.options.includeFiles) {
const files = this.parseArray(obs.files_modified);
if (files.length > 0) {
parts.push(`Files: ${files.slice(0, 3).join(', ')}`);
}
}
return parts.join(this.options.separator!);
}
/**
* Format multiple observations
*/
formatObservations(observations: Observation[]): string {
return observations.map(obs => this.formatObservation(obs)).join('\n');
}
/**
* Format a summary
*/
formatSummary(summary: Summary): string {
const parts: string[] = [];
if (summary.completed) {
parts.push(`Done: ${this.truncate(summary.completed, 150)}`);
}
if (summary.learned) {
parts.push(`Learned: ${this.truncate(summary.learned, 150)}`);
}
if (summary.next_steps) {
parts.push(`Next: ${this.truncate(summary.next_steps, 100)}`);
}
return parts.join(this.options.separator!);
}
/**
* Format context for injection
*/
formatContext(observations: Observation[], summary?: Summary): string {
const lines: string[] = [];
if (summary) {
lines.push('## Session Summary');
lines.push(this.formatSummary(summary));
lines.push('');
}
if (observations.length > 0) {
lines.push('## Recent Observations');
lines.push(this.formatObservations(observations));
}
return lines.join('\n');
}
/**
* Estimate token count
*/
estimateTokens(text: string): number {
// Rough approximation: ~4 chars per token
return Math.ceil(text.length / 4);
}
/**
* Format to fit within token budget
*/
formatWithBudget(
observations: Observation[],
summary: Summary | undefined,
maxTokens: number
): string {
let result = '';
let currentTokens = 0;
// Add summary first if available
if (summary) {
const summaryText = '## Summary\n' + this.formatSummary(summary) + '\n\n';
const summaryTokens = this.estimateTokens(summaryText);
if (summaryTokens < maxTokens) {
result += summaryText;
currentTokens += summaryTokens;
}
}
// Add observations until budget exhausted
if (observations.length > 0) {
result += '## Observations\n';
currentTokens += 5; // Header tokens
for (const obs of observations) {
const obsText = this.formatObservation(obs) + '\n';
const obsTokens = this.estimateTokens(obsText);
if (currentTokens + obsTokens > maxTokens) {
break;
}
result += obsText;
currentTokens += obsTokens;
}
}
return result;
}
private truncate(text: string, maxLength: number): string {
if (text.length <= maxLength) return text;
return text.slice(0, maxLength - 3) + '...';
}
private parseArray(value: any): string[] {
if (Array.isArray(value)) return value;
if (typeof value === 'string') {
try {
const parsed = JSON.parse(value);
return Array.isArray(parsed) ? parsed : [];
} catch {
return [];
}
}
return [];
}
}
