import Database from 'better-sqlite3';
import { existsSync, mkdirSync } from 'fs';
import { dirname } from 'path';
export interface Snapshot {
id: number;
name: string | null;
summary: string;
context: string;
next_steps: string | null;
continuation_prompt: string;
created_at: string;
}
export interface SaveSnapshotInput {
name?: string;
summary: string;
context: string | StructuredContext;
next_steps?: string;
}
export interface StructuredContext {
files?: string[];
decisions?: string[];
blockers?: string[];
code_state?: Record<string, any>;
[key: string]: any;
}
export class SnapshotDatabase {
private db: Database.Database;
constructor(dbPath: string) {
// Ensure directory exists
const dir = dirname(dbPath);
if (!existsSync(dir)) {
mkdirSync(dir, { recursive: true });
}
this.db = new Database(dbPath);
this.initializeSchema();
}
private initializeSchema(): void {
this.db.exec(`
CREATE TABLE IF NOT EXISTS snapshots (
id INTEGER PRIMARY KEY AUTOINCREMENT,
name TEXT,
summary TEXT NOT NULL,
context TEXT NOT NULL,
next_steps TEXT,
created_at TEXT NOT NULL DEFAULT (datetime('now'))
);
CREATE INDEX IF NOT EXISTS idx_snapshots_created_at
ON snapshots(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_snapshots_name
ON snapshots(name) WHERE name IS NOT NULL;
`);
// Migration: Add continuation_prompt column if it doesn't exist
const columns = this.db.pragma('table_info(snapshots)') as Array<{ name: string }>;
const hasContinuationPrompt = columns.some((col) => col.name === 'continuation_prompt');
if (!hasContinuationPrompt) {
this.db.exec(`
ALTER TABLE snapshots ADD COLUMN continuation_prompt TEXT NOT NULL DEFAULT '';
`);
}
}
private formatStructuredContext(context: string | StructuredContext): string {
if (typeof context === 'string') {
return context;
}
const parts: string[] = [];
if (context.files && context.files.length > 0) {
parts.push('Files:');
parts.push(...context.files.map(f => `- ${f}`));
parts.push('');
}
if (context.decisions && context.decisions.length > 0) {
parts.push('Decisions:');
parts.push(...context.decisions.map(d => `- ${d}`));
parts.push('');
}
if (context.blockers && context.blockers.length > 0) {
parts.push('Blockers:');
parts.push(...context.blockers.map(b => `- ${b}`));
parts.push('');
}
if (context.code_state && Object.keys(context.code_state).length > 0) {
parts.push('Code State:');
parts.push(JSON.stringify(context.code_state, null, 2));
parts.push('');
}
// Add any other custom fields
for (const [key, value] of Object.entries(context)) {
if (!['files', 'decisions', 'blockers', 'code_state'].includes(key)) {
parts.push(`${key}:`);
if (typeof value === 'string') {
parts.push(value);
} else {
parts.push(JSON.stringify(value, null, 2));
}
parts.push('');
}
}
return parts.join('\n').trim();
}
private generateContinuationPrompt(summary: string, context: string, next_steps?: string | null): string {
const parts: string[] = [
`Resuming: ${summary}`,
'',
'Context:',
context,
];
if (next_steps) {
parts.push('', 'Next:', next_steps);
}
return parts.join('\n');
}
saveSnapshot(input: SaveSnapshotInput): Snapshot {
// Format context (handle both string and structured input)
const formattedContext = this.formatStructuredContext(input.context);
// Generate continuation prompt
const continuationPrompt = this.generateContinuationPrompt(
input.summary,
formattedContext,
input.next_steps
);
const stmt = this.db.prepare(`
INSERT INTO snapshots (name, summary, context, next_steps, continuation_prompt)
VALUES (?, ?, ?, ?, ?)
`);
const result = stmt.run(
input.name || null,
input.summary,
formattedContext,
input.next_steps || null,
continuationPrompt
);
return this.getSnapshotById(result.lastInsertRowid as number)!;
}
getSnapshotById(id: number): Snapshot | undefined {
const stmt = this.db.prepare(`
SELECT * FROM snapshots WHERE id = ?
`);
return stmt.get(id) as Snapshot | undefined;
}
getSnapshotByName(name: string): Snapshot | undefined {
const stmt = this.db.prepare(`
SELECT * FROM snapshots WHERE name = ? ORDER BY created_at DESC, id DESC LIMIT 1
`);
return stmt.get(name) as Snapshot | undefined;
}
getLatestSnapshot(): Snapshot | undefined {
const stmt = this.db.prepare(`
SELECT * FROM snapshots ORDER BY created_at DESC, id DESC LIMIT 1
`);
return stmt.get() as Snapshot | undefined;
}
listSnapshots(limit?: number): Snapshot[] {
const stmt = this.db.prepare(`
SELECT * FROM snapshots ORDER BY created_at DESC, id DESC LIMIT ?
`);
return stmt.all(limit || 100) as Snapshot[];
}
deleteSnapshot(id: number): boolean {
const stmt = this.db.prepare(`
DELETE FROM snapshots WHERE id = ?
`);
const result = stmt.run(id);
return result.changes > 0;
}
close(): void {
this.db.close();
}
}
