/**
 * Simple file-backed memory under the agent workspace.
 */

const path = require('path');
const fs = require('fs');
const { ensureDir } = require('../lib/paths.js');
const { formatInject } = require('./memory-format.js');
const sandbox = require('./sandbox.js');

function memoryDir(origin) {
  return ensureDir(path.join(sandbox.defaultCwd(origin), '.agent-harness', 'memory'));
}

function writeNote(origin, name, text) {
  const dir = memoryDir(origin);
  const file = path.join(dir, sandbox.sanitizeId(name || 'note') + '.md');
  fs.writeFileSync(file, String(text || ''));
  return file;
}

function listNotes(origin) {
  const dir = memoryDir(origin);
  let names = [];
  try {
    names = fs.readdirSync(dir);
  } catch (_) {
    return [];
  }
  return names.filter((n) => n.endsWith('.md'));
}

function readNote(origin, name) {
  const file = path.join(memoryDir(origin), sandbox.sanitizeId(name.replace(/\.md$/, '')) + '.md');
  return fs.readFileSync(file, 'utf8');
}

function search(origin, query) {
  const q = String(query || '').toLowerCase();
  const hits = [];
  for (const n of listNotes(origin)) {
    let text = '';
    try {
      text = readNote(origin, n);
    } catch (_) {
      continue;
    }
    if (!q || n.toLowerCase().includes(q) || text.toLowerCase().includes(q)) {
      hits.push({ name: n, snippet: text.slice(0, 400) });
    }
  }
  return hits.slice(0, 20);
}

function injectBlock(origin, query) {
  try {
    return formatInject(search(origin, query), 5);
  } catch (_) {
    return '';
  }
}

module.exports = { writeNote, listNotes, readNote, search, formatInject, injectBlock };