// Runtime settings for the autonomy stack. The env vars stay the default, the
// table is the override, so nothing changes behaviour until somebody deliberately
// writes a row. Kept deliberately tiny -- this is a control plane, not a config
// system, and every key here can move real money or stop the pipeline.

const EXECUTION_MODES = ['shadow', 'paper'];

const KEYS = {
  executionMode: 'execution_mode',
  killSwitch: 'execution_kill_switch',
};

function readSetting(db, key) {
  try {
    const row = db.prepare('SELECT value FROM autonomy_settings WHERE key = ?').get(key);
    return row ? row.value : null;
  } catch (error) {
    // A missing table means an older schema, which should behave like "no override"
    // rather than taking the worker down with it.
    console.error(`[settings] could not read ${key}:`, error.message);
    return null;
  }
}

function writeSetting(db, key, value, updatedBy = 'admin') {
  db.prepare(`
    INSERT INTO autonomy_settings(key, value, updated_by) VALUES (?, ?, ?)
    ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_by = excluded.updated_by,
      updated_at = datetime('now')
  `).run(key, String(value), updatedBy);
}

// Truthy strings people actually type, rather than only accepting 'true'
function isOn(value) {
  return ['1', 'true', 'on', 'yes', 'engaged'].includes(String(value || '').trim().toLowerCase());
}

function getExecutionControls(db, env = process.env) {
  const stored = readSetting(db, KEYS.executionMode);
  const fallback = env.AUTONOMY_EXECUTION_MODE || 'shadow';
  const mode = EXECUTION_MODES.includes(String(stored)) ? String(stored) : fallback;

  return {
    mode: EXECUTION_MODES.includes(mode) ? mode : 'shadow',
    modeSource: EXECUTION_MODES.includes(String(stored)) ? 'settings' : 'env',
    killSwitch: isOn(readSetting(db, KEYS.killSwitch)),
  };
}

function setExecutionMode(db, mode, updatedBy) {
  if (!EXECUTION_MODES.includes(mode)) {
    throw new Error(`unsupported execution mode: ${mode} (expected ${EXECUTION_MODES.join(' or ')})`);
  }
  writeSetting(db, KEYS.executionMode, mode, updatedBy);
  return getExecutionControls(db);
}

function setKillSwitch(db, engaged, updatedBy) {
  writeSetting(db, KEYS.killSwitch, engaged ? 'true' : 'false', updatedBy);
  return getExecutionControls(db);
}

module.exports = {
  EXECUTION_MODES, KEYS, isOn,
  readSetting, writeSetting,
  getExecutionControls, setExecutionMode, setKillSwitch,
};