<?php
class Ledger extends AppModel {

  var $belongsTo = array(
    'Account',
    'PriorLedger' => array('className' => 'Ledger'),
    'CloseTransaction' => array('className' => 'Transaction'),
  );

  var $hasMany = array(
    'Transaction',
    'LedgerEntry',
  );


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: accountID
   *  - Returns the account ID for the given ledger
   */
  function accountID($id) {
    $this->cacheQueries = true;
    $item = $this->find('first', array
			('link' => array('Account'),
			 'conditions' => array('Ledger.id' => $id),
			 ));
    $this->cacheQueries = false;
    //pr(compact('id', 'item'));
    return $item['Account']['id'];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: currentLedgerID
   *  - Returns the current ledger ID of the account for the given ledger.
   */
  function currentLedgerID($id) {
    return $this->Account->currentLedgerID($this->accountID($id));
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: closeLedger
   *  - Closes the current ledger, and returns a fresh one
   */
  function closeLedgers($ids) {
    $ret = array('new_ledger_ids' => array());

    $entries = array();
    foreach ($ids AS $id) {
      // Query stats to get the balance forward
      $stats = $this->stats($id);

      // Populate fields from the current ledger
      $this->recursive = -1;
      $this->id = $id;
      $this->read();

      // Build a new ledger to replace the current one
      $this->data['Ledger']['id'] = null;
      $this->data['Ledger']['close_transaction_id'] = null;
      $this->data['Ledger']['prior_ledger_id'] = $id;
      $this->data['Ledger']['comment'] = null;
      ++$this->data['Ledger']['sequence'];
      $this->data['Ledger']['name'] =
	($this->data['Ledger']['account_id'] .
	 '-' .
	 $this->data['Ledger']['sequence']);

      // Save the new ledger
      $this->id = null;
      if (!$this->save($this->data, false))
	return array('error' => true, 'new_ledger_data' => $this->data) + $ret;
      $ret['new_ledger_ids'][] = $this->id;

      $entries[] = array('old_ledger_id' => $id,
			 'new_ledger_id' => $this->id,
			 'amount' => $stats['balance']);
    }

    // Perform the close
    $result = $this->Transaction->addClose(array('Transaction' => array(),
						 'Ledger' => $entries));
    $ret['Transaction'] = $result;
    if ($result['error'])
      return array('error' => true) + $ret;

    return $ret + array('error' => false);
    }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: debitCreditFields
   *  - Returns the fields necessary to determine whether the queried
   *    entries are a debit, or a credit, and also the effect each have
   *    on the overall balance of the ledger.
   */
  function debitCreditFields($sum = false, $balance = true,
			     $entry_name = 'LedgerEntry', $account_name = 'Account') {
    return $this->LedgerEntry->debitCreditFields
      ($sum, $balance, $entry_name, $account_name);
  }

  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: ledgerEntries
   *  - Returns an array of ledger entries that belong to a given
   *    ledger. There is extra work done to establish debit/credit
   */
  function ledgerEntries($ids, $query = null) {
    if (empty($ids))
      return null;

    $entries = $this->LedgerEntry->find
      ('all', array
       ('link' => array('Ledger' => array('Account')),
	'fields' => array_merge(array("LedgerEntry.*"),
				$this->LedgerEntry->debitCreditFields()),
	'conditions' => array('LedgerEntry.ledger_id' => $ids),
	));

    //pr(compact('entries'));
    return $entries;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: stats
   *  - Returns summary data from the requested ledger.
   */
  function stats($id, $query = null) {
    if (!$id)
      return null;

    $this->queryInit($query);

/*     if (!isset($query['link']['Ledger'])) */
/*       $query['link']['Ledger'] = array(); */
/*     if (!isset($query['link']['Ledger']['fields'])) */
/*       $query['link']['Ledger']['fields'] = array(); */
    if (!isset($query['link']['Account']))
      $query['link']['Account'] = array();
    if (!isset($query['link']['Account']['fields']))
      $query['link']['Account']['fields'] = array();
/*     if (!isset($query['link']['Transaction'])) */
/*       $query['link']['Transaction'] = array(); */
/*     if (!isset($query['link']['Transaction']['fields'])) */
/*       $query['link']['Transaction']['fields'] = array(); */
/*     $query['link']['Transaction']['fields'][] = 'stamp'; */

    if (!isset($query['fields']))
      $query['fields'] = array();

    $query['fields'] = array_merge($query['fields'],
				   $this->debitCreditFields(true));

    $query['conditions'][] = array('LedgerEntry.ledger_id' => $id);
    $query['group'][] = 'LedgerEntry.ledger_id';

    $stats = $this->LedgerEntry->find('first', $query);
    //pr(compact('stats'));


/*     unset($query['group']); */
/*     $query['fields'] = $this->debitCreditFields($id, false); */
/*     $stats = $this->find('all', $query); */
/*     pr(compact('query', 'stats')); */

    // The fields are all tucked into the [0] index,
    // and the rest of the array is useless (empty).
    $stats = $stats[0];

    // Make sure we have a member for debit/credit
    foreach(array('debits', 'credits') AS $crdr)
      if (!isset($stats[$crdr]))
	$stats[$crdr] = null;

    // Make sure we have a non-null balance
    if (!isset($stats['balance']))
      $stats['balance'] = 0;

    return $stats;
  }

}
?>