<?php
class Account extends AppModel {

	var $name = 'Account';
	var $validate = array(
		'id' => array('numeric'),
		'name' => array('notempty'),
		'external_name' => array('notempty')
	);

	var $hasOne = array(
		'CurrentLedger' => array(
			'className' => 'Ledger',
			'conditions' => array('NOT' => array('CurrentLedger.closed'))
		),
	);

	var $hasMany = array(
		'Ledger',
	);


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: type
   *  - Returns the type of this account
   */
  function type($id) {
    $this->cacheQueries = true;
    $account = $this->find('first', array
			   ('recursive' => -1,
			    'fields' => array('type'),
			    'conditions' => array(array('Account.id' => $id)),
			    ));
    $this->cacheQueries = false;

    return $account['Account']['type'];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: fundamentalType
   *  - Returns the fundmental type of the account, credit or debit
   */
  function fundamentalType($id_or_type) {
    if (is_numeric($id_or_type))
      $type = $this->type($id_or_type);
    else
      $type = $id_or_type;

    // Asset and Expense accounts are debit accounts
    if (in_array($type, array('ASSET', 'EXPENSE')))
      return 'debit';

    // Otherwise, it's a credit account
    return 'credit';
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: fundamentalOpposite
   *  - Returns the opposite fundmental type of the account, credit or debit
   */
  function fundamentalOpposite($id_or_type) {
    $fund = $this->fundamentalType($id_or_type);

    if ($fund == 'debit')
      return 'credit';

    return 'debit';
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: securityDepositAccountID
   *  - Returns the ID of the Security Deposit Account
   */
  function securityDepositAccountID() {
    $this->cacheQueries = true;
    $account = $this->find('first', array
			   ('recursive' => -1,
			    'conditions' => array
			    (array('name' => 'Security Deposit')),
			    ));
    $this->cacheQueries = false;
    return $account['Account']['id'];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function:rentAccountID
   *  - Returns the ID of the Rent Account
   */
  function rentAccountID() {
    $this->cacheQueries = true;
    $account = $this->find('first', array
			   ('recursive' => -1,
			    'conditions' => array
			    (array('name' => 'Rent')),
			    ));
    $this->cacheQueries = false;
    return $account['Account']['id'];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: ledgers
   *  - Returns an array of ledger ids from the given account
   */
  function ledgers($id, $all = false) {
    $cachekey = $all ? 'all' : 'current';
    if (isset($this->cache[$id]['ledgers'][$cachekey])) {
      return $this->cache[$id]['ledgers'][$cachekey];
    }

    if ($all) {
      $contain = array('Ledger' => array('fields' => array('Ledger.id')));
    } else {
      $contain = array('CurrentLedger' => array('fields' => array('CurrentLedger.id')));
    }

    $account = $this->find('first', array
			   ('contain' => $contain,
			    'fields' => array(),
			    'conditions' => array(array('Account.id' => $id)),
			    ));

    if ($all) {
      $ledger_ids = array();
      foreach ($account['Ledger'] AS $ledger)
	array_push($ledger_ids, $ledger['id']);
    }
    else {
      $ledger_ids = array($account['CurrentLedger']['id']);
    }

    // Save the ledgers in our cache for future reference
    $this->cache[$id]['ledgers'][$cachekey] = $ledger_ids;

/*     pr(array('function' => 'Account::ledgers', */
/* 	     'args' => compact('id', 'all'), */
/* 	     'return' => $this->cache[$id]['ledgers'][$cachekey])); */

    return $this->cache[$id]['ledgers'][$cachekey];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: findLedgerEntries
   *  - Returns an array of ledger entries that belong to the given
   *    account, either just from the current ledger, or from all ledgers.
   */
  function findLedgerEntries($id, $all = false, $cond = null, $link = null) {
/*     pr(array('function' => 'Account::findLedgerEntries', */
/* 	     'args' => compact('id', 'all', 'cond', 'link'), */
/* 	     )); */

    $entries = array();
    foreach ($this->ledgers($id, $all) AS $ledger_id) {
      $ledger_entries = $this->Ledger->findLedgerEntries
	($ledger_id, $this->type($id), $cond, $link);
      $entries = array_merge($entries, $ledger_entries);
    }

    $stats = $this->stats($id, $all, $cond);
    $entries = array('Entries' => $entries,
		     'summary' => $stats['Ledger']);

/*     pr(array('function' => 'Account::findLedgerEntries', */
/* 	     'args' => compact('id', 'all', 'cond', 'link'), */
/* 	     'vars' => compact('stats'), */
/* 	     'return' => compact('entries'), */
/* 	     )); */

    return $entries;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: findLedgerEntriesRelatedToAccount
   *  - Returns an array of ledger entries that belong to the given
   *    account, and are related to a specific account, either just from
   *    the current ledger, or from all ledgers.
   */
  function findLedgerEntriesRelatedToAccount($id, $rel_ids, $all = false, $cond = null, $link = null) {
/*     pr(array('function' => 'Account::findLedgerEntriesRelatedToAccount', */
/* 	     'args' => compact('id', 'rel_ids', 'all', 'cond', 'link'), */
/* 	     )); */

    if (!isset($cond))
      $cond = array();
    if (!is_array($rel_ids))
      $rel_ids = array($rel_ids);

    $ledger_ids = array();
    foreach ($rel_ids AS $rel_id)
      $ledger_ids = array_merge($ledger_ids, $this->ledgers($rel_id));

    array_push($cond, $this->Ledger->LedgerEntry->conditionEntryAsCreditOrDebit($ledger_ids));
    $entries = $this->findLedgerEntries($id, $all, $cond, $link);

/*     pr(array('function' => 'Account::findLedgerEntriesRelatedToAccount', */
/* 	     'args' => compact('id', 'relid', 'all', 'cond', 'link'), */
/* 	     'vars' => compact('ledger_ids'), */
/* 	     'return' => compact('entries'), */
/* 	     )); */
    return $entries;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: findUnreconciledLedgerEntries
   *  - Returns ledger entries that are not yet reconciled
   *    (such as charges not paid).
   */

  function findUnreconciledLedgerEntries($id = null, $fundamental_type = null) {
    foreach (($fundamental_type
	      ? array($fundamental_type)
	      : array('debit', 'credit')) AS $fund) {
      $ucfund = ucfirst($fund);
      $unreconciled[$fund]['entry'] = $this->find
	('all', array
	 ('link' => array
	  ('Ledger' => array
	   ('fields' => array(),
	    "LedgerEntry" => array
	    ('class' => "{$ucfund}LedgerEntry",
	     'fields' => array('id', 'amount'),
	     "ReconciliationLedgerEntry" => array
	     ('class' => "{$ucfund}ReconciliationLedgerEntry",
	      'fields' => array
	      ("COALESCE(SUM(Reconciliation.amount),0) AS 'reconciled'",
	       "LedgerEntry.amount - COALESCE(SUM(Reconciliation.amount),0) AS 'balance'",
	       ),
	      ),
	     ),
	    ),
	   ),
	  'group' => ("LedgerEntry.id" .
		      " HAVING LedgerEntry.amount" .
		      " <> COALESCE(SUM(Reconciliation.amount),0)"),
	  'conditions' => array('Account.id' => $id),
	  'fields' => array(),
	  ));
      $balance = 0;
      foreach ($unreconciled[$fund]['entry'] AS &$entry) {
	$entry = array_merge(array_diff_key($entry["LedgerEntry"], array(0=>true)),
			     $entry[0]);
	$balance += $entry['balance'];
      }
      $unreconciled[$fund]['balance'] = $balance;
    }

    return $unreconciled;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: reconcileNewLedgerEntry
   *  - Returns which ledger entries a new credit/debit would
   *    reconcile, and how much.
   *
   *  - REVISIT <AP> 20090617
   *    This should be subject to different algorithms, such
   *    as apply to oldest charges first, newest first, to fees
   *    before rent, etc.  Until we get there, I'll hardcode
   *    whatever algorithm is simplest.
   */

  function reconcileNewLedgerEntry($id, $fundamental_type, $amount) {
    $ofund = $this->fundamentalOpposite($fundamental_type);
    $unreconciled = array($ofund => array('entry'=>array(), 'balance'=>0));
    $applied = 0;

    // if there is no money in the entry, it can reconcile nothing
    // don't bother wasting time sifting ledger entries.
    if ($amount > 0) {
      $unreconciled = $this->findUnreconciledLedgerEntries($id, $ofund);

      foreach ($unreconciled[$ofund]['entry'] AS $i => &$entry) {
	// Determine if amount is sufficient to cover the entry
	if ($amount > $entry['balance'])
	  $apply = $entry['balance'];
	elseif ($amount > 0)
	  $apply = $amount;
	else {
	  unset($unreconciled[$i]);
	  continue;
	}

	$entry['applied']     = $apply;
	$entry['reconciled'] += $apply;
	$entry['balance']    -= $apply;
	$applied             += $apply;
	$amount              -= $apply;
      }
    }

    $unreconciled[$ofund]['unapplied']  = $amount;
    $unreconciled[$ofund]['applied']    = $applied;
    $unreconciled[$ofund]['balance']   -= $applied;
    return $unreconciled;
  }

  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: stats
   *  - Returns summary data from the requested account.
   */

  function stats($id = null, $all = false, $cond = null) {
    if (!$id)
      return null;

    // All old, closed ledgers MUST balance to 0.
    // However, the user may want the ENTIRE running totals,
    // (not just the balance), so we may have to query all
    // ledgers, as dictated by the $all parameter.

    $account = $this->find('first',
			   array('contain' =>
				 ($all
				  ? array('Ledger' => array
					  ('fields' => array('id')))
				  : array('CurrentLedger' => array
					  ('fields' => array('id')))
				  ),
				 'conditions' => array
				 (array('Account.id' => $id))
				 ));

    $stats = array();
    if ($all) {
      foreach ($account['Ledger'] AS $ledger)
	$this->statsMerge($stats['Ledger'],
			  $this->Ledger->stats($ledger['id'], $cond));
    }
    else {
      $stats['Ledger'] =
	$this->Ledger->stats($account['CurrentLedger']['id'], $cond);
    }

    return $stats;
  }

}
?>