<?php
class LedgerEntry extends AppModel {

	var $name = 'LedgerEntry';
	var $validate = array(
		'id' => array('numeric'),
		'transaction_id' => array('numeric'),
		'amount' => array('money')
	);

	var $hasMany = array(
		'DebitReconciliation' => array(
			'className' => 'Reconciliation',
			'foreignKey' => 'debit_ledger_entry_id',
		),
		'CreditReconciliation' => array(
			'className' => 'Reconciliation',
			'foreignKey' => 'credit_ledger_entry_id',
		),
	);
	var $belongsTo = array(
		'MonetarySource',
		'Transaction',
		'Customer',
		'Lease',

		'DebitLedger' => array(
			'className' => 'Ledger',
			'foreignKey' => 'debit_ledger_id',
		),
		'CreditLedger' => array(
			'className' => 'Ledger',
			'foreignKey' => 'credit_ledger_id',
		),

		'Ledger' => array(
			'foreignKey' => false,
			// conditions will be used when JOINing tables
			// (such as find with LinkableBehavior)
			'conditions' => array('OR' =>
			    array('%{MODEL_ALIAS}.debit_ledger_id  = Ledger.id',
				  '%{MODEL_ALIAS}.credit_ledger_id = Ledger.id')),

			// finderQuery will be used when tables are put
			// together across several querys, not with JOIN.
			// (such as find with ContainableBehavior)
			'finderQuery' => 'NOT-IMPLEMENTED',

			'counterQuery' => ''
		),

	);

	var $hasAndBelongsToMany = array(
		'DebitReconciliationLedgerEntry' => array(
			'className' => 'LedgerEntry',
			'joinTable' => 'reconciliations',
			'foreignKey' => 'credit_ledger_entry_id',
			'associationForeignKey' => 'debit_ledger_entry_id',
		),
		'CreditReconciliationLedgerEntry' => array(
			'className' => 'LedgerEntry',
			'joinTable' => 'reconciliations',
			'foreignKey' => 'debit_ledger_entry_id',
			'associationForeignKey' => 'credit_ledger_entry_id',
		),
	);

  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: conditionEntryAsCreditOrDebit
   *  - returns the condition necessary to match a set of
   *    Ledgers to all related LedgerEntries
   */
  function conditionEntryAsCreditOrDebit($ledger_ids) {
    return array('OR' =>
		 array(array('debit_ledger_id'  => $ledger_ids),
		       array('credit_ledger_id' => $ledger_ids)));
  }

    
  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: ledgerContext query helpers
   *  - Returns parameters necessary to generate a query which
   *    puts ledger entries into the context of a ledger.  Since
   *    debit/credit depends on the account type, it is required
   *    as an argument for each function to avoid having to
   *    query the ledger/account to find it out.
   */
  function ledgerContextFields($ledger_id = null, $account_type = null) {
    $fields = array('id', 'effective_date', 'through_date',
		    'lease_id', 'customer_id', 'comment', 'amount');

    if (isset($ledger_id)) {
      $fields[] = ("IF(LedgerEntry.debit_ledger_id = $ledger_id," .
		   "   LedgerEntry.amount, NULL) AS debit");
      $fields[] = ("IF(LedgerEntry.credit_ledger_id = $ledger_id," .
		   "   LedgerEntry.amount, NULL) AS credit");

      if (isset($account_type)) {
	if (in_array($account_type, array('ASSET', 'EXPENSE')))
	  $ledger_type = 'debit';
	else
	  $ledger_type = 'credit';

	$fields[] = ("(IF(LedgerEntry.{$ledger_type}_ledger_id = $ledger_id," .
		     "    1, -1) * LedgerEntry.amount) AS balance");
      }
    }

    return $fields;
  }

  function ledgerContextFields2($ledger_id = null, $account_id = null, $account_type = null) {
    $fields = array('id', 'effective_date', 'through_date', 'comment', 'amount');

    if (isset($ledger_id)) {
      $fields[] = ("IF(LedgerEntry.debit_ledger_id = $ledger_id," .
		   "   SUM(LedgerEntry.amount), NULL) AS debit");
      $fields[] = ("IF(LedgerEntry.credit_ledger_id = $ledger_id," .
		   "   SUM(LedgerEntry.amount), NULL) AS credit");

      if (isset($account_id) || isset($account_type)) {
	$Account = new Account();
	$account_ftype = $Account->fundamentalType($account_id ? $account_id : $account_type);
	$fields[] = ("(IF(LedgerEntry.{$account_ftype}_ledger_id = $ledger_id," .
		     "    1, -1) * SUM(LedgerEntry.amount)) AS balance");
      }
    }
    elseif (isset($account_id)) {
      $fields[] = ("IF(DebitLedger.account_id = $account_id," .
		   "   SUM(LedgerEntry.amount), NULL) AS debit");
      $fields[] = ("IF(CreditLedger.account_id = $account_id," .
		   "   SUM(LedgerEntry.amount), NULL) AS credit");

      $Account = new Account();
      $account_ftype = ucfirst($Account->fundamentalType($account_id));
      $fields[] = ("(IF({$account_ftype}Ledger.account_id = $account_id," .
		   "    1, -1) * SUM(LedgerEntry.amount)) AS balance");
    }

    return $fields;
  }


  function ledgerContextConditions($ledger_id, $account_type) {
    if (isset($ledger_id)) {
      return array
	('OR' =>
	 array(array('LedgerEntry.debit_ledger_id' => $ledger_id),
	       array('LedgerEntry.credit_ledger_id' => $ledger_id)),
	 );
    }

    return array();
  }      

  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: findInLedgerContext
   *  - Returns an array of ledger entries that belong to a given ledger.
   *    There is extra logic to also figure out whether the ledger_entry
   *    amount is either a credit, or a debit, depending on how it was
   *    written into the ledger, as well as whether the amount increases or
   *    decreases the balance depending on the particular account type of
   *    the ledger.
   */
  function findInLedgerContext($ledger_id, $account_type, $cond = null, $link = null) {
    if (!isset($link))
      $link = array('Transaction');

    if (!isset($cond))
      $cond = array();

    $fields = $this->ledgerContextFields($ledger_id, $account_type);
    $cond[] = $this->ledgerContextConditions($ledger_id, $account_type);
    $order  = array('Transaction.stamp');

    $entries = $this->find
      ('all',
       array('link'       => $link,
	     'fields'     => $fields,
	     'conditions' => $cond,
	     'order'      => $order,
	     ));

    return $entries;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: findReconciledLedgerEntries
   *  - Returns ledger entries that are reconciled to the given entry.
   *    (such as payments towards a charge).
   */

  function findReconciledLedgerEntries($id = null, $fundamental_type = null) {
    foreach (($fundamental_type
	      ? array($fundamental_type)
	      : array('debit', 'credit')) AS $fund) {
      $ucfund = ucfirst($fund);
      $reconciled[$fund]['entry'] = $this->find
	('all', array
	 ('link' => array
	  ("ReconciliationLedgerEntry" => array
	   ('class' => "{$ucfund}ReconciliationLedgerEntry",
	    'fields' => array
	    ('id',
	     "COALESCE(SUM(Reconciliation.amount),0) AS 'reconciled'",
	     "LedgerEntry.amount - COALESCE(SUM(Reconciliation.amount),0) AS 'balance'",
	     ),
	    ),
	   ),
	  'group' => ("ReconciliationLedgerEntry.id"),
	  'conditions' => array('LedgerEntry.id' => $id),
	  'fields' => array(),
	  ));
      //pr($reconciled);
      $balance = 0;
      foreach ($reconciled[$fund]['entry'] AS &$entry) {
	$entry = array_merge($entry["ReconciliationLedgerEntry"], $entry[0]);
	$balance += $entry['balance'];
      }
      $reconciled[$fund]['balance'] = $balance;
    }

    return $reconciled;
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: reverse
   *  - Reverses the ledger entry
   */

  function reverse($id, $amount = null, $transaction_id = null, $rec_id = null) {
/*     pr(array('LedgerEntry::reverse', */
/* 	     compact('id', 'amount', 'transaction_id', 'rec_id'))); */

    // Get the LedgerEntry and related fields
    $entry = $this->find
      ('first',
       array('contain' => array('MonetarySource.id',
				'Transaction.id',
				'DebitLedger.id',
				'DebitLedger.account_id',
				'CreditLedger.id',
				'CreditLedger.account_id',
				'DebitReconciliationLedgerEntry'
/* 				=> */
/* 				array('DebitLedger.id', */
/* 				      'DebitLedger.account_id', */
/* 				      'CreditLedger.id', */
/* 				      'CreditLedger.account_id', */
/* 				      ) */
				,
				'CreditReconciliationLedgerEntry'
/* 				=> */
/* 				array('DebitLedger.id', */
/* 				      'DebitLedger.account_id', */
/* 				      'CreditLedger.id', */
/* 				      'CreditLedger.account_id', */
/* 				      ) */
				,
				'Customer.id',
				'Lease.id',
				),

	     'fields' => array('LedgerEntry.*'),

	     'conditions' => array(array('LedgerEntry.id' => $id),
/* 				   array('NOT' => */
/* 					 array('OR' =>  */
/* 					       array(array('DebitReconciliationLedgerEntry.id' => $rec_id), */
/* 						     array('CreditReconciliationLedgerEntry.id' => $rec_id), */
/* 						     ), */
/* 					       ), */
/* 					 ), */
				   ),
	     ));
    //pr($entry);

    if (!isset($amount))
      $amount = $entry['LedgerEntry']['amount'];

    $A = new Account();

    $ids = $this->Ledger->Account->postLedgerEntry
      (array('transaction_id' => $transaction_id),
       null,
       array('debit_ledger_id' => $A->currentLedgerID($entry['CreditLedger']['account_id']),
	     'credit_ledger_id' => $A->currentLedgerID($entry['DebitLedger']['account_id']),
	     'effective_date' => $entry['LedgerEntry']['effective_date'],
	     //'effective_date' => $entry['LedgerEntry']['effective_date'],
	     'amount' => $amount,
	     'lease_id' => $entry['Lease']['id'],
	     'customer_id' => $entry['Customer']['id'],
	     'comment' => "Reversal of Ledger Entry #{$id}",
	     ),
       array('debit' => array(array('LedgerEntry' => array('id' => $entry['LedgerEntry']['id'],
							   'amount' => $amount,
							   ))),
	     'credit' => array(array('LedgerEntry' => array('id' => $entry['LedgerEntry']['id'],
							    'amount' => $amount,
							    ))),
	     ));

    if ($ids['error'])
      return null;

    $tid = $ids['transaction_id'];

/*     pr(compact('entry')); */
      
    foreach (array('Debit', 'Credit') AS $dc_type) {
      foreach ($entry[$dc_type . 'ReconciliationLedgerEntry'] AS $RLE) {
/* 	pr(array('checkpoint' => "Reverse $dc_type LE", */
/* 		 compact('id', 'RLE'))); */
	if ($RLE['id'] == $rec_id)
	  continue;

	if (!$this->reverse($RLE['id'], $RLE['Reconciliation']['amount'], $tid, $id))
	  $ids['error'] = true;
	
/* 	$rids = $this->Ledger->Account->postLedgerEntry */
/* 	  (array('transaction_id' => $tid), */
/* 	   null, */
/* 	   array('debit_ledger_id' => $A->currentLedgerID($RLE['CreditLedger']['account_id']), */
/* 		 'credit_ledger_id' => $A->currentLedgerID($RLE['DebitLedger']['account_id']), */
/* 		 'effective_date' => $RLE['effective_date'], */
/* 		 //'effective_date' => $RLE['effective_date'], */
/* 		 'amount' => $RLE['Reconciliation']['amount'], */
/* 		 'lease_id' => $entry['Lease']['id'], */
/* 		 'customer_id' => $entry['Customer']['id'], */
/* 		 'comment' => "Reversal of Ledger Entry #{$RLE['id']}", */
/* 		 ), */
/* 	   array('debit' => array(array('LedgerEntry' => array('id' => $RLE['id'], */
/* 							       'amount' => $RLE['Reconciliation']['amount'], */
/* 							       ))), */
/* 		 'credit' => array(array('LedgerEntry' => array('id' => $RLE['id'], */
/* 								'amount' => $RLE['Reconciliation']['amount'], */
/* 								))), */
/* 		 )); */

/* 	if ($rids['error']) */
/* 	  $ids['error'] = true; */
      }
    }

    if ($ids['error'])
      return null;

    return $ids['id'];
  }


  /**************************************************************************
   **************************************************************************
   **************************************************************************
   * function: stats
   *  - Returns summary data from the requested ledger entry
   */
  function stats($id) {

    $query = array
      (
       'fields' => array("SUM(Reconciliation.amount) AS 'reconciled'"),

       'conditions' => array(isset($cond) ? $cond : array(),
			     array('LedgerEntry.id' => $id)),

       'group' => 'LedgerEntry.id',
       );

    // Get the applied amounts on the debit side
    $query['link'] =
      array('DebitReconciliationLedgerEntry' => array('alias' => 'DRLE', 'DRLETransaction' => array('class' => 'Transaction')));
    $tmpstats = $this->find('first', $query);
    $stats['debit_amount_reconciled'] = $tmpstats[0]['reconciled'];

    // Get the applied amounts on the credit side
    $query['link'] =
      array('CreditReconciliationLedgerEntry' => array('alias' => 'CRLE', 'CRLETransaction' => array('class' => 'Transaction')));
    $tmpstats = $this->find('first', $query);
    $stats['credit_amount_reconciled'] = $tmpstats[0]['reconciled'];

    return $stats;
  }

}