Fixes and tests for indirect transfers. Extended balance.

TrsrDB:
    fixed Id -> credId
    autobalance -> make_transfers

TrsrDB::Account:
    added history accessor
TrsrDB::Balance:
    added fieds earned spent and even_until, renamed credit to available
TrsrDB::CurrentArrears:
    fixed account -> debtor in relation declaration
schema.sql:
    fixed triggers
    deactivated trigger enforceFixedCredit
    extended Balance with some more fields
t/schema.{sql,out}
    trivial fixes
t/schema.t added tests:
    Get balances after transfers
    partial use of credit,
    indirect transfers

TrsrDB.pm

@@ -23,7 +23,7 @@ sub import {
     );
 }
 
-sub autobalance {
+sub make_transfers {
     my ($self, @pairs) = @_;
 
     my $from_to = [
@@ -32,7 +32,7 @@ sub autobalance {
     ];
     my $to_from = [
         undef, CurrentArrears => 'billId',
-        payable_with => 'Id', undef
+        payable_with => 'credId', undef
     ];
 
     my $transfers = $self->resultset('Transfer');

TrsrDB/Account.pm

@@ -30,5 +30,9 @@ __PACKAGE__->has_many(
 __PACKAGE__->has_one(
     balance => 'TrsrDB::Balance', 'ID'
 );
+__PACKAGE__->has_many(
+    history => 'TrsrDB::History',
+    { 'foreign.account' => 'self.ID' }
+);
 
 1;

TrsrDB/Balance.pm

@@ -4,7 +4,7 @@ package TrsrDB::Balance;
 use base qw/DBIx::Class::Core/;
 
 __PACKAGE__->table("Balance");
-__PACKAGE__->add_columns(qw/ID credit promised arrears/);
+__PACKAGE__->add_columns(qw/ ID available earned promised spent arrears even_until /);
 __PACKAGE__->set_primary_key("ID");
 
 __PACKAGE__->belongs_to(

TrsrDB/CurrentArrears.pm

@@ -8,12 +8,12 @@ __PACKAGE__->add_columns(qw/billId debtor targetCredit date purpose difference/)
 __PACKAGE__->set_primary_key("billId");
 
 __PACKAGE__->belongs_to(
-    account => 'TrsrDB::Account',
+    debtor => 'TrsrDB::Account',
-    { 'foreign.ID' => 'self.account' }
+    { 'foreign.ID' => 'self.debtor' }
 );
 
 __PACKAGE__->many_to_many(
-    payable_with => account => 'available_credits'
+    payable_with => debtor => 'available_credits'
 );
 
 1;

schema.sql

@@ -84,20 +84,14 @@ BEGIN
       END
       WHERE billId=NEW.billId;
 
-  UPDATE Credit
-      SET value = value + (SELECT m FROM _temp)
-      WHERE credId = (
-          SELECT targetCredit
-          FROM Debit
-          WHERE billId=NEW.billId
-      );
-
   UPDATE Credit
       SET spent = spent + CASE
         WHEN (SELECT c FROM _temp) <= 0
           THEN RAISE(FAIL, "Credit spent")
-        ELSE
+        ELSE IFNULL(
-          (SELECT m FROM _temp)
+          (SELECT m FROM _temp),
+          RAISE(FAIL,"Oops, lost _temp record before increasing spent")
+        )
       END
       WHERE credId=NEW.credId;
 
@@ -106,6 +100,17 @@ BEGIN
       WHERE billId=NEW.billId AND credId=NEW.credId
         ;
 
+  UPDATE Credit
+      SET value = value + IFNULL(
+          (SELECT m FROM _temp),
+          RAISE(FAIL, "Oops, lost _temp record before increasing value")
+      )
+      WHERE credId = (
+          SELECT targetCredit
+          FROM Debit
+          WHERE billId=NEW.billId
+      );
+
   DELETE FROM _temp;
 
 END;
@@ -245,12 +250,12 @@ BEGIN
     WHERE (NEW.spent + IFNULL((SELECT m FROM _temp WHERE c IS NULL AND d IS NULL),0) ) <> OLD.spent;
 END;
 
-CREATE TRIGGER enforceFixedCredit
+-- CREATE TRIGGER enforceFixedCredit
-    BEFORE UPDATE OF value ON Credit
+--     BEFORE UPDATE OF value ON Credit
-BEGIN
+-- BEGIN
-    SELECT RAISE(FAIL, "Credit involved in transactions to revoke at first")
+--     SELECT RAISE(FAIL, "Credit involved in transactions to revoke at first")
-    WHERE EXISTS (SELECT * FROM Transfer WHERE credId=NEW.credId);
+--     WHERE EXISTS (SELECT * FROM Transfer WHERE credId=NEW.credId);
-END;
+-- END;
 
 CREATE TRIGGER checkIBANatTransfer
     BEFORE INSERT ON Debit
@@ -283,11 +288,43 @@ CREATE VIEW AvailableCredits AS
     WHERE value != spent
 ;
       
+
+-- Log of internal transfers
+CREATE VIEW History AS
+  -- internal transfers with account as source
+  SELECT DATE(timestamp) AS date,
+         d.purpose       AS purpose,
+         d.debtor        AS account,
+         NULL            AS credit,
+         t.amount        AS debit,
+         c.account       AS contra,
+         d.billId        AS billId
+  FROM Transfer t
+    LEFT JOIN Debit  AS d ON d.billId = t.billId
+    LEFT JOIN Credit AS c ON c.credId = d.targetCredit
+  -- internal transfers with account as target
+  UNION
+  SELECT DATE(timestamp) AS date,
+         d.purpose       AS purpose,
+         c.account       AS account,
+         t.amount        AS credit,
+         NULL            AS debit,
+         d.debtor        AS contra,
+         d.billId        AS billId
+  FROM Transfer t
+    LEFT JOIN Debit  AS d ON d.billId = t.billId
+    LEFT JOIN Credit AS c ON c.credId = d.targetCredit
+  ORDER BY date ASC
+;
+
 CREATE VIEW Balance AS
   SELECT Account.ID             AS ID,
-      IFNULL(ac.allCredits,0)   AS credit,
+      IFNULL(ac.allCredits,0)   AS available,
+      IFNULL(hi.credit,0)       AS earned,
+      IFNULL(hi.debit,0)        AS spent,
       IFNULL(pr.allPromises, 0) AS promised,
-      IFNULL(ca.allArrears, 0)  AS arrears
+      IFNULL(ca.allArrears, 0)  AS arrears,
+      even.until                AS even_until
   FROM Account
      LEFT OUTER JOIN (
          SELECT debtor, sum(difference) AS allArrears
@@ -306,6 +343,21 @@ CREATE VIEW Balance AS
              JOIN Account a ON a.ID = c.account
          GROUP BY a.ID
      )                          AS pr ON Account.ID=pr.ID
+     LEFT OUTER JOIN (
+         SELECT account,
+                sum(credit) AS credit,
+                sum(debit) AS debit
+         FROM History
+         GROUP BY account
+     )                          AS hi ON Account.ID=hi.account
+     LEFT OUTER JOIN (
+         SELECT d.debtor     AS account,
+                max(d.date)  AS until
+         FROM Debit d
+             LEFT OUTER JOIN CurrentArrears ca ON d.debtor = ca.debtor
+         GROUP BY d.debtor, ca.debtor
+         HAVING d.date <= IFNULL( min(ca.date), d.date )
+     )                          AS even ON Account.ID=even.account
   ;
 
 CREATE VIEW ReconstructedBankStatement AS
@@ -328,41 +380,3 @@ CREATE VIEW ReconstructedBankStatement AS
   WHERE targetCredit IS NULL    -- exclude internal transfers
   ORDER BY date ASC
 ;
-
--- History view: All incoming, outgoing payments and internal transfers
-CREATE VIEW History AS
-  SELECT c.date          AS date,
-         c.purpose       AS purpose,
-                            account,
-         c.value         AS credit,
-         NULL            AS debit,
-         NULL            AS contra,    
-         NULL            AS billId
-  FROM Credit AS c
-    LEFT OUTER JOIN Debit AS d ON c.credId=d.targetCredit
-  GROUP BY c.credId
-    HAVING count(d.billId) == 0 -- exclude internal transfers
-  UNION -- internal transfers with account as source
-  SELECT DATE(timestamp) AS date,
-         d.purpose       AS purpose,
-         d.debtor        AS account,
-         NULL            AS credit,
-         t.amount        AS debit,
-         c.account       AS contra,
-         d.billId        AS billId
-  FROM Transfer t
-    LEFT JOIN Credit AS c ON c.credId = t.credId
-    LEFT JOIN Debit  AS d ON d.billId = t.billId
-  UNION -- internal transfers with account as target
-  SELECT DATE(timestamp) AS date,
-         d.purpose       AS purpose,
-         c.account       AS account,
-         t.amount        AS credit,
-         NULL            AS debit,
-         d.debtor        AS contra,
-         d.billId        AS billId
-  FROM Transfer t
-    LEFT JOIN Debit  AS d ON d.billId = t.billId
-    LEFT JOIN Credit AS c ON c.credId = t.credId
-  ORDER BY date ASC
-;

t/schema.out

@@ -1,4 +1,4 @@
-ID:	credit	promise debt
+ID:	availbl	promise debt
 --------------------------------
 Club:	0	+7200	-23450
 john:	7200	+0	-7200

t/schema.sql

@@ -24,18 +24,18 @@ INSERT INTO Debit VALUES ("MB1605-john", "john", 1, "2016-05-01", "Membership fe
                         ("TWX2016/123", "Club", 3, "2016-01-15", "Server Hosting 2016", 23450, 0);
 
 .separator "	"
-SELECT "ID:	credit	promise debt";
+SELECT "ID:	availbl	promise debt";
 SELECT "--------------------------------";
 
-SELECT ID || ":", credit, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("john", "Club");
+SELECT ID || ":", available, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("john", "Club");
 
 SELECT "# Reflect john paying its bills all at once ...";
 INSERT INTO Transfer (billId, credId) VALUES ("MB1605-john", 2), ("MB1606-john", 2), ("MB1607-john", 2), ("MB1608-john", 2), ("MB1609-john", 2), ("MB1610-john", 2), ("MB1611-john", 2), ("MB1612-john", 2), ("MB1701-john", 2), ("MB1702-john", 2), ("MB1703-john", 2), ("MB1704-john", 2); 
-SELECT ID || ":", credit, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("john", "Club");
+SELECT ID || ":", available, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("john", "Club");
 
 SELECT "# Charge Club with server hosting provided by alex ...";
 INSERT INTO Transfer (billId, credId) VALUES ("TWX2016/123", 1);
-SELECT ID || ":", credit, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
+SELECT ID || ":", available, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
 
 SELECT "# Some updates and deletes that could, unless denied, destroy consistency ...";
 UPDATE Debit SET paid = 20000 WHERE billId="TWX2016/123";
@@ -47,11 +47,11 @@ BEGIN TRANSACTION;
 DELETE FROM Transfer WHERE billId="TWX2016/123";
 UPDATE Debit SET value = 20000 WHERE billId="TWX2016/123";
 DELETE FROM Debit WHERE billId="TWX2016/123"; -- *SHOULD* work
-SELECT ID || ":", credit, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
+SELECT ID || ":", available, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
 ROLLBACK TRANSACTION;
 
 SELECT '# But let''s rollback that what-if excurse. This is how it currently is ...';
-SELECT ID || ":", credit, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
+SELECT ID || ":", available, '+' || promised, arrears * -1 FROM Balance WHERE ID in ("Club", "alex");
 
 SELECT '###################################################################';
 SELECT '# Now it is your turn: Study the sql code yielding the output above';

t/schema.t

@@ -46,7 +46,7 @@ my %months = (
 while ( my ($num, $month) = each %months ) {
     my $yy = substr $month, -2;
     $db->resultset("Debit")->create({
-        billId => "MB$yy$num-john",
+        billId => "MB$yy$num/john",
         debtor => "john",
         targetCredit => 1,
         date => "16-05-01",
@@ -70,17 +70,60 @@ is $db->resultset("Debit")->search({ debtor => 'Club' })->single->billId, "TWX20
 
 is_deeply {
     map { $_->ID => {$_->get_columns} }
-    $db->resultset("Balance")->all
+    $db->resultset("Balance")->search(
+        {}, { columns => [qw|ID available arrears promised|] }
+    )
 }, {
-    john => { ID => 'john', credit => 7200, arrears => 7200,  promised => 0 },
+    john => { ID=>'john', available=>7200, arrears=>7200, promised=>0 },
-    Club => { ID => 'Club', credit => 0, arrears => 23450, promised => 7200 },
+    Club => { ID=>'Club', available=>0, arrears=>23450, promised=>7200 },
-    alex => { ID => 'alex', credit => 0, arrears => 0, promised => 23450 },
+    alex => { ID=>'alex', available=>0, arrears=>0, promised=>23450 },
 },
-"Get balances"
+"Get balances before transfers"
 ;    
 
 # Transfer 72 Euro (6 Euro per month) from john's to Club account.
 # Transfer same 72 Euro from Club account to alex hosting the web site.
-is $db->autobalance( (q{*} => q{*}) x 2 ), 14400, 'Automatically balanced credits and debits';
+is $db->make_transfers( (q{*} => q{*}) x 2 ), 14400, 'Automatically balanced credits and debits';
+
+is_deeply {
+    map { $_->ID => {$_->get_columns} }
+    $db->resultset("Balance")->search(
+        {}, { columns => [qw|ID available arrears promised|] }
+    )
+}, {
+    john => { ID=>'john', available=>0, arrears=>0, promised=>0 },
+    Club => { ID=>'Club', available=>0, arrears=>16250, promised=>0 },
+    alex => { ID=>'alex', available=>7200, arrears=>0, promised=>16250 },
+},
+"Get balances after transfers"
+;    
+
+$db->resultset("Account")->create({ ID => "rose", altId => 45, type => 'member' }); 
+%months = (
+    '07' => 'July 2016',     '08' => 'August 2016',
+    '09' => 'September 2016', '10' => 'October 2016',  '11' => 'November 2016', '12' => 'December 2016',
+);
+while ( my ($num, $month) = each %months ) {
+    my $yy = substr $month, -2;
+    $db->resultset("Debit")->create({
+        billId => "MB$yy$num/rose",
+        debtor => "rose",
+        targetCredit => 1,
+        date => "16-07-10",
+        purpose => "Membership fee $month",
+        value => 600
+    });
+}
+
+my $rose = $db->resultset("Account")->find("rose");
+$rose->add_to_credits({
+    value => 7200, purpose => "Membership fees until 6/17",
+    date => '16-08-12'
+});
+
+$db->make_transfers( q{*} => q{*} );
+
+is $rose->available_credits->get_column("difference")->sum, 3600, "partial use of credit";
+is $db->resultset("Balance")->find("alex")->earned, '10800', 'indirect transfers';
 
 done_testing();