tab/app/controllers/concerns/transactions_query.rb
2015-09-11 12:07:43 +02:00

73 lines
2 KiB
Ruby

class TransactionsQuery
attr_reader :arel_table
def initialize user
@user = user
@transactions = Arel::Table.new(:transactions)
@perspectived = Arel::Table.new(:perspectived_transactions)
@peers = Arel::Table.new(:users).alias('peers')
@arel_table = Arel::Table.new(@user.name.concat('_transactions'))
end
def query
Arel::SelectManager.new(ActiveRecord::Base)
.from(arel)
end
def arel
Arel::Nodes::TableAlias.new(
issued_by(User).union(:all, issued_by(Client)),
arel_table.name
)
end
def issued_by klass
issuers = klass.arel_table.alias('issuer')
Arel::SelectManager.new(ActiveRecord::Base)
.from(transactions)
.join(@peers).on(@peers[:id].eq(@perspectived[:peer_id]))
.join(issuers).on(issuers[:id].eq(@perspectived[:issuer_id]))
.where(@perspectived[:issuer_type].eq(klass.name))
.project(
@perspectived[:amount],
@perspectived[:time],
@perspectived[:message],
@peers[:name].as('peer'),
issuers[:name].as('issuer')
)
end
def transactions
Arel::Nodes::TableAlias.new(
incoming.union(:all, outgoing),
@perspectived.name
)
end
def outgoing
@transactions
.where(@transactions[:debtor_id].eq(@user.id))
.project(
(@transactions[:amount]*Arel::Nodes::SqlLiteral.new("-1")).as('amount'),
@transactions[:creditor_id].as('peer_id'),
@transactions[:created_at].as('time'),
@transactions[:issuer_id],
@transactions[:issuer_type],
@transactions[:message]
)
end
def incoming
@user.incoming_transactions.arel
@transactions
.where(@transactions[:creditor_id].eq(@user.id))
.project(
@transactions[:amount],
@transactions[:debtor_id].as('peer_id'),
@transactions[:created_at].as('time'),
@transactions[:issuer_id],
@transactions[:issuer_type],
@transactions[:message]
)
end
end