require 'spec_helper'
require 'active_record_spec_helper'
require 'tempfile'

if defined? ActiveRecord

  require 'active_record/schema_dumper'

  # migrations used in tests. our factories/fixtures
  # their class names are the same if they are functionally
  # equivalent, but are organized in different modules depending on
  # whether it is implemented using
  # schema_statements, create_table or change_table
  module SchemaStatements
    class CreateLoanAndMoney < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans do |t|
            t.string :name
          end
          add_money :loans, :principal
        end
      end
    end

    class CreateLoanWithCurrency < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans do |t|
            t.string :name
            t.currency
          end
          add_money :loans, :principal, :repaid, :npa
        end
      end
    end

    class RemoveMoneyColumnsFromLoan  < ActiveRecord::Migration
      def change
        suppress_messages do
          remove_money :loans, :principal, :repaid, :npa
        end
      end
    end

    class RemoveMoneyColumnsExceptPrincipalFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          remove_money :loans, :repaid, :npa
        end
      end
    end

    class RemovePrincipalFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          remove_money :loans, :principal
        end
      end
    end

    class RemoveCurrencyFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          remove_currency :loans
        end
      end
    end
  end # module SchemaStatements

  module ChangeTable
    class AddPrincipalToLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans do |t|
            t.money :principal
          end
        end
      end
    end

    class RemoveCurrencyFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans, force: true do |t|
            t.remove_currency
          end
        end
      end
    end

    class RemovePrincipalFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans do |t|
            t.remove_money :principal
          end
        end
      end
    end
    
    class AddSingleCurrencyToLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans, force: true do |t|
            t.currency
          end
        end
      end
    end

    class RemoveMoneyColumnsFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans, force: true do |t|
            t.remove_money :principal, :repaid, :npa
          end
        end
      end
    end

    class RemoveMoneyColumnsExceptPrincipalFromLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          change_table :loans, force: true do |t|
            t.remove_money :repaid, :npa
          end
        end
      end
    end
  end # module ChangeTable

  module CreateTableDefinition
    class CreateLoan < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans do |t|
            t.string :name
          end
        end
      end
    end

    class CreateLoanAndMoney < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans do |t|
            t.string :name
            t.money  :principal
          end
        end
      end
    end

    class CreateLoanWithCurrency < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans, force: true do |t|
            t.string :name
            t.money  :principal
            t.money  :repaid
            t.money  :npa
            t.currency
          end
        end
      end
    end

    class CreateLoanWithoutCurrency < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans, force: true do |t|
            t.string :name
            t.money  :principal
            t.money  :repaid
            t.money  :npa
          end
        end
      end
    end
    
    class CreateLoanWithCurrencySpecifiedFirst < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans, force: true do |t|
            t.string :name
            t.currency
            t.money  :principal
            t.money  :repaid
            t.money  :npa
          end
        end
      end
    end

    class CreateLoanWithCurrencySpecifiedInBetween  < ActiveRecord::Migration
      def change
        suppress_messages do
          create_table :loans, force: true do |t|
            t.string :name
            t.money  :principal
            t.money  :repaid
            t.currency
            t.money  :npa
          end
        end
      end
    end
  end # module CreateTableDefinition
  
  # class Loan < ActiveRecord::Base   
  #   attr_accessible :principal, :name
  #   # money :principal
  # end
  
  describe "Migrating Money columns" do

    let(:schema_with_principal) do
      <<-EOF.strip_spaces
  create_table "loans", :force => true do |t|
    t.string  "name"
    t.integer "principal_money"
    t.string  "principal_currency"
  end
EOF
    end

    let(:schema_with_principal_and_single_currency_column) do
      <<-EOF.strip_spaces
  create_table "loans", :force => true do |t|
    t.string  "name"
    t.integer "principal_money"
    t.string  "currency"
  end
EOF
    end

    let(:schema_with_only_name) do
      <<-EOF.strip_spaces
  create_table "loans", :force => true do |t|
    t.string  "name"
  end
EOF
    end

    let(:schema_with_single_currency_column) do
      <<-EOF.strip_spaces
  create_table "loans", :force => true do |t|
    t.string  "name"
    t.integer "npa_money"
    t.integer "principal_money"
    t.integer "repaid_money"
    t.string "currency"
  end
EOF
    end

    let(:schema_with_multiple_currency_columns) do
      <<-EOF.strip_spaces
  create_table "loans", :force => true do |t|
    t.string  "name"
    t.string  "npa_currency"
    t.integer "npa_money"
    t.string  "principal_currency"
    t.integer "principal_money"
    t.string  "repaid_currency"
    t.integer "repaid_money"
  end
EOF
    end

    context "and testing schema statements", :schema_statements do
      context "which have one currency column for each money column" do
        before(:each) do
          migrate SchemaStatements::CreateLoanAndMoney
        end

        describe "#add_money" do
          it "creates two columns for each money attribute. one to store the lower denomination as an integer and the currency as a string" do
            expect(dump_schema).to eq schema_with_principal
          end
        end
      
        describe "#remove_money" do
          it "drops two columns for each money attribute. one which stored the lower denomination as an integer and the currency as a string" do
            expect { migrate SchemaStatements::RemovePrincipalFromLoan }.to change { dump_schema }.from(schema_with_principal).to(schema_with_only_name)
          end
        end
      end

      context "which has a single currency", :single_currency do
        before(:each) do
          migrate SchemaStatements::CreateLoanWithCurrency
        end

        describe "#add_money" do
          it "creates one column for each money attribute, to store the lower denomination as an integer. currency is stored in a common column" do
            expect(dump_schema).to eq schema_with_single_currency_column
          end
        end

        describe "#remove_money" do
          it "drops the money column for each money attribute and the common currency column as well", :fixme, :fixme_need_to_clear_table_cache do
            expect { migrate SchemaStatements::RemoveMoneyColumnsFromLoan }.to change { dump_schema }.from(schema_with_single_currency_column).to(schema_with_only_name)
          end

          it "drops the money column for each money attribute but keeps the common currency column because some money columns still remain" do
            expect { migrate SchemaStatements::RemoveMoneyColumnsExceptPrincipalFromLoan }.to change { dump_schema }.
              from(schema_with_single_currency_column).
              to(schema_with_principal_and_single_currency_column)
          end
        end

        describe "#remove_currency" do
          it "drops the common currency column and adds a currency columns to each of the existing money columns" do
            expect { migrate SchemaStatements::RemoveCurrencyFromLoan }.to change { dump_schema }.from(schema_with_single_currency_column).to(schema_with_multiple_currency_columns)
          end

          pending "remove currency while side-by-side adding a money column"
        end
      end
    end # context "schema_statements"

    context "and testing table statements", :table_statements do
      context "which have one currency column for each money column" do
        before(:each) do
          migrate CreateTableDefinition::CreateLoanAndMoney
        end
        
        describe "#add_money" do
          it "creates two columns for each money attribute. one to store the lower denomination as an integer and the currency as a string" do
            expect(dump_schema).to eq schema_with_principal
          end
        end

        describe "#remove_money" do
          it "drops two columns for each money attribute. one which stored the lower denomination as an integer and the currency as a string" do
            expect { migrate ChangeTable::RemovePrincipalFromLoan }.to change { dump_schema }.from(schema_with_principal).to(schema_with_only_name)
          end
        end
      end

      context "which has a single currency", :single_currency do
        describe "#add_money" do
          context "and tests that order of statements does not matter" do
            it "creates money and common currency cilumns when currency column is specified last" do
              migrate CreateTableDefinition::CreateLoanWithCurrency
              expect(dump_schema).to eq schema_with_single_currency_column
            end
            
            it "creates money and common currency cilumns when currency column is specified first" do
              migrate CreateTableDefinition::CreateLoanWithCurrencySpecifiedFirst
              expect(dump_schema).to eq schema_with_single_currency_column
            end

            it "creates money and common currency cilumns when currency column is specified in-between" do
              migrate CreateTableDefinition::CreateLoanWithCurrencySpecifiedInBetween
              expect(dump_schema).to eq schema_with_single_currency_column
            end
          end
        end

        describe "#remove_money" do
          before(:each) do
            migrate CreateTableDefinition::CreateLoanWithCurrency
          end
          
          it "drops the money column for each money attribute and the common currency column as well" do
            expect { migrate ChangeTable::RemoveMoneyColumnsFromLoan }.to change { dump_schema }.from(schema_with_single_currency_column).to(schema_with_only_name)
          end
          
          it "drops the money column for each money attribute but keeps the common currency column because some money columns still remain" do
            expect { migrate ChangeTable::RemoveMoneyColumnsExceptPrincipalFromLoan }.to change { dump_schema }.
              from(schema_with_single_currency_column).
              to(schema_with_principal_and_single_currency_column)
          end
        end
        
        describe "#remove_currency" do
          it "drops the common currency column and adds a currency columns to each of the existing money columns" do
            migrate CreateTableDefinition::CreateLoanWithCurrency
            expect { migrate ChangeTable::RemoveCurrencyFromLoan }.to change { dump_schema }.from(schema_with_single_currency_column).to(schema_with_multiple_currency_columns)
          end
        end
          
        it "can add a single currrency column later" do
          migrate CreateTableDefinition::CreateLoanWithoutCurrency
          expect { migrate ChangeTable::AddSingleCurrencyToLoan }.to change { dump_schema }.from(schema_with_multiple_currency_columns).to(schema_with_single_currency_column)
        end
      end # context "which has a single currency"
    end # context "and testing table statements"

    it "can add a money column later" do
      migrate CreateTableDefinition::CreateLoan
      expect { migrate ChangeTable::AddPrincipalToLoan }.to change { dump_schema }.from(schema_with_only_name).to(schema_with_principal)
    end

    pending "separate up and down migration methods. using add_money and remove_money"
  end # describe "Migrating Money columns"
end # if defined? ActiveRecord