require "cases/helper"
require "support/connection_helper"

module ActiveRecord
  class PostgresqlConnectionTest < ActiveRecord::PostgreSQLTestCase
    include ConnectionHelper

    class NonExistentTable < ActiveRecord::Base
    end

    fixtures :comments

    def setup
      super
      @subscriber = SQLSubscriber.new
      @subscription = ActiveSupport::Notifications.subscribe("sql.active_record", @subscriber)
      @connection = ActiveRecord::Base.connection
    end

    def teardown
      ActiveSupport::Notifications.unsubscribe(@subscription)
      super
    end

    def test_truncate
      count = ActiveRecord::Base.connection.execute("select count(*) from comments").first["count"].to_i
      assert_operator count, :>, 0
      ActiveRecord::Base.connection.truncate("comments")
      count = ActiveRecord::Base.connection.execute("select count(*) from comments").first["count"].to_i
      assert_equal 0, count
    end

    def test_encoding
      assert_not_nil @connection.encoding
    end

    def test_collation
      assert_not_nil @connection.collation
    end

    def test_ctype
      assert_not_nil @connection.ctype
    end

    def test_default_client_min_messages
      assert_equal "warning", @connection.client_min_messages
    end

    # Ensure, we can set connection params using the example of Generic
    # Query Optimizer (geqo). It is 'on' per default.
    def test_connection_options
      params = ActiveRecord::Base.connection_config.dup
      params[:options] = "-c geqo=off"
      NonExistentTable.establish_connection(params)

      # Verify the connection param has been applied.
      expect = NonExistentTable.connection.query("show geqo").first.first
      assert_equal "off", expect
    end

    def test_reset
      @connection.query("ROLLBACK")
      @connection.query("SET geqo TO off")

      # Verify the setting has been applied.
      expect = @connection.query("show geqo").first.first
      assert_equal "off", expect

      @connection.reset!

      # Verify the setting has been cleared.
      expect = @connection.query("show geqo").first.first
      assert_equal "on", expect
    end

    def test_reset_with_transaction
      @connection.query("ROLLBACK")
      @connection.query("SET geqo TO off")

      # Verify the setting has been applied.
      expect = @connection.query("show geqo").first.first
      assert_equal "off", expect

      @connection.query("BEGIN")
      @connection.reset!

      # Verify the setting has been cleared.
      expect = @connection.query("show geqo").first.first
      assert_equal "on", expect
    end

    def test_tables_logs_name
      ActiveSupport::Deprecation.silence { @connection.tables("hello") }
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_indexes_logs_name
      @connection.indexes("items", "hello")
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_table_exists_logs_name
      ActiveSupport::Deprecation.silence { @connection.table_exists?("items") }
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_table_alias_length_logs_name
      @connection.instance_variable_set("@table_alias_length", nil)
      @connection.table_alias_length
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_current_database_logs_name
      @connection.current_database
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_encoding_logs_name
      @connection.encoding
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    def test_schema_names_logs_name
      @connection.schema_names
      assert_equal "SCHEMA", @subscriber.logged[0][1]
    end

    if ActiveRecord::Base.connection.prepared_statements
      def test_statement_key_is_logged
        bind = Relation::QueryAttribute.new(nil, 1, Type::Value.new)
        @connection.exec_query("SELECT $1::integer", "SQL", [bind], prepare: true)
        name = @subscriber.payloads.last[:statement_name]
        assert name
        res = @connection.exec_query("EXPLAIN (FORMAT JSON) EXECUTE #{name}(1)")
        plan = res.column_types["QUERY PLAN"].deserialize res.rows.first.first
        assert_operator plan.length, :>, 0
      end
    end

    # Must have PostgreSQL >= 9.2, or with_manual_interventions set to
    # true for this test to run.
    #
    # When prompted, restart the PostgreSQL server with the
    # "-m fast" option or kill the individual connection assuming
    # you know the incantation to do that.
    # To restart PostgreSQL 9.1 on OS X, installed via MacPorts, ...
    # sudo su postgres -c "pg_ctl restart -D /opt/local/var/db/postgresql91/defaultdb/ -m fast"
    def test_reconnection_after_actual_disconnection_with_verify
      original_connection_pid = @connection.query("select pg_backend_pid()")

      # Sanity check.
      assert @connection.active?

      if @connection.send(:postgresql_version) >= 90200
        secondary_connection = ActiveRecord::Base.connection_pool.checkout
        secondary_connection.query("select pg_terminate_backend(#{original_connection_pid.first.first})")
        ActiveRecord::Base.connection_pool.checkin(secondary_connection)
      elsif ARTest.config["with_manual_interventions"]
        puts "Kill the connection now (e.g. by restarting the PostgreSQL " +
          'server with the "-m fast" option) and then press enter.'
        $stdin.gets
      else
        # We're not capable of terminating the backend ourselves, and
        # we're not allowed to seek assistance; bail out without
        # actually testing anything.
        return
      end

      @connection.verify!

      assert @connection.active?

      # If we get no exception here, then either we re-connected successfully, or
      # we never actually got disconnected.
      new_connection_pid = @connection.query("select pg_backend_pid()")

      assert_not_equal original_connection_pid, new_connection_pid,
        "umm -- looks like you didn't break the connection, because we're still " +
        "successfully querying with the same connection pid."

      # Repair all fixture connections so other tests won't break.
      @fixture_connections.each(&:verify!)
    end

    def test_set_session_variable_true
      run_without_connection do |orig_connection|
        ActiveRecord::Base.establish_connection(orig_connection.deep_merge(variables: { debug_print_plan: true }))
        set_true = ActiveRecord::Base.connection.exec_query "SHOW DEBUG_PRINT_PLAN"
        assert_equal set_true.rows, [["on"]]
      end
    end

    def test_set_session_variable_false
      run_without_connection do |orig_connection|
        ActiveRecord::Base.establish_connection(orig_connection.deep_merge(variables: { debug_print_plan: false }))
        set_false = ActiveRecord::Base.connection.exec_query "SHOW DEBUG_PRINT_PLAN"
        assert_equal set_false.rows, [["off"]]
      end
    end

    def test_set_session_variable_nil
      run_without_connection do |orig_connection|
        # This should be a no-op that does not raise an error
        ActiveRecord::Base.establish_connection(orig_connection.deep_merge(variables: { debug_print_plan: nil }))
      end
    end

    def test_set_session_variable_default
      run_without_connection do |orig_connection|
        # This should execute a query that does not raise an error
        ActiveRecord::Base.establish_connection(orig_connection.deep_merge(variables: { debug_print_plan: :default }))
      end
    end

    def test_get_and_release_advisory_lock
      lock_id = 5295901941911233559
      list_advisory_locks = <<-SQL
        SELECT locktype,
              (classid::bigint << 32) | objid::bigint AS lock_id
        FROM pg_locks
        WHERE locktype = 'advisory'
      SQL

      got_lock = @connection.get_advisory_lock(lock_id)
      assert got_lock, "get_advisory_lock should have returned true but it didn't"

      advisory_lock = @connection.query(list_advisory_locks).find { |l| l[1] == lock_id }
      assert advisory_lock,
        "expected to find an advisory lock with lock_id #{lock_id} but there wasn't one"

      released_lock = @connection.release_advisory_lock(lock_id)
      assert released_lock, "expected release_advisory_lock to return true but it didn't"

      advisory_locks = @connection.query(list_advisory_locks).select { |l| l[1] == lock_id }
      assert_empty advisory_locks,
        "expected to have released advisory lock with lock_id #{lock_id} but it was still held"
    end

    def test_release_non_existent_advisory_lock
      fake_lock_id = 2940075057017742022
      with_warning_suppression do
        released_non_existent_lock = @connection.release_advisory_lock(fake_lock_id)
        assert_equal released_non_existent_lock, false,
          "expected release_advisory_lock to return false when there was no lock to release"
      end
    end

    private

      def with_warning_suppression
        log_level = @connection.client_min_messages
        @connection.client_min_messages = "error"
        yield
        @connection.client_min_messages = log_level
      end
  end
end