start_server {tags {"pubsub"}} {
    proc __consume_subscribe_messages {client type channels} {
        set numsub -1
        set counts {}

        for {set i [llength $channels]} {$i > 0} {incr i -1} {
            set msg [$client read]
            assert_equal $type [lindex $msg 0]

            # when receiving subscribe messages the channels names
            # are ordered. when receiving unsubscribe messages
            # they are unordered
            set idx [lsearch -exact $channels [lindex $msg 1]]
            if {[string match "*unsubscribe" $type]} {
                assert {$idx >= 0}
            } else {
                assert {$idx == 0}
            }
            set channels [lreplace $channels $idx $idx]

            # aggregate the subscription count to return to the caller
            lappend counts [lindex $msg 2]
        }

        # we should have received messages for channels
        assert {[llength $channels] == 0}
        return $counts
    }

    proc subscribe {client channels} {
        $client subscribe {*}$channels
        __consume_subscribe_messages $client subscribe $channels
    }

    proc unsubscribe {client {channels {}}} {
        $client unsubscribe {*}$channels
        __consume_subscribe_messages $client unsubscribe $channels
    }

    proc psubscribe {client channels} {
        $client psubscribe {*}$channels
        __consume_subscribe_messages $client psubscribe $channels
    }

    proc punsubscribe {client {channels {}}} {
        $client punsubscribe {*}$channels
        __consume_subscribe_messages $client punsubscribe $channels
    }

    test "PUBLISH/SUBSCRIBE basics" {
        set rd1 [redis_deferring_client]

        # subscribe to two channels
        assert_equal {1 2} [subscribe $rd1 {chan1 chan2}]
        assert_equal 1 [r publish chan1 hello]
        assert_equal 1 [r publish chan2 world]
        assert_equal {message chan1 hello} [$rd1 read]
        assert_equal {message chan2 world} [$rd1 read]

        # unsubscribe from one of the channels
        unsubscribe $rd1 {chan1}
        assert_equal 0 [r publish chan1 hello]
        assert_equal 1 [r publish chan2 world]
        assert_equal {message chan2 world} [$rd1 read]

        # unsubscribe from the remaining channel
        unsubscribe $rd1 {chan2}
        assert_equal 0 [r publish chan1 hello]
        assert_equal 0 [r publish chan2 world]

        # clean up clients
        $rd1 close
    }

    test "PUBLISH/SUBSCRIBE with two clients" {
        set rd1 [redis_deferring_client]
        set rd2 [redis_deferring_client]

        assert_equal {1} [subscribe $rd1 {chan1}]
        assert_equal {1} [subscribe $rd2 {chan1}]
        assert_equal 2 [r publish chan1 hello]
        assert_equal {message chan1 hello} [$rd1 read]
        assert_equal {message chan1 hello} [$rd2 read]

        # clean up clients
        $rd1 close
        $rd2 close
    }

    test "PUBLISH/SUBSCRIBE after UNSUBSCRIBE without arguments" {
        set rd1 [redis_deferring_client]
        assert_equal {1 2 3} [subscribe $rd1 {chan1 chan2 chan3}]
        unsubscribe $rd1
        assert_equal 0 [r publish chan1 hello]
        assert_equal 0 [r publish chan2 hello]
        assert_equal 0 [r publish chan3 hello]

        # clean up clients
        $rd1 close
    }

    test "SUBSCRIBE to one channel more than once" {
        set rd1 [redis_deferring_client]
        assert_equal {1 1 1} [subscribe $rd1 {chan1 chan1 chan1}]
        assert_equal 1 [r publish chan1 hello]
        assert_equal {message chan1 hello} [$rd1 read]

        # clean up clients
        $rd1 close
    }

    test "UNSUBSCRIBE from non-subscribed channels" {
        set rd1 [redis_deferring_client]
        assert_equal {0 0 0} [unsubscribe $rd1 {foo bar quux}]

        # clean up clients
        $rd1 close
    }

    test "PUBLISH/PSUBSCRIBE basics" {
        set rd1 [redis_deferring_client]

        # subscribe to two patterns
        assert_equal {1 2} [psubscribe $rd1 {foo.* bar.*}]
        assert_equal 1 [r publish foo.1 hello]
        assert_equal 1 [r publish bar.1 hello]
        assert_equal 0 [r publish foo1 hello]
        assert_equal 0 [r publish barfoo.1 hello]
        assert_equal 0 [r publish qux.1 hello]
        assert_equal {pmessage foo.* foo.1 hello} [$rd1 read]
        assert_equal {pmessage bar.* bar.1 hello} [$rd1 read]

        # unsubscribe from one of the patterns
        assert_equal {1} [punsubscribe $rd1 {foo.*}]
        assert_equal 0 [r publish foo.1 hello]
        assert_equal 1 [r publish bar.1 hello]
        assert_equal {pmessage bar.* bar.1 hello} [$rd1 read]

        # unsubscribe from the remaining pattern
        assert_equal {0} [punsubscribe $rd1 {bar.*}]
        assert_equal 0 [r publish foo.1 hello]
        assert_equal 0 [r publish bar.1 hello]

        # clean up clients
        $rd1 close
    }

    test "PUBLISH/PSUBSCRIBE with two clients" {
        set rd1 [redis_deferring_client]
        set rd2 [redis_deferring_client]

        assert_equal {1} [psubscribe $rd1 {chan.*}]
        assert_equal {1} [psubscribe $rd2 {chan.*}]
        assert_equal 2 [r publish chan.foo hello]
        assert_equal {pmessage chan.* chan.foo hello} [$rd1 read]
        assert_equal {pmessage chan.* chan.foo hello} [$rd2 read]

        # clean up clients
        $rd1 close
        $rd2 close
    }

    test "PUBLISH/PSUBSCRIBE after PUNSUBSCRIBE without arguments" {
        set rd1 [redis_deferring_client]
        assert_equal {1 2 3} [psubscribe $rd1 {chan1.* chan2.* chan3.*}]
        punsubscribe $rd1
        assert_equal 0 [r publish chan1.hi hello]
        assert_equal 0 [r publish chan2.hi hello]
        assert_equal 0 [r publish chan3.hi hello]

        # clean up clients
        $rd1 close
    }

    test "PUNSUBSCRIBE from non-subscribed channels" {
        set rd1 [redis_deferring_client]
        assert_equal {0 0 0} [punsubscribe $rd1 {foo.* bar.* quux.*}]

        # clean up clients
        $rd1 close
    }

    test "Mix SUBSCRIBE and PSUBSCRIBE" {
        set rd1 [redis_deferring_client]
        assert_equal {1} [subscribe $rd1 {foo.bar}]
        assert_equal {2} [psubscribe $rd1 {foo.*}]

        assert_equal 2 [r publish foo.bar hello]
        assert_equal {message foo.bar hello} [$rd1 read]
        assert_equal {pmessage foo.* foo.bar hello} [$rd1 read]

        # clean up clients
        $rd1 close
    }

    test "PUNSUBSCRIBE and UNSUBSCRIBE should always reply." {
        # Make sure we are not subscribed to any channel at all.
        r punsubscribe
        r unsubscribe
        # Now check if the commands still reply correctly.
        set reply1 [r punsubscribe]
        set reply2 [r unsubscribe]
        concat $reply1 $reply2
    } {punsubscribe {} 0 unsubscribe {} 0}
}
