[ircbot] / bot.tcl

# Core bot code

proc defset {varname val} {
    upvar #0 $varname var
    if {![info exists var]} { set var $val }
}

# must set host
defset port 6667

defset nick testbot
defset ownfullname "testing bot"
defset ownmailaddr test-irc-bot@example.com

defset musthaveping_ms 10000
defset out_maxburst 6
defset out_interval 2100
defset out_lag_lag 5000
defset out_lag_very 25000

proc manyset {list args} {
    foreach val $list var $args {
        upvar 1 $var my
        set my $val
    }
}

proc try_except_finally {try except finally} {
    global errorInfo errorCode
    set er [catch { uplevel 1 $try } emsg]
    if {$er} {
        set ei $errorInfo
        set ec $errorCode
        if {[catch { uplevel 1 $except } emsg3]} {
            append ei "\nALSO ERROR HANDLING ERROR:\n$emsg3"
        }
    }
    set er2 [catch { uplevel 1 $finally } emsg2]
    if {$er} {
        if {$er2} {
            append ei "\nALSO ERROR CLEANING UP:\n$emsg2"
        }
        return -code $er -errorinfo $ei -errorcode $ec $emsg
    } elseif {$er2} {
        return -code $er2 -errorinfo $errorInfo -errorcode $errorCode $emsg2
    } else {
        return $emsg
    }
}

proc out__vars {} {
    uplevel 1 {
        global out_queue out_creditms out_creditat out_interval out_maxburst
        global out_lag_lag out_lag_very
#set pr [lindex [info level 0] 0]
#puts $pr>[clock seconds]|$out_creditat|$out_creditms|[llength $out_queue]<
    }
}

proc out_lagged {} {
    out__vars
    if {[llength $out_queue]*$out_interval > $out_lag_very} {
        return 2
    } elseif {[llength $out_queue]*$out_interval > $out_lag_lag} {
        return 1
    } else {
        return 0
    }
}

proc out_restart {} {
    out__vars
    
    set now [clock seconds]
    incr out_creditms [expr {($now - $out_creditat) * 1000}]
    set out_creditat $now
    if {$out_creditms > $out_maxburst*$out_interval} {
        set out_creditms [expr {$out_maxburst*$out_interval}]
    }
    out_runqueue $now
}

proc out_runqueue {now} {
    global sock
    out__vars
    
    while {[llength $out_queue] && $out_creditms >= $out_interval} {
#puts rq>$now|$out_creditat|$out_creditms|[llength $out_queue]<
        manyset [lindex $out_queue 0] orgwhen msg
        set out_queue [lrange $out_queue 1 end]
        if {[llength $out_queue]} {
            append orgwhen "+[expr {$now - $orgwhen}]"
            append orgwhen ([llength $out_queue])"
        }
        puts "$orgwhen -> $msg"
        puts $sock $msg
        incr out_creditms -$out_interval
    }
    if {[llength $out_queue]} {
        after $out_interval out_nextmessage
    }
}

proc out_nextmessage {} {
    out__vars
    set now [clock seconds]
    incr out_creditms $out_interval
    set out_creditat $now
    out_runqueue $now
}

proc sendout_priority {priority command args} {
    global sock out_queue
    if {[llength $args]} {
        set la [lindex $args end]
        set args [lreplace $args end end]
        foreach i $args {
            if {[regexp {[: ]} $i]} {
                error "bad argument in output $i ($command $args)"
            }
        }
        lappend args :$la
    }
    set args [lreplace $args 0 -1 $command]
    set string [join $args { }]
    set now [clock seconds]
    set newe [list $now $string]
    if {$priority} {
        set out_queue [concat [list $newe] $out_queue]
    } else {
        lappend out_queue $newe
    }
    if {[llength $out_queue] == 1} {
        out_restart
    }
}

proc sendout {command args} { eval sendout_priority [list 0 $command] $args }
    
proc log {data} {
    puts $data
}

proc logerror {data} {
    log $data
}

proc saveeic {} {
    global saveei saveec errorInfo errorCode

    set saveei $errorInfo
    set saveec $errorCode

    puts ">$saveec|$saveei<"
}

proc bgerror {msg} {
    global save
    logerror $msg
    saveeic
}

proc onread {args} {
    global sock nick calling_nick errorInfo errorCode
    
    if {[gets $sock line] == -1} { fail "EOF/error on input" }
    regsub -all "\[^ -\176\240-\376\]" $line ? line
    set org $line
    
    set ei $errorInfo
    set ec $errorCode
    catch { unset calling_nick }
    set errorInfo $ei
    set errorCode $ec
    
    if {[regexp -nocase {^:([^ ]+) (.*)} $line dummy prefix remain]} {
        set line $remain
        if {[regexp {^([^!]+)!} $prefix dummy maybenick]} {
            set calling_nick $maybenick
            if {"[irctolower $maybenick]" == "[irctolower $nick]"} return
        }
    } else {
        set prefix {}
    }
    if {![string length $line]} { return }
    if {![regexp -nocase {^([0-9a-z]+) *(.*)} $line dummy command line]} {
        log "bad command: $org"
        return
    }
    set command [string toupper $command]
    set params {}
    while {[regexp {^([^ :]+) *(.*)} $line dummy thisword line]} {
        lappend params $thisword
    }
    if {[regexp {^:(.*)} $line dummy thisword]} {
        lappend params $thisword
    } elseif {[string length $line]} {
        log "junk at end: $org"
        return
    }
    if {"$command" == "PRIVMSG" &&
        [regexp {^[&#+!]} [lindex $params 0]] &&
        ![regexp {^!} [lindex $params 1]]} {
        # on-channel message, ignore
        catch {
            recordlastseen_p $prefix "talking on [lindex $params 0]" 1
        }
        return
    }
    log "[clock seconds] <- $org"
    set procname msg_$command
    if {[catch { info body $procname }]} { return }
    if {[catch {
        eval [list $procname $prefix $command] $params
    } emsg]} {
        logerror "error: $emsg ($prefix $command $params)"
        saveeic
    }
}

proc sendprivmsg {dest l} {
    foreach v [split $l "\n"] {
        sendout [expr {[ischan $dest] ? "PRIVMSG" : "NOTICE"}] $dest $v
    }
}
proc sendaction_priority {priority dest what} {
    sendout_priority $priority PRIVMSG $dest "\001ACTION $what\001"
}
proc msendprivmsg {dest ll} { foreach l $ll { sendprivmsg $dest $l } }
proc msendprivmsg_delayed {delay dest ll} { after $delay [list msendprivmsg $dest $ll] }

proc prefix_none {} {
    upvar 1 p p
    if {[string length $p]} { error "prefix specified" }
}

proc msg_PING {p c s1} {
    global musthaveping_after
    prefix_none
    sendout PONG $s1
    if {[info exists musthaveping_after]} connected
}

proc check_nick {n} {
    if {[regexp -nocase {[^][\\`_^{|}a-z0-9-]} $n]} { error "bad char in nick" }
    if {[regexp {^[-0-9]} $n]} { error "bad nick start" }
}

proc ischan {dest} {
    return [regexp {^[&#+!]} $dest]
}

proc irctolower {v} {
    foreach {from to} [list "\\\[" "{" \
                          "\\\]" "}" \
                          "\\\\" "|" \
                          "~"    "^"] {
        regsub -all $from $v $to v
    }
    return [string tolower $v]
}

proc prefix_nick {} {
    global nick
    upvar 1 p p
    upvar 1 n n
    if {![regexp {^([^!]+)!} $p dummy n]} { error "not from nick" }
    check_nick $n
    if {"[irctolower $n]" == "[irctolower $nick]"} {
        error "from myself" {} {}
    }
}

proc showintervalsecs {howlong} {
    return [showintervalsecs/[opt timeformat] $howlong]
}

proc showintervalsecs/ks {howlong} {
    if {$howlong < 1000} {
        return "${howlong}s"
    } else {
        if {$howlong < 1000000} {
            set pfx k
            set scale 1000
        } else {
            set pfx M
            set scale 1000000
        }
        set value [expr "$howlong.0 / $scale"]
        foreach {min format} {100 %.0f 10 %.1f 1 %.2f} {
            if {$value < $min} continue
            return [format "$format${pfx}s" $value]
        }
    }
}

proc format_qty {qty unit} {
    set o $qty
    append o " "
    append o $unit
    if {$qty != 1} { append o s }
    return $o
}

proc showintervalsecs/hms {qty} {
    set ul {second 60 minute 60 hour 24 day 7 week}
    set remainv 0
    while {[llength $ul] > 1 && $qty >= [set uv [lindex $ul 1]]} {
        set remainu [lindex $ul 0]
        set remainv [expr {$qty % $uv}]
        set qty [expr {($qty-$remainv)/$uv}]
        set ul [lreplace $ul 0 1]
    }
    set o [format_qty $qty [lindex $ul 0]]
    if {$remainv} {
        append o " "
        append o [format_qty $remainv $remainu]
    }
    return $o
}

proc showinterval {howlong} {
    if {$howlong <= 0} {
        return {just now}
    } else {
        return "[showintervalsecs $howlong] ago"
    }
}

proc showtime {when} {
    return [showinterval [expr {[clock seconds] - $when}]]
}

proc def_msgproc {name argl body} {
    proc msg_$name "varbase $argl" "\
    upvar #0 msg/\$varbase/dest d\n\
    upvar #0 msg/\$varbase/str s\n\
    upvar #0 msg/\$varbase/accum a\n\
$body"
}

def_msgproc begin {dest str} {
    set d $dest
    set s $str
    set a {}
}

def_msgproc append {str} {
    set ns "$s$str"
    if {[string length $s] && [string length $ns] > 65} {
        msg__sendout $varbase
        set s " [string trimleft $str]"
    } else {
        set s $ns
    }
}

def_msgproc finish {} {
    msg__sendout $varbase
    unset s
    unset d
    return $a
}

def_msgproc _sendout {} {
    lappend a [string trimright $s]
    set s {}
}

proc looking_whenwhere {when where} {
    set str [showtime [expr {$when-1}]]
    if {[string length $where]} { append str " on $where" }
    return $str
}

proc recordlastseen_n {n how here} {
    global lastseen lookedfor
    set lastseen([irctolower $n]) [list $n [clock seconds] $how]
    if {!$here} return
    upvar #0 lookedfor([irctolower $n]) lf
    if {[info exists lf]} {
        switch -exact [llength $lf] {
            0 {
                set ml {}
            }
            1 {
                manyset [lindex $lf 0] when who where
                set ml [list \
 "FYI, $who was looking for you [looking_whenwhere $when $where]."]
            }
            default {
                msg_begin tosend $n "FYI, people have been looking for you:"
                set i 0
                set fin ""
                foreach e $lf {
                    incr i
                    if {$i == 1} {
                        msg_append tosend " "
                    } elseif {$i == [llength $lf]} {
                        msg_append tosend " and "
                        set fin .
                    } else {
                        msg_append tosend ", "
                    }
                    manyset $e when who where
                    msg_append tosend \
                            "$who ([looking_whenwhere $when $where])$fin"
                }
                set ml [msg_finish tosend]
            }
        }
        unset lf
        msendprivmsg_delayed 1000 $n $ml
    }
}

proc note_topic {showoff whoby topic} {
    if {[string length $whoby]} {
        set msg "FYI, $whoby has changed the topic on $showoff"
    } else {
        set msg "FYI, I have reset the topic on $showoff"
    }
    if {[string length $topic] < 160} {
        append msg " to $topic"
    } else {
        append msg " but it is too long to reproduce here !"
    }
    set showoff [irctolower $showoff]
    set tell [chandb_get $showoff topictell]
    if {[lsearch -exact $tell *] >= 0} {
        set tryspies [chandb_list]
    } else {
        set tryspies $tell
    }
puts "NT>showoff $showoff|whoby $whoby|topic $topic|tell $tell|tryspies $tryspies|msg $msg<"
    foreach spy $tryspies {
        set see [chandb_get $spy topicsee]
puts "NT>spy $spy|see $see<"
        if {[lsearch -exact $see $showoff] >= 0 || \
                ([lsearch -exact $see *] >= 0 && \
                [lsearch -exact $tell $spy] >= 0)} {
            sendprivmsg $spy $msg
        }
    }
}

proc recordlastseen_p {p how here} {
    prefix_nick
    recordlastseen_n $n $how $here
}

proc chanmode_arg {} {
    upvar 2 args cm_args
    set rv [lindex $cm_args 0]
    set cm_args [lreplace cm_args 0 0]
    return $rv
}

proc chanmode_o1 {m g p chan} {
    global nick chan_initialop
    prefix_nick
    set who [chanmode_arg]
    recordlastseen_n $n "being nice to $who" 1
    if {"[irctolower $who]" == "[irctolower $nick]"} {
        set nlower [irctolower $n]
        upvar #0 nick_unique($nlower) u
        if {[chandb_exists $chan]} {
            sendprivmsg $n Thanks.
        } elseif {![info exists u]} {
            sendprivmsg $n {Op me while not on the channel, why don't you ?}
        } else {
            set chan_initialop([irctolower $chan]) $u
            sendprivmsg $n \
 "Thanks. You can use `channel manager ...' to register this channel."
            if {![nickdb_exists $n] || ![string length [nickdb_get $n username]]} {
                sendprivmsg $n \
 "(But to do that you must register your nick securely first.)"
            }
        }
    }
}

proc chanmode_o0 {m g p chan} {
    global nick chandeop
    prefix_nick
    set who [chanmode_arg]
    recordlastseen_p $p "being mean to $who" 1
    if {"[irctolower $who]" == "[irctolower $nick]"} {
        set chandeop($chan) [list [clock seconds] $p]
    }
}

proc msg_MODE {p c dest modelist args} {
    if {![ischan $dest]} return
    if {[regexp {^\-(.+)$} $modelist dummy modelist]} {
        set give 0
    } elseif {[regexp {^\+(.+)$} $modelist dummy modelist]} {
        set give 1
    } else {
        error "invalid modelist"
    }
    foreach m [split $modelist] {
        set procname chanmode_$m$give
        if {[catch { info body $procname }]} {
            recordlastseen_p $p "fiddling with $dest" 1
        } else {
            $procname $m $give  $p $dest
        }
    }
}

proc leaving {lchan} {
    foreach luser [array names nick_onchans] {
        upvar #0 nick_onchans($luser) oc
        set oc [grep tc {"$tc" != "$lchan"} $oc]
    }
    upvar #0 chan_nicks($lchan) nlist
    unset nlist
}

proc dojoin {lchan} {
    global chan_nicks
    sendout JOIN $lchan
    set chan_nicks($lchan) {}
}

proc check_justme {lchan} {
    global nick
    upvar #0 chan_nicks($lchan) nlist
    if {[llength $nlist] != 1} return
    if {"[lindex $nlist 0]" != "$nick"} return
    if {[chandb_exists $lchan]} {
        set mode [chandb_get $lchan mode]
        if {"$mode" != "*"} {
            sendout MODE $lchan $mode
        }
        set topic [chandb_get $lchan topicset]
        if {[string length $topic]} {
            sendout TOPIC $lchan $topic
            note_topic $lchan {} $topic
        }
    } else {
        sendout PART $lchan
        leaving $lchan
    }
}

proc process_kickpart {chan user} {
    global nick
    check_nick $user
    set luser [irctolower $user]
    set lchan [irctolower $chan]
    if {![ischan $chan]} { error "not a channel" }
    if {"$luser" == "[irctolower $nick]"} {
        leaving $lchan
    } else {
        upvar #0 nick_onchans($luser) oc
        upvar #0 chan_nicks($lchan) nlist
        set oc [grep tc {"$tc" != "$lchan"} $oc]
        set nlist [grep tn {"$tn" != "$luser"} $nlist]
        nick_case $user
        if {![llength $oc]} {
            nick_forget $luser
        } else {
            check_justme $lchan
        }
    }
}

proc msg_TOPIC {p c dest topic} {
    prefix_nick
    if {![ischan $dest]} return
    recordlastseen_n $n "changing the topic on $dest" 1
    note_topic [irctolower $dest] $n $topic
}

proc msg_KICK {p c chans users comment} {
    set chans [split $chans ,]
    set users [split $users ,]
    if {[llength $chans] > 1} {
        foreach chan $chans user $users { process_kickpart $chan $user }
    } else {
        foreach user $users { process_kickpart [lindex $chans 0] $user }
    }
}

proc msg_KILL {p c user why} {
    nick_forget $user
}

set nick_counter 0
set nick_arys {onchans username unique}
# nick_onchans($luser) -> [list ... $lchan ...]
# nick_username($luser) -> <securely known local username>
# nick_unique($luser) -> <counter>
# nick_case($luser) -> $user  (valid even if no longer visible)

# chan_nicks($lchan) -> [list ... $luser ...]

proc lnick_forget {luser} {
    global nick_arys chan_nicks
    foreach ary $nick_arys {
        upvar #0 nick_${ary}($luser) av
        catch { unset av }
    }
    foreach lch [array names chan_nicks] {
        upvar #0 chan_nicks($lch) nlist
        set nlist [grep tn {"$tn" != "$luser"} $nlist]
        check_justme $lch
    }
}

proc nick_forget {user} {
    global nick_arys chan_nicks
    lnick_forget [irctolower $user]
    nick_case $user
}

proc nick_case {user} {
    global nick_case
    set nick_case([irctolower $user]) $user
}

proc msg_NICK {p c newnick} {
    global nick_arys nick_case
    prefix_nick
    recordlastseen_n $n "changing nicks to $newnick" 0
    recordlastseen_n $newnick "changing nicks from $n" 1
    foreach ary $nick_arys {
        upvar #0 nick_${ary}($n) old
        upvar #0 nick_${ary}($newnick) new
        if {[info exists new]} { error "nick collision ?! $ary $n $newnick" }
        if {[info exists old]} { set new $old; unset old }
    }
    upvar #0 nick_onchans($new)
    set luser [irctolower $n]
    set lusernew [irctolower $newnick]
    foreach ch $oc {
        upvar #0 chan_nicks($ch) nlist
        set nlist [grep tn {"$tn" != "$luser"} $nlist]
        lappend nlist $lusernew
    }
    nick_case $newnick
}

proc nick_ishere {n} {
    global nick_counter
    upvar #0 nick_unique([irctolower $n]) u
    if {![info exists u]} { set u [incr nick_counter].$n.[clock seconds] }
    nick_case $n
}

proc msg_JOIN {p c chan} {
    prefix_nick
    recordlastseen_n $n "joining $chan" 1
    upvar #0 nick_onchans([irctolower $n]) oc
    lappend oc [irctolower $chan]
    nick_ishere $n
}
proc msg_PART {p c chan} {
    prefix_nick
    recordlastseen_n $n "leaving $chan" 1
    process_kickpart $chan $n
}
proc msg_QUIT {p c why} {
    prefix_nick
    recordlastseen_n $n "leaving ($why)" 0
    nick_forget $n
}

proc msg_PRIVMSG {p c dest text} {
    prefix_nick
    if {[ischan $dest]} {
        recordlastseen_n $n "invoking me in $dest" 1
        set output $dest
    } else {
        recordlastseen_n $n "talking to me" 1
        set output $n
    }
    nick_case $n

    if {[catch {
        regsub {^! *} $text {} text
        set ucmd [ta_word]
        set procname ucmd/[string tolower $ucmd]
        if {[catch { info body $procname }]} {
            error "unknown command; try help for help"
        }
        $procname $p $dest
    } rv]} {
        sendprivmsg $n "error: $rv"
    } else {
        manyset $rv priv_msgs pub_msgs priv_acts pub_acts
        foreach {td val} [list $n $priv_acts $output $pub_acts] {
            foreach l [split $val "\n"] {
                sendaction_priority 0 $td $l
            }
        }
        foreach {td val} [list $n $priv_msgs $output $pub_msgs] {
            foreach l [split $val "\n"] {
                sendprivmsg $td $l
            }
        }
    }
}

proc msg_INVITE {p c n chan} {
    after 1000 [list dojoin [irctolower $chan]]
}

proc grep {var predicate list} {
    set o {}
    upvar 1 $var v
    foreach v $list {
        if {[uplevel 1 [list expr $predicate]]} { lappend o $v }
    }
    return $o
}

proc msg_353 {p c dest type chan nicklist} {
    global names_chans nick_onchans
    set lchan [irctolower $chan]
    upvar #0 chan_nicks($lchan) nlist
    lappend names_chans $lchan
    if {![info exists nlist]} {
        # We don't think we're on this channel, so ignore it !
        # Unfortunately, because we don't get a reply to PART,
        # we have to remember ourselves whether we're on a channel,
        # and ignore stuff if we're not, to avoid races.  Feh.
        return
    }
    set nlist_new {}
    foreach user [split $nicklist { }] {
        regsub {^[@+]} $user {} user
        if {![string length $user]} continue
        check_nick $user
        set luser [irctolower $user]
        upvar #0 nick_onchans($luser) oc
        lappend oc $lchan
        lappend nlist_new $luser
        nick_ishere $user
    }
    set nlist $nlist_new
}

proc msg_366 {p c args} {
    global names_chans nick_onchans
    set lchan [irctolower $c]
    foreach luser [array names nick_onchans] {
        upvar #0 nick_onchans($luser) oc
        if {[llength names_chans] > 1} {
            set oc [grep tc {[lsearch -exact $tc $names_chans] >= 0} $oc]
        }
        if {![llength $oc]} { lnick_forget $n }
    }
    unset names_chans
}

proc ta_anymore {} {
    upvar 1 text text
    return [expr {!![string length $text]}]
}

proc ta_nomore {} {
    upvar 1 text text
    if {[string length $text]} { error "too many parameters" }
}

proc ta_word {} {
    upvar 1 text text
    if {![regexp {^([^  ]+) *(.*)} $text dummy firstword text]} {
        error "too few parameters"
    }
    return $firstword
}

proc ta_nick {} {
    upvar 1 text text
    set v [ta_word]
    check_nick $v
    return $v
}

proc def_ucmd {cmdname body} {
    proc ucmd/$cmdname {p dest} "    upvar 1 text text\n$body"
}

proc ucmdr {priv pub args} {
    return -code return [concat [list $priv $pub] $args]
}

proc loadhelp {} {
    global help_topics errorInfo

    catch { unset help_topics }
    set f [open helpinfos r]
    try_except_finally {
        set lno 0
        while {[gets $f l] >= 0} {
            incr lno
            if {[regexp {^#.*} $l]} {
            } elseif {[regexp {^ *$} $l]} {
                if {[info exists topic]} {
                    set help_topics($topic) [join $lines "\n"]
                    unset topic
                    unset lines
                }
            } elseif {[regexp {^\:\:} $l]} {
            } elseif {[regexp {^\:([-+._0-9a-z]*)$} $l dummy newtopic]} {
                if {[info exists topic]} {
                    error "help $newtopic while in $topic"
                }
                set topic $newtopic
                set lines {}
            } elseif {[regexp {^[^:#]} $l]} {
                set topic
                regsub -all {([^\\])\!\$?} _$l {\1} l
                regsub -all {\\(.)} $l {\1} l
                regsub {^_} $l {} l
                lappend lines [string trimright $l]
            } else {
                error "eh ? $lno: $l"
            }
        }
        if {[info exists topic]} { error "unfinished topic $topic" }
    } {
        set errorInfo "in helpinfos line $lno\n$errorInfo"
    } {
        close $f
    }
}

def_ucmd help {
    if {[set lag [out_lagged]]} {
        if {[ischan $dest]} { set replyto $dest } else { set replyto $n }
        if {$lag > 1} {
            sendaction_priority 1 $replyto \
                "is very lagged.  Please ask for help again later."
            ucmdr {} {}
        } else {
            sendaction_priority 1 $replyto \
                "is lagged.  Your help will arrive shortly ..."
        }
    }
    
    upvar #0 help_topics([irctolower [string trim $text]]) info
    if {![info exists info]} { ucmdr "No help on $text, sorry." {} }
    ucmdr $info {}
}

def_ucmd ? {
    global help_topics
    ucmdr $help_topics() {}
}

proc check_username {target} {
    if {
        [string length $target] > 8 ||
        [regexp {[^-0-9a-z]} $target] ||
        ![regexp {^[a-z]} $target]
    } { error "invalid username" }
}

proc somedb__head {} {
    uplevel 1 {
        set idl [irctolower $id]
        upvar #0 ${nickchan}db($idl) ndbe
        binary scan $idl H* idh
        set idfn $fprefix$idh
        if {![info exists iddbe] && [file exists $idfn]} {
            set f [open $idfn r]
            try_except_finally { set newval [read $f] } {} { close $f }
            if {[llength $newval] % 2} { error "invalid length" }
            set iddbe $newval
        }
    }
}

proc def_somedb {name arglist body} {
    foreach {nickchan fprefix} {nick users/n chan chans/c} {
        proc ${nickchan}db_$name $arglist \
            "set nickchan $nickchan; set fprefix $fprefix; $body"
    }
}

def_somedb list {} {
    set list {}
    foreach path [glob -nocomplain -path $fprefix *] {
        binary scan $path "A[string length $fprefix]A*" afprefix thinghex
        if {"$afprefix" != "$fprefix"} { error "wrong prefix $path $afprefix" }
        lappend list [binary format H* $thinghex]
    }
    return $list
}

proc def_somedb_id {name arglist body} {
    def_somedb $name [concat id $arglist] "somedb__head; $body"
}

def_somedb_id exists {} {
    return [info exists iddbe]
}

def_somedb_id delete {} {
    catch { unset iddbe }
    file delete $idfn
}

set default_settings_nick {timeformat ks}
set default_settings_chan {
    autojoin 1
    mode *
    userinvite pub
    topicset {}
    topicsee {}
    topictell {}
}

def_somedb_id set {args} {
    upvar #0 default_settings_$nickchan def
    if {![info exists iddbe]} { set iddbe $def }
    foreach {key value} [concat $iddbe $args] { set a($key) $value }
    set newval {}
    foreach {key value} [array get a] { lappend newval $key $value }
    set f [open $idfn.new w]
    try_except_finally {
        puts $f $newval
        close $f
        file rename -force $idfn.new $idfn
    } {
    } {
        catch { close $f }
    }
    set iddbe $newval
}

def_somedb_id get {key} {
    upvar #0 default_settings_$nickchan def
    if {[info exists iddbe]} {
        set l [concat $iddbe $def]
    } else {
        set l $def
    }
    foreach {tkey value} $l {
        if {"$tkey" == "$key"} { return $value }
    }
    error "unset setting $key"
}

proc opt {key} {
    global calling_nick
    if {[info exists calling_nick]} { set n $calling_nick } { set n {} }
    return [nickdb_get $n $key]
}

proc check_notonchan {} {
    upvar 1 dest dest
    if {[ischan $dest]} { error "that command must be sent privately" }
}

proc nick_securitycheck {strict} {
    upvar 1 n n
    if {![nickdb_exists $n]} { error "you are unknown to me, use `register'." }
    set wantu [nickdb_get $n username]
    if {![string length $wantu]} {
        if {$strict} {
            error "that feature is only available to secure users, sorry."
        } else {
            return
        }
    }
    set luser [irctolower $n]
    upvar #0 nick_username($luser) nu
    if {![info exists nu]} {
        error "nick $n is secure, you must identify yourself first."
    }
    if {"$wantu" != "$nu"} {
        error "you are the wrong user - the nick $n belongs to $wantu, not $nu"
    }
}

proc channel_securitycheck {channel n} {
    # You must also call `nick_securitycheck 1'
    set mgrs [chandb_get $channel managers]
    if {[lsearch -exact [irctolower $mgrs] [irctolower $n]] < 0} {
        error "you are not a manager of $channel"
    }
}

proc def_chancmd {name body} {
    proc channel/$name {} \
            "    upvar 1 target chan; upvar 1 n n; upvar 1 text text; $body"
}

proc ta_listop {findnow procvalue} {
    # findnow and procvalue are code fragments which will be executed
    # in the caller's level.  findnow should set ta_listop_ev to
    # the current list, and procvalue should treat ta_listop_ev as
    # a proposed value in the list and check and possibly modify
    # (canonicalise?) it.  After ta_listop, ta_listop_ev will
    # be the new value of the list.
    upvar 1 ta_listop_ev exchg
    upvar 1 text text
    set opcode [ta_word]
    switch -exact _$opcode {
        _= { }
        _+ - _- {
            uplevel 1 $findnow
            foreach item $exchg { set array($item) 1 }
        }
        default {
            error "list change opcode must be one of + - ="
        }
    }
    foreach exchg [split $text " "] {
        if {![string length $exchg]} continue
        uplevel 1 $procvalue
        if {"$opcode" != "-"} {
            set array($exchg) 1
        } else {
            catch { unset array($exchg) }
        }
    }
    set exchg [lsort [array names array]]
}

def_chancmd manager {
    ta_listop {
        if {[chandb_exists $chan]} {
            set ta_listop_ev [chandb_get $chan managers]
        } else {
            set ta_listop_ev [list [irctolower $n]]
        }
    } {
        check_nick $ta_listop_ev
        set ta_listop_ev [irctolower $ta_listop_ev]
    }
    if {[llength $ta_listop_ev]} {
        chandb_set $chan managers $ta_listop_ev
        ucmdr "Managers of $chan: $ta_listop_ev" {}
    } else {
        chandb_delete $chan
        ucmdr {} {} "forgets about managing $chan." {}
    }
}

def_chancmd autojoin {
    set yesno [ta_word]
    switch -exact [string tolower $yesno] {
        no { set nv 0 }
        yes { set nv 1 }
        default { error "channel autojoin must be `yes' or `no' }
    }
    chandb_set $chan autojoin $nv
    ucmdr [expr {$nv ? "I will join $chan when I'm restarted " : \
            "I won't join $chan when I'm restarted "}] {}
}

def_chancmd userinvite {
    set nv [string tolower [ta_word]]
    switch -exact $nv {
        pub { set txt "!invite will work for $chan, but it won't work by /msg" }
        here { set txt "!invite and /msg invite will work, but only for users who are already on $chan." }
        all { set txt "Any user will be able to invite themselves or anyone else to $chan." }
        none { set txt "I will not invite anyone to $chan." }
        default {
            error "channel userinvite must be `pub', `here', `all' or `none'
        }
    }
    chandb_set $chan userinvite $nv
    ucmdr $txt {}
}

def_chancmd topic {
    set what [ta_word]
    switch -exact $what {
        leave {
            ta_nomore
            chandb_set $chan topicset {}
            ucmdr "I won't ever change the topic of $chan." {}
        }
        set {
            set t [string trim $text]
            if {![string length $t]} {
                error "you must specific the topic to set"
            }
            chandb_set $chan topicset $t
            ucmdr "Whenever I'm alone on $chan, I'll set the topic to $t." {}
        }
        see - tell {
            ta_listop {
                set ta_listop_ev [chandb_get $chan topic$what]
            } {
                if {"$ta_listop_ev" != "*"} {
                    if {![ischan $ta_listop_ev]} {
                        error "bad channel \`$ta_listop_ev' in topic $what"
                    }
                    set ta_listop_ev [irctolower $ta_listop_ev]
                }
            }
            chandb_set $chan topic$what $ta_listop_ev
            ucmdr "Topic $what list for $chan: $ta_listop_ev" {}
        }
        default {
            error "unknown channel topic subcommand - see help channel"
        }
    }
}

def_chancmd mode {
    set mode [ta_word]
    if {"$mode" != "*" && ![regexp {^(([-+][imnpst]+)+)$} $mode mode]} {
        error {channel mode must be * or match ([-+][imnpst]+)+}
    }
    chandb_set $chan mode $mode
    if {"$mode" == "*"} {
        ucmdr "I won't ever change the mode of $chan." {}
    } else {
        ucmdr "Whenever I'm alone on $chan, I'll set the mode to $mode." {}
    }
}

def_chancmd show {
    if {[chandb_exists $chan]} {
        set l "Settings for $chan: autojoin "
        append l [lindex {no yes} [chandb_get $chan autojoin]]
        append l ", mode " [chandb_get $chan mode]
        append l ", userinvite " [chandb_get $chan userinvite] "."
        append l "\nManagers: "
        append l [join [chandb_get $chan managers] " "]
        foreach {ts sep} {see "\n" tell "  "} {
            set t [chandb_get $chan topic$ts]
            append l $sep
            if {[llength $t]} {
                append l "Topic $ts list: $t."
            } else {
                append l "Topic $ts list is empty."
            }
        }
        append l "\n"
        set t [chandb_get $chan topicset]
        if {[string length $t]} {
            append l "Topic to set: $t"
        } else {
            append l "I will not change the topic."
        }
        ucmdr {} $l
    } else {
        ucmdr {} "The channel $chan is not managed."
    }
}

def_ucmd op {
    if {[ischan $dest]} { set target $dest }
    if {[ta_anymore]} { set target [ta_word] }
    ta_nomore
    if {![info exists target]} { error "you must specify, or !... on, the channel" }
    if {![ischan $target]} { error "not a valid channel" }
    if {![chandb_exists $target]} { error "$target is not a managed channel." }
    prefix_nick
    nick_securitycheck 1
    channel_securitycheck $target $n
    sendout MODE $target +o $n
}

def_ucmd invite {
    global chan_nicks
    
    if {[ischan $dest]} {
        set target $dest
        set onchan 1
    } else {
        set target [ta_word]
        set onchan 0
    }
    set ltarget [irctolower $target]
    if {![ischan $target]} { error "$target is not a channel." }
    if {![info exists chan_nicks($ltarget)]} { error "I am not on $target." }
    set ui [chandb_get $ltarget userinvite]
    if {"$ui" == "pub" && !$onchan} {
        error "Invitations to $target must be made with !invite."
    }
    if {"$ui" != "all"} {
        prefix_nick
        if {[lsearch -exact $chan_nicks($ltarget) [irctolower $n]] < 0} {
 error "Invitations to $target may only be made by a user on the channel."
        }
    }
    if {"$ui" == "none"} {
        error "Sorry, I've not been authorised to invite people to $target."
    }
    if {![ta_anymore]} {
        error "You have to say who to invite."
    }
    set invitees {}
    while {[ta_anymore]} {
        set invitee [ta_word]
        check_nick $invitee
        lappend invitees $invitee
    }
    foreach invitee $invitees {
        sendout INVITE $invitee $ltarget
    }
    set who [lindex $invitees 0]
    switch -exact llength $invitees {
        0 { error "zero invitees" }
        1 { }
        2 { append who " and [lindex $invitees 1]" }
        * {
            set who [join [lreplace $invitees end end] ", "]
            append who " and [lindex $invitees [llength $invitees]]"
        }
    }
    ucmdr {} "invites $who to $target."
}

def_ucmd channel {
    if {[ischan $dest]} { set target $dest }
    if {![ta_anymore]} {
        set subcmd show
    } else {
        set subcmd [ta_word]
    }
    if {[ischan $subcmd]} {
        set target $subcmd
        if {![ta_anymore]} {
            set subcmd show
        } else {
            set subcmd [ta_word]
        }
    }
    if {![info exists target]} { error "privately, you must specify a channel" }
    set procname channel/$subcmd
    if {"$subcmd" != "show"} {
        if {[catch { info body $procname }]} { error "unknown channel setting $subcmd" }
        prefix_nick
        nick_securitycheck 1
        if {[chandb_exists $target]} {
            channel_securitycheck $target $n
        } else {
            upvar #0 chan_initialop([irctolower $target]) io
            upvar #0 nick_unique([irctolower $n]) u
            if {![info exists io]} { error "$target is not a managed channel" }
            if {"$io" != "$u"} { error "you are not the interim manager of $target" }
            if {"$subcmd" != "manager"} { error "use `channel manager' first" }
        }
    }
    channel/$subcmd
}

def_ucmd who {
    if {[ta_anymore]} {
        set target [ta_word]; ta_nomore
        set myself 1
    } else {
        prefix_nick
        set target $n
        set myself [expr {"$target" != "$n"}]
    }
    set ltarget [irctolower $target]
    upvar #0 nick_case($ltarget) ctarget
    set nshow $target
    if {[info exists ctarget]} {
        upvar #0 nick_onchans($ltarget) oc
        upvar #0 nick_username($ltarget) nu
        if {[info exists oc]} { set nshow $ctarget }
    }
    if {![nickdb_exists $ltarget]} {
        set ol "$nshow is not a registered nick."
    } elseif {[string length [set username [nickdb_get $target username]]]} {
        set ol "The nick $nshow belongs to the user $username."
    } else {
        set ol "The nick $nshow is registered (but not to a username)."
    }
    if {![info exists ctarget] || ![info exists oc]} {
        if {$myself} {
            append ol "\nI can't see $nshow on anywhere."
        } else {
            append ol "\nYou aren't on any channels with me."
        }
    } elseif {![info exists nu]} {
        append ol "\n$nshow has not identified themselves."
    } elseif {![info exists username]} {
        append ol "\n$nshow has identified themselves as the user $nu."
    } elseif {"$nu" != "$username"} {
        append ol "\nHowever, $nshow is being used by the user $nu."
    } else {
        append ol "\n$nshow has identified themselves to me."
    }
    ucmdr {} $ol
}

def_ucmd register {
    prefix_nick
    check_notonchan
    set old [nickdb_exists $n]
    if {$old} { nick_securitycheck 0 }
    set luser [irctolower $n]
    switch -exact [string tolower [string trim $text]] {
        {} {
            upvar #0 nick_username($luser) nu
            if {![info exists nu]} {
                ucmdr {} \
 "You must identify yourself before using `register'.  See `help identify', or use `register insecure'."
            }
            nickdb_set $n username $nu
            ucmdr {} {} "makes a note of your username." {}
        }
        delete {
            nickdb_delete $n
            ucmdr {} {} "forgets your nickname." {}
        }
        insecure {
            nickdb_set $n username {}
            if {$old} {
                ucmdr {} "Security is now disabled for your nickname !"
            } else {
                ucmdr {} "This is fine, but bear in mind that people will be able to mess with your settings.  Channel management features need a secure registration." "makes an insecure registration for your nick."
            }
        }
    }
}

proc timeformat_desc {tf} {
    switch -exact $tf {
        ks { return "Times will be displayed in seconds or kiloseconds." }
        hms { return "Times will be displayed in hours, minutes, etc." }
        default { error "invalid timeformat: $v" }
    }
}

proc def_setting {opt show_body set_body} {
    proc set_show/$opt {} "
        upvar 1 n n
        set opt $opt
        $show_body"
    if {![string length $set_body]} return
    proc set_set/$opt {} "
        upvar 1 n n
        upvar 1 text text
        set opt $opt
        $set_body"
}

def_setting timeformat {
    set tf [nickdb_get $n timeformat]
    return "$tf: [timeformat_desc $tf]"
} {
    set tf [string tolower [ta_word]]
    ta_nomore
    set desc [timeformat_desc $tf]
    nickdb_set $n timeformat $tf
    ucmdr {} $desc
}

def_setting security {
    set s [nickdb_get $n username]
    if {[string length $s]} {
        return "Your nick, $n, is controlled by the user $s."
    } else {
        return "Your nick, $n, is not secure."
    }
} {}

def_ucmd set {
    prefix_nick
    check_notonchan
    if {![nickdb_exists $n]} {
        ucmdr {} "You are unknown to me and so have no settings.  (Use `register'.)"
    }
    if {![ta_anymore]} {
        set ol {}
        foreach proc [lsort [info procs]] {
            if {![regexp {^set_show/(.*)$} $proc dummy opt]} continue
            lappend ol [format "%-10s %s" $opt [set_show/$opt]]
        }
        ucmdr {} [join $ol "\n"]
    } else {
        set opt [ta_word]
        if {[catch { info body set_show/$opt }]} {
            error "no setting $opt"
        }
        if {![ta_anymore]} {
            ucmdr {} "$opt [set_show/$opt]"
        } else {
            nick_securitycheck 0
            if {[catch { info body set_set/$opt }]} {
                error "setting $opt cannot be set with `set'"
            }
            set_set/$opt
        }
    }
}

def_ucmd identpass {
    set username [ta_word]
    set passmd5 [md5sum "[ta_word]\n"]
    ta_nomore
    prefix_nick
    check_notonchan
    set luser [irctolower $n]
    upvar #0 nick_onchans($luser) onchans
    if {![info exists onchans] || ![llength $onchans]} {
        ucmdr "You must be on a channel with me to identify yourself." {}
    }
    check_username $username
    exec userv --timeout 3 $username << "$passmd5\n" > /dev/null \
            irc-identpass $n
    upvar #0 nick_username($luser) rec_username
    set rec_username $username
    ucmdr "Pleased to see you, $username." {}
}

def_ucmd summon {
    set target [ta_word]
    ta_nomore
    check_username $target
    prefix_nick

    upvar #0 lastsummon($target) ls
    set now [clock seconds]
    if {[info exists ls]} {
        set interval [expr {$now - $ls}]
        if {$interval < 30} {
            ucmdr {} \
 "Please be patient; $target was summoned only [showinterval $interval]."
        }
    }
    regsub {^[^!]*!} $p {} path
    if {[catch {
        exec userv --timeout 3 $target irc-summon $n $path \
                [expr {[ischan $dest] ? "$dest" : ""}] \
                < /dev/null
    } rv]} {
        regsub -all "\n" $rv { / } rv
        error $rv
    }
    if {[regexp {^problem (.*)} $rv dummy problem]} {
        ucmdr {} "The user `$target' $problem."
    } elseif {[regexp {^ok ([^ ]+) ([0-9]+)$} $rv dummy tty idlesince]} {
        set idletime [expr {$now - $idlesince}]
        set ls $now
        ucmdr {} {} {} "invites $target ($tty[expr {
            $idletime > 10 ? ", idle for [showintervalsecs $idletime]" : ""
        }]) to [expr {
            [ischan $dest] ? "join us here" : "talk to you"
        }]."
    } else {
        error "unexpected response from userv service: $rv"
    }
}

proc md5sum {value} { exec md5sum << $value }

def_ucmd seen {
    global lastseen nick
    prefix_nick
    set ncase [ta_nick]
    set nlower [irctolower $ncase]
    ta_nomore
    set now [clock seconds]
    if {"$nlower" == "[irctolower $nick]"} {
        error "I am not self-aware."
    } elseif {![info exists lastseen($nlower)]} {
        set rstr "I've never seen $ncase."
    } else {
        manyset $lastseen($nlower) realnick time what
        set howlong [expr {$now - $time}]
        set string [showinterval $howlong]
        set rstr "I last saw $realnick $string, $what."
    }
    if {[ischan $dest]} {
        set where $dest
    } else {
        set where {}
    }
    upvar #0 lookedfor($nlower) lf
    if {[info exists lf]} { set oldvalue $lf } else { set oldvalue {} }
    set lf [list [list $now $n $where]]
    foreach v $oldvalue {
        if {"[irctolower [lindex $v 1]]" == "[irctolower $n]"} continue
        lappend lf $v
    }
    ucmdr {} $rstr
}

proc ensure_globalsecret {} {
    global globalsecret
    
    if {[info exists globalsecret]} return
    set gsfile [open /dev/urandom r]
    fconfigure $gsfile -translation binary
    set globalsecret [read $gsfile 32]
    binary scan $globalsecret H* globalsecret
    close $gsfile
    unset gsfile
}

proc ensure_outqueue {} {
    out__vars
    if {[info exists out_queue]} return
    set out_creditms 0
    set out_creditat [clock seconds]
    set out_queue {}
    set out_lag_reported 0
    set out_lag_reportwhen $out_creditat
}

proc fail {msg} {
    logerror "failing: $msg"
    exit 1
}

proc ensure_connecting {} {
    global sock ownfullname host port nick
    global musthaveping_ms musthaveping_after
    
    if {[info exists sock]} return
    set sock [socket $host $port]
    fconfigure $sock -buffering line
    fconfigure $sock -translation crlf

    sendout USER blight 0 * $ownfullname
    sendout NICK $nick
    fileevent $sock readable onread

    set musthaveping_after [after $musthaveping_ms \
            {fail "no ping within timeout"}]
}

proc connected {} {
    global musthaveping_after

    after cancel $musthaveping_after
    unset musthaveping_after

    foreach chan [chandb_list] {
        if {[chandb_get $chan autojoin]} { dojoin $chan }
    }
}

ensure_globalsecret
ensure_outqueue
loadhelp
ensure_connecting