#!/bin/sh
# Tcl ignores the next line -*- tcl -*- \
exec wish "$0" -- "${1+$@}"

# Copyright (C) 2005 Paul Mackerras.  All rights reserved.
# This program is free software; it may be used, copied, modified
# and distributed under the terms of the GNU General Public Licence,
# either version 2, or (at your option) any later version.

# CVS $Revision: 1.6 $

set datemode 0
set boldnames 0
set revtreeargs {}
set diffopts "-U 5 -p"

set mainfont {Helvetica 9}
set namefont $mainfont
set textfont {Courier 9}
if {$boldnames} {
    lappend namefont bold
}

set colors {green red blue magenta darkgrey brown orange}
set colorbycommitter false

catch {source ~/.gitk}

foreach arg $argv {
    switch -regexp -- $arg {
        "^$" { }
        "^-b" { set boldnames 1 }
        "^-c" { set colorbycommitter 1 }
        "^-d" { set datemode 1 }
        "^-.*" {
            puts stderr "unrecognized option $arg"
            exit 1
        }
        default {
            lappend revtreeargs $arg
        }
    }
}

proc getcommits {rargs} {
    global commits parents cdate nparents children nchildren
    if {$rargs == {}} {
        set rargs HEAD
    }
    set commits {}
    foreach c [split [eval exec git-rev-tree $rargs] "\n"] {
        set i 0
        set cid {}
        foreach f $c {
            if {$i == 0} {
                set d $f
            } else {
                set id [lindex [split $f :] 0]
                if {![info exists nchildren($id)]} {
                    set children($id) {}
                    set nchildren($id) 0
                }
                if {$i == 1} {
                    set cid $id
                    lappend commits $id
                    set parents($id) {}
                    set cdate($id) $d
                    set nparents($id) 0
                } else {
                    lappend parents($cid) $id
                    incr nparents($cid)
                    incr nchildren($id)
                    lappend children($id) $cid
                }
            }
            incr i
        }
    }
}

proc readcommit {id} {
    global commitinfo
    set inhdr 1
    set comment {}
    set headline {}
    set auname {}
    set audate {}
    set comname {}
    set comdate {}
    foreach line [split [exec git-cat-file commit $id] "\n"] {
        if {$inhdr} {
            if {$line == {}} {
                set inhdr 0
            } else {
                set tag [lindex $line 0]
                if {$tag == "author"} {
                    set x [expr {[llength $line] - 2}]
                    set audate [lindex $line $x]
                    set auname [lrange $line 1 [expr {$x - 1}]]
                } elseif {$tag == "committer"} {
                    set x [expr {[llength $line] - 2}]
                    set comdate [lindex $line $x]
                    set comname [lrange $line 1 [expr {$x - 1}]]
                }
            }
        } else {
            if {$comment == {}} {
                set headline $line
            } else {
                append comment "\n"
            }
            append comment $line
        }
    }
    if {$audate != {}} {
        set audate [clock format $audate -format "%Y-%m-%d %H:%M:%S"]
    }
    if {$comdate != {}} {
        set comdate [clock format $comdate -format "%Y-%m-%d %H:%M:%S"]
    }
    set commitinfo($id) [list $headline $auname $audate \
                             $comname $comdate $comment]
}

proc makewindow {} {
    global canv canv2 canv3 linespc charspc ctext cflist textfont
    panedwindow .ctop -orient vertical
    panedwindow .ctop.clist -orient horizontal -sashpad 0 -handlesize 4
    .ctop add .ctop.clist
    set canv .ctop.clist.canv
    set cscroll .ctop.clist.dates.csb
    set height [expr 25 * $linespc + 4]
    canvas $canv -height $height -width [expr 45 * $charspc] \
        -bg white -bd 0 \
        -yscrollincr $linespc -yscrollcommand "$cscroll set"
    .ctop.clist add $canv
    set canv2 .ctop.clist.canv2
    canvas $canv2 -height $height -width [expr 30 * $charspc] \
        -bg white -bd 0 -yscrollincr $linespc
    .ctop.clist add $canv2
    frame .ctop.clist.dates
    .ctop.clist add .ctop.clist.dates
    set canv3 .ctop.clist.dates.canv3
    canvas $canv3 -height $height -width [expr 15 * $charspc] \
        -bg white -bd 0 -yscrollincr $linespc
    scrollbar $cscroll -command {allcanvs yview} -highlightthickness 0
    pack .ctop.clist.dates.csb -side right -fill y
    pack $canv3 -side left -fill both -expand 1

    panedwindow .ctop.cdet -orient horizontal
    .ctop add .ctop.cdet
    frame .ctop.cdet.left
    set ctext .ctop.cdet.left.ctext
    text $ctext -bg white -state disabled -font $textfont -height 32 \
        -yscrollcommand ".ctop.cdet.left.sb set"
    scrollbar .ctop.cdet.left.sb -command "$ctext yview"
    pack .ctop.cdet.left.sb -side right -fill y
    pack $ctext -side left -fill both -expand 1
    .ctop.cdet add .ctop.cdet.left

    $ctext tag conf filesep -font [concat $textfont bold]
    $ctext tag conf hunksep -back blue -fore white
    $ctext tag conf d0 -back "#ff8080"
    $ctext tag conf d1 -back green

    frame .ctop.cdet.right
    set cflist .ctop.cdet.right.cfiles
    listbox $cflist -width 30 -bg white -selectmode extended \
        -yscrollcommand ".ctop.cdet.right.sb set"
    scrollbar .ctop.cdet.right.sb -command "$cflist yview"
    pack .ctop.cdet.right.sb -side right -fill y
    pack $cflist -side left -fill both -expand 1
    .ctop.cdet add .ctop.cdet.right

    pack .ctop -side top -fill both -expand 1

    bindall <1> {selcanvline %x %y}
    bindall <B1-Motion> {selcanvline %x %y}
    bindall <ButtonRelease-4> "allcanvs yview scroll -5 u"
    bindall <ButtonRelease-5> "allcanvs yview scroll 5 u"
    bindall <2> "allcanvs scan mark 0 %y"
    bindall <B2-Motion> "allcanvs scan dragto 0 %y"
    bind . <Key-Up> "selnextline -1"
    bind . <Key-Down> "selnextline 1"
    bind . p "selnextline -1"
    bind . n "selnextline 1"
    bind . <Key-Prior> "allcanvs yview scroll -1 p"
    bind . <Key-Next> "allcanvs yview scroll 1 p"
    bind . <Key-Delete> "$ctext yview scroll -1 p"
    bind . <Key-BackSpace> "$ctext yview scroll -1 p"
    bind . <Key-space> "$ctext yview scroll 1 p"
    bind . b "$ctext yview scroll -1 p"
    bind . d "$ctext yview scroll 18 u"
    bind . u "$ctext yview scroll -18 u"
    bind . Q "set stopped 1; destroy ."
    bind $cflist <<ListboxSelect>> listboxsel
}

proc allcanvs args {
    global canv canv2 canv3
    eval $canv $args
    eval $canv2 $args
    eval $canv3 $args
}

proc bindall {event action} {
    global canv canv2 canv3
    bind $canv $event $action
    bind $canv2 $event $action
    bind $canv3 $event $action
}

proc truncatetofit {str width font} {
    if {[font measure $font $str] <= $width} {
        return $str
    }
    set best 0
    set bad [string length $str]
    set tmp $str
    while {$best < $bad - 1} {
        set try [expr {int(($best + $bad) / 2)}]
        set tmp "[string range $str 0 [expr $try-1]]..."
        if {[font measure $font $tmp] <= $width} {
            set best $try
        } else {
            set bad $try
        }
    }
    return $tmp
}

proc assigncolor {id} {
    global commitinfo colormap commcolors colors nextcolor
    global colorbycommitter
    global parents nparents children nchildren
    if [info exists colormap($id)] return
    set ncolors [llength $colors]
    if {$colorbycommitter} {
        if {![info exists commitinfo($id)]} {
            readcommit $id
        }
        set comm [lindex $commitinfo($id) 3]
        if {![info exists commcolors($comm)]} {
            set commcolors($comm) [lindex $colors $nextcolor]
            if {[incr nextcolor] >= $ncolors} {
                set nextcolor 0
            }
        }
        set colormap($id) $commcolors($comm)
    } else {
        if {$nparents($id) == 1 && $nchildren($id) == 1} {
            set child [lindex $children($id) 0]
            if {[info exists colormap($child)]
                && $nparents($child) == 1} {
                set colormap($id) $colormap($child)
                return
            }
        }
        set badcolors {}
        foreach child $children($id) {
            if {[info exists colormap($child)]
                && [lsearch -exact $badcolors $colormap($child)] < 0} {
                lappend badcolors $colormap($child)
            }
            if {[info exists parents($child)]} {
                foreach p $parents($child) {
                    if {[info exists colormap($p)]
                        && [lsearch -exact $badcolors $colormap($p)] < 0} {
                        lappend badcolors $colormap($p)
                    }
                }
            }
        }
        if {[llength $badcolors] >= $ncolors} {
            set badcolors {}
        }
        for {set i 0} {$i <= $ncolors} {incr i} {
            set c [lindex $colors $nextcolor]
            if {[incr nextcolor] >= $ncolors} {
                set nextcolor 0
            }
            if {[lsearch -exact $badcolors $c]} break
        }
        set colormap($id) $c
    }
}

proc drawgraph {start} {
    global parents children nparents nchildren commits
    global canv canv2 canv3 mainfont namefont canvx0 canvy0 canvy linespc
    global datemode cdate
    global lineid linehtag linentag linedtag commitinfo
    global nextcolor colormap

    set nextcolor 0
    assigncolor $start
    foreach id $commits {
        set ncleft($id) $nchildren($id)
    }
    set todo [list $start]
    set level 0
    set y2 $canvy0
    set linestarty(0) $canvy0
    set nullentry -1
    set lineno -1
    while 1 {
        set canvy $y2
        allcanvs conf -scrollregion [list 0 0 0 $canvy]
        update
        incr lineno
        set nlines [llength $todo]
        set id [lindex $todo $level]
        set lineid($lineno) $id
        set actualparents {}
        foreach p $parents($id) {
            if {[info exists ncleft($p)]} {
                incr ncleft($p) -1
                lappend actualparents $p
            }
        }
        if {![info exists commitinfo($id)]} {
            readcommit $id
        }
        set x [expr $canvx0 + $level * $linespc]
        set y2 [expr $canvy + $linespc]
        if {$linestarty($level) < $canvy} {
            set t [$canv create line $x $linestarty($level) $x $canvy \
                       -width 2 -fill $colormap($id)]
            $canv lower $t
            set linestarty($level) $canvy
        }
        set t [$canv create oval [expr $x - 4] [expr $canvy - 4] \
                   [expr $x + 3] [expr $canvy + 3] \
                   -fill blue -outline black -width 1]
        $canv raise $t
        set xt [expr $canvx0 + $nlines * $linespc]
        set headline [lindex $commitinfo($id) 0]
        set name [lindex $commitinfo($id) 1]
        set date [lindex $commitinfo($id) 2]
        set linehtag($lineno) [$canv create text $xt $canvy -anchor w \
                                   -text $headline -font $mainfont ]
        set linentag($lineno) [$canv2 create text 3 $canvy -anchor w \
                                   -text $name -font $namefont]
        set linedtag($lineno) [$canv3 create text 3 $canvy -anchor w \
                                 -text $date -font $mainfont]
        if {!$datemode && [llength $actualparents] == 1} {
            set p [lindex $actualparents 0]
            if {$ncleft($p) == 0 && [lsearch -exact $todo $p] < 0} {
                assigncolor $p
                set todo [lreplace $todo $level $level $p]
                continue
            }
        }

        set oldtodo $todo
        set oldlevel $level
        set lines {}
        for {set i 0} {$i < $nlines} {incr i} {
            if {[lindex $todo $i] == {}} continue
            set oldstarty($i) $linestarty($i)
            if {$i != $level} {
                lappend lines [list $i [lindex $todo $i]]
            }
        }
        unset linestarty
        if {$nullentry >= 0} {
            set todo [lreplace $todo $nullentry $nullentry]
            if {$nullentry < $level} {
                incr level -1
            }
        }

        set todo [lreplace $todo $level $level]
        if {$nullentry > $level} {
            incr nullentry -1
        }
        set i $level
        foreach p $actualparents {
            set k [lsearch -exact $todo $p]
            if {$k < 0} {
                assigncolor $p
                set todo [linsert $todo $i $p]
                if {$nullentry >= $i} {
                    incr nullentry
                }
            }
            lappend lines [list $oldlevel $p]
        }

        # choose which one to do next time around
        set todol [llength $todo]
        set level -1
        set latest {}
        for {set k $todol} {[incr k -1] >= 0} {} {
            set p [lindex $todo $k]
            if {$p == {}} continue
            if {$ncleft($p) == 0} {
                if {$datemode} {
                    if {$latest == {} || $cdate($p) > $latest} {
                        set level $k
                        set latest $cdate($p)
                    }
                } else {
                    set level $k
                    break
                }
            }
        }
        if {$level < 0} {
            if {$todo != {}} {
                puts "ERROR: none of the pending commits can be done yet:"
                foreach p $todo {
                    puts "  $p"
                }
            }
            break
        }

        # If we are reducing, put in a null entry
        if {$todol < $nlines} {
            if {$nullentry >= 0} {
                set i $nullentry
                while {$i < $todol
                       && [lindex $oldtodo $i] == [lindex $todo $i]} {
                    incr i
                }
            } else {
                set i $oldlevel
                if {$level >= $i} {
                    incr i
                }
            }
            if {$i >= $todol} {
                set nullentry -1
            } else {
                set nullentry $i
                set todo [linsert $todo $nullentry {}]
                if {$level >= $i} {
                    incr level
                }
            }
        } else {
            set nullentry -1
        }

        foreach l $lines {
            set i [lindex $l 0]
            set dst [lindex $l 1]
            set j [lsearch -exact $todo $dst]
            if {$i == $j} {
                set linestarty($i) $oldstarty($i)
                continue
            }
            set xi [expr {$canvx0 + $i * $linespc}]
            set xj [expr {$canvx0 + $j * $linespc}]
            set coords {}
            if {$oldstarty($i) < $canvy} {
                lappend coords $xi $oldstarty($i)
            }
            lappend coords $xi $canvy
            if {$j < $i - 1} {
                lappend coords [expr $xj + $linespc] $canvy
            } elseif {$j > $i + 1} {
                lappend coords [expr $xj - $linespc] $canvy
            }
            lappend coords $xj $y2
            set t [$canv create line $coords -width 2 -fill $colormap($dst)]
            $canv lower $t
            if {![info exists linestarty($j)]} {
                set linestarty($j) $y2
            }
        }
    }
}

proc selcanvline {x y} {
    global canv canvy0 ctext linespc selectedline
    global lineid linehtag linentag linedtag
    set ymax [lindex [$canv cget -scrollregion] 3]
    set yfrac [lindex [$canv yview] 0]
    set y [expr {$y + $yfrac * $ymax}]
    set l [expr {int(($y - $canvy0) / $linespc + 0.5)}]
    if {$l < 0} {
        set l 0
    }
    if {[info exists selectedline] && $selectedline == $l} return
    selectline $l
}

proc selectline {l} {
    global canv canv2 canv3 ctext commitinfo selectedline
    global lineid linehtag linentag linedtag
    global canvy canvy0 linespc nparents treepending
    global cflist treediffs currentid
    if {![info exists lineid($l)] || ![info exists linehtag($l)]} return
    $canv delete secsel
    set t [eval $canv create rect [$canv bbox $linehtag($l)] -outline {{}} \
               -tags secsel -fill [$canv cget -selectbackground]]
    $canv lower $t
    $canv2 delete secsel
    set t [eval $canv2 create rect [$canv2 bbox $linentag($l)] -outline {{}} \
               -tags secsel -fill [$canv2 cget -selectbackground]]
    $canv2 lower $t
    $canv3 delete secsel
    set t [eval $canv3 create rect [$canv3 bbox $linedtag($l)] -outline {{}} \
               -tags secsel -fill [$canv3 cget -selectbackground]]
    $canv3 lower $t
    set y [expr {$canvy0 + $l * $linespc}]
    set ytop [expr {($y - $linespc / 2.0) / $canvy}]
    set ybot [expr {($y + $linespc / 2.0) / $canvy}]
    set wnow [$canv yview]
    if {$ytop < [lindex $wnow 0]} {
        allcanvs yview moveto $ytop
    } elseif {$ybot > [lindex $wnow 1]} {
        set wh [expr {[lindex $wnow 1] - [lindex $wnow 0]}]
        allcanvs yview moveto [expr {$ybot - $wh}]
    }
    set selectedline $l

    set id $lineid($l)
    $ctext conf -state normal
    $ctext delete 0.0 end
    set info $commitinfo($id)
    $ctext insert end "Author: [lindex $info 1]  [lindex $info 2]\n"
    $ctext insert end "Committer: [lindex $info 3]  [lindex $info 4]\n"
    $ctext insert end "\n"
    $ctext insert end [lindex $info 5]
    $ctext insert end "\n"
    $ctext tag delete Comments
    $ctext conf -state disabled

    $cflist delete 0 end
    set currentid $id
    if {$nparents($id) == 1} {
        if {![info exists treediffs($id)]} {
            if {![info exists treepending]} {
                gettreediffs $id
            }
        } else {
            addtocflist $id
        }
    }
}

proc selnextline {dir} {
    global selectedline
    if {![info exists selectedline]} return
    set l [expr $selectedline + $dir]
    selectline $l
}

proc addtocflist {id} {
    global currentid treediffs cflist treepending
    if {$id != $currentid} {
        gettreediffs $currentid
        return
    }
    $cflist insert end "All files"
    foreach f $treediffs($currentid) {
        $cflist insert end $f
    }
    getblobdiffs $id
}

proc gettreediffs {id} {
    global treediffs parents treepending
    set treepending $id
    set treediffs($id) {}
    set p [lindex $parents($id) 0]
    if [catch {set gdtf [open "|git-diff-tree -r $p $id" r]}] return
    fconfigure $gdtf -blocking 0
    fileevent $gdtf readable "gettreediffline $gdtf $id"
}

proc gettreediffline {gdtf id} {
    global treediffs treepending
    set n [gets $gdtf line]
    if {$n < 0} {
        if {![eof $gdtf]} return
        close $gdtf
        unset treepending
        addtocflist $id
        return
    }
    set type [lindex $line 1]
    set file [lindex $line 3]
    if {$type == "blob"} {
        lappend treediffs($id) $file
    }
}

proc getblobdiffs {id} {
    global parents diffopts blobdifffd env curdifftag curtagstart
    set p [lindex $parents($id) 0]
    set env(GIT_DIFF_OPTS) $diffopts
    if [catch {set bdf [open "|git-diff-tree -r -p $p $id" r]} err] {
        puts "error getting diffs: $err"
        return
    }
    fconfigure $bdf -blocking 0
    set blobdifffd($id) $bdf
    set curdifftag Comments
    set curtagstart 0.0
    fileevent $bdf readable "getblobdiffline $bdf $id"
}

proc getblobdiffline {bdf id} {
    global currentid blobdifffd ctext curdifftag curtagstart
    set n [gets $bdf line]
    if {$n < 0} {
        if {[eof $bdf]} {
            close $bdf
            if {$id == $currentid && $bdf == $blobdifffd($id)} {
                $ctext tag add $curdifftag $curtagstart end
            }
        }
        return
    }
    if {$id != $currentid || $bdf != $blobdifffd($id)} {
        return
    }
    $ctext conf -state normal
    if {[regexp {^---[ \t]+([^/])+/(.*)} $line match s1 fname]} {
        # start of a new file
        $ctext insert end "\n"
        $ctext tag add $curdifftag $curtagstart end
        set curtagstart [$ctext index "end - 1c"]
        set curdifftag "f:$fname"
        $ctext tag delete $curdifftag
        set l [expr {(78 - [string length $fname]) / 2}]
        set pad [string range "----------------------------------------" 1 $l]
        $ctext insert end "$pad $fname $pad\n" filesep
    } elseif {[string range $line 0 2] == "+++"} {
        # no need to do anything with this
    } elseif {[regexp {^@@ -([0-9]+),([0-9]+) \+([0-9]+),([0-9]+) @@(.*)} \
                   $line match f1l f1c f2l f2c rest]} {
        $ctext insert end "\t" hunksep
        $ctext insert end "    $f1l    " d0 "    $f2l    " d1
        $ctext insert end "    $rest \n" hunksep
    } else {
        set x [string range $line 0 0]
        if {$x == "-" || $x == "+"} {
            set tag [expr {$x == "+"}]
            set line [string range $line 1 end]
            $ctext insert end "$line\n" d$tag
        } elseif {$x == " "} {
            set line [string range $line 1 end]
            $ctext insert end "$line\n"
        } else {
            # Something else we don't recognize
            if {$curdifftag != "Comments"} {
                $ctext insert end "\n"
                $ctext tag add $curdifftag $curtagstart end
                set curtagstart [$ctext index "end - 1c"]
                set curdifftag Comments
            }
            $ctext insert end "$line\n" filesep
        }
    }
    $ctext conf -state disabled
}

proc listboxsel {} {
    global ctext cflist currentid treediffs
    set sel [$cflist curselection]
    if {$sel == {} || [lsearch -exact $sel 0] >= 0} {
        # show everything
        $ctext tag conf Comments -elide 0
        foreach f $treediffs($currentid) {
            $ctext tag conf "f:$f" -elide 0
        }
    } else {
        # just show selected files
        $ctext tag conf Comments -elide 1
        set i 1
        foreach f $treediffs($currentid) {
            set elide [expr {[lsearch -exact $sel $i] < 0}]
            $ctext tag conf "f:$f" -elide $elide
            incr i
        }
    }
}

getcommits $revtreeargs

set linespc [font metrics $mainfont -linespace]
set charspc [font measure $mainfont "m"]

set canvy0 [expr 3 + 0.5 * $linespc]
set canvx0 [expr 3 + 0.5 * $linespc]
set namex [expr 45 * $charspc]
set datex [expr 75 * $charspc]

makewindow

set start {}
foreach id $commits {
    if {$nchildren($id) == 0} {
        set start $id
        break
    }
}
if {$start != {}} {
    drawgraph $start
}