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

# Copyright (C) 2006 Shawn Pearce, 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.

######################################################################
##
## task management

set single_commit 0
set status_active 0
set diff_active 0
set checkin_active 0
set commit_active 0
set update_index_fd {}

set disable_on_lock [list]
set index_lock_type none

set HEAD {}
set PARENT {}
set commit_type {}

proc lock_index {type} {
        global index_lock_type disable_on_lock

        if {$index_lock_type == {none}} {
                set index_lock_type $type
                foreach w $disable_on_lock {
                        uplevel #0 $w disabled
                }
                return 1
        } elseif {$index_lock_type == {begin-update} && $type == {update}} {
                set index_lock_type $type
                return 1
        }
        return 0
}

proc unlock_index {} {
        global index_lock_type disable_on_lock

        set index_lock_type none
        foreach w $disable_on_lock {
                uplevel #0 $w normal
        }
}

######################################################################
##
## status

proc repository_state {hdvar ctvar} {
        global gitdir
        upvar $hdvar hd $ctvar ct

        if {[catch {set hd [exec git rev-parse --verify HEAD]}]} {
                set ct initial
        } elseif {[file exists [file join $gitdir MERGE_HEAD]]} {
                set ct merge
        } else {
                set ct normal
        }
}

proc update_status {{final Ready.}} {
        global HEAD PARENT commit_type
        global ui_index ui_other ui_status_value ui_comm
        global status_active file_states

        if {$status_active || ![lock_index read]} return

        repository_state new_HEAD new_type
        if {$commit_type == {amend} 
                && $new_type == {normal}
                && $new_HEAD == $HEAD} {
        } else {
                set HEAD $new_HEAD
                set PARENT $new_HEAD
                set commit_type $new_type
        }

        array unset file_states
        foreach w [list $ui_index $ui_other] {
                $w conf -state normal
                $w delete 0.0 end
                $w conf -state disabled
        }

        if {![$ui_comm edit modified]
            || [string trim [$ui_comm get 0.0 end]] == {}} {
                if {[load_message GITGUI_MSG]} {
                } elseif {[load_message MERGE_MSG]} {
                } elseif {[load_message SQUASH_MSG]} {
                }
                $ui_comm edit modified false
        }

        set status_active 1
        set ui_status_value {Refreshing file status...}
        set fd_rf [open "| git update-index -q --unmerged --refresh" r]
        fconfigure $fd_rf -blocking 0 -translation binary
        fileevent $fd_rf readable [list read_refresh $fd_rf $final]
}

proc read_refresh {fd final} {
        global gitdir PARENT commit_type
        global ui_index ui_other ui_status_value ui_comm
        global status_active file_states

        read $fd
        if {![eof $fd]} return
        close $fd

        set ls_others [list | git ls-files --others -z \
                --exclude-per-directory=.gitignore]
        set info_exclude [file join $gitdir info exclude]
        if {[file readable $info_exclude]} {
                lappend ls_others "--exclude-from=$info_exclude"
        }

        set status_active 3
        set ui_status_value {Scanning for modified files ...}
        set fd_di [open "| git diff-index --cached -z $PARENT" r]
        set fd_df [open "| git diff-files -z" r]
        set fd_lo [open $ls_others r]

        fconfigure $fd_di -blocking 0 -translation binary
        fconfigure $fd_df -blocking 0 -translation binary
        fconfigure $fd_lo -blocking 0 -translation binary
        fileevent $fd_di readable [list read_diff_index $fd_di $final]
        fileevent $fd_df readable [list read_diff_files $fd_df $final]
        fileevent $fd_lo readable [list read_ls_others $fd_lo $final]
}

proc load_message {file} {
        global gitdir ui_comm

        set f [file join $gitdir $file]
        if {[file isfile $f]} {
                if {[catch {set fd [open $f r]}]} {
                        return 0
                }
                set content [string trim [read $fd]]
                close $fd
                $ui_comm delete 0.0 end
                $ui_comm insert end $content
                return 1
        }
        return 0
}

proc read_diff_index {fd final} {
        global buf_rdi

        append buf_rdi [read $fd]
        set pck [split $buf_rdi "\0"]
        set buf_rdi [lindex $pck end]
        foreach {m p} [lrange $pck 0 end-1] {
                if {$m != {} && $p != {}} {
                        display_file $p [string index $m end]_
                }
        }
        status_eof $fd buf_rdi $final
}

proc read_diff_files {fd final} {
        global buf_rdf

        append buf_rdf [read $fd]
        set pck [split $buf_rdf "\0"]
        set buf_rdf [lindex $pck end]
        foreach {m p} [lrange $pck 0 end-1] {
                if {$m != {} && $p != {}} {
                        display_file $p _[string index $m end]
                }
        }
        status_eof $fd buf_rdf $final
}

proc read_ls_others {fd final} {
        global buf_rlo

        append buf_rlo [read $fd]
        set pck [split $buf_rlo "\0"]
        set buf_rlo [lindex $pck end]
        foreach p [lrange $pck 0 end-1] {
                display_file $p _O
        }
        status_eof $fd buf_rlo $final
}

proc status_eof {fd buf final} {
        global status_active $buf
        global ui_fname_value ui_status_value file_states

        if {[eof $fd]} {
                set $buf {}
                close $fd
                if {[incr status_active -1] == 0} {
                        unlock_index

                        set ui_status_value $final
                        if {$ui_fname_value != {} && [array names file_states \
                                -exact $ui_fname_value] != {}}  {
                                show_diff $ui_fname_value
                        } else {
                                clear_diff
                        }
                }
        }
}

######################################################################
##
## diff

proc clear_diff {} {
        global ui_diff ui_fname_value ui_fstatus_value

        $ui_diff conf -state normal
        $ui_diff delete 0.0 end
        $ui_diff conf -state disabled
        set ui_fname_value {}
        set ui_fstatus_value {}
}

proc show_diff {path} {
        global file_states PARENT diff_3way diff_active
        global ui_diff ui_fname_value ui_fstatus_value ui_status_value

        if {$diff_active || ![lock_index read]} return

        clear_diff
        set s $file_states($path)
        set m [lindex $s 0]
        set diff_3way 0
        set diff_active 1
        set ui_fname_value $path
        set ui_fstatus_value [mapdesc $m $path]
        set ui_status_value "Loading diff of $path..."

        set cmd [list | git diff-index -p $PARENT -- $path]
        switch $m {
        AM {
        }
        MM {
                set cmd [list | git diff-index -p -c $PARENT $path]
        }
        _O {
                if {[catch {
                                set fd [open $path r]
                                set content [read $fd]
                                close $fd
                        } err ]} {
                        set diff_active 0
                        unlock_index
                        set ui_status_value "Unable to display $path"
                        error_popup "Error loading file:\n$err"
                        return
                }
                $ui_diff conf -state normal
                $ui_diff insert end $content
                $ui_diff conf -state disabled
                return
        }
        }

        if {[catch {set fd [open $cmd r]} err]} {
                set diff_active 0
                unlock_index
                set ui_status_value "Unable to display $path"
                error_popup "Error loading diff:\n$err"
                return
        }

        fconfigure $fd -blocking 0 -translation auto
        fileevent $fd readable [list read_diff $fd]
}

proc read_diff {fd} {
        global ui_diff ui_status_value diff_3way diff_active

        while {[gets $fd line] >= 0} {
                if {[string match {diff --git *} $line]} continue
                if {[string match {diff --combined *} $line]} continue
                if {[string match {--- *} $line]} continue
                if {[string match {+++ *} $line]} continue
                if {[string match index* $line]} {
                        if {[string first , $line] >= 0} {
                                set diff_3way 1
                        }
                }

                $ui_diff conf -state normal
                if {!$diff_3way} {
                        set x [string index $line 0]
                        switch -- $x {
                        "@" {set tags da}
                        "+" {set tags dp}
                        "-" {set tags dm}
                        default {set tags {}}
                        }
                } else {
                        set x [string range $line 0 1]
                        switch -- $x {
                        default {set tags {}}
                        "@@" {set tags da}
                        "++" {set tags dp; set x " +"}
                        " +" {set tags {di bold}; set x "++"}
                        "+ " {set tags dni; set x "-+"}
                        "--" {set tags dm; set x " -"}
                        " -" {set tags {dm bold}; set x "--"}
                        "- " {set tags di; set x "+-"}
                        default {set tags {}}
                        }
                        set line [string replace $line 0 1 $x]
                }
                $ui_diff insert end $line $tags
                $ui_diff insert end "\n"
                $ui_diff conf -state disabled
        }

        if {[eof $fd]} {
                close $fd
                set diff_active 0
                unlock_index
                set ui_status_value {Ready.}
        }
}

######################################################################
##
## commit

proc load_last_commit {} {
        global HEAD PARENT commit_type ui_comm

        if {$commit_type == {amend}} return
        if {$commit_type != {normal}} {
                error_popup "Can't amend a $commit_type commit."
                return
        }

        set msg {}
        set parent {}
        set parent_count 0
        if {[catch {
                        set fd [open "| git cat-file commit $HEAD" r]
                        while {[gets $fd line] > 0} {
                                if {[string match {parent *} $line]} {
                                        set parent [string range $line 7 end]
                                        incr parent_count
                                }
                        }
                        set msg [string trim [read $fd]]
                        close $fd
                } err]} {
                error_popup "Error loading commit data for amend:\n$err"
                return
        }

        if {$parent_count == 0} {
                set commit_type amend
                set HEAD {}
                set PARENT {}
                update_status
        } elseif {$parent_count == 1} {
                set commit_type amend
                set PARENT $parent
                $ui_comm delete 0.0 end
                $ui_comm insert end $msg
                $ui_comm edit modified false
                update_status
        } else {
                error_popup {You can't amend a merge commit.}
                return
        }
}

proc commit_tree {} {
        global tcl_platform HEAD gitdir commit_type file_states
        global commit_active ui_status_value
        global ui_comm

        if {$commit_active || ![lock_index update]} return

        # -- Our in memory state should match the repository.
        #
        repository_state curHEAD cur_type
        if {$commit_type == {amend} 
                && $cur_type == {normal}
                && $curHEAD == $HEAD} {
        } elseif {$commit_type != $cur_type || $HEAD != $curHEAD} {
                error_popup {Last scanned state does not match repository state.

Its highly likely that another Git program modified the
repository since our last scan.  A rescan is required
before committing.
}
                unlock_index
                update_status
                return
        }

        # -- At least one file should differ in the index.
        #
        set files_ready 0
        foreach path [array names file_states] {
                set s $file_states($path)
                switch -glob -- [lindex $s 0] {
                _* {continue}
                A* -
                D* -
                M* {set files_ready 1; break}
                U* {
                        error_popup "Unmerged files cannot be committed.

File $path has merge conflicts.
You must resolve them and check the file in before committing.
"
                        unlock_index
                        return
                }
                default {
                        error_popup "Unknown file state [lindex $s 0] detected.

File $path cannot be committed by this program.
"
                }
                }
        }
        if {!$files_ready} {
                error_popup {No checked-in files to commit.

You must check-in at least 1 file before you can commit.
}
                unlock_index
                return
        }

        # -- A message is required.
        #
        set msg [string trim [$ui_comm get 1.0 end]]
        if {$msg == {}} {
                error_popup {Please supply a commit message.

A good commit message has the following format:

- First line: Describe in one sentance what you did.
- Second line: Blank
- Remaining lines: Describe why this change is good.
}
                unlock_index
                return
        }

        # -- Ask the pre-commit hook for the go-ahead.
        #
        set pchook [file join $gitdir hooks pre-commit]
        if {$tcl_platform(platform) == {windows} && [file isfile $pchook]} {
                set pchook [list sh -c \
                        "if test -x \"$pchook\"; then exec \"$pchook\"; fi"]
        } elseif {[file executable $pchook]} {
                set pchook [list $pchook]
        } else {
                set pchook {}
        }
        if {$pchook != {} && [catch {eval exec $pchook} err]} {
                hook_failed_popup pre-commit $err
                unlock_index
                return
        }

        # -- Write the tree in the background.
        #
        set commit_active 1
        set ui_status_value {Committing changes...}

        set fd_wt [open "| git write-tree" r]
        fileevent $fd_wt readable \
                [list commit_stage2 $fd_wt $curHEAD $msg]
}

proc commit_stage2 {fd_wt curHEAD msg} {
        global single_commit gitdir PARENT commit_type
        global commit_active ui_status_value ui_comm

        gets $fd_wt tree_id
        close $fd_wt

        if {$tree_id == {}} {
                error_popup "write-tree failed"
                set commit_active 0
                set ui_status_value {Commit failed.}
                unlock_index
                return
        }

        # -- Create the commit.
        #
        set cmd [list git commit-tree $tree_id]
        if {$PARENT != {}} {
                lappend cmd -p $PARENT
        }
        if {$commit_type == {merge}} {
                if {[catch {
                                set fd_mh [open [file join $gitdir MERGE_HEAD] r]
                                while {[gets $fd_mh merge_head] > 0} {
                                        lappend -p $merge_head
                                }
                                close $fd_mh
                        } err]} {
                        error_popup "Loading MERGE_HEADs failed:\n$err"
                        set commit_active 0
                        set ui_status_value {Commit failed.}
                        unlock_index
                        return
                }
        }
        if {$PARENT == {}} {
                # git commit-tree writes to stderr during initial commit.
                lappend cmd 2>/dev/null
        }
        lappend cmd << $msg
        if {[catch {set cmt_id [eval exec $cmd]} err]} {
                error_popup "commit-tree failed:\n$err"
                set commit_active 0
                set ui_status_value {Commit failed.}
                unlock_index
                return
        }

        # -- Update the HEAD ref.
        #
        set reflogm commit
        if {$commit_type != {normal}} {
                append reflogm " ($commit_type)"
        }
        set i [string first "\n" $msg]
        if {$i >= 0} {
                append reflogm {: } [string range $msg 0 [expr $i - 1]]
        } else {
                append reflogm {: } $msg
        }
        set cmd [list git update-ref -m $reflogm HEAD $cmt_id $curHEAD]
        if {[catch {eval exec $cmd} err]} {
                error_popup "update-ref failed:\n$err"
                set commit_active 0
                set ui_status_value {Commit failed.}
                unlock_index
                return
        }

        # -- Cleanup after ourselves.
        #
        catch {file delete [file join $gitdir MERGE_HEAD]}
        catch {file delete [file join $gitdir MERGE_MSG]}
        catch {file delete [file join $gitdir SQUASH_MSG]}
        catch {file delete [file join $gitdir GITGUI_MSG]}

        # -- Let rerere do its thing.
        #
        if {[file isdirectory [file join $gitdir rr-cache]]} {
                catch {exec git rerere}
        }

        $ui_comm delete 0.0 end
        $ui_comm edit modified false

        if {$single_commit} do_quit

        set commit_type {}
        set commit_active 0
        unlock_index
        update_status "Changes committed as $cmt_id."
}

######################################################################
##
## ui helpers

proc mapcol {state path} {
        global all_cols

        if {[catch {set r $all_cols($state)}]} {
                puts "error: no column for state={$state} $path"
                return o
        }
        return $r
}

proc mapicon {state path} {
        global all_icons

        if {[catch {set r $all_icons($state)}]} {
                puts "error: no icon for state={$state} $path"
                return file_plain
        }
        return $r
}

proc mapdesc {state path} {
        global all_descs

        if {[catch {set r $all_descs($state)}]} {
                puts "error: no desc for state={$state} $path"
                return $state
        }
        return $r
}

proc bsearch {w path} {
        set hi [expr [lindex [split [$w index end] .] 0] - 2]
        if {$hi == 0} {
                return -1
        }
        set lo 0
        while {$lo < $hi} {
                set mi [expr [expr $lo + $hi] / 2]
                set ti [expr $mi + 1]
                set cmp [string compare [$w get $ti.1 $ti.end] $path]
                if {$cmp < 0} {
                        set lo $ti
                } elseif {$cmp == 0} {
                        return $mi
                } else {
                        set hi $mi
                }
        }
        return -[expr $lo + 1]
}

proc merge_state {path state} {
        global file_states

        if {[array names file_states -exact $path] == {}}  {
                set o __
                set s [list $o none none]
        } else {
                set s $file_states($path)
                set o [lindex $s 0]
        }

        set m [lindex $s 0]
        if {[string index $state 0] == "_"} {
                set state [string index $m 0][string index $state 1]
        } elseif {[string index $state 0] == "*"} {
                set state _[string index $state 1]
        }

        if {[string index $state 1] == "_"} {
                set state [string index $state 0][string index $m 1]
        } elseif {[string index $state 1] == "*"} {
                set state [string index $state 0]_
        }

        set file_states($path) [lreplace $s 0 0 $state]
        return $o
}

proc display_file {path state} {
        global ui_index ui_other file_states

        set old_m [merge_state $path $state]
        set s $file_states($path)
        set m [lindex $s 0]

        if {[mapcol $m $path] == "o"} {
                set ii 1
                set ai 2
                set iw $ui_index
                set aw $ui_other
        } else {
                set ii 2
                set ai 1
                set iw $ui_other
                set aw $ui_index
        }

        set d [lindex $s $ii]
        if {$d != "none"} {
                set lno [bsearch $iw $path]
                if {$lno >= 0} {
                        incr lno
                        $iw conf -state normal
                        $iw delete $lno.0 [expr $lno + 1].0
                        $iw conf -state disabled
                        set s [lreplace $s $ii $ii none]
                }
        }

        set d [lindex $s $ai]
        if {$d == "none"} {
                set lno [expr abs([bsearch $aw $path] + 1) + 1]
                $aw conf -state normal
                set ico [$aw image create $lno.0 \
                        -align center -padx 5 -pady 1 \
                        -image [mapicon $m $path]]
                $aw insert $lno.1 "$path\n"
                $aw conf -state disabled
                set file_states($path) [lreplace $s $ai $ai [list $ico]]
        } elseif {[mapicon $m $path] != [mapicon $old_m $path]} {
                set ico [lindex $d 0]
                $aw image conf $ico -image [mapicon $m $path]
        }
}

proc with_update_index {body} {
        global update_index_fd

        if {$update_index_fd == {}} {
                if {![lock_index update]} return
                set update_index_fd [open \
                        "| git update-index --add --remove -z --stdin" \
                        w]
                fconfigure $update_index_fd -translation binary
                uplevel 1 $body
                close $update_index_fd
                set update_index_fd {}
                unlock_index
        } else {
                uplevel 1 $body
        }
}

proc update_index {path} {
        global update_index_fd

        if {$update_index_fd == {}} {
                error {not in with_update_index}
        } else {
                puts -nonewline $update_index_fd "$path\0"
        }
}

proc toggle_mode {path} {
        global file_states

        set s $file_states($path)
        set m [lindex $s 0]

        switch -- $m {
        AM -
        _O {set new A*}
        _M -
        MM {set new M*}
        _D {set new D*}
        default {return}
        }

        with_update_index {update_index $path}
        display_file $path $new
}

######################################################################
##
## icons

set filemask {
#define mask_width 14
#define mask_height 15
static unsigned char mask_bits[] = {
   0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f,
   0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f,
   0xfe, 0x1f, 0xfe, 0x1f, 0xfe, 0x1f};
}

image create bitmap file_plain -background white -foreground black -data {
#define plain_width 14
#define plain_height 15
static unsigned char plain_bits[] = {
   0xfe, 0x01, 0x02, 0x03, 0x02, 0x05, 0x02, 0x09, 0x02, 0x1f, 0x02, 0x10,
   0x02, 0x10, 0x02, 0x10, 0x02, 0x10, 0x02, 0x10, 0x02, 0x10, 0x02, 0x10,
   0x02, 0x10, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_mod -background white -foreground blue -data {
#define mod_width 14
#define mod_height 15
static unsigned char mod_bits[] = {
   0xfe, 0x01, 0x02, 0x03, 0x7a, 0x05, 0x02, 0x09, 0x7a, 0x1f, 0x02, 0x10,
   0xfa, 0x17, 0x02, 0x10, 0xfa, 0x17, 0x02, 0x10, 0xfa, 0x17, 0x02, 0x10,
   0xfa, 0x17, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_fulltick -background white -foreground "#007000" -data {
#define file_fulltick_width 14
#define file_fulltick_height 15
static unsigned char file_fulltick_bits[] = {
   0xfe, 0x01, 0x02, 0x1a, 0x02, 0x0c, 0x02, 0x0c, 0x02, 0x16, 0x02, 0x16,
   0x02, 0x13, 0x00, 0x13, 0x86, 0x11, 0x8c, 0x11, 0xd8, 0x10, 0xf2, 0x10,
   0x62, 0x10, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_parttick -background white -foreground "#005050" -data {
#define parttick_width 14
#define parttick_height 15
static unsigned char parttick_bits[] = {
   0xfe, 0x01, 0x02, 0x03, 0x7a, 0x05, 0x02, 0x09, 0x7a, 0x1f, 0x02, 0x10,
   0x7a, 0x14, 0x02, 0x16, 0x02, 0x13, 0x8a, 0x11, 0xda, 0x10, 0x72, 0x10,
   0x22, 0x10, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_question -background white -foreground black -data {
#define file_question_width 14
#define file_question_height 15
static unsigned char file_question_bits[] = {
   0xfe, 0x01, 0x02, 0x02, 0xe2, 0x04, 0xf2, 0x09, 0x1a, 0x1b, 0x0a, 0x13,
   0x82, 0x11, 0xc2, 0x10, 0x62, 0x10, 0x62, 0x10, 0x02, 0x10, 0x62, 0x10,
   0x62, 0x10, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_removed -background white -foreground red -data {
#define file_removed_width 14
#define file_removed_height 15
static unsigned char file_removed_bits[] = {
   0xfe, 0x01, 0x02, 0x03, 0x02, 0x05, 0x02, 0x09, 0x02, 0x1f, 0x02, 0x10,
   0x1a, 0x16, 0x32, 0x13, 0xe2, 0x11, 0xc2, 0x10, 0xe2, 0x11, 0x32, 0x13,
   0x1a, 0x16, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

image create bitmap file_merge -background white -foreground blue -data {
#define file_merge_width 14
#define file_merge_height 15
static unsigned char file_merge_bits[] = {
   0xfe, 0x01, 0x02, 0x03, 0x62, 0x05, 0x62, 0x09, 0x62, 0x1f, 0x62, 0x10,
   0xfa, 0x11, 0xf2, 0x10, 0x62, 0x10, 0x02, 0x10, 0xfa, 0x17, 0x02, 0x10,
   0xfa, 0x17, 0x02, 0x10, 0xfe, 0x1f};
} -maskdata $filemask

set max_status_desc 0
foreach i {
                {__ i plain    "Unmodified"}
                {_M i mod      "Modified"}
                {M_ i fulltick "Checked in"}
                {MM i parttick "Partially checked in"}

                {_O o plain    "Untracked"}
                {A_ o fulltick "Added"}
                {AM o parttick "Partially added"}

                {_D i question "Missing"}
                {D_ i removed  "Removed"}
                {DD i removed  "Removed"}
                {DO i removed  "Removed (still exists)"}

                {UM i merge    "Merge conflicts"}
                {U_ i merge    "Merge conflicts"}
        } {
        if {$max_status_desc < [string length [lindex $i 3]]} {
                set max_status_desc [string length [lindex $i 3]]
        }
        set all_cols([lindex $i 0]) [lindex $i 1]
        set all_icons([lindex $i 0]) file_[lindex $i 2]
        set all_descs([lindex $i 0]) [lindex $i 3]
}
unset filemask i

######################################################################
##
## util

proc error_popup {msg} {
        set w .error
        toplevel $w
        wm transient $w .
        show_msg $w $w $msg
}

proc show_msg {w top msg} {
        global gitdir appname

        message $w.m -text $msg -justify left -aspect 400
        pack $w.m -side top -fill x -padx 5 -pady 10
        button $w.ok -text OK \
                -width 15 \
                -command "destroy $top"
        pack $w.ok -side bottom
        bind $top <Visibility> "grab $top; focus $top"
        bind $top <Key-Return> "destroy $top"
        wm title $top "error: $appname ([file normalize [file dirname $gitdir]])"
        tkwait window $top
}

proc hook_failed_popup {hook msg} {
        global gitdir mainfont difffont appname

        set w .hookfail
        toplevel $w
        wm transient $w .

        frame $w.m
        label $w.m.l1 -text "$hook hook failed:" \
                -anchor w \
                -justify left \
                -font [concat $mainfont bold]
        text $w.m.t \
                -background white -borderwidth 1 \
                -relief sunken \
                -width 80 -height 10 \
                -font $difffont \
                -yscrollcommand [list $w.m.sby set]
        label $w.m.l2 \
                -text {You must correct the above errors before committing.} \
                -anchor w \
                -justify left \
                -font [concat $mainfont bold]
        scrollbar $w.m.sby -command [list $w.m.t yview]
        pack $w.m.l1 -side top -fill x
        pack $w.m.l2 -side bottom -fill x
        pack $w.m.sby -side right -fill y
        pack $w.m.t -side left -fill both -expand 1
        pack $w.m -side top -fill both -expand 1 -padx 5 -pady 10

        $w.m.t insert 1.0 $msg
        $w.m.t conf -state disabled

        button $w.ok -text OK \
                -width 15 \
                -command "destroy $w"
        pack $w.ok -side bottom

        bind $w <Visibility> "grab $w; focus $w"
        bind $w <Key-Return> "destroy $w"
        wm title $w "error: $appname ([file normalize [file dirname $gitdir]])"
        tkwait window $w
}

######################################################################
##
## ui commands

set starting_gitk_msg {Please wait... Starting gitk...}
proc do_gitk {} {
        global tcl_platform ui_status_value starting_gitk_msg

        set ui_status_value $starting_gitk_msg
        after 10000 {
                if {$ui_status_value == $starting_gitk_msg} {
                        set ui_status_value {Ready.}
                }
        }

    if {$tcl_platform(platform) == "windows"} {
                exec sh -c gitk &
        } else {
                exec gitk &
        }
}

proc do_quit {} {
        global gitdir ui_comm

        set save [file join $gitdir GITGUI_MSG]
        set msg [string trim [$ui_comm get 0.0 end]]
        if {[$ui_comm edit modified] && $msg != {}} {
                catch {
                        set fd [open $save w]
                        puts $fd [string trim [$ui_comm get 0.0 end]]
                        close $fd
                }
        } elseif {$msg == {} && [file exists $save]} {
                file delete $save
        }

        destroy .
}

proc do_rescan {} {
        update_status
}

proc do_checkin_all {} {
        global checkin_active ui_status_value

        if {$checkin_active || ![lock_index begin-update]} return

        set checkin_active 1
        set ui_status_value {Checking in all files...}
        after 1 {
                with_update_index {
                        foreach path [array names file_states] {
                                set s $file_states($path)
                                set m [lindex $s 0]
                                switch -- $m {
                                AM -
                                MM -
                                _M -
                                _D {toggle_mode $path}
                                }
                        }
                }
                set checkin_active 0
                set ui_status_value {Ready.}
        }
}

proc do_signoff {} {
        global ui_comm

        catch {
                set me [exec git var GIT_COMMITTER_IDENT]
                if {[regexp {(.*) [0-9]+ [-+0-9]+$} $me me name]} {
                        set str "Signed-off-by: $name"
                        if {[$ui_comm get {end -1c linestart} {end -1c}] != $str} {
                                $ui_comm insert end "\n"
                                $ui_comm insert end $str
                                $ui_comm see end
                        }
                }
        }
}

proc do_amend_last {} {
        load_last_commit
}

proc do_commit {} {
        commit_tree
}

# shift == 1: left click
#          3: right click  
proc click {w x y shift wx wy} {
        global ui_index ui_other

        set pos [split [$w index @$x,$y] .]
        set lno [lindex $pos 0]
        set col [lindex $pos 1]
        set path [$w get $lno.1 $lno.end]
        if {$path == {}} return

        if {$col > 0 && $shift == 1} {
                $ui_index tag remove in_diff 0.0 end
                $ui_other tag remove in_diff 0.0 end
                $w tag add in_diff $lno.0 [expr $lno + 1].0
                show_diff $path
        }
}

proc unclick {w x y} {
        set pos [split [$w index @$x,$y] .]
        set lno [lindex $pos 0]
        set col [lindex $pos 1]
        set path [$w get $lno.1 $lno.end]
        if {$path == {}} return

        if {$col == 0} {
                toggle_mode $path
        }
}

######################################################################
##
## ui init

set mainfont {Helvetica 10}
set difffont {Courier 10}
set maincursor [. cget -cursor]

switch -- $tcl_platform(platform) {
windows {set M1B Control; set M1T Ctrl}
default {set M1B M1; set M1T M1}
}

# -- Menu Bar
menu .mbar -tearoff 0
.mbar add cascade -label Project -menu .mbar.project
.mbar add cascade -label Commit -menu .mbar.commit
.mbar add cascade -label Fetch -menu .mbar.fetch
.mbar add cascade -label Pull -menu .mbar.pull
. configure -menu .mbar

# -- Project Menu
menu .mbar.project
.mbar.project add command -label Visualize \
        -command do_gitk \
        -font $mainfont
.mbar.project add command -label Quit \
        -command do_quit \
        -accelerator $M1T-Q \
        -font $mainfont

# -- Commit Menu
menu .mbar.commit
.mbar.commit add command -label Rescan \
        -command do_rescan \
        -accelerator F5 \
        -font $mainfont
lappend disable_on_lock \
        [list .mbar.commit entryconf [.mbar.commit index last] -state]
.mbar.commit add command -label {Amend Last Commit} \
        -command do_amend_last \
        -font $mainfont
lappend disable_on_lock \
        [list .mbar.commit entryconf [.mbar.commit index last] -state]
.mbar.commit add command -label {Check-in All Files} \
        -command do_checkin_all \
        -accelerator $M1T-U \
        -font $mainfont
lappend disable_on_lock \
        [list .mbar.commit entryconf [.mbar.commit index last] -state]
.mbar.commit add command -label {Sign Off} \
        -command do_signoff \
        -accelerator $M1T-S \
        -font $mainfont
.mbar.commit add command -label Commit \
        -command do_commit \
        -accelerator $M1T-Return \
        -font $mainfont
lappend disable_on_lock \
        [list .mbar.commit entryconf [.mbar.commit index last] -state]

# -- Fetch Menu
menu .mbar.fetch

# -- Pull Menu
menu .mbar.pull

# -- Main Window Layout
panedwindow .vpane -orient vertical
panedwindow .vpane.files -orient horizontal
.vpane add .vpane.files -sticky nsew -height 100 -width 400
pack .vpane -anchor n -side top -fill both -expand 1

# -- Index File List
set ui_index .vpane.files.index.list
frame .vpane.files.index -height 100 -width 400
label .vpane.files.index.title -text {Modified Files} \
        -background green \
        -font $mainfont
text $ui_index -background white -borderwidth 0 \
        -width 40 -height 10 \
        -font $mainfont \
        -yscrollcommand {.vpane.files.index.sb set} \
        -cursor $maincursor \
        -state disabled
scrollbar .vpane.files.index.sb -command [list $ui_index yview]
pack .vpane.files.index.title -side top -fill x
pack .vpane.files.index.sb -side right -fill y
pack $ui_index -side left -fill both -expand 1
.vpane.files add .vpane.files.index -sticky nsew

# -- Other (Add) File List
set ui_other .vpane.files.other.list
frame .vpane.files.other -height 100 -width 100
label .vpane.files.other.title -text {Untracked Files} \
        -background red \
        -font $mainfont
text $ui_other -background white -borderwidth 0 \
        -width 40 -height 10 \
        -font $mainfont \
        -yscrollcommand {.vpane.files.other.sb set} \
        -cursor $maincursor \
        -state disabled
scrollbar .vpane.files.other.sb -command [list $ui_other yview]
pack .vpane.files.other.title -side top -fill x
pack .vpane.files.other.sb -side right -fill y
pack $ui_other -side left -fill both -expand 1
.vpane.files add .vpane.files.other -sticky nsew

$ui_index tag conf in_diff -font [concat $mainfont bold]
$ui_other tag conf in_diff -font [concat $mainfont bold]

# -- Diff Header
set ui_fname_value {}
set ui_fstatus_value {}
frame .vpane.diff -height 200 -width 400
frame .vpane.diff.header
label .vpane.diff.header.l1 -text {File:} -font $mainfont
label .vpane.diff.header.l2 -textvariable ui_fname_value \
        -anchor w \
        -justify left \
        -font $mainfont
label .vpane.diff.header.l3 -text {Status:} -font $mainfont
label .vpane.diff.header.l4 -textvariable ui_fstatus_value \
        -width $max_status_desc \
        -anchor w \
        -justify left \
        -font $mainfont
pack .vpane.diff.header.l1 -side left
pack .vpane.diff.header.l2 -side left -fill x
pack .vpane.diff.header.l4 -side right
pack .vpane.diff.header.l3 -side right

# -- Diff Body
frame .vpane.diff.body
set ui_diff .vpane.diff.body.t
text $ui_diff -background white -borderwidth 0 \
        -width 80 -height 15 -wrap none \
        -font $difffont \
        -xscrollcommand {.vpane.diff.body.sbx set} \
        -yscrollcommand {.vpane.diff.body.sby set} \
        -cursor $maincursor \
        -state disabled
scrollbar .vpane.diff.body.sbx -orient horizontal \
        -command [list $ui_diff xview]
scrollbar .vpane.diff.body.sby -orient vertical \
        -command [list $ui_diff yview]
pack .vpane.diff.body.sbx -side bottom -fill x
pack .vpane.diff.body.sby -side right -fill y
pack $ui_diff -side left -fill both -expand 1
pack .vpane.diff.header -side top -fill x
pack .vpane.diff.body -side bottom -fill both -expand 1
.vpane add .vpane.diff -stick nsew

$ui_diff tag conf dm -foreground red
$ui_diff tag conf dp -foreground blue
$ui_diff tag conf da -font [concat $difffont bold]
$ui_diff tag conf di -foreground "#00a000"
$ui_diff tag conf dni -foreground "#a000a0"
$ui_diff tag conf bold -font [concat $difffont bold]

# -- Commit Area
frame .vpane.commarea -height 170
.vpane add .vpane.commarea -stick nsew

# -- Commit Area Buttons
frame .vpane.commarea.buttons
label .vpane.commarea.buttons.l -text {} \
        -anchor w \
        -justify left \
        -font $mainfont
pack .vpane.commarea.buttons.l -side top -fill x
pack .vpane.commarea.buttons -side left -fill y

button .vpane.commarea.buttons.rescan -text {Rescan} \
        -command do_rescan \
        -font $mainfont
pack .vpane.commarea.buttons.rescan -side top -fill x
lappend disable_on_lock {.vpane.commarea.buttons.rescan conf -state}

button .vpane.commarea.buttons.amend -text {Amend Last} \
        -command do_amend_last \
        -font $mainfont
pack .vpane.commarea.buttons.amend -side top -fill x
lappend disable_on_lock {.vpane.commarea.buttons.amend conf -state}

button .vpane.commarea.buttons.ciall -text {Check-in All} \
        -command do_checkin_all \
        -font $mainfont
pack .vpane.commarea.buttons.ciall -side top -fill x
lappend disable_on_lock {.vpane.commarea.buttons.ciall conf -state}

button .vpane.commarea.buttons.signoff -text {Sign Off} \
        -command do_signoff \
        -font $mainfont
pack .vpane.commarea.buttons.signoff -side top -fill x

button .vpane.commarea.buttons.commit -text {Commit} \
        -command do_commit \
        -font $mainfont
pack .vpane.commarea.buttons.commit -side top -fill x
lappend disable_on_lock {.vpane.commarea.buttons.commit conf -state}

# -- Commit Message Buffer
frame .vpane.commarea.buffer
set ui_comm .vpane.commarea.buffer.t
label .vpane.commarea.buffer.l -text {Commit Message:} \
        -anchor w \
        -justify left \
        -font $mainfont
text $ui_comm -background white -borderwidth 1 \
        -relief sunken \
        -width 75 -height 10 -wrap none \
        -font $difffont \
        -yscrollcommand {.vpane.commarea.buffer.sby set} \
        -cursor $maincursor
scrollbar .vpane.commarea.buffer.sby -command [list $ui_comm yview]
pack .vpane.commarea.buffer.l -side top -fill x
pack .vpane.commarea.buffer.sby -side right -fill y
pack $ui_comm -side left -fill y
pack .vpane.commarea.buffer -side left -fill y

# -- Status Bar
set ui_status_value {Initializing...}
label .status -textvariable ui_status_value \
        -anchor w \
        -justify left \
        -borderwidth 1 \
        -relief sunken \
        -font $mainfont
pack .status -anchor w -side bottom -fill x

# -- Key Bindings
bind $ui_comm <$M1B-Key-Return> {do_commit;break}
bind . <Destroy> do_quit
bind . <Key-F5> do_rescan
bind . <$M1B-Key-r> do_rescan
bind . <$M1B-Key-R> do_rescan
bind . <$M1B-Key-s> do_signoff
bind . <$M1B-Key-S> do_signoff
bind . <$M1B-Key-u> do_checkin_all
bind . <$M1B-Key-U> do_checkin_all
bind . <$M1B-Key-Return> do_commit
bind . <$M1B-Key-q> do_quit
bind . <$M1B-Key-Q> do_quit
foreach i [list $ui_index $ui_other] {
        bind $i <Button-1> {click %W %x %y 1 %X %Y; break}
        bind $i <Button-3> {click %W %x %y 3 %X %Y; break}
        bind $i <ButtonRelease-1> {unclick %W %x %y; break}
}
unset i M1B M1T

######################################################################
##
## main

if {[catch {set gitdir [exec git rev-parse --git-dir]} err]} {
        show_msg {} . "Cannot find the git directory: $err"
        exit 1
}

set appname [lindex [file split $argv0] end]
if {$appname == {git-citool}} {
        set single_commit 1
}

wm title . "$appname ([file normalize [file dirname $gitdir]])"
focus -force $ui_comm
update_status