# git-gui branch merge support
# Copyright (C) 2006, 2007 Shawn Pearce

class merge {

field w         ; # top level window
field w_list    ; # widget of available branches
field list      ; # list of available branches

method _can_merge {} {
        global HEAD commit_type file_states

        if {[string match amend* $commit_type]} {
                info_popup {Cannot merge while amending.

You must finish amending this commit before starting any type of merge.
}
                return 0
        }

        if {[committer_ident] eq {}} {return 0}
        if {![lock_index merge]} {return 0}

        # -- Our in memory state should match the repository.
        #
        repository_state curType curHEAD curMERGE_HEAD
        if {$commit_type ne $curType || $HEAD ne $curHEAD} {
                info_popup {Last scanned state does not match repository state.

Another Git program has modified this repository since the last scan.  A rescan must be performed before a merge can be performed.

The rescan will be automatically started now.
}
                unlock_index
                rescan ui_ready
                return 0
        }

        foreach path [array names file_states] {
                switch -glob -- [lindex $file_states($path) 0] {
                _O {
                        continue; # and pray it works!
                }
                U? {
                        error_popup "You are in the middle of a conflicted merge.

File [short_path $path] has merge conflicts.

You must resolve them, add the file, and commit to complete the current merge.  Only then can you begin another merge.
"
                        unlock_index
                        return 0
                }
                ?? {
                        error_popup "You are in the middle of a change.

File [short_path $path] is modified.

You should complete the current commit before starting a merge.  Doing so will help you abort a failed merge, should the need arise.
"
                        unlock_index
                        return 0
                }
                }
        }

        return 1
}

method _refs {} {
        set r {}
        foreach i [$w_list curselection] {
                lappend r [lindex [lindex $list $i] 0]
        }
        return $r
}

method _visualize {} {
        set revs [_refs $this]
        if {$revs eq {}} return
        lappend revs --not HEAD
        do_gitk $revs
}

method _start {} {
        global HEAD current_branch

        set cmd [list git merge]
        set names [_refs $this]
        set revcnt [llength $names]
        append cmd { } $names

        if {$revcnt == 0} {
                return
        } elseif {$revcnt == 1} {
                set unit branch
        } elseif {$revcnt <= 15} {
                set unit branches

                if {[tk_dialog \
                $w.confirm_octopus \
                [wm title $w] \
                "Use octopus merge strategy?

You are merging $revcnt branches at once.  This requires using the octopus merge driver, which may not succeed if there are file-level conflicts.
" \
                question \
                0 \
                {Cancel} \
                {Use octopus} \
                ] != 1} return
        } else {
                tk_messageBox \
                        -icon error \
                        -type ok \
                        -title [wm title $w] \
                        -parent $w \
                        -message "Too many branches selected.

You have requested to merge $revcnt branches in an octopus merge.  This exceeds Git's internal limit of 15 branches per merge.

Please select fewer branches.  To merge more than 15 branches, merge the branches in batches.
"
                return
        }

        set msg "Merging $current_branch, [join $names {, }]"
        ui_status "$msg..."
        set cons [console::new "Merge" $msg]
        console::exec $cons $cmd [cb _finish $revcnt $cons]

        wm protocol $w WM_DELETE_WINDOW {}
        destroy $w
}

method _finish {revcnt cons ok} {
        console::done $cons $ok
        if {$ok} {
                set msg {Merge completed successfully.}
        } else {
                if {$revcnt != 1} {
                        info_popup "Octopus merge failed.

Your merge of $revcnt branches has failed.

There are file-level conflicts between the branches which must be resolved manually.

The working directory will now be reset.

You can attempt this merge again by merging only one branch at a time." $w

                        set fd [git_read read-tree --reset -u HEAD]
                        fconfigure $fd -blocking 0 -translation binary
                        fileevent $fd readable [cb _reset_wait $fd]
                        ui_status {Aborting... please wait...}
                        return
                }

                set msg {Merge failed.  Conflict resolution is required.}
        }
        unlock_index
        rescan [list ui_status $msg]
        delete_this
}

constructor dialog {} {
        global current_branch
        global M1B

        if {![_can_merge $this]} {
                delete_this
                return
        }

        set fmt {list %(objectname) %(*objectname) %(refname) %(subject)}
        set fr_fd [git_read for-each-ref \
                --tcl \
                --format=$fmt \
                refs/heads \
                refs/remotes \
                refs/tags \
                ]
        fconfigure $fr_fd -translation binary
        while {[gets $fr_fd line] > 0} {
                set line [eval $line]
                set ref [lindex $line 2]
                regsub ^refs/(heads|remotes|tags)/ $ref {} ref
                set subj($ref) [lindex $line 3]
                lappend sha1([lindex $line 0]) $ref
                if {[lindex $line 1] ne {}} {
                        lappend sha1([lindex $line 1]) $ref
                }
        }
        close $fr_fd

        set list [list]
        set fr_fd [git_read rev-list --all --not HEAD]
        while {[gets $fr_fd line] > 0} {
                if {[catch {set ref $sha1($line)}]} continue
                foreach n $ref {
                        lappend list [list $n $line]
                }
        }
        close $fr_fd
        set list [lsort -unique $list]

        make_toplevel top w
        wm title $top "[appname] ([reponame]): Merge"
        if {$top ne {.}} {
                wm geometry $top "+[winfo rootx .]+[winfo rooty .]"
        }

        set _visualize [cb _visualize]
        set _start [cb _start]

        label $w.header \
                -text "Merge Into $current_branch" \
                -font font_uibold
        pack $w.header -side top -fill x

        frame $w.buttons
        button $w.buttons.visualize -text Visualize -command $_visualize
        pack $w.buttons.visualize -side left
        button $w.buttons.create -text Merge -command $_start
        pack $w.buttons.create -side right
        button $w.buttons.cancel \
                -text {Cancel} \
                -command [cb _cancel]
        pack $w.buttons.cancel -side right -padx 5
        pack $w.buttons -side bottom -fill x -pady 10 -padx 10

        labelframe $w.source -text {Source Branches}
        set w_list $w.source.l
        listbox $w_list \
                -height 10 \
                -width 70 \
                -font font_diff \
                -selectmode extended \
                -yscrollcommand [list $w.source.sby set]
        scrollbar $w.source.sby -command [list $w_list yview]
        pack $w.source.sby -side right -fill y
        pack $w_list -side left -fill both -expand 1
        pack $w.source -fill both -expand 1 -pady 5 -padx 5

        foreach ref $list {
                set n [lindex $ref 0]
                if {[string length $n] > 20} {
                        set n "[string range $n 0 16]..."
                }
                $w_list insert end [format {%s %-20s %s} \
                        [string range [lindex $ref 1] 0 5] \
                        $n \
                        $subj([lindex $ref 0])]
        }

        bind $w_list <Key-K> [list event generate %W <Shift-Key-Up>]
        bind $w_list <Key-J> [list event generate %W <Shift-Key-Down>]
        bind $w_list <Key-k> [list event generate %W <Key-Up>]
        bind $w_list <Key-j> [list event generate %W <Key-Down>]
        bind $w_list <Key-h> [list event generate %W <Key-Left>]
        bind $w_list <Key-l> [list event generate %W <Key-Right>]
        bind $w_list <Key-v> $_visualize

        bind $w <$M1B-Key-Return> $_start
        bind $w <Visibility> [cb _visible]
        bind $w <Key-Escape> [cb _cancel]
        wm protocol $w WM_DELETE_WINDOW [cb _cancel]
        tkwait window $w
}

method _visible {} {
        grab $w
        focus $w_list
}

method _cancel {} {
        wm protocol $w WM_DELETE_WINDOW {}
        unlock_index
        destroy $w
        delete_this
}

}

namespace eval merge {

proc reset_hard {} {
        global HEAD commit_type file_states

        if {[string match amend* $commit_type]} {
                info_popup {Cannot abort while amending.

You must finish amending this commit.
}
                return
        }

        if {![lock_index abort]} return

        if {[string match *merge* $commit_type]} {
                set op merge
        } else {
                set op commit
        }

        if {[ask_popup "Abort $op?

Aborting the current $op will cause *ALL* uncommitted changes to be lost.

Continue with aborting the current $op?"] eq {yes}} {
                set fd [git_read read-tree --reset -u HEAD]
                fconfigure $fd -blocking 0 -translation binary
                fileevent $fd readable [namespace code [list _reset_wait $fd]]
                ui_status {Aborting... please wait...}
        } else {
                unlock_index
        }
}

proc _reset_wait {fd} {
        global ui_comm

        read $fd
        if {[eof $fd]} {
                close $fd
                unlock_index

                $ui_comm delete 0.0 end
                $ui_comm edit modified false

                catch {file delete [gitdir MERGE_HEAD]}
                catch {file delete [gitdir rr-cache MERGE_RR]}
                catch {file delete [gitdir SQUASH_MSG]}
                catch {file delete [gitdir MERGE_MSG]}
                catch {file delete [gitdir GITGUI_MSG]}

                rescan {ui_status {Abort completed.  Ready.}}
        }
}

}