# git-gui merge conflict resolution
# parts based on git-mergetool (c) 2006 Theodore Y. Ts'o

proc merge_resolve_one {stage} {
        global current_diff_path

        switch -- $stage {
                1 { set target [mc "the base version"] }
                2 { set target [mc "this branch"] }
                3 { set target [mc "the other branch"] }
        }

        set op_question [mc "Force resolution to %s?
Note that the diff shows only conflicting changes.

%s will be overwritten.

This operation can be undone only by restarting the merge." \
                $target [short_path $current_diff_path]]

        if {[ask_popup $op_question] eq {yes}} {
                merge_load_stages $current_diff_path [list merge_force_stage $stage]
        }
}

proc merge_add_resolution {path} {
        global current_diff_path

        if {$path eq $current_diff_path} {
                set after {reshow_diff;}
        } else {
                set after {}
        }

        update_index \
                [mc "Adding resolution for %s" [short_path $path]] \
                [list $path] \
                [concat $after [list ui_ready]]
}

proc merge_force_stage {stage} {
        global current_diff_path merge_stages

        if {$merge_stages($stage) ne {}} {
                git checkout-index -f --stage=$stage -- $current_diff_path
        } else {
                file delete -- $current_diff_path
        }

        merge_add_resolution $current_diff_path
}

proc merge_load_stages {path cont} {
        global merge_stages_fd merge_stages merge_stages_buf

        if {[info exists merge_stages_fd]} {
                catch { kill_file_process $merge_stages_fd }
                catch { close $merge_stages_fd }
        }

        set merge_stages(0) {}
        set merge_stages(1) {}
        set merge_stages(2) {}
        set merge_stages(3) {}
        set merge_stages_buf {}

        set merge_stages_fd [eval git_read ls-files -u -z -- $path]

        fconfigure $merge_stages_fd -blocking 0 -translation binary -encoding binary
        fileevent $merge_stages_fd readable [list read_merge_stages $merge_stages_fd $cont]
}

proc read_merge_stages {fd cont} {
        global merge_stages_buf merge_stages_fd merge_stages

        append merge_stages_buf [read $fd]
        set pck [split $merge_stages_buf "\0"]
        set merge_stages_buf [lindex $pck end]

        if {[eof $fd] && $merge_stages_buf ne {}} {
                lappend pck {}
                set merge_stages_buf {}
        }

        foreach p [lrange $pck 0 end-1] {
                set fcols [split $p "\t"]
                set cols  [split [lindex $fcols 0] " "]
                set stage [lindex $cols 2]
                
                set merge_stages($stage) [lrange $cols 0 1]
        }

        if {[eof $fd]} {
                close $fd
                unset merge_stages_fd
                eval $cont
        }
}