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

class merge {

field w         ; # top level window
field w_rev     ; # mega-widget to pick the revision to merge

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 _rev {} {
        if {[catch {$w_rev commit_or_die}]} {
                return {}
        }
        return [$w_rev get]
}

method _visualize {} {
        set rev [_rev $this]
        if {$rev ne {}} {
                do_gitk [list $rev --not HEAD]
        }
}

method _start {} {
        global HEAD current_branch remote_url

        set name [_rev $this]
        if {$name eq {}} {
                return
        }

        set spec [$w_rev get_tracking_branch]
        set cmit [$w_rev get_commit]
        set cmd [list git]
        lappend cmd merge
        lappend cmd --strategy=recursive

        set fh [open [gitdir FETCH_HEAD] w]
        fconfigure $fh -translation lf
        if {$spec eq {}} {
                set remote .
                set branch $name
                set stitle $branch
        } else {
                set remote $remote_url([lindex $spec 1])
                set branch [lindex $spec 2]
                set stitle "$branch of $remote"
        }
        regsub ^refs/heads/ $branch {} branch
        puts $fh "$cmit\t\tbranch '$branch' of $remote"
        close $fh

        lappend cmd [git fmt-merge-msg <[gitdir FETCH_HEAD]]
        lappend cmd HEAD
        lappend cmd $cmit

        set msg "Merging $current_branch and $stitle"
        ui_status "$msg..."
        set cons [console::new "Merge" "merge $stitle"]
        console::exec $cons $cmd [cb _finish $cons]

        wm protocol $w WM_DELETE_WINDOW {}
        destroy $w
}

method _finish {cons ok} {
        console::done $cons $ok
        if {$ok} {
                set msg {Merge completed successfully.}
        } else {
                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
        }

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

        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 [cb _visualize]
        pack $w.buttons.visualize -side left
        button $w.buttons.merge \
                -text Merge \
                -command $_start
        pack $w.buttons.merge -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

        set w_rev [::choose_rev::new_unmerged $w.rev {Revision To Merge}]
        pack $w.rev -anchor nw -fill both -expand 1 -pady 5 -padx 5

        bind $w <$M1B-Key-Return> $_start
        bind $w <Key-Return> $_start
        bind $w <Key-Escape> [cb _cancel]
        wm protocol $w WM_DELETE_WINDOW [cb _cancel]

        bind $w.buttons.merge <Visibility> [cb _visible]
        tkwait window $w
}

method _visible {} {
        grab $w
        if {[is_config_true gui.matchtrackingbranch]} {
                $w_rev pick_tracking_branch
        }
        $w_rev focus_filter
}

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.}}
        }
}

}