# git-gui branch (create/delete) support
# Copyright (C) 2006, 2007 Shawn Pearce

proc load_all_heads {} {
        global all_heads

        set all_heads [list]
        set fd [open "| git for-each-ref --format=%(refname) refs/heads" r]
        while {[gets $fd line] > 0} {
                if {[is_tracking_branch $line]} continue
                if {![regsub ^refs/heads/ $line {} name]} continue
                lappend all_heads $name
        }
        close $fd

        set all_heads [lsort $all_heads]
}

proc load_all_tags {} {
        set all_tags [list]
        set fd [open "| git for-each-ref --format=%(refname) refs/tags" r]
        while {[gets $fd line] > 0} {
                if {![regsub ^refs/tags/ $line {} name]} continue
                lappend all_tags $name
        }
        close $fd

        return [lsort $all_tags]
}

proc populate_branch_menu {} {
        global all_heads disable_on_lock

        set m .mbar.branch
        set last [$m index last]
        for {set i 0} {$i <= $last} {incr i} {
                if {[$m type $i] eq {separator}} {
                        $m delete $i last
                        set new_dol [list]
                        foreach a $disable_on_lock {
                                if {[lindex $a 0] ne $m || [lindex $a 2] < $i} {
                                        lappend new_dol $a
                                }
                        }
                        set disable_on_lock $new_dol
                        break
                }
        }

        if {$all_heads ne {}} {
                $m add separator
        }
        foreach b $all_heads {
                $m add radiobutton \
                        -label $b \
                        -command [list switch_branch $b] \
                        -variable current_branch \
                        -value $b
                lappend disable_on_lock \
                        [list $m entryconf [$m index last] -state]
        }
}

proc radio_selector {varname value args} {
        upvar #0 $varname var
        set var $value
}

proc switch_branch {new_branch} {
        global HEAD commit_type current_branch repo_config

        if {![lock_index switch]} return

        # -- Our in memory state should match the repository.
        #
        repository_state curType curHEAD curMERGE_HEAD
        if {[string match amend* $commit_type]
                && $curType eq {normal}
                && $curHEAD eq $HEAD} {
        } elseif {$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 the current branch can be changed.

The rescan will be automatically started now.
}
                unlock_index
                rescan {set ui_status_value {Ready.}}
                return
        }

        # -- Don't do a pointless switch.
        #
        if {$current_branch eq $new_branch} {
                unlock_index
                return
        }

        if {$repo_config(gui.trustmtime) eq {true}} {
                switch_branch_stage2 {} $new_branch
        } else {
                set ui_status_value {Refreshing file status...}
                set cmd [list git update-index]
                lappend cmd -q
                lappend cmd --unmerged
                lappend cmd --ignore-missing
                lappend cmd --refresh
                set fd_rf [open "| $cmd" r]
                fconfigure $fd_rf -blocking 0 -translation binary
                fileevent $fd_rf readable \
                        [list switch_branch_stage2 $fd_rf $new_branch]
        }
}

proc switch_branch_stage2 {fd_rf new_branch} {
        global ui_status_value HEAD

        if {$fd_rf ne {}} {
                read $fd_rf
                if {![eof $fd_rf]} return
                close $fd_rf
        }

        set ui_status_value "Updating working directory to '$new_branch'..."
        set cmd [list git read-tree]
        lappend cmd -m
        lappend cmd -u
        lappend cmd --exclude-per-directory=.gitignore
        lappend cmd $HEAD
        lappend cmd $new_branch
        set fd_rt [open "| $cmd" r]
        fconfigure $fd_rt -blocking 0 -translation binary
        fileevent $fd_rt readable \
                [list switch_branch_readtree_wait $fd_rt $new_branch]
}

proc switch_branch_readtree_wait {fd_rt new_branch} {
        global selected_commit_type commit_type HEAD MERGE_HEAD PARENT
        global current_branch
        global ui_comm ui_status_value

        # -- We never get interesting output on stdout; only stderr.
        #
        read $fd_rt
        fconfigure $fd_rt -blocking 1
        if {![eof $fd_rt]} {
                fconfigure $fd_rt -blocking 0
                return
        }

        # -- The working directory wasn't in sync with the index and
        #    we'd have to overwrite something to make the switch. A
        #    merge is required.
        #
        if {[catch {close $fd_rt} err]} {
                regsub {^fatal: } $err {} err
                warn_popup "File level merge required.

$err

Staying on branch '$current_branch'."
                set ui_status_value "Aborted checkout of '$new_branch' (file level merging is required)."
                unlock_index
                return
        }

        # -- Update the symbolic ref.  Core git doesn't even check for failure
        #    here, it Just Works(tm).  If it doesn't we are in some really ugly
        #    state that is difficult to recover from within git-gui.
        #
        if {[catch {git symbolic-ref HEAD "refs/heads/$new_branch"} err]} {
                error_popup "Failed to set current branch.

This working directory is only partially switched.  We successfully updated your files, but failed to update an internal Git file.

This should not have occurred.  [appname] will now close and give up.

$err"
                do_quit
                return
        }

        # -- Update our repository state.  If we were previously in amend mode
        #    we need to toss the current buffer and do a full rescan to update
        #    our file lists.  If we weren't in amend mode our file lists are
        #    accurate and we can avoid the rescan.
        #
        unlock_index
        set selected_commit_type new
        if {[string match amend* $commit_type]} {
                $ui_comm delete 0.0 end
                $ui_comm edit reset
                $ui_comm edit modified false
                rescan {set ui_status_value "Checked out branch '$current_branch'."}
        } else {
                repository_state commit_type HEAD MERGE_HEAD
                set PARENT $HEAD
                set ui_status_value "Checked out branch '$current_branch'."
        }
}