zit with command

[zit] / zit

#!/bin/bash

abort() {
        echo $1
        exit 1
}

cmd="$1"
shift

USAGE="usage: zit COMMAND FILE [ARGS...]"

zit_help() {
        cmd="$1"
        shift
        case $cmd in
                git)
                git help "$@"
                ;;
                list|tracked)
                echo "usage: zit list"
                echo "Show tracked files, with a one-letter prefix indicating their status:"
                echo "   H   cached"
                echo "   M   unmerged"
                echo "   R   removed/deleted"
                echo "   C   modified/changed"
                echo "   K   to be killed"
                echo "   ?   other"
                ;;
                import)
                echo "usage: zit import FILE"
                echo "Import history from an RCS-tracked file. Requires rcs-fast-export."
                ;;
                view)
                echo "usage: zit view FILE"
                echo "Browse FILE's history with gitk"
                ;;
                with)
                echo "usage: zit with FILE COMMAND..."
                echo "Run COMMAND after setting up the git environment for FILE."
                ;;
                *)
                echo $USAGE
                echo ""
                echo "Set up a git repository under .zit.FILE to track changes for FILE."
                echo "File must be a regular file and in the current directory."
                echo ""
                echo "Zit commands:"
                echo "   import Import RCS history for FILE"
                echo "   init           Synonym for track"
                echo "   list           Synonym for tracked"
                echo "   track  Start tracking changes to FILE"
                echo "   tracked        List tracked files in current directory"
                echo "   view           Browse FILE's history with gitk"
                echo "   with           Run a command in FILE's context"
                echo ""
                echo "See 'zit help git' or 'git help' for git commands."
                ;;
        esac
}

ZIT_DIR=.zit

zit_setup() {
        ZIT_FILE="$1"
        test $ZIT_FILE || abort "Please specify a file"
        test -f $ZIT_FILE || abort "No such file $ZIT_FILE"
        test $ZIT_FILE = "`basename $ZIT_FILE`" || abort "Sorry, Zit only works on files in the current directory"

        export GIT_WORK_TREE="`pwd`"

        # first, check if a repo exists already, looking for
        # .zit/file.git or .file.git, in that order
        # if neither is found, and .zit exists, set the repo dir
        # to .zit/file.git, otherwise set it to .file.git
        GIT_DIR="$ZIT_DIR/$ZIT_FILE.git"
        if ! test -d "$GIT_DIR"; then
                GIT_DIR=".$ZIT_FILE.git"
                if ! test -d "$GIT_DIR"; then
                        test -d "$ZIT_DIR" && GIT_DIR="$ZIT_DIR/$ZIT_FILE.git"
                fi
        fi
        export GIT_DIR
}

# initialize the zitdir, without actually making the first commit
zitdir_init() {
        zit_setup $1
        test -e $GIT_DIR && abort "$GIT_DIR exists, is $ZIT_FILE tracked already?"
        mkdir $GIT_DIR && echo "Initializing Zit repository in $GIT_DIR"
        test -d $GIT_DIR || abort "Failed to create $GIT_DIR"
        git init || abort "Failed to initialize Git repository in $GIT_DIR"
        rm -rf $GIT_DIR/{hooks,info,branches,refs/tags,objects/pack,description}
        if test -d "$ZIT_DIR"; then
                ZIT_EXCLUDE="$ZIT_DIR/exclude"
        else
                ZIT_EXCLUDE="$GIT_DIR/exclude"
        fi
        if ! test -f "$ZIT_EXCLUDE"; then
                touch "$ZIT_EXCLUDE" || abort "Cannot create $ZIT_EXCLUDE file"
                echo "# Ignore patterns used by Zit repositories in the parent worktree." > "$ZIT_EXCLUDE"
                echo "# By default it's the single '*' glob, since we want to ignore all" >> "$ZIT_EXCLUDE"
                echo "# non-tracked files in the work-tree." >> "$ZIT_EXCLUDE"
                echo "# This file is autogenerated and there's usually no need to edit it." >> "$ZIT_EXCLUDE"
                echo "*" >> "$ZIT_EXCLUDE"
        fi
        git config core.excludesfile "$ZIT_EXCLUDE"
}

zit_init() {
        if test "$1"; then
                zitdir_init "$1"
                git add -f $ZIT_FILE || abort "Failed to add $ZIT_FILE"
                git commit "$@" || abort "Failed to make first commit for $ZIT_FILE"
        else
                if test -d "$ZIT_DIR"; then
                        echo "$ZIT_DIR exists already"
                        exit
                fi
                test -e $ZIT_DIR && abort "$ZIT_DIR exists but it's not a directory, cannot continue"
                mkdir $ZIT_DIR
        fi
}

zit_list() {
        export GIT_WORK_TREE="`pwd`"
        GIT_DIR=""
        for file in "$ZIT_DIR"/*.git .*.git; do
                if ! test -e $file; then
                        continue
                fi
                export GIT_DIR="$file"
                file="${file#.}"
                file="${file#zit/}"
                file="${file%.git}"
                (git ls-files -m -d -t; git ls-files -t) | uniq -f 1
        done;
        # if $GIT_DIR is empty, no files were found
        test "$GIT_DIR" || echo "(no files tracked by zit)"
}

# import an RCS-tracked file using rcs-fast-export, if found
zit_import() {
        which rcs-fast-export || abort "rcs-fast-export not found, I can't import RCS-tracked files, sorry"
        zitdir_init $1
        # git-fast-import creates a pack file, so (re)build the objects/pack dir
        mkdir -p $GIT_DIR/objects/pack
        rcs-fast-export $1 | git-fast-import
        # for some reason, rcs-fast-export | git-fast-import leaves the original
        # file in 'deleted' state, a situation which is easily fixed by adding
        # it back
        git add -f $1
}

case $cmd in
        "")
        echo $USAGE
        ;;
        help)
        zit_help "$@"
        ;;
        init|track)
        zit_init $1
        ;;
        list|tracked)
        zit_list
        ;;
        import)
        zit_import $1
        ;;
        view)
        zit_setup $1
        shift
        gitk "$@"
        ;;
        with)
        zit_setup $1
        shift
        "$@"
        ;;
        # Most commands will work with the generic catch-all mechanism used
        # below, but some of them require a more thorough analysis of the
        # parameters to decide whether $ZIT_FILE should be put back into the
        # parameter list or not. For example,
        # $ zit commit somefile
        # wouldn't do what one expects it to do, unless 'add' is run first,
        # (except that
        # $ zit add somefile
        # wouldn't work either), however
        # $ zit commit somefile -a
        # would work correctly. So we handle some commands separately (for the
        # moment just add and commit)
        add|commit)
        zit_setup $1
        shift
        git $cmd "$@" "$ZIT_FILE"
        ;;
        # the raw<command> method can be used to not replicate $ZIT_FILE in the
        # parameter list
        raw*)
        zit_setup $1
        shift
        git ${cmd#raw} "$@"
        ;;
        *)
        zit_setup $1
        shift
        git $cmd "$@"
        ;;
esac