[code/vcsh.git] / vcsh

#!/bin/sh

[ -n "$VCSH_DEBUG" ]      && set -vx
[ -z "$XDG_CONFIG_HOME" ] && XDG_CONFIG_HOME="$HOME/.config"
[ -z "$VCSH_BASE" ]       && VCSH_BASE="$XDG_CONFIG_HOME/vcsh/repo.d"

SELF=$(basename $0)

help() {
        echo "usage: $SELF <args>

   clone <remote> \\
         [<repo>]       Clone from an existing repository
   help                 Display this help text
   delete               Delete an existing repository
   enter                Enter repository; spawn new $SHELL
   init <repo>          Initialize a new repository
   list                 List all repositories
   list-tracked         List all files tracked by vcsh
   list-tracked-by \\
        <repo>          List files tracked by a repository
   rename <repo> \\
          <newname>     Rename repository
   run <repo> \\
       <command>        Use this repository
   setup                Set up repository with recommended settings
   write-gitignore \\
   <repo>               Write .gitignore.d/<repo> via git ls-files

   <repo> <git command> Special command that allows you to run git commands
                        directly without having to type so much ;)" >&2
   <repo>               Special command that enters a repository
}

debug() {
        [ -n "$VCSH_DEBUG" ] && echo "$SELF: debug: $@"
}

verbose() {
        if [ -n "$VCSH_DEBUG" ] || [ -n "$VCSH_VERBOSE" ]; then echo "$SELF: verbose: $@"; fi
}

fatal() {
        echo "$SELF: fatal: $1" >&2
        exit $2
}

error() {
        echo "$SELF: error: $1" >&2
}

info() {
        echo "$SELF: info: $1"
}

clone() {
        init
        git remote add origin "$GIT_REMOTE"
        git config branch.master.remote origin
        git config branch.master.merge  refs/heads/master
        git fetch
        for object in $(git ls-tree -r origin/master | awk '{print $4}'); do
                [ -e "$object" ] &&
                        error "'$object' exists." &&
                        VCSH_CONFLICT=1;
        done
        [ "$VCSH_CONFLICT" = '1' ] &&
                fatal "will stop after fetching and not try to merge!
  Once this situation has been resolved, run 'vcsh run $VCSH_REPO_NAME git pull' to finish cloning.\n" 17
        git merge origin/master
}

delete() {
        cd "$HOME" || fatal "could not enter '$HOME'" 11
        use
        info "This operation WILL DETROY DATA!"
        files=$(git ls-files)
        echo "These files will be deleted:

$files

AGAIN, THIS WILL DELETE YOUR DATA!
To continue, type \"Yes, do as I say\""
        read answer
        [ "x$answer" = "xYes, do as I say" ] || exit 16
        for file in $files; do
                rm -f $file || info "could not delete '$file', continuing with deletion"
        done
        rmdir "$GIT_DIR" || error "could not delete '$GIT_DIR'"
}

enter() {
        use
        $SHELL
}

git_dir_exists() {
        [ -d "$GIT_DIR" ] || fatal "no repository found for '$VCSH_REPO_NAME'" 12
}

init() {
        [ ! -e "$GIT_DIR" ] || fatal "'$GIT_DIR' exists" 10
        export GIT_WORK_TREE="$HOME"
        mkdir -p "$GIT_WORK_TREE" || fatal "could not create '$GIT_WORK_TREE'" 50
        cd "$GIT_WORK_TREE" || fatal "could not enter '$GIT_WORK_TREE'" 11
        git init
        setup
}

list() {
        for i in "$VCSH_BASE"/*.git; do
                echo $(basename "$i" .git)
        done
}

get_files() {
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        git ls-files
}

list_tracked() {
        for VCSH_REPO_NAME in $(list); do
                get_files
        done | sort -u
}

list_tracked_by() {
        use
        git ls-files | sort -u
}

rename() {
        git_dir_exists
        [ -d "$GIT_DIR_NEW" ] && fatal "'$GIT_DIR_NEW' exists" 54
        mv -f "$GIT_DIR" "$GIT_DIR_NEW" || fatal "Could not mv '$GIT_DIR' '$GIT_DIR_NEW'" 52

}

run() {
        use
        $VCSH_EXTERNAL_COMMAND
}

setup() {
        use
        git config core.worktree     "$GIT_WORK_TREE"
        git config core.excludesfile ".gitignore.d/$VCSH_REPO_NAME"
        git config vcsh.vcsh         'true'
        [ -e "$HOME/.gitignore.d/$VCSH_REPO_NAME" ] && git add -f "$HOME/.gitignore.d/$VCSH_REPO_NAME"
}

use() {
        git_dir_exists
        export GIT_WORK_TREE="$(git config --get core.worktree)"
        export VCSH_DIRECTORY="$VCSH_REPO_NAME"
}

write_gitignore() {
        use
        cd "$HOME" || fatal "could not enter '$HOME'" 11
        gitignores=$(for file in $(git ls-files); do
                while true; do
                        echo $file; new="${file%/*}"
                        [ "$file" = "$new" ] && break
                        file="$new"
                done;
        done | sort -u)
        tempfile=$(mktemp) || fatal "could not create tempfile" 51
        echo '*' > "$tempfile" || fatal "could not write to '$tempfile'" 57
        for gitignore in $gitignores; do
                echo "$gitignore" | sed 's/^/!/' >> "$tempfile" || fatal "could not write to '$tempfile'" 57
                [ -d "$gitignore" ] && { echo "$gitignore/*" | sed 's/^/!/' >> "$tempfile" || fatal "could not write to '$tempfile'" 57; }
        done
        if diff -N "$tempfile" "$HOME/.gitignore.d/$VCSH_REPO_NAME" > /dev/null; then
                rm -f "$tempfile" || error "could not delete '$tempfile'"
                exit
        fi
        if [ -e "$HOME/.gitignore.d/$VCSH_REPO_NAME" ]; then
                info "'$HOME/.gitignore.d/$VCSH_REPO_NAME' differs from new data, moving it to '$HOME/.gitignore.d/$VCSH_REPO_NAME.bak'"
                mv -f "$HOME/.gitignore.d/$VCSH_REPO_NAME" "$HOME/.gitignore.d/$VCSH_REPO_NAME.bak" ||
                        fatal "could not move '$HOME/.gitignore.d/$VCSH_REPO_NAME' to '$HOME/.gitignore.d/$VCSH_REPO_NAME.bak'" 53
        fi
        mv -f "$tempfile" "$HOME/.gitignore.d/$VCSH_REPO_NAME" ||
                fatal "could not move '$tempfile' to '$HOME/.gitignore.d/$VCSH_REPO_NAME'" 53
}

if [ "$1" = 'clone' ]; then
        [ -z $2 ] && fatal "$1: please specify a remote" 1
        export VCSH_COMMAND="$1"
        GIT_REMOTE="$2"
        [ -n "$3" ] && VCSH_REPO_NAME="$3" || VCSH_REPO_NAME=$(basename "$GIT_REMOTE" .git)
        export VCSH_REPO_NAME
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
elif [ "$1" = 'delete' ] ||
     [ "$1" = 'enter' ] ||
     [ "$1" = 'init' ] ||
     [ "$1" = 'list-tracked-by' ] ||
     [ "$1" = 'rename' ] ||
     [ "$1" = 'run' ] ||
     [ "$1" = 'setup' ] ||
     [ "$1" = 'write-gitignore' ]; then
        [ -z $2 ]                      && fatal "$1: please specify repository to work on" 1
        [ "$1" = 'rename' -a -z "$3" ] && fatal "$1: please specify a target name" 1
        [ "$1" = 'run' -a -z "$3" ]    && fatal "$1: please specify a command" 1
        export VCSH_COMMAND="$1"
        export VCSH_REPO_NAME="$2"
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        [ "$VCSH_COMMAND" = 'rename' ]         && export GIT_DIR_NEW="$VCSH_BASE/$3.git"
        [ "$VCSH_COMMAND" = 'run' ] && shift 2 && export VCSH_EXTERNAL_COMMAND="$*"
        [ "$VCSH_COMMAND" = 'write-gitignore' ]
elif [ "$1" = 'list' ] ||
     [ "$1" = 'list-tracked' ]; then
        export VCSH_COMMAND="$1"
elif [ -n "$1" -a -n "$2" ]; then
        export VCSH_COMMAND='run'
        export VCSH_REPO_NAME="$1"
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        [ -d $GIT_DIR ] || { help; exit 1; }
        shift 1
        export VCSH_EXTERNAL_COMMAND="git $*"
elif [ -n "$1" ]; then
        export VCSH_COMMAND='enter'
        export VCSH_REPO_NAME="$1"
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        [ -d $GIT_DIR ] || { help; exit 1; }
else
        # $1 is empty, or 'help'
        help && exit
fi

# Did we receive a directory instead of a name?
# Mangle the input to fit normal operation.
if echo $VCSH_REPO_NAME | grep -q '/'; then
        export GIT_DIR=$VCSH_REPO_NAME
        export VCSH_REPO_NAME=$(basename $VCSH_REPO_NAME .git)
fi


for check_directory in "$VCSH_BASE" "$HOME/.gitignore.d"
do
        if [ ! -d "$check_directory" ]; then
                if [ -e "$check_directory" ]; then
                        fatal "'$check_directory' exists but is not a directory" 13
                else
                        info "attempting to create '$check_directory'"
                        mkdir -p "$check_directory" || fatal "could not create '$check_directory'" 50
                fi
        fi
done

verbose "$VCSH_COMMAND begin"
export VCSH_COMMAND=$(echo $VCSH_COMMAND | sed 's/-/_/g')
$VCSH_COMMAND
verbose "$VCSH_COMMAND end, exiting"