Introduce `vcsh enter`

[code/vcsh.git] / vcsh

#!/bin/sh

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

SELF=$(basename $0)
if [ "$SELF" = 'bash' ] ||
   [ "$SELF" = 'dash' ] ||
   [ "$SELF" = 'sh' ] ||
   [ "$SELF" = 'zsh' ]; then
        SELF='vcsh'
        VCSH_SOURCED=1
fi


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
   exit                 Exit repository; unset ENV
   init <repo>          Initialize a new repository
   list                 List all repositories
   run <repo> \\
       <command>        Use this repository

   seed-gitignore \\
   <repo>               Seed .gitignore.d/<repo> from git ls-files
   use <repo>           Use repository; set ENV

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

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

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

use() {
        verbose "use() begin"
        if [ ! -d "$GIT_DIR" ]; then
                echo E: no repository found for "$VCSH_REPO_NAME" >&2
                return 1
        fi
        export GIT_DIR
        export GIT_WORK_TREE="$(git config --get core.worktree)"
        export VCSH_DIRECTORY="$VCSH_REPO_NAME"
        verbose "use() end"
}

init() {
        verbose "init() begin"
        [ -e "$GIT_DIR" ] &&
                echo "$SELF: fatal: $GIT_DIR exists" &&
                return 21
        export GIT_WORK_TREE="$HOME"
        mkdir -p "$GIT_WORK_TREE"
        cd "$GIT_WORK_TREE" ||
                (echo "$SELF: fatal: could not enter $GIT_WORK_TREE" &&
                 return 1) || return $?
        cd "$GIT_WORK_TREE"
        git init
        git config core.worktree     "$GIT_WORK_TREE"
        git config core.excludesfile ".gitignore.d/$VCSH_REPO_NAME"
        touch   "$HOME/.gitignore.d/$VCSH_REPO_NAME"
        git add "$HOME/.gitignore.d/$VCSH_REPO_NAME"
        verbose "init() end"
}

leave() {
        unset GIT_DIR
        unset GIT_WORK_TREE
        unset VCSH_DIRECTORY
}


if [ "$1" = 'clone' ]; then
        GIT_REMOTE="$2"
        export GIT_REMOTE
        VCSH_REPO_NAME="$3"
        [ -z "$VCSH_REPO_NAME" ] && 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" = 'run' ] ||
     [ "$1" = 'seed-gitignore' ] ||
     [ "$1" = 'use' ]; then
        [ -z $2 ] && echo "$SELF $1: error: please specify repository to work on" && return 1
        export VCSH_COMMAND="$1"
        export VCSH_REPO_NAME="$2"
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        shift 2
        export VCSH_EXTERNAL_COMMAND="$*"
        if [ "$VCSH_COMMAND" = 'run' ]; then
                [ -z "$VCSH_EXTERNAL_COMMAND" ] && echo "$SELF $1 $2: error: please specify a command" && return 1
        fi
elif [ "$1" = 'exit' ] ||
     [ "$1" = 'help' ] ||
     [ "$1" = 'list' ]; then
        export VCSH_COMMAND="$1"
else
        [ -z $1 ] && help && return 0
        export VCSH_COMMAND='run'
        export VCSH_REPO_NAME="$1"
        export GIT_DIR="$VCSH_BASE/$VCSH_REPO_NAME.git"
        [ -d $GIT_DIR ] || (help && return 1) || return 0
        shift 1
        export VCSH_EXTERNAL_COMMAND="git $*"
fi


for check_directory in "$VCSH_BASE" "$HOME/.gitignore.d"
do
        if [ ! -d "$check_directory" ]; then
                if [ -e "$check_directory" ]; then
                        echo "$SELF: error: $check_directory exists but is not a directory" >&2
                        return 2
                else
                        echo "$SELF: info: attempting to create $check_directory"
                        mkdir -p "$check_directory" || (echo "$SELF: error: could not create $check_directory" >&2; return 2) || return $?
                fi
        fi
done


if [ "$VCSH_COMMAND" = 'clone' ]; then
        verbose "clone begin"
        init
        git remote add origin "$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" ] &&
                        echo "$SELF: error: $object exists." &&
                        VCSH_CONFLICT=1;
        done
        [ "$VCSH_CONFLICT" = '1' ] &&
                echo "$SELF: fatal: will stop after fetching and not try to merge!\n" &&
                echo "  Once this situation has been resolved, run 'vcsh run <foo> git pull' to finish cloning.\n" &&
                return 3
        git merge origin/master
#       use || return $?
        verbose "clone end"

#elif [ "$VCSH_COMMAND" = 'help' ] || [ "$#" -eq 0 ]; then
elif [ "$VCSH_COMMAND" = 'help' ]; then
        help

elif [ "$VCSH_COMMAND" = 'delete' ]; then
        verbose "delete begin"
        old_dir="$PWD"
        cd "$HOME"
        use || return $?
        echo "$SELF: 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" ] || return 1
        for file in $files; do
                rm -f $file || echo "$SELF: info: could not delete '$file', continuing with deletion"
        done
        rm -rf "$GIT_DIR" || echo "$SELF: info: could not delete '$GIT_DIR'"
        cd "$old_dir"
        verbose "delete end"

elif [ "$VCSH_COMMAND" = 'enter' ]; then
        verbose "enter begin"
        use || return $?
        $SHELL
        leave
        verbose "enter end"

elif [ "$VCSH_COMMAND" = 'exit' ]; then
        verbose "exit begin"
#       if [ -n "$ZSH_VERSION" ] && [ "$VCSH_NO_IGNORE_EOF" = '1' ]; then
#               unset VCSH_NO_IGNORE_EOF
#               setopt NO_IGNORE_EOF
#       fi
        [ -z "$VCSH_SOURCED" ] && echo "$SELF $VCSH_COMMAND: You need to source vcsh if you want to run in this mode" && return 10
        leave
#       [ -n "$ZSH_VERSION" ] && [ "$USER" = richih ] && buildPS1
        verbose "exit end"
        return 0

elif [ "$VCSH_COMMAND" = 'init' ]; then
        verbose "init begin"
        init
#       use || return $?
        verbose "init end"

elif [ "$VCSH_COMMAND" = 'list' ]; then
        verbose "list begin"
        for i in "$VCSH_BASE"/*.git; do
                echo $(basename "$i" .git)
        done
        verbose "list end"

elif [ "$VCSH_COMMAND" = 'run' ]; then
        verbose "run begin"
        use || return $?
        $VCSH_EXTERNAL_COMMAND
        leave
        verbose "run end"

elif [ "$VCSH_COMMAND" = 'seed-gitignore' ]; then
        verbose "seed-gitignore begin"
        use || return $?
        # Switching directory as this has to be executed from $HOME to be of any use.
        # Going back into old directory at the end in case `vcsh use` is reactivated.
        old_dir="$PWD"
        cd "$HOME"
        git config core.excludesfile ".gitignore.d/$VCSH_REPO_NAME"
        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) ||
                (echo "$SELF: fatal: could not create tempfile" && return 1) || return $?
        echo '*' > "$tempfile"
        for gitignore in $gitignores; do
                echo "$gitignore" | sed 's/^/!/' >> "$tempfile"
                [ -d "$gitignore" ] && echo "$gitignore/*" | sed 's/^/!/'>> "$tempfile"
        done
        diff -N "$tempfile" "$HOME/.gitignore.d/$VCSH_REPO_NAME" > /dev/null &&
                rm -f "$tempfile" &&
                return
        if [ -e "$HOME/.gitignore.d/$VCSH_REPO_NAME" ]; then
                echo "$SELF: 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" ||
                        (echo "$SELF: fatal: could not move $HOME/.gitignore.d/$VCSH_REPO_NAME to $HOME/.gitignore.d/$VCSH_REPO_NAME.bak" &&
                         return 1) || return $?
        fi
        mv -f "$tempfile" "$HOME/.gitignore.d/$VCSH_REPO_NAME" ||
                (echo "$SELF: fatal: could not move $tempfile to $HOME/.gitignore.d/$VCSH_REPO_NAME" && return 1) || return $?
        cd "$old_dir"
        verbose "seed-gitignore end"

elif [ "$VCSH_COMMAND" = 'use' ]; then
        verbose "use begin"
#       if [ -n "$ZSH_VERSION" ]; then
#               if [ -o NO_IGNORE_EOF ]; then
#                       export VCSH_NO_IGNORE_EOF=1
#                       setopt IGNORE_EOF
#               fi
#               vcsh_exit() {
#                       vcsh exit;
#                       zle reset-prompt;
#               }
#               zle -N vcsh_exit
#               bindkey '^d' 'vcsh_exit'
#       fi
        [ -z "$VCSH_SOURCED" ] && echo "$SELF $VCSH_COMMAND: You need to source vcsh if you want to run in this mode" && return 10
        use || return $?
#       [ -n "$ZSH_VERSION" ] && [ "$USER" = richih ] && buildPS1
        verbose "use end"

else
        verbose "defaulting to calling help()"
        help
        echo "$SELF: fatal: You should never reach this code. File a bug, please."
        return 99

fi