oneoff: a utility for managing exploratory project dirs

oneoff.sh

#!/bin/bash
#
# oneoff: a utility for managing exploratory project dirs
#
# This exists because I needed something to fill the gap between `mkdir
# ~/Projects/some-project` and `mktemp -d`.
#
# I got tired of having to think of a name as the very first step every time I
# wanted to kick some code around, and as `~/tmp` began to fill up with `foo`
# and `asdf` dirs I realized something had to change or I'd lose it.
#
# With oneoff, the workflow becomes:
#
#   .oO( inspiration! )
#
#   [me@home ~]$ oneoff new 'tinkering with some new library'
#   [me@home ~/Projects/oneoffs/pikidono]$
#
#   .oO( hack hack hack... )
#
#   ~ several days later ~
#
#   [me@home ~]$ oneoff ls
#   #  ID        CREATED AT                 DESCRIPTION
#   1  butonoba  2019-05-29T10:01:48-07:00  xml parsing
#   2  moyohuse  2019-06-01T13:30:10-07:00  neural networks
#   3  pikidono  2019-06-03T22:27:17-07:00  tinkering with some new library
#
#   [me@home ~]$ oneoff cd 3  # or pikidono
#
#   .oO( hack hack hack )
#   .oO( ... hey, this thing looks like it might actually pan out! )
#
#   [me@home ~/Projects/oneoffs/pikidono]$ oneoff promote
#   enter project name: librarian
#
#   [me@home ~/Projects/librarian]$ cat README.md
#   # librarian
#   tinkering with some new library
#
# Pretty cool!
#
# /!\ FYI: Requires jq
# /!\ FYI: Source this file in your shell profile
# (i) Tip: alias oo='oneoff'. It's quick to type and it's also the sound one
#     might make when one has a cool idea.

#############################################################################
# Config

# Location of oneoffs directory
ONEOFF_HOME="${ONEOFF_HOME:-${XDG_DATA_HOME:-$HOME/.local/share}/oneoffs}"

# Name of per-oneoff metadata file
ONEOFF_FILE="${ONEOFF_FILE:-.oneoff.json}"

# Location of "real" project directory
PROJECT_HOME="${PROJECT_HOME:-$HOME/src}"

#############################################################################
# Internal helpers

# Generate a short string of lowercase chars (just for aesthetics)
# Hat tip to @cincodenada for the "pronounceable-ish" implementation
function _oneoff_generate_id() {
    paste \
        <(tr -dc 'a-z' < /dev/urandom | tr -d 'aeiou' | fold -w1) \
        <(tr -dc 'aeiou' < /dev/urandom | fold -w1) \
    | head -n4 | tr -d '\t\n'
}

# Given an ID or an index, return the path for the matching oneoff directory
function _oneoff_resolve_dir() {
    local id_or_index=$1

    if [ -z "${id_or_index}" ]; then
        local dir="$(pwd)"
    else
        if [[ "${id_or_index}" =~ ^[0-9]+$ ]]; then
            # It's an index! Convert it to an id
            id_or_index=$(sed "${id_or_index}q;d" <(ls "${ONEOFF_HOME}") 2>/dev/null)
            if [ -z "${id_or_index}" ]; then
                # Uh, but wait, it's not a valid index
                >&2 echo 'error: index does not match any oneoffs'
                return 1
            fi
        fi
        local dir="${ONEOFF_HOME}/${id_or_index}"
    fi

    if [ ! -e "${dir}/${ONEOFF_FILE}" ]; then
        >&2 echo "error: target dir isn't a oneoff"
        return 1
    fi

    echo "${dir}"
}


#############################################################################
# Commands

# Change to a oneoff's directory
function oneoff_cd() {
    local dir="$(_oneoff_resolve_dir "$1")"
    [ $? -eq 0 -a -n "${dir}" ] || return 1

    cd "${dir}"
}

# Print metadata for a oneoff
function oneoff_info() {
    local dir="$(_oneoff_resolve_dir "$1")"
    [ $? -eq 0 -a -n "${dir}" ] || return 1

    cat "${dir}/${ONEOFF_FILE}"
}

# List oneoffs
function oneoff_ls() {
    local index=1
    (
        echo '#|ID|CREATED AT|DESCRIPTION'
        for dir in ${ONEOFF_HOME}/*/; do
            echo -n $index
            echo -n '|'
            echo -n "$(basename ${dir})"
            echo -n '|'
            jq -r '"\(.createdAt)|\(.description)"' < "${dir}${ONEOFF_FILE}"
            index=$((index + 1))
        done
    ) 2>/dev/null | column -t -s '|'
}

# Create a oneoff
function oneoff_new() {
    local description=$1
    local id=$(_oneoff_generate_id)
    local dir="${ONEOFF_HOME}/${id}"
    mkdir -p "${dir}"
    cd "${dir}"
    jq -rn '{
        createdAt: $createdAt,
        description: $description
    }' \
        --arg description "${description}" \
        --arg createdAt "$(date --iso-8601=seconds)" \
        > "${ONEOFF_FILE}"
    git init
}

# Promote a oneoff to a real project
function oneoff_promote() {
    local dir="$(_oneoff_resolve_dir "$1")"
    [ $? -eq 0 ] || return 1

    local name=$2

    if [ -z "${name}" ]; then
        # Prompt if not provided
        # Weird, but allows promotion of cwd
        echo -n 'enter project name: '
        read -r name
    fi

    if [ -z "${name}" ]; then
        >&2 echo "error: missing project NAME"
        return 1
    fi

    local project_dir="${PROJECT_HOME}/${name}"

    if ! mkdir -p "${project_dir}"; then
        >&2 echo "error: couldn't promote to that project name (is it taken?)"
        return 1
    fi

    # We're going to move the whole oneoff dir
    rmdir "${project_dir}"

    # Possibly generate a README.md from oneoff metadata
    if [ ! -e "${dir}/README.md" ]; then
        cat <<EOF > README.md
# ${name}

$(jq -r .description < "${dir}/${ONEOFF_FILE}")
EOF
    fi

    mv "${dir}" "${project_dir}"
    cd "${project_dir}"
}

# Delete a oneoff
function oneoff_rm() {
    local dir="$(_oneoff_resolve_dir "$1")"
    [ $? -eq 0 -a -n "${dir}" ] || return 1

    # A visual hint, since we're about to delete this sucker
    echo "${dir}"

    rm -rfI "${dir}" && cd "${HOME}"
}

# Prints usage documentation
function oneoff_usage() {
    echo "Usage: oneoff [-h] COMMAND"
    echo "Manage exploratory project directories."
    echo
    echo "Commands:"
    echo "  cd [ID|INDEX]              Change to a oneoff's directory"
    echo "  info [ID|INDEX]            Print metadata for a oneoff"
    echo "  ls                         List oneoffs"
    echo "  new [DESC]                 Create a oneoff"
    echo "  promote [ID|INDEX] [NAME]  Promote a oneoff to a real project"
    echo "  rm [ID|INDEX]              Delete a oneoff"
    echo
    echo "Options: "
    echo "  -h      Show this usage message and exit"
}

#############################################################################
# Main

function oneoff() {
    while getopts ":h" opt; do
        case "${opt}" in
            h) oneoff_usage && return 0 ;;
            \?) oneoff_usage >&2 && return 1 ;;
        esac
    done

    shift $((OPTIND -1))

    cmd=$1

    [ -z "${cmd}" ] && oneoff_usage && return 0

    shift

    case "${cmd}" in
        cd) oneoff_cd "$@" ;;
        info) oneoff_info "$@" ;;
        ls) oneoff_ls ;;
        new) oneoff_new "$@" ;;
        promote) oneoff_promote "$@" ;;
        rm) oneoff_rm "$@" ;;
        *) oneoff_usage >&2 && return 1 ;;
    esac
}