install

#!/bin/sh
INSTALL_DIR="${HOME}/.shell"
BACKUP_DIR="${INSTALL_DIR}/backup"
TARBALL_URL='https://api.github.com/repos/djlambert/shell-profile/tarball/master'
TARBALL_FILE=".shell-profile_${RANDOM}${RANDOM}.tgz"
PATH_FILE_BASE='paths.local'
PATH_FILE_LEGACY="${INSTALL_DIR}/${PATH_FILE_BASE}"
PATH_FILE_PREPEND="${PATH_FILE_LEGACY}.prepend"
VAR_FILE_LOCAL="${INSTALL_DIR}/vars.local"
BOOTSTRAP_FILES='profile bashrc zprofile'
INSTALL_FILES='dir_colors vimrc'
INSTALL_FORCE=0
INSTALL_LOCAL=0
INSTALL_EXISTING=0
INSTALL_SAVE_PATH=1
TIMESTAMP=$(date +%Y%m%d%H%M%S)
DEBUG=1
RESULT=0

cancel() {
    printf 'Cancelling...\n'
}

ioOpen() {
    exec 3>/dev/null
    exec 4>/dev/null
}

ioClose() {
    3>&-
    4>&-
}

ioCopyStd() {
    exec 3>&1
    exec 4>&2
}

checkDebug() {
    if [ $((${DEBUG:-0})) -eq 1 ]; then
        ioCopyStd

        printf 'Debugging enabled\n'
    fi
}

ioCloseAndExit() {
    LAST_RESULT=$?

    if [ -z $RESULT ]; then
        RESULT=$LAST_RESULT
    fi

    ioClose

    exit $RESULT
}

findSetting() {
    if [ ! -f "${2}" ]; then
        return 0
    fi

    while read -r LINE; do
        if expr "${LINE}" : "${1}=" >/dev/null; then
            MATCH="${LINE}"
        fi
    done < "${2}"

    if [ -n "${MATCH}" ]; then
        echo "${MATCH}"
        return 1
    else
        return 0
    fi
}

cleanUp() {
    RESULT=$?

    if [ $RESULT -ne 0 ] && [ ${INSTALL_EXISTING:-0} -ne 1 ]; then
        printf 'Cleaning up...\n'

        if [ -d "${INSTALL_DIR}" ]; then
            printf 'Removing install directory\n'
            rm -rf "${INSTALL_DIR}" 1>&3 2>&4
        fi
    fi

    if [ -f "${TARBALL_FILE}" ]; then
        printf 'Removing tarball\n'
        rm "${TARBALL_FILE}"
    fi

    ioCloseAndExit
}

trap cancel INT

ioOpen

# Set exit handler
trap ioCloseAndExit TERM EXIT

checkDebug

# Process command line options
while getopts i:flp opt; do
    case $opt in
        i) INSTALL_DIR="${OPTARG}";; # Specify install directory
        f) INSTALL_FORCE=1;;         # Force install over existing files
        l) INSTALL_LOCAL=1;;         # Use current directory as install source
        p) INSTALL_SAVE_PATH=0;;     # Save existing $PATH
        ?)
            printf 'Usage: %s: [-f][-l][-p][-i install dir]\n' "$0"
            exit 2
            ;;
    esac
done

# Create install directory
# Exit with error on failure or directory exists and not force install
if [ -d "${INSTALL_DIR}" ]; then
    if [ ${INSTALL_FORCE:-0} -ne 1 ]; then
        printf "Aborting install, directory %s already exists\n" "${INSTALL_DIR}"
        exit 1
    else
        INSTALL_EXISTING=1
        printf 'Installing over existing files in %s\n' "${INSTALL_DIR}"
    fi
else
    if ! mkdir "${INSTALL_DIR}" 1>&3 2>&4; then
        printf 'Aborting install, error creating directory %s\n' "${INSTALL_DIR}"
        exit 1
    fi
fi

# Set exit handler
# Changes may now have been made
trap cleanUp TERM EXIT

# Create backup directory
# Continue if exists (force install)
# Exit with error on failure
if [ ! -d "${BACKUP_DIR}" ]; then
    mkdir "${BACKUP_DIR}" 1>&3 2>&4

    if [ $? -ne 0 ]; then
        printf 'Aborting install, error creating backup directory %s\n' "${INSTALL_DIR}"
        exit 1
    fi
fi

# Determine tar executable
if [ "$(uname)" = 'SunOS' ]; then
    printf 'Detected SunOS\n'
    TAR_CMD="gtar"
else
    TAR_CMD="tar"
fi

# Download package files
# Continue on local install source
if [ ${INSTALL_LOCAL:-0} -ne 1 ]; then
    printf 'Downloading package files...\n'

    if command -v wget >/dev/null 2>&1; then
        getCommand="wget --no-verbose --no-check-certificate --output-document=${TARBALL_FILE} ${TARBALL_URL}"
    elif command -v curl >/dev/null 2>&1; then
        getCommand="curl --silent --fail --insecure --location --output ${TARBALL_FILE} ${TARBALL_URL}"
    else
        printf 'Aborting install, wget or curl not found\n'
        exit 1
    fi

    if ! ${getCommand} 2>&4; then
        printf 'Aborting install, error downloading installation files\n'
        exit 1
    fi

    if ! ${TAR_CMD} -xzC "${INSTALL_DIR}" --strip-components=1 -f "${TARBALL_FILE}" 1>&3 2>&4; then
        printf 'Aborting install, error extracting installation files\n'
        exit 1
    fi
else
    printf 'Installing from local source\n'
    cp ./* "${INSTALL_DIR}"
fi

# Install bootstrap files
# Create backup if non-bootstrap exists
for basename in $BOOTSTRAP_FILES; do
    filename=".${basename}"
    destFile="${HOME}/${filename}"
    bakFile="${BACKUP_DIR}/${basename}.${TIMESTAMP}"

    if [ -f "${destFile}" ] && ! grep -q 'shell-profile-bootstrap' "${destFile}"; then
        printf 'Saving %s to %s\n' "${destFile}" "${bakFile}"
        mv "${destFile}" "${bakFile}" 1>&3 2>&4
    fi

    printf 'Bootstrapping %s\n' "${basename}"

    sed "s|##INSTALL##|$INSTALL_DIR|;s|##SCRIPT##|${basename}|" "${INSTALL_DIR}/bootstrap" > "${destFile}"
done

# Copy additional files
# Create backup if not package file
# TODO error handling
for basename in $INSTALL_FILES; do
    # TODO track file operations to allow for error recovery in cleanup
    filename=".${basename}"
    destFile="${HOME}/${filename}"
    bakFile="${BACKUP_DIR}/${basename}.${TIMESTAMP}"

    if [ -f "${destFile}" ] && ! grep -q 'shell-profile-bootstrap' "${destFile}"; then
        printf 'Saving %s to %s\n' "${destFile}" "${bakFile}"
        mv "${destFile}" "${bakFile}" 1>&3 2>&4
    fi

    printf 'Installing %s\n' "${basename}"

    cp "${INSTALL_DIR}/${basename}" "${destFile}"
done

# Migrate old paths.local file
if [ -f "${PATH_FILE_LEGACY}" ]; then
    bakFile="${BACKUP_DIR}/${PATH_FILE_BASE}.${TIMESTAMP}"
    printf 'Moving legacy paths from %s to %s\n' "${PATH_FILE_LEGACY}" "${PATH_FILE_PREPEND}"
    cat "${PATH_FILE_LEGACY}" >> "${PATH_FILE_PREPEND}"
    printf 'Moving legacy paths file to %s\n' "${bakFile}"
    mv "${PATH_FILE_LEGACY}" "${bakFile}"
fi

if [ "${INSTALL_SAVE_PATH}" -ne 1 ]; then
    printf 'Skipping saving existing path\n'
else
    findSetting 'PATH' "${VAR_FILE_LOCAL}" >/dev/null

    if [ $? -ne 0 ]; then
        printf 'PATH already in %s\n' "${VAR_FILE_LOCAL}"
    else
        printf 'Saving current path in %s\n' "${VAR_FILE_LOCAL}"
        printf 'PATH=%s\n' "${PATH}" >> "${VAR_FILE_LOCAL}"
    fi
fi
# vim: syntax=sh:ts=4:sw=4