gshell

#!/bin/bash

VERSION="1.0.0"

ensure_gcloud() {
    if ! command -v gcloud >/dev/null 2>&1; then
        echo "gcloud not found. Install Google Cloud SDK: https://cloud.google.com/sdk/docs/install"
        return 1
    fi

    # Check cloud-shell subcommand availability
    if ! gcloud alpha cloud-shell --help >/dev/null 2>&1; then
        echo "Cloud Shell 'alpha' subcommand not available."
        read -p "Install alpha components now? [y/N] " ans
        if [ "$ans" = "y" ] || [ "$ans" = "Y" ]; then
            echo "Will run: gcloud components install alpha (in background)"
            gcloud components install alpha >/dev/null 2>&1 &
            echo "Installation started in background. Re-run this command after installation completes."
        else
            echo "You can enable it with: gcloud components install alpha"
            return 1
        fi
    fi
}

get_md5_local() {
    local f="$1"
    if command -v md5sum >/dev/null 2>&1; then
        md5sum "$f" 2>/dev/null | awk '{print $1}'
    elif command -v md5 >/dev/null 2>&1; then
        md5 -q "$f" 2>/dev/null
    else
        # fallback: size:mtime
        if stat -c%s "$f" >/dev/null 2>&1; then
            printf "%s:%s" "$(stat -c%s "$f")" "$(stat -c%Y "$f")"
        else
            printf "%s:%s" "$(stat -f%z "$f" 2>/dev/null)" "$(stat -f%m "$f" 2>/dev/null)"
        fi
    fi
}

get_md5_remote() {
    local rel="$1"
    gcloud alpha cloud-shell ssh --authorize-session --command \
        "if command -v md5sum >/dev/null 2>&1; then md5sum \"~/$rel\" 2>/dev/null | awk '{print \\\$1}'; elif command -v md5 >/dev/null 2>&1; then md5 -q \"~/$rel\" 2>/dev/null; else if stat -c%s \"~/$rel\" >/dev/null 2>&1; then echo \"\$(stat -c%s \"~/$rel\"):\$(stat -c%Y \"~/$rel\")\"; else echo \"\$(stat -f%z \"~/$rel\" 2>/dev/null):\$(stat -f%m \"~/$rel\" 2>/dev/null)\"; fi; fi" 2>/dev/null || true
}

DRY_RUN=0

ensure_gcloud || true

case "$1" in
    "-h"|"--help"|"help")
        echo ""
        echo "  gshell — a wrapper around gcloud alpha cloud-shell"
        echo ""
        echo "  Usage:"
        echo "    gshell                           Enter Cloud Shell (interactive SSH)"
        echo "    gshell send [-r] <file|folder>   Upload file or folder to Cloud Shell"
        echo "    gshell get  [-r] <file|folder>   Download file or folder from Cloud Shell"
        echo "    gshell sync [-r] <file|folder>   Sync only changed files to Cloud Shell"
        echo "    gshell run  <command>             Run a command on Cloud Shell"
        echo "    gshell open                       Open Cloud Shell in browser"
        echo "    gshell status                     Show current gcloud project & account info"
        echo "    gshell -v | --version             Show version"
        echo "    gshell -h | --help                Show this help message"
        echo ""
        ;;

    "-v"|"--version"|"version")
        echo "gshell v$VERSION"
        ;;

    "send")
        shift
        RECURSE=""
        DRY_RUN=0
        while [ "${1:0:1}" = "-" ]; do
            case "$1" in
                -r) RECURSE="--recurse"; shift ;;
                -n|--dry-run) DRY_RUN=1; shift ;;
                *) break ;;
            esac
        done
        ITEM=$1

        if [ -z "$ITEM" ]; then
            echo "Usage: gshell send [-r] [-n|--dry-run] <file_or_folder>"
            exit 1
        fi

        REL_PATH="${ITEM#./}"
        REMOTE_DIR=$(dirname "$REL_PATH")
        BASENAME=$(basename "$REL_PATH")

        echo "Uploading $ITEM to Cloud Shell..."
        if [ "$DRY_RUN" -eq 1 ]; then
            echo "DRY RUN: gcloud alpha cloud-shell scp $RECURSE \"localhost:$REL_PATH\" \"cloudshell:~/\""
        else
            gcloud alpha cloud-shell scp $RECURSE \
                "localhost:$REL_PATH" \
                "cloudshell:~/"
        fi

        if [ "$DRY_RUN" -eq 0 ]; then
            gcloud alpha cloud-shell ssh --authorize-session --command "
                if [ \"$REMOTE_DIR\" != \".\" ]; then
                    mkdir -p \"~/$(printf '%s' "$REMOTE_DIR")\"
                    if [ ! -e \"~/$(printf '%s' "$REL_PATH")\" ]; then
                        mv \"~/$(printf '%s' "$BASENAME")\" \"~/$(printf '%s' "$REL_PATH")\"
                    fi
                fi
            "
        fi
        ;;

    "get")
        shift
        RECURSE=""
        DRY_RUN=0
        while [ "${1:0:1}" = "-" ]; do
            case "$1" in
                -r) RECURSE="--recurse"; shift ;;
                -n|--dry-run) DRY_RUN=1; shift ;;
                *) break ;;
            esac
        done
        ITEM=$1

        if [ -z "$ITEM" ]; then
            echo "Usage: gshell get [-r] [-n|--dry-run] <remote_item>"
            exit 1
        fi

        REL_PATH="${ITEM#./}"
        LOCAL_DIR=$(dirname "$REL_PATH")

        echo "Downloading $ITEM from Cloud Shell..."
        mkdir -p "$LOCAL_DIR"

        if [ "$DRY_RUN" -eq 1 ]; then
            echo "DRY RUN: gcloud alpha cloud-shell scp $RECURSE \"cloudshell:~/$REL_PATH\" \"localhost:$REL_PATH\""
        else
            gcloud alpha cloud-shell scp $RECURSE \
                "cloudshell:~/$REL_PATH" \
                "localhost:$REL_PATH"
        fi
        ;;

    "status")
        echo "Cloud Shell Info:"
        echo "-----------------"
        echo "Account : $(gcloud config get-value core/account 2>/dev/null)"
        echo "Project : $(gcloud config get-value core/project 2>/dev/null)"
        echo "Region  : $(gcloud config get-value compute/region 2>/dev/null || echo 'not set')"
        echo "Zone    : $(gcloud config get-value compute/zone 2>/dev/null || echo 'not set')"
        ;;

    "open")
        echo "Opening Cloud Shell in browser..."
        open "https://shell.cloud.google.com" 2>/dev/null \
            || xdg-open "https://shell.cloud.google.com" 2>/dev/null \
            || echo "Visit: https://shell.cloud.google.com"
        ;;

    "run")
        shift

        if [ -z "$1" ]; then
            echo "Usage: gshell run <command>"
            exit 1
        fi

        echo "Running command on Cloud Shell: $@"
        gcloud alpha cloud-shell ssh --authorize-session --command "$*"
        ;;

    "sync")
        shift
        RECURSE=""
        if [ "$1" == "-r" ]; then RECURSE=1; shift; fi
        FOLDER=$1

        if [ -z "$FOLDER" ]; then
            echo "Usage: gshell sync [-r] <file_or_folder>"
            exit 1
        fi

        FOLDER="${FOLDER%/}"  # strip trailing slash

        echo "Syncing $FOLDER to Cloud Shell..."

        sync_file() {
            LOCAL_FILE=$1
            REL="${LOCAL_FILE#./}"
            LOCAL_MD5=$(get_md5_local "$LOCAL_FILE")

            REMOTE_MD5=$(get_md5_remote "$REL")

            if [ "$LOCAL_MD5" != "$REMOTE_MD5" ]; then
                echo "  Uploading: $REL"
                REMOTE_DIR=$(dirname "$REL")
                BASENAME=$(basename "$REL")

                if [ "$DRY_RUN" -eq 1 ]; then
                    echo "    DRY RUN: gcloud alpha cloud-shell scp \"localhost:$LOCAL_FILE\" \"cloudshell:~/$BASENAME\""
                else
                    gcloud alpha cloud-shell scp \
                        "localhost:$LOCAL_FILE" \
                        "cloudshell:~/$BASENAME"

                    gcloud alpha cloud-shell ssh --authorize-session --command "
                        if [ \"$REMOTE_DIR\" != \".\" ]; then
                            mkdir -p \"~/$(printf '%s' "$REMOTE_DIR")\"
                            mv \"~/$(printf '%s' "$BASENAME")\" \"~/$(printf '%s' "$REL")\"
                        fi
                    "
                fi
            fi
        }

        if [ -n "$RECURSE" ]; then
            if [ ! -d "$FOLDER" ]; then
                echo "Error: $FOLDER is not a valid folder"
                exit 1
            fi
            mapfile -t FILES < <(find "$FOLDER" -type f)
            for LOCAL_FILE in "${FILES[@]}"; do
                sync_file "$LOCAL_FILE"
            done
        else
            if [ ! -f "$FOLDER" ]; then
                echo "Error: $FOLDER is not a valid file. Use -r for folders."
                exit 1
            fi
            sync_file "$FOLDER"
        fi

        echo "Sync complete!"
        ;;

    *)
        gcloud alpha cloud-shell ssh --authorize-session "$@"
        ;;
esac