#!/bin/bash
# tin machine rm - Remove machine environment

set -euo pipefail

# Get tinsnip root and source libraries
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TINSNIP_ROOT="$(dirname "$(dirname "$SCRIPT_DIR")")"
source "$TINSNIP_ROOT/lib/core.sh"
source "$TINSNIP_ROOT/lib/uid.sh"
source "$TINSNIP_ROOT/lib/registry.sh"
source "$TINSNIP_ROOT/lib/nas.sh"

# Remove machine environment
remove_machine() {
    local service_env="$1"
    local delete_data="${2:-false}"
    local no_confirm="${3:-false}"

    # Parse service-environment
    local parsed_output
    if ! parsed_output=$(parse_machine_name "$service_env" 2>/dev/null); then
        error_with_prefix "Machine Remove" "Invalid machine environment format: '$service_env'"
        echo "Expected: <service>-<environment> (e.g., pds-dev, bsky-pds-dev)" >&2
        exit 1
    fi

    local service=$(echo "$parsed_output" | sed -n '1p')
    local environment=$(echo "$parsed_output" | sed -n '2p')
    local service_user="$service_env"

    log_with_prefix "Machine Remove" "Removing machine: $service_env"
    echo

    # Check if user exists
    if ! id "$service_user" &>/dev/null 2>&1; then
        warn_with_prefix "Machine Remove" "User '$service_user' does not exist"
        echo "Machine may have already been removed or never created." >&2
        exit 0
    fi

    local service_uid=$(id -u "$service_user")
    local mount_point="/mnt/$service_env"

    echo "Machine Details:"
    echo "  User: $service_user"
    echo "  UID: $service_uid"
    echo "  Mount: $mount_point"
    echo

    # Check for deployed services
    local services=()
    if [[ -d "$mount_point/service" ]]; then
        while IFS= read -r -d '' service_dir; do
            services+=("$(basename "$service_dir")")
        done < <(find "$mount_point/service" -mindepth 1 -maxdepth 1 -type d -print0 2>/dev/null)
    fi

    if [[ ${#services[@]} -gt 0 ]]; then
        echo "WARNING: Found ${#services[@]} deployed service(s):"
        for svc in "${services[@]}"; do
            echo "  - $svc"
        done
        echo

        if [[ "$no_confirm" == "true" ]]; then
            # Auto-confirm when called from sheet removal
            log_with_prefix "Machine Remove" "Removing all services..."
        else
            read -p "Remove all services first? [Y/n]: " remove_services
            case "${remove_services:-y}" in
                [Yy]*|"")
                    ;;
                *)
                    error_with_prefix "Machine Remove" "Cannot remove machine with deployed services"
                    echo "Remove services first with: tin service rm $service_env <service>" >&2
                    exit 1
                    ;;
            esac
        fi

        for svc in "${services[@]}"; do
            log_with_prefix "Machine Remove" "Removing service: $svc"
            "$TINSNIP_ROOT/cmd/service/rm.sh" "$service_env" "$svc" <<< "y"
        done
        echo
    fi

    # Show data policy
    if [[ "$delete_data" == "true" ]]; then
        echo "WARNING: NAS data will be DELETED"
    else
        echo "SUCCESS: NAS data will be PRESERVED"
    fi
    echo

    if [[ "$no_confirm" == "true" ]]; then
        # Auto-confirm when called from sheet removal
        log_with_prefix "Machine Remove" "Proceeding with removal..."
    else
        read -p "Remove this machine? [y/N]: " confirm
        case "${confirm}" in
            [Yy])
                log_with_prefix "Machine Remove" "Proceeding with removal..."
                ;;
            *)
                log_with_prefix "Machine Remove" "Removal cancelled"
                exit 0
                ;;
        esac
    fi

    # Delete NAS data if requested
    if [[ "$delete_data" == "true" ]]; then
        log_with_prefix "Machine Remove" "Deleting NAS data..."

        # Find NAS server from fstab
        local nas_path=$(grep "$mount_point" /etc/fstab 2>/dev/null | awk '{print $1}' | head -1)
        if [[ -n "$nas_path" ]]; then
            echo "  NAS path: $nas_path"
            local nas_server=$(echo "$nas_path" | cut -d: -f1)
            local nas_dir=$(echo "$nas_path" | cut -d: -f2)

            echo "  Deleting data on NAS: $nas_server"
            echo "  This will require sudo password on the NAS..."
            echo ""

            # Use interactive SSH with -t flag to enable password prompt
            # This also removes the NFS export and reloads
            if ssh -t "$nas_server" "echo 'Removing NAS data and export...' && \
                sudo rm -rf '$nas_dir' && \
                echo 'Data deleted: $nas_dir' && \
                sudo sed -i '\|$nas_dir|d' /etc/exports && \
                echo 'Export removed from /etc/exports' && \
                sudo exportfs -ra && \
                echo 'NFS exports reloaded'"; then
                echo ""
                log_with_prefix "Machine Remove" "✅ NAS data and export deleted successfully"
            else
                echo ""
                warn_with_prefix "Machine Remove" "Failed to delete NAS data"
                echo "  Manually delete with:" >&2
                echo "    ssh $nas_server" >&2
                echo "    sudo rm -rf '$nas_dir'" >&2
                echo "    sudo sed -i '\|$nas_dir|d' /etc/exports" >&2
                echo "    sudo exportfs -ra" >&2
            fi
        else
            warn_with_prefix "Machine Remove" "Could not find NAS path in /etc/fstab"
            echo "  NFS mount information not available for cleanup" >&2
        fi
    else
        log_with_prefix "Machine Remove" "Preserving NAS data (use --delete-data to remove)"
    fi

    # Unmount NFS
    log_with_prefix "Machine Remove" "Unmounting NFS..."
    if mountpoint -q "$mount_point" 2>/dev/null; then
        sudo umount "$mount_point" 2>/dev/null || sudo umount -l "$mount_point"
    fi

    # Remove from fstab
    log_with_prefix "Machine Remove" "Removing from /etc/fstab..."
    sudo sed -i "\|$mount_point|d" /etc/fstab

    # Remove user
    log_with_prefix "Machine Remove" "Removing user $service_user..."

    # Kill any processes owned by the user first
    if id "$service_user" &>/dev/null; then
        sudo pkill -9 -u "$service_user" 2>/dev/null || true
        sleep 1  # Give processes time to terminate
    fi

    # Remove user and home directory
    if sudo userdel -r "$service_user" 2>/dev/null; then
        log_with_prefix "Machine Remove" "User removed successfully"
    else
        warn_with_prefix "Machine Remove" "Failed to remove user (may need manual cleanup)"
    fi

    # Remove mount point directory
    if [[ -d "$mount_point" ]]; then
        sudo rmdir "$mount_point" 2>/dev/null || sudo rm -rf "$mount_point"
    fi

    # Remove service from registry
    log_with_prefix "Machine Remove" "Removing from machine registry..."

    # Detect sheet from UID
    local sheet=$(get_sheet_from_uid "$service_uid")
    log_with_prefix "Machine Remove" "Detected sheet: $sheet (from UID $service_uid)"

    if unregister_service "$service" "$sheet" 2>/dev/null; then
        log_with_prefix "Machine Remove" "Service unregistered from $sheet registry"
    else
        warn_with_prefix "Machine Remove" "Service was not in registry for sheet $sheet"
    fi

    echo
    log_with_prefix "Machine Remove" "Machine '$service_env' removed successfully"
    if [[ "$delete_data" != "true" ]]; then
        echo
        log_with_prefix "Machine Remove" "NAS data preserved. To restore:"
        log_with_prefix "Machine Remove" "  tin machine create $service $environment <nas-server>"
        log_with_prefix "Machine Remove" "  tin service deploy $service_env <service-name>"
    fi
}

show_help() {
    cat << EOF
tin machine rm - Remove machine environment

USAGE:
    tin machine rm <service-env> [--delete-data] [--no-confirm]

DESCRIPTION:
    Remove a machine environment including user and NFS mount.
    By default, NAS data is PRESERVED for recovery.
    Automatically removes all deployed services first.

ARGUMENTS:
    <service-env>   Machine to remove (e.g., pds-dev)

OPTIONS:
    --delete-data   Also delete data on NAS (DANGEROUS!)
    --no-confirm    Skip confirmation prompts (for automation)

EXAMPLES:
    tin machine rm pds-dev                      # Remove machine, keep NAS data
    tin machine rm pds-dev --delete-data        # Remove machine AND delete NAS data
    tin machine rm pds-dev --no-confirm         # Remove without prompts

NOTES:
    - Automatically removes deployed services (with confirmation unless --no-confirm)
    - Default behavior preserves NAS data (CD-friendly)
    - Machine can be recreated and data remounted for recovery
    - Use --delete-data only when permanently decommissioning
    - NAS deletion requires sudo password (interactive prompt)
    - Also removes NFS export from /etc/exports and reloads
    - --no-confirm keeps stdin as terminal for interactive NAS password

WARNING:
    --delete-data will PERMANENTLY DELETE all data on the NAS!
    You will be prompted for the NAS sudo password during deletion.

EOF
}

# Handle help flags
case "${1:-}" in
    --help|-h|help)
        show_help
        exit 0
        ;;
esac

# Main execution
if [[ $# -eq 0 ]]; then
    error_with_prefix "Machine Remove" "Service environment required"
    echo "Usage: tin machine rm <service-env> [--delete-data] [--no-confirm]" >&2
    exit 1
fi

service_env="$1"
delete_data="false"
no_confirm="false"

# Parse flags
shift
while [[ $# -gt 0 ]]; do
    case "$1" in
        --delete-data)
            delete_data="true"
            ;;
        --no-confirm)
            no_confirm="true"
            ;;
        *)
            error_with_prefix "Machine Remove" "Unknown flag: $1"
            echo "Usage: tin machine rm <service-env> [--delete-data] [--no-confirm]" >&2
            exit 1
            ;;
    esac
    shift
done

remove_machine "$service_env" "$delete_data" "$no_confirm"