#!/bin/bash
# tin sheet rm - Remove sheet and all its machines

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"

# Remove sheet and cascade to machines
remove_sheet() {
    local sheet="$1"
    local delete_data="${2:-false}"

    log_with_prefix "Sheet Remove" "Removing sheet: $sheet"
    echo

    # Check if sheet exists
    local sheet_num
    if ! sheet_num=$(get_sheet_number "$sheet" 2>/dev/null); then
        error_with_prefix "Sheet Remove" "Sheet '$sheet' is not registered"
        echo "Available sheets:" >&2
        list_sheets | while IFS='=' read -r name number; do
            echo "  $name (sheet $number)" >&2
        done
        exit 1
    fi

    echo "Sheet Details:"
    echo "  Name: $sheet"
    echo "  Number: $sheet_num"
    echo

    # Find all machines on this sheet
    local machines=()
    for user_entry in $(getent passwd | grep "^[^:]*:[^:]*:[0-9]\{5\}:"); do
        local username=$(echo "$user_entry" | cut -d: -f1)
        local uid=$(echo "$user_entry" | cut -d: -f3)

        # Extract sheet number from UID (first digit)
        local user_sheet_num="${uid:0:1}"

        # Check if this user belongs to this sheet
        if [[ "$user_sheet_num" == "$sheet_num" ]]; then
            machines+=("$username")
        fi
    done

    if [[ ${#machines[@]} -gt 0 ]]; then
        echo "WARNING: Found ${#machines[@]} machine(s) on this sheet:"
        for machine in "${machines[@]}"; do
            echo "  - $machine"
        done
        echo
        read -p "Remove all machines first? [Y/n]: " remove_machines
        case "${remove_machines:-y}" in
            [Yy]*|"")
                for machine in "${machines[@]}"; do
                    log_with_prefix "Sheet Remove" "Removing machine: $machine"
                    if [[ "$delete_data" == "true" ]]; then
                        # Use --no-confirm to skip prompts but keep stdin as terminal for NAS deletion
                        "$TINSNIP_ROOT/cmd/machine/rm.sh" "$machine" --delete-data --no-confirm
                    else
                        "$TINSNIP_ROOT/cmd/machine/rm.sh" "$machine" --no-confirm
                    fi
                done
                echo
                ;;
            *)
                log_with_prefix "Sheet Remove" "Removal cancelled"
                exit 0
                ;;
        esac
    fi

    # Remove sheet from registry
    echo
    log_with_prefix "Sheet Remove" "Removing from sheet registry..."

    # Check if we're removing topsheet
    if [[ "$sheet" == "topsheet" ]]; then
        error_with_prefix "Sheet Remove" "Cannot remove topsheet (infrastructure sheet)"
        echo "The topsheet contains the station machine and registry." >&2
        exit 1
    fi

    # Remove from station registry (as station-prod)
    if [[ -f "$SHEET_REGISTRY" ]]; then
        sudo -u station-prod sed -i "/^${sheet}=/d" "$SHEET_REGISTRY"
        echo "  SUCCESS: Removed from sheet registry"
    fi

    # Remove per-sheet machine registry file (as station-prod)
    local machine_registry="$MACHINE_REGISTRY_DIR/$sheet"
    if [[ -f "$machine_registry" ]]; then
        log_with_prefix "Sheet Remove" "Removing machine registry for sheet..."
        sudo -u station-prod rm -f "$machine_registry"
        echo "  SUCCESS: Removed machine registry"
    fi

    echo
    log_with_prefix "Sheet Remove" "SUCCESS: Sheet '$sheet' removed successfully"
    if [[ "$delete_data" != "true" ]]; then
        echo
        echo "NAS data preserved. To restore:"
        echo "  tin sheet create $sheet"
        echo "  tin machine create <machine> <env> <nas-server>"
    fi
}

show_help() {
    cat << EOF
tin sheet rm - Remove sheet and all its machines

USAGE:
    tin sheet rm <sheet-name> [--delete-data]

DESCRIPTION:
    Remove a sheet including all its machines and catalog services.
    By default, NAS data is PRESERVED for recovery.
    Automatically removes all machines (which cascade to catalog services).

ARGUMENTS:
    <sheet-name>    Sheet to remove (e.g., infrastructure)

OPTIONS:
    --delete-data   Also delete ALL data on NAS for this sheet (DANGEROUS!)

EXAMPLES:
    tin sheet rm infrastructure              # Remove sheet, keep NAS data
    tin sheet rm infrastructure --delete-data # Remove sheet AND delete ALL NAS data

NOTES:
    - Automatically removes all machines on the sheet (with confirmation)
    - Each machine removal cascades to its catalog services
    - Default behavior preserves NAS data (CD-friendly)
    - Sheet can be recreated and machines restored from preserved data
    - Use --delete-data only when permanently decommissioning entire sheet

WARNING:
    --delete-data will PERMANENTLY DELETE all data for all catalog services on this sheet!
    Cannot remove 'topsheet' (infrastructure sheet containing station registry)

EOF
}

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

# Main execution
if [[ $# -eq 0 ]]; then
    error_with_prefix "Sheet Remove" "Sheet name required"
    echo "Usage: tin sheet rm <sheet-name> [--delete-data]" >&2
    exit 1
fi

sheet="$1"
delete_data="false"

if [[ "${2:-}" == "--delete-data" ]]; then
    delete_data="true"
fi

remove_sheet "$sheet" "$delete_data"