#!/bin/bash
# Registry management functions for tinsnip

# Source core functions
LIB_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$LIB_DIR/core.sh"

# Registry paths
TINSNIP_STATION_DATA="/mnt/station-prod/data"
SHEET_REGISTRY="$TINSNIP_STATION_DATA/sheets"
MACHINE_REGISTRY_DIR="$TINSNIP_STATION_DATA/machines"
NAS_CREDENTIALS_DIR="$TINSNIP_STATION_DATA/nas-credentials"

# Check if tinsnip.station-prod is available
check_tinsnip_station() {
    if [[ ! -d "$TINSNIP_STATION_DATA" ]]; then
        error_with_prefix "Registry" "tinsnip.station-prod not found at $TINSNIP_STATION_DATA"
        error_with_prefix "Registry" "Run: TIN_SHEET=topsheet tin machine station prod <nas-server>"
        return 1
    fi
    return 0
}

# Sheet registry functions
list_sheets() {
    check_tinsnip_station || return 1
    if [[ -f "$SHEET_REGISTRY" ]]; then
        grep -v '^#' "$SHEET_REGISTRY" | grep -v '^$'
    fi
}

get_sheet_from_registry() {
    local sheet="$1"
    check_tinsnip_station || return 1
    
    if [[ -f "$SHEET_REGISTRY" ]]; then
        grep "^${sheet}=" "$SHEET_REGISTRY" | cut -d= -f2
    fi
}

register_sheet_in_registry() {
    local sheet="$1"
    local number="$2"
    check_tinsnip_station || return 1

    # Check if already registered
    if get_sheet_from_registry "$sheet" >/dev/null 2>&1; then
        error_with_prefix "Sheet Registry" "Sheet '$sheet' already registered"
        return 1
    fi

    # Check if number already used
    if grep -q "=${number}$" "$SHEET_REGISTRY" 2>/dev/null; then
        error_with_prefix "Sheet Registry" "Sheet number '$number' already in use"
        return 1
    fi

    # Add to registry (must write as station-prod user)
    echo "${sheet}=${number}" | sudo -u station-prod tee -a "$SHEET_REGISTRY" > /dev/null
    log_with_prefix "Sheet Registry" "Registered sheet: $sheet = $number"
}

find_next_sheet_number() {
    check_tinsnip_station || return 1
    
    # Create registry if it doesn't exist
    if [[ ! -f "$SHEET_REGISTRY" ]]; then
        cat > "$SHEET_REGISTRY" << EOF
# Sheet Registry
# Format: sheet_name=sheet_number
# Sheet 5 (topsheet) is reserved for platform services
# User sheets use numbers 1-4

topsheet=5
EOF
    fi
    
    # Find next available number (1-4)
    for num in {1..4}; do
        if ! grep -q "=${num}$" "$SHEET_REGISTRY" 2>/dev/null; then
            echo "$num"
            return 0
        fi
    done
    
    # No available numbers
    error_with_prefix "Sheet Registry" "Sheet registry full (range 1-4, 5 reserved for topsheet)"
    return 1
}

# Machine registry functions
list_machines() {
    local sheet="${1:-topsheet}"
    local machine_registry="$MACHINE_REGISTRY_DIR/$sheet/registry"

    if [[ -f "$machine_registry" ]]; then
        grep -v '^#' "$machine_registry" | grep -v '^$'
    else
        # Return empty - no machines registered yet for this sheet
        return 0
    fi
}

get_machine_number() {
    local machine="$1"
    local sheet="${2:-topsheet}"
    local machine_registry="$MACHINE_REGISTRY_DIR/$sheet/registry"

    if [[ -f "$machine_registry" ]]; then
        grep "^${machine}=" "$machine_registry" | cut -d= -f2
    fi
}

register_machine() {
    local machine="$1"
    local machine_number="$2"
    local sheet="${3:-${TIN_SHEET:-topsheet}}"
    local machine_registry="$MACHINE_REGISTRY_DIR/$sheet/registry"

    check_tinsnip_station || return 1

    # Create sheet directory if needed (as station-prod)
    sudo -u station-prod mkdir -p "$MACHINE_REGISTRY_DIR/$sheet"

    # Create registry file if needed (as station-prod)
    if [[ ! -f "$machine_registry" ]]; then
        cat << EOF | sudo -u station-prod tee "$machine_registry" > /dev/null
# Machine Registry for sheet: $sheet
# Format: machine_name=machine_number
# Machine numbers are 2-digit (00-99) and used in UID calculation
EOF
    fi

    # Add or update machine entry (as station-prod)
    if grep -q "^${machine}=" "$machine_registry" 2>/dev/null; then
        sudo -u station-prod sed -i "s/^${machine}=.*/${machine}=${machine_number}/" "$machine_registry"
    else
        echo "${machine}=${machine_number}" | sudo -u station-prod tee -a "$machine_registry" > /dev/null
    fi

    log_with_prefix "Machine Registry" "Registered $machine = $machine_number (sheet: $sheet)"
}

unregister_machine() {
    local machine="$1"
    local sheet="${2:-${TIN_SHEET:-topsheet}}"
    local machine_registry="$MACHINE_REGISTRY_DIR/$sheet/registry"

    check_tinsnip_station || return 1

    if [[ ! -f "$machine_registry" ]]; then
        return 1
    fi

    # Remove machine entry (as station-prod)
    sudo -u station-prod sed -i "/^${machine}=/d" "$machine_registry"
    log_with_prefix "Machine Registry" "Unregistered $machine (sheet: $sheet)"
}

# NAS credential functions
list_nas_servers() {
    check_tinsnip_station || return 1
    if [[ -f "$NAS_CREDENTIALS_DIR/nas-servers" ]]; then
        grep -v '^#' "$NAS_CREDENTIALS_DIR/nas-servers" | grep -v '^$'
    fi
}

get_nas_server() {
    local sheet="$1"
    check_tinsnip_station || return 1
    
    if [[ -f "$NAS_CREDENTIALS_DIR/nas-servers" ]]; then
        grep "^${sheet}=" "$NAS_CREDENTIALS_DIR/nas-servers" | cut -d= -f2
    fi
}

register_nas_server() {
    local sheet="$1"
    local nas_server="$2"
    check_tinsnip_station || return 1

    # Create nas-servers file if it doesn't exist (as station-prod)
    local nas_servers_file="$NAS_CREDENTIALS_DIR/nas-servers"
    sudo -u station-prod mkdir -p "$NAS_CREDENTIALS_DIR"

    if [[ ! -f "$nas_servers_file" ]]; then
        cat << EOF | sudo -u station-prod tee "$nas_servers_file" > /dev/null
# NAS Server Registry
# Format: sheet=nas_server_hostname
# Used for automatic NAS discovery during machine setup

EOF
    fi

    # Update or add entry (as station-prod)
    if grep -q "^${sheet}=" "$nas_servers_file" 2>/dev/null; then
        sudo -u station-prod sed -i "s/^${sheet}=.*/${sheet}=${nas_server}/" "$nas_servers_file"
        log_with_prefix "NAS Registry" "Updated NAS server for $sheet: $nas_server"
    else
        echo "${sheet}=${nas_server}" | sudo -u station-prod tee -a "$nas_servers_file" > /dev/null
        log_with_prefix "NAS Registry" "Registered NAS server for $sheet: $nas_server"
    fi
}

# Auto-discover NAS server for a sheet
discover_nas_server() {
    local sheet="$1"
    check_tinsnip_station || return 1
    
    # First check if explicitly registered for this sheet
    local nas_server=$(get_nas_server "$sheet")
    if [[ -n "$nas_server" ]]; then
        echo "$nas_server"
        return 0
    fi
    
    # Fall back to default sheet server if no specific entry
    nas_server=$(get_nas_server "default")
    if [[ -n "$nas_server" ]]; then
        echo "$nas_server"
        return 0
    fi
    
    # No NAS server found
    return 1
}

# SSH key management functions
has_nas_key() {
    local nas_server="$1"
    check_tinsnip_station || return 1
    [[ -f "$NAS_CREDENTIALS_DIR/${nas_server}.key" ]]
}

get_nas_key_path() {
    local nas_server="$1"
    check_tinsnip_station || return 1
    echo "$NAS_CREDENTIALS_DIR/${nas_server}.key"
}

# Usage examples
show_registry_usage() {
    cat << EOF
Registry Management Functions

Sheet Registry:
  list_sheets                         # Show all registered sheets
  get_sheet_from_registry <sheet>     # Get number for sheet
  register_sheet_in_registry <name> <number>  # Register new sheet
  find_next_sheet_number             # Find next available sheet number

Machine Registry:
  list_machines [sheet]              # Show machines in sheet
  get_machine_number <machine> [sheet]  # Get machine number

NAS Management:
  list_nas_servers                   # Show registered NAS servers
  get_nas_server <sheet>             # Get NAS server for sheet
  register_nas_server <sheet> <server>  # Register NAS server
  discover_nas_server <sheet>        # Auto-discover NAS server

SSH Keys:
  has_nas_key <server>              # Check if SSH key exists
  get_nas_key_path <server>         # Get path to SSH key

Example Usage:
  source "\$TINSNIP_ROOT/lib/registry.sh"
  list_sheets
  register_sheet_in_registry infrastructure 2
  register_nas_server infrastructure DS412plus.local
EOF
}