#!/usr/bin/env bash
set -euo pipefail

# =============================================================================
# Register an existing Changemaker Lite instance with a Control Panel (CCP)
#
# Usage:
#   bash scripts/register-with-ccp.sh
#   bash scripts/register-with-ccp.sh --ccp-url https://ccp.example.com --invite-code ABCD-1234 --agent-url https://myhost:7443
# =============================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
BASE_DIR="$(dirname "$SCRIPT_DIR")"
ENV_FILE="$BASE_DIR/.env"

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
CYAN='\033[0;36m'
YELLOW='\033[1;33m'
BOLD='\033[1m'
NC='\033[0m'

info()    { echo -e "${CYAN}[INFO]${NC} $*"; }
success() { echo -e "${GREEN}[OK]${NC}   $*"; }
warn()    { echo -e "${YELLOW}[WARN]${NC} $*"; }
error()   { echo -e "${RED}[ERR]${NC}  $*" >&2; }

header() {
  echo ""
  echo -e "${BOLD}── $* ──${NC}"
  echo ""
}

update_env_var() {
  local key=$1
  local value=$2
  if grep -q "^${key}=" "$ENV_FILE"; then
    local tmpfile
    tmpfile=$(mktemp)
    while IFS= read -r line; do
      if [[ "$line" =~ ^${key}= ]]; then
        echo "${key}=${value}" >> "$tmpfile"
      else
        echo "$line" >> "$tmpfile"
      fi
    done < "$ENV_FILE"
    mv "$tmpfile" "$ENV_FILE"
  else
    echo "${key}=${value}" >> "$ENV_FILE"
  fi
}

# --- Parse args ---
CCP_URL=""
INVITE_CODE=""
AGENT_URL=""
UNREGISTER=false

while [[ $# -gt 0 ]]; do
  case "$1" in
    --ccp-url)      CCP_URL="$2"; shift 2 ;;
    --invite-code)  INVITE_CODE="$2"; shift 2 ;;
    --agent-url)    AGENT_URL="$2"; shift 2 ;;
    --unregister)   UNREGISTER=true; shift ;;
    --help|-h)
      echo "Usage: bash scripts/register-with-ccp.sh [OPTIONS]"
      echo ""
      echo "Options:"
      echo "  --ccp-url URL        Control Panel URL (e.g., https://ccp.example.com)"
      echo "  --invite-code CODE   Invite code from CCP admin"
      echo "  --agent-url URL      How the CCP can reach this host (e.g., https://myhost:7443)"
      echo "  --unregister         Remove CCP registration and stop agent"
      echo "  --help               Show this help"
      echo ""
      echo "If options are omitted, you will be prompted interactively."
      exit 0
      ;;
    *)
      error "Unknown option: $1"
      exit 1
      ;;
  esac
done

# --- Verify .env exists ---
if [[ ! -f "$ENV_FILE" ]]; then
  error ".env file not found at $ENV_FILE"
  error "Run config.sh first to initialize the environment."
  exit 1
fi

# --- Unregister mode ---
if [[ "$UNREGISTER" == "true" ]]; then
  header "Unregister from Control Panel"

  update_env_var "ENABLE_CCP_AGENT" "false"
  update_env_var "CCP_URL" ""
  update_env_var "CCP_INVITE_CODE" ""
  update_env_var "CCP_AGENT_URL" ""

  # Remove ccp-agent from COMPOSE_PROFILES
  existing_profiles=$(grep -oP 'COMPOSE_PROFILES=\K.*' "$ENV_FILE" 2>/dev/null || echo "")
  new_profiles=$(echo "$existing_profiles" | sed 's/,*ccp-agent//g; s/^,//; s/,$//')
  update_env_var "COMPOSE_PROFILES" "$new_profiles"

  # Stop the agent container if running
  info "Stopping ccp-agent container..."
  cd "$BASE_DIR"
  docker compose --profile ccp-agent stop ccp-agent 2>/dev/null || true
  docker compose --profile ccp-agent rm -f ccp-agent 2>/dev/null || true

  success "CCP registration removed. Agent stopped."
  exit 0
fi

# --- Interactive prompts ---
header "Register with Changemaker Control Panel"

if [[ -z "$CCP_URL" ]]; then
  read -rp "  Control Panel URL (e.g., https://ccp.example.com): " CCP_URL
fi
if [[ -z "$CCP_URL" ]]; then
  error "CCP URL is required."
  exit 1
fi

if [[ -z "$INVITE_CODE" ]]; then
  read -rp "  Invite code from CCP admin: " INVITE_CODE
fi
if [[ -z "$INVITE_CODE" ]]; then
  error "Invite code is required."
  exit 1
fi

if [[ -z "$AGENT_URL" ]]; then
  echo ""
  info "The Agent URL is how the CCP will reach this machine."
  info "It must be accessible from the CCP server (e.g., via public IP, VPN, or Pangolin tunnel)."
  echo ""
  # Try to auto-detect
  local_ip=$(hostname -I 2>/dev/null | awk '{print $1}' || echo "")
  if [[ -n "$local_ip" ]]; then
    info "Detected local IP: $local_ip"
    read -rp "  Agent URL [https://${local_ip}:7443]: " AGENT_URL
    AGENT_URL="${AGENT_URL:-https://${local_ip}:7443}"
  else
    read -rp "  Agent URL (e.g., https://this-host:7443): " AGENT_URL
  fi
fi
if [[ -z "$AGENT_URL" ]]; then
  error "Agent URL is required."
  exit 1
fi

# --- Confirm ---
echo ""
info "Configuration:"
echo "  CCP URL:     $CCP_URL"
echo "  Invite Code: $INVITE_CODE"
echo "  Agent URL:   $AGENT_URL"
echo ""
read -rp "Proceed with registration? (y/n): " confirm
if [[ "$confirm" != "y" && "$confirm" != "Y" ]]; then
  info "Registration cancelled."
  exit 0
fi

# --- Update .env ---
header "Updating Configuration"

update_env_var "ENABLE_CCP_AGENT" "true"
update_env_var "CCP_URL" "$CCP_URL"
update_env_var "CCP_INVITE_CODE" "$INVITE_CODE"
update_env_var "CCP_AGENT_URL" "$AGENT_URL"
success "Environment variables set"

# Add ccp-agent to compose profiles
existing_profiles=$(grep -oP 'COMPOSE_PROFILES=\K.*' "$ENV_FILE" 2>/dev/null || echo "")
if [[ "$existing_profiles" != *"ccp-agent"* ]]; then
  if [[ -n "$existing_profiles" ]]; then
    update_env_var "COMPOSE_PROFILES" "${existing_profiles},ccp-agent"
  else
    update_env_var "COMPOSE_PROFILES" "ccp-agent"
  fi
  success "Added ccp-agent to COMPOSE_PROFILES"
fi

# --- Start the agent ---
header "Starting CCP Agent"

cd "$BASE_DIR"
docker compose --profile ccp-agent up -d ccp-agent
success "CCP Agent container started"

echo ""
info "The agent is now phoning home to $CCP_URL"
info "It will poll every 30 seconds until the CCP admin approves the registration."
info ""
info "Once approved, the agent will:"
info "  1. Receive mTLS certificates automatically"
info "  2. Restart with secure communication enabled"
info "  3. Begin accepting management commands from the CCP"
echo ""
info "You can monitor the agent with:"
echo "  docker compose --profile ccp-agent logs -f ccp-agent"
echo ""
success "Registration initiated! Waiting for CCP admin approval..."