#!/bin/bash
#
# PgBouncer Setup Script for LeoCRM
# ===================================
#
# This script installs and configures PgBouncer for PostgreSQL connection pooling.
# It creates the configuration files and starts the service.
#
# Usage:
#   ./scripts/setup_pgbouncer.sh [--docker] [--password PASSWORD]
#
# Options:
#   --docker          Configure for Docker Compose environment
#   --password PASS   Set PostgreSQL password (default: from .env or prompt)
#

set -euo pipefail

# ─── Color Output ───
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

log_info()  { echo -e "${GREEN}[INFO]${NC} $1"; }
log_warn()  { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

# ─── Default Values ───
PGBOUNCER_VERSION="1.23.1"
PGBOUNCER_PORT="6432"
POOL_MODE="transaction"
DEFAULT_POOL_SIZE="25"
MAX_CLIENT_CONN="200"

# ─── Parse Arguments ───
DOCKER_MODE=false
POSTGRES_PASSWORD=""

while [[ $# -gt 0 ]]; do
    case $1 in
        --docker)
            DOCKER_MODE=true
            shift
            ;;
        --password)
            POSTGRES_PASSWORD="$2"
            shift 2
            ;;
        --help)
            echo "Usage: $0 [--docker] [--password PASSWORD]"
            echo ""
            echo "Options:"
            echo "  --docker          Configure for Docker Compose environment"
            echo "  --password PASS   Set PostgreSQL password (default: from .env or prompt)"
            exit 0
            ;;
        *)
            log_error "Unknown option: $1"
            exit 1
            ;;
    esac
done

# ─── Detect Environment ───
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

if [ -f "$PROJECT_DIR/.env" ]; then
    source "$PROJECT_DIR/.env"
fi

if [ -z "$POSTGRES_PASSWORD" ]; then
    POSTGRES_PASSWORD="${POSTGRES_PASSWORD:-}"
fi

if [ -z "$POSTGRES_PASSWORD" ]; then
    read -s -p "Enter PostgreSQL password: " POSTGRES_PASSWORD
    echo ""
fi

# ─── Docker Mode ───
if [ "$DOCKER_MODE" = true ]; then
    log_info "Configuring PgBouncer for Docker Compose..."

    # Check if docker-compose.yml exists
    if [ ! -f "$PROJECT_DIR/docker-compose.yml" ]; then
        log_error "docker-compose.yml not found in $PROJECT_DIR"
        exit 1
    fi

    # Check if PgBouncer service already exists
    if grep -q "pgbouncer" "$PROJECT_DIR/docker-compose.yml" 2>/dev/null; then
        log_warn "PgBouncer service already exists in docker-compose.yml"
    else
        log_info "Adding PgBouncer service to docker-compose.yml..."

        # Add PgBouncer service before the last line of services
        cat >> "$PROJECT_DIR/docker-compose.yml" << 'EOF'

  pgbouncer:
    image: bitnami/pgbouncer:latest
    container_name: leocrm-pgbouncer
    ports:
      - "6432:6432"
    environment:
      - POSTGRESQL_HOST=crm-postgres
      - POSTGRESQL_PORT=5432
      - POSTGRESQL_USERNAME=leocrm
      - POSTGRESQL_PASSWORD=${POSTGRES_PASSWORD}
      - POSTGRESQL_DATABASE=crm_db
      - PGBOUNCER_POOL_MODE=transaction
      - PGBOUNCER_DEFAULT_POOL_SIZE=25
      - PGBOUNCER_MAX_CLIENT_CONN=200
    depends_on:
      - crm-postgres
    restart: unless-stopped
EOF
        log_info "PgBouncer service added to docker-compose.yml"
    fi

    log_info "Docker PgBouncer configuration complete!"
    log_info "Run 'docker-compose up -d pgbouncer' to start PgBouncer"
    exit 0
fi

# ─── Native Installation ───
log_info "Installing PgBouncer v${PGBOUNCER_VERSION}..."

# Check if PgBouncer is already installed
if command -v pgbouncer &>/dev/null; then
    log_info "PgBouncer is already installed: $(pgbouncer --version)"
else
    # Install PgBouncer
    if command -v apt-get &>/dev/null; then
        apt-get update
        apt-get install -y pgbouncer
    elif command -v yum &>/dev/null; then
        yum install -y pgbouncer
    else
        log_error "Unsupported package manager. Install PgBouncer manually."
        exit 1
    fi
    log_info "PgBouncer installed successfully"
fi

# ─── Create Configuration ───
log_info "Creating PgBouncer configuration..."

PGBOUNCER_CONF_DIR="/etc/pgbouncer"
mkdir -p "$PGBOUNCER_CONF_DIR"

# Generate md5 password hash
PG_MD5_HASH=$(echo -n "md5$(echo -n "${POSTGRES_PASSWORD}leocrm" | md5sum | cut -d' ' -f1)")

# Create pgbouncer.ini
cat > "${PGBOUNCER_CONF_DIR}/pgbouncer.ini" << INI
[databases]
leocrm = host=localhost port=5432 dbname=crm_db
leocrm_test = host=localhost port=5432 dbname=leocrm_test

[pgbouncer]
listen_addr = 0.0.0.0
listen_port = ${PGBOUNCER_PORT}
unix_socket_dir = /var/run/pgbouncer

auth_type = md5
auth_file = ${PGBOUNCER_CONF_DIR}/userlist.txt

pool_mode = ${POOL_MODE}
default_pool_size = ${DEFAULT_POOL_SIZE}
max_client_conn = ${MAX_CLIENT_CONN}
max_db_connections = 50

server_idle_timeout = 600
server_lifetime = 3600
client_idle_timeout = 1800
query_timeout = 30

log_connections = 1
log_disconnections = 1
log_pooler_errors = 1
stats_period = 60

listen_backlog = 128
INI

log_info "Created ${PGBOUNCER_CONF_DIR}/pgbouncer.ini"

# Create userlist.txt
cat > "${PGBOUNCER_CONF_DIR}/userlist.txt" << USERLIST
"leocrm" "${PG_MD5_HASH}"
"postgres" "${PG_MD5_HASH}"
USERLIST

log_info "Created ${PGBOUNCER_CONF_DIR}/userlist.txt"

# Set proper permissions
chmod 640 "${PGBOUNCER_CONF_DIR}/pgbouncer.ini"
chmod 640 "${PGBOUNCER_CONF_DIR}/userlist.txt"
chown -R pgbouncer:pgbouncer "$PGBOUNCER_CONF_DIR" 2>/dev/null || true

# ─── Create Systemd Service ───
log_info "Creating systemd service..."

cat > /etc/systemd/system/pgbouncer.service << 'SYSTEMD'
[Unit]
Description=PgBouncer PostgreSQL Connection Pooler
After=network.target

[Service]
Type=forking
User=pgbouncer
ExecStart=/usr/sbin/pgbouncer -d /etc/pgbouncer/pgbouncer.ini
ExecReload=/bin/kill -HUP $MAINPID
ExecStop=/bin/kill -INT $MAINPID
PIDFile=/var/run/pgbouncer/pgbouncer.pid
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
SYSTEMD

log_info "Created systemd service"

# ─── Start PgBouncer ───
log_info "Starting PgBouncer..."

systemctl daemon-reload
systemctl enable pgbouncer
systemctl start pgbouncer

# Wait for PgBouncer to start
sleep 2

# Check status
if systemctl is-active --quiet pgbouncer; then
    log_info "PgBouncer is running on port ${PGBOUNCER_PORT}"
else
    log_error "PgBouncer failed to start. Check logs: journalctl -u pgbouncer"
    exit 1
fi

# ─── Verify Connection ───
log_info "Verifying PgBouncer connection..."

if command -v psql &>/dev/null; then
    if PGPASSWORD="$POSTGRES_PASSWORD" psql -h localhost -p "$PGBOUNCER_PORT" -U leocrm -d leocrm -c "SELECT 1 AS pgbouncer_test;" &>/dev/null; then
        log_info "PgBouncer connection verified successfully!"
    else
        log_warn "Could not verify PgBouncer connection. Check PostgreSQL credentials."
    fi
fi

# ─── Summary ───
echo ""
echo "═══════════════════════════════════════════════"
echo "  PgBouncer Setup Complete"
echo "═══════════════════════════════════════════════"
echo ""
echo "  Configuration:"
echo "    Config file:  ${PGBOUNCER_CONF_DIR}/pgbouncer.ini"
echo "    User list:    ${PGBOUNCER_CONF_DIR}/userlist.txt"
echo "    Listen port:  ${PGBOUNCER_PORT}"
echo "    Pool mode:    ${POOL_MODE}"
echo "    Pool size:    ${DEFAULT_POOL_SIZE}"
echo ""
echo "  Commands:"
echo "    Status:       systemctl status pgbouncer"
echo "    Restart:      systemctl restart pgbouncer"
echo "    Reload:       systemctl reload pgbouncer"
echo "    Stop:         systemctl stop pgbouncer"
echo ""
echo "  Monitoring:"
echo "    Pools:        echo 'SHOW POOLS;' | psql -h localhost -p ${PGBOUNCER_PORT} -U leocrm -d pgbouncer"
echo "    Stats:        echo 'SHOW STATS;' | psql -h localhost -p ${PGBOUNCER_PORT} -U leocrm -d pgbouncer"
echo ""
echo "═══════════════════════════════════════════════"