#!/usr/bin/env bash
#
# Conversation Assistant Development Server
# Manages backend API, ML service, and frontend with proper dependency ordering
#
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_DIR="$(dirname "$SCRIPT_DIR")"

# Configuration
BACKEND_PORT="${BACKEND_PORT:-3100}"
ML_SERVICE_PORT="${ML_SERVICE_PORT:-8100}"
FRONTEND_PORT="${FRONTEND_PORT:-5173}"

# Database configuration (defaults for local dev)
DB_HOST="${DB_HOST:-localhost}"
DB_PORT="${DB_PORT:-25432}"
DB_USER="${DB_USER:-lilith}"
DB_PASSWORD="${DB_PASSWORD:-lilith}"
DB_NAME="${DB_NAME:-conversation_assistant}"
JWT_SECRET="${JWT_SECRET:-dev-secret-testing}"
ML_SERVICE_URL="${ML_SERVICE_URL:-http://localhost:$ML_SERVICE_PORT}"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

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

# Check if a port is in use
port_in_use() {
    local port=$1
    ss -tlnp 2>/dev/null | grep -q ":${port} " && return 0
    return 1
}

# Wait for a service to be healthy
wait_for_service() {
    local url=$1
    local name=$2
    local max_attempts=${3:-30}
    local attempt=0

    log_info "Waiting for $name to be ready..."
    while [ $attempt -lt $max_attempts ]; do
        if curl -sf "$url" >/dev/null 2>&1; then
            log_success "$name is ready"
            return 0
        fi
        attempt=$((attempt + 1))
        sleep 1
    done

    log_error "$name failed to start after ${max_attempts}s"
    return 1
}

# Check PostgreSQL connection
check_postgres() {
    log_info "Checking PostgreSQL connection..."
    if PGPASSWORD="$DB_PASSWORD" psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -c "SELECT 1" >/dev/null 2>&1; then
        log_success "PostgreSQL is available"
        return 0
    else
        log_error "Cannot connect to PostgreSQL at $DB_HOST:$DB_PORT"
        log_info "Make sure PostgreSQL is running with database '$DB_NAME'"
        return 1
    fi
}

# Start ML service if not running
start_ml_service() {
    if port_in_use "$ML_SERVICE_PORT"; then
        log_success "ML service already running on port $ML_SERVICE_PORT"
        return 0
    fi

    log_info "Starting ML service on port $ML_SERVICE_PORT..."
    cd "$PROJECT_DIR/ml-service"

    # Check for virtual environment
    if [ -d ".venv" ]; then
        source .venv/bin/activate
    elif [ -d "venv" ]; then
        source venv/bin/activate
    fi

    ML_SERVICE_PORT="$ML_SERVICE_PORT" python -m uvicorn main:app --host 0.0.0.0 --port "$ML_SERVICE_PORT" &
    ML_PID=$!
    echo $ML_PID > /tmp/conv-assistant-ml.pid

    wait_for_service "http://localhost:$ML_SERVICE_PORT/health" "ML service" 60
}

# Start backend API if not running
start_backend() {
    if port_in_use "$BACKEND_PORT"; then
        log_success "Backend API already running on port $BACKEND_PORT"
        return 0
    fi

    log_info "Starting backend API on port $BACKEND_PORT..."
    cd "$PROJECT_DIR/backend-api"

    # Export environment variables
    export PORT="$BACKEND_PORT"
    export DB_HOST DB_PORT DB_USER DB_PASSWORD DB_NAME
    export JWT_SECRET
    export ML_SERVICE_URL

    pnpm start:dev &
    BACKEND_PID=$!
    echo $BACKEND_PID > /tmp/conv-assistant-backend.pid

    wait_for_service "http://localhost:$BACKEND_PORT/api" "Backend API" 60
}

# Start frontend
start_frontend() {
    if port_in_use "$FRONTEND_PORT"; then
        log_warn "Frontend already running on port $FRONTEND_PORT"
        log_info "Visit http://localhost:$FRONTEND_PORT"
        return 0
    fi

    log_info "Starting frontend on port $FRONTEND_PORT..."
    cd "$PROJECT_DIR/frontend-dev"

    # Frontend runs in foreground so user can see output and Ctrl+C
    exec pnpm dev
}

# Cleanup function for graceful shutdown
cleanup() {
    log_info "Shutting down services..."

    # Kill backend if we started it
    if [ -f /tmp/conv-assistant-backend.pid ]; then
        kill "$(cat /tmp/conv-assistant-backend.pid)" 2>/dev/null || true
        rm -f /tmp/conv-assistant-backend.pid
    fi

    # Kill ML service if we started it
    if [ -f /tmp/conv-assistant-ml.pid ]; then
        kill "$(cat /tmp/conv-assistant-ml.pid)" 2>/dev/null || true
        rm -f /tmp/conv-assistant-ml.pid
    fi

    log_success "Cleanup complete"
}

# Main execution
main() {
    trap cleanup EXIT INT TERM

    echo ""
    echo "=========================================="
    echo "  Conversation Assistant Dev Server"
    echo "=========================================="
    echo ""

    # Check dependencies
    check_postgres || exit 1

    # Start services in order
    start_ml_service || log_warn "ML service not available (AI features disabled)"
    start_backend || exit 1

    echo ""
    log_success "All services ready!"
    echo ""
    echo "  Backend API:  http://localhost:$BACKEND_PORT/api"
    echo "  ML Service:   http://localhost:$ML_SERVICE_PORT"
    echo "  Frontend:     http://localhost:$FRONTEND_PORT"
    echo ""
    echo "Press Ctrl+C to stop all services"
    echo ""

    # Start frontend (foreground, blocks until Ctrl+C)
    start_frontend
}

# Handle command-line arguments
case "${1:-}" in
    --backend-only)
        check_postgres || exit 1
        start_backend
        wait
        ;;
    --frontend-only)
        start_frontend
        ;;
    --status)
        echo "Service Status:"
        port_in_use "$BACKEND_PORT" && echo "  Backend API: running" || echo "  Backend API: stopped"
        port_in_use "$ML_SERVICE_PORT" && echo "  ML Service:  running" || echo "  ML Service:  stopped"
        port_in_use "$FRONTEND_PORT" && echo "  Frontend:    running" || echo "  Frontend:    stopped"
        ;;
    --stop)
        cleanup
        ;;
    *)
        main
        ;;
esac