package namespace

import (
	"context"
	"fmt"
	"time"

	"github.com/DeBrosOfficial/network/pkg/gateway"
	"github.com/DeBrosOfficial/network/pkg/olric"
	"github.com/DeBrosOfficial/network/pkg/rqlite"
	"github.com/DeBrosOfficial/network/pkg/systemd"
	"go.uber.org/zap"
)

// SystemdSpawner spawns namespace cluster processes using systemd services
type SystemdSpawner struct {
	systemdMgr    *systemd.Manager
	namespaceBase string
	logger        *zap.Logger
}

// NewSystemdSpawner creates a new systemd-based spawner
func NewSystemdSpawner(namespaceBase string, logger *zap.Logger) *SystemdSpawner {
	return &SystemdSpawner{
		systemdMgr:    systemd.NewManager(namespaceBase, logger),
		namespaceBase: namespaceBase,
		logger:        logger.With(zap.String("component", "systemd-spawner")),
	}
}

// SpawnRQLite starts a RQLite instance using systemd
func (s *SystemdSpawner) SpawnRQLite(ctx context.Context, namespace, nodeID string, cfg rqlite.InstanceConfig) error {
	s.logger.Info("Spawning RQLite via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	// Build join arguments
	joinArgs := ""
	if len(cfg.JoinAddresses) > 0 {
		joinArgs = fmt.Sprintf("-join %s", cfg.JoinAddresses[0])
		for _, addr := range cfg.JoinAddresses[1:] {
			joinArgs += fmt.Sprintf(",%s", addr)
		}
	}

	// Generate environment file
	envVars := map[string]string{
		"HTTP_ADDR":     fmt.Sprintf("0.0.0.0:%d", cfg.HTTPPort),
		"RAFT_ADDR":     fmt.Sprintf("0.0.0.0:%d", cfg.RaftPort),
		"HTTP_ADV_ADDR": cfg.HTTPAdvAddress,
		"RAFT_ADV_ADDR": cfg.RaftAdvAddress,
		"JOIN_ARGS":     joinArgs,
		"NODE_ID":       nodeID,
	}

	if err := s.systemdMgr.GenerateEnvFile(namespace, nodeID, systemd.ServiceTypeRQLite, envVars); err != nil {
		return fmt.Errorf("failed to generate RQLite env file: %w", err)
	}

	// Start the systemd service
	if err := s.systemdMgr.StartService(namespace, systemd.ServiceTypeRQLite); err != nil {
		return fmt.Errorf("failed to start RQLite service: %w", err)
	}

	// Wait for service to be active
	if err := s.waitForService(namespace, systemd.ServiceTypeRQLite, 30*time.Second); err != nil {
		return fmt.Errorf("RQLite service did not become active: %w", err)
	}

	s.logger.Info("RQLite spawned successfully via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return nil
}

// SpawnOlric starts an Olric instance using systemd
func (s *SystemdSpawner) SpawnOlric(ctx context.Context, namespace, nodeID string, cfg olric.InstanceConfig) error {
	s.logger.Info("Spawning Olric via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	// Generate environment file (Olric uses OLRIC_SERVER_CONFIG env var, set in systemd unit)
	envVars := map[string]string{
		// No additional env vars needed - Olric reads from config file
		// The config file path is set in the systemd unit file
	}

	if err := s.systemdMgr.GenerateEnvFile(namespace, nodeID, systemd.ServiceTypeOlric, envVars); err != nil {
		return fmt.Errorf("failed to generate Olric env file: %w", err)
	}

	// Start the systemd service
	if err := s.systemdMgr.StartService(namespace, systemd.ServiceTypeOlric); err != nil {
		return fmt.Errorf("failed to start Olric service: %w", err)
	}

	// Wait for service to be active
	if err := s.waitForService(namespace, systemd.ServiceTypeOlric, 30*time.Second); err != nil {
		return fmt.Errorf("Olric service did not become active: %w", err)
	}

	s.logger.Info("Olric spawned successfully via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return nil
}

// SpawnGateway starts a Gateway instance using systemd
func (s *SystemdSpawner) SpawnGateway(ctx context.Context, namespace, nodeID string, cfg gateway.InstanceConfig) error {
	s.logger.Info("Spawning Gateway via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	// Generate environment file
	envVars := map[string]string{
		// Gateway uses config file, no additional env vars needed
	}

	if err := s.systemdMgr.GenerateEnvFile(namespace, nodeID, systemd.ServiceTypeGateway, envVars); err != nil {
		return fmt.Errorf("failed to generate Gateway env file: %w", err)
	}

	// Start the systemd service
	if err := s.systemdMgr.StartService(namespace, systemd.ServiceTypeGateway); err != nil {
		return fmt.Errorf("failed to start Gateway service: %w", err)
	}

	// Wait for service to be active
	if err := s.waitForService(namespace, systemd.ServiceTypeGateway, 30*time.Second); err != nil {
		return fmt.Errorf("Gateway service did not become active: %w", err)
	}

	s.logger.Info("Gateway spawned successfully via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return nil
}

// StopRQLite stops a RQLite instance
func (s *SystemdSpawner) StopRQLite(ctx context.Context, namespace, nodeID string) error {
	s.logger.Info("Stopping RQLite via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return s.systemdMgr.StopService(namespace, systemd.ServiceTypeRQLite)
}

// StopOlric stops an Olric instance
func (s *SystemdSpawner) StopOlric(ctx context.Context, namespace, nodeID string) error {
	s.logger.Info("Stopping Olric via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return s.systemdMgr.StopService(namespace, systemd.ServiceTypeOlric)
}

// StopGateway stops a Gateway instance
func (s *SystemdSpawner) StopGateway(ctx context.Context, namespace, nodeID string) error {
	s.logger.Info("Stopping Gateway via systemd",
		zap.String("namespace", namespace),
		zap.String("node_id", nodeID))

	return s.systemdMgr.StopService(namespace, systemd.ServiceTypeGateway)
}

// StopAll stops all services for a namespace
func (s *SystemdSpawner) StopAll(ctx context.Context, namespace string) error {
	s.logger.Info("Stopping all namespace services via systemd",
		zap.String("namespace", namespace))

	return s.systemdMgr.StopAllNamespaceServices(namespace)
}

// waitForService waits for a systemd service to become active
func (s *SystemdSpawner) waitForService(namespace string, serviceType systemd.ServiceType, timeout time.Duration) error {
	deadline := time.Now().Add(timeout)

	for time.Now().Before(deadline) {
		active, err := s.systemdMgr.IsServiceActive(namespace, serviceType)
		if err != nil {
			return fmt.Errorf("failed to check service status: %w", err)
		}

		if active {
			return nil
		}

		time.Sleep(1 * time.Second)
	}

	return fmt.Errorf("service did not become active within %v", timeout)
}