package main

import (
	"context"
	"log"
	"os"
	"os/signal"
	"syscall"

	"com.navi.medici.janus/config"
	"com.navi.medici.janus/lib"
	producer_client "com.navi.medici.janus/producer"
	"com.navi.medici.janus/server"
	"com.navi.medici.janus/utils"
	"github.com/spf13/viper"
	"go.uber.org/zap"
)

var (
	port   string
	cors   string
	logger *zap.Logger
)

const METRICS_PORT = "4000"

func init() {
	configs := getConfigs()
	utils.InitializeLogger(configs.Env)
	logger = utils.GetLogger()
	port = configs.Server.Port
	logger.Info("Service started on PORT: " + port)
	logger.Info("Kafka Bootstrap Servers: " + configs.Kafka.Bootstrap_Servers)
	producer_client.InitializeProducers(configs.Kafka, configs.Env)
	logger.Info("Producer Initialized")
}

func getConfigs() config.Configurations {
	viper.SetConfigName("config")
	viper.AddConfigPath("./config")
	viper.SetConfigType("yml")
	viper.AutomaticEnv()

	var configuration config.Configurations
	if err := viper.ReadInConfig(); err != nil {
		log.Fatalf("Error reading config file: %s", err)
	}

	err := viper.Unmarshal(&configuration)
	if err != nil {
		log.Fatalf("Unable to decode into struct: %v", err)
	}

	// Read configurations from environment variables
	configuration.Env = viper.GetString("ENVIRONMENT")
	configuration.Kafka.Bootstrap_Servers = viper.GetString("BOOTSTRAP_SERVERS")
	configuration.Kafka.Kafka_Topic_Json = viper.GetString("KAFKA_TOPIC_JSON")
	configuration.Kafka.Kafka_Topic_Protobuf = viper.GetString("KAFKA_TOPIC_PROTOBUF")
	configuration.Kafka.Sasl_User = viper.GetString("KAFKA_SASL_USER")
	configuration.Kafka.Sasl_Password = viper.GetString("KAFKA_SASL_PASSWORD")
	cors = viper.GetString("CORS_LIST")

	return configuration
}

func main() {
	defer logger.Sync()

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	configs := getConfigs()

	// Initialize worker pool
	workerPool := lib.NewWorkerPool(configs.Server.Goroutines)
	workerPool.Start(ctx)

	// Initialize HTTP server
	httpServer, err := server.NewServer(port, cors, workerPool, logger)
	if err != nil {
		logger.Fatal("Unable to create HTTP server", zap.Error(err))
	}

	// Initialize metrics server
	metricsServer, err := server.MetricServer(METRICS_PORT, logger)
	if err != nil {
		logger.Fatal("Unable to create Metric server", zap.Error(err))
	}

	// Start servers
	httpServer.StartServer()
	metricsServer.StartServer()

	// Handle graceful shutdown
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)

	<-sigChan
	logger.Info("Shutting down servers...")

	// Stop servers
	httpServer.StopServer()
	metricsServer.StopServer()

	// Stop worker pool
	cancel()

	logger.Info("Servers shut down gracefully")
}