// Copyright © 2023 OpenIM. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"context"
	"flag"
	"fmt"
	"net"
	"net/url"
	"os"
	"strings"
	"time"

	"github.com/minio/minio-go/v7"
	"github.com/redis/go-redis/v9"
	"gopkg.in/yaml.v3"

	"github.com/IBM/sarama"
	"github.com/OpenIMSDK/tools/errs"
	"github.com/go-zookeeper/zk"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"

	"github.com/openimsdk/open-im-server/v3/pkg/common/config"

	"github.com/minio/minio-go/v7/pkg/credentials"
)

const (
	// defaultCfgPath is the default path of the configuration file.
	defaultCfgPath           = "../../../../../config/config.yaml"
	minioHealthCheckDuration = 1
	maxRetry                 = 100
	componentStartErrCode    = 6000
	configErrCode            = 6001
)

const (
	colorRed    = 31
	colorGreen  = 32
	colorYellow = 33
)

var (
	cfgPath = flag.String("c", defaultCfgPath, "Path to the configuration file")

	ErrComponentStart = errs.NewCodeError(componentStartErrCode, "ComponentStartErr")
	ErrConfig         = errs.NewCodeError(configErrCode, "Config file is incorrect")
)

func initCfg() error {
	data, err := os.ReadFile(*cfgPath)
	if err != nil {
		return err
	}

	return yaml.Unmarshal(data, &config.Config)
}

type checkFunc struct {
	name     string
	function func() error
}

func main() {
	flag.Parse()

	if err := initCfg(); err != nil {
		fmt.Printf("Read config failed: %v\n", err)

		return
	}

	checks := []checkFunc{
		//{name: "Mysql", function: checkMysql},
		{name: "Mongo", function: checkMongo},
		{name: "Minio", function: checkMinio},
		{name: "Redis", function: checkRedis},
		{name: "Zookeeper", function: checkZookeeper},
		{name: "Kafka", function: checkKafka},
	}

	for i := 0; i < maxRetry; i++ {
		if i != 0 {
			time.Sleep(3 * time.Second)
		}
		fmt.Printf("Checking components Round %v...\n", i+1)

		allSuccess := true
		for _, check := range checks {
			err := check.function()
			if err != nil {
				errorPrint(fmt.Sprintf("Starting %s failed: %v", check.name, err))
				allSuccess = false
				break
			} else {
				successPrint(fmt.Sprintf("%s starts successfully", check.name))
			}
		}

		if allSuccess {
			successPrint("All components started successfully!")

			return
		}
	}
	os.Exit(1)
}

func exactIP(urll string) string {
	u, _ := url.Parse(urll)
	host, _, err := net.SplitHostPort(u.Host)
	if err != nil {
		host = u.Host
	}
	if strings.HasSuffix(host, ":") {
		host = host[0 : len(host)-1]
	}

	return host
}

// Helper function to get environment variable or default value
func getEnv(key, fallback string) string {
	if value, exists := os.LookupEnv(key); exists {
		return value
	}
	return fallback
}

// checkMongo checks the MongoDB connection
func checkMongo() error {
	// Use environment variables or fallback to config
	uri := getEnv("MONGO_URI", buildMongoURI())

	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI(uri))
	if err != nil {
		return errs.Wrap(err)
	}
	defer client.Disconnect(context.TODO())

	if err = client.Ping(context.TODO(), nil); err != nil {
		return errs.Wrap(err)
	}

	return nil
}

// buildMongoURI constructs the MongoDB URI using configuration settings
func buildMongoURI() string {
	// Fallback to config if environment variables are not set
	username := config.Config.Mongo.Username
	password := config.Config.Mongo.Password
	database := config.Config.Mongo.Database
	maxPoolSize := config.Config.Mongo.MaxPoolSize

	mongodbHosts := strings.Join(config.Config.Mongo.Address, ",")

	if username != "" && password != "" {
		return fmt.Sprintf("mongodb://%s:%s@%s/%s?maxPoolSize=%d&authSource=admin",
			username, password, mongodbHosts, database, maxPoolSize)
	}
	return fmt.Sprintf("mongodb://%s/%s?maxPoolSize=%d&authSource=admin",
		mongodbHosts, database, maxPoolSize)
}

// checkMinio checks the MinIO connection
func checkMinio() error {
	// Check if MinIO is enabled
	if config.Config.Object.Enable != "minio" {
		return nil
	}

	// Prioritize environment variables
	endpoint := getEnv("MINIO_ENDPOINT", config.Config.Object.Minio.Endpoint)
	accessKeyID := getEnv("MINIO_ACCESS_KEY_ID", config.Config.Object.Minio.AccessKeyID)
	secretAccessKey := getEnv("MINIO_SECRET_ACCESS_KEY", config.Config.Object.Minio.SecretAccessKey)
	useSSL := getEnv("MINIO_USE_SSL", "false") // Assuming SSL is not used by default

	if endpoint == "" || accessKeyID == "" || secretAccessKey == "" {
		return ErrConfig.Wrap("MinIO configuration missing")
	}

	// Parse endpoint URL to determine if SSL is enabled
	u, err := url.Parse(endpoint)
	if err != nil {
		return errs.Wrap(err)
	}
	secure := u.Scheme == "https" || useSSL == "true"

	// Initialize MinIO client
	minioClient, err := minio.New(u.Host, &minio.Options{
		Creds:  credentials.NewStaticV4(accessKeyID, secretAccessKey, ""),
		Secure: secure,
	})
	if err != nil {
		return errs.Wrap(err)
	}

	// Perform health check
	cancel, err := minioClient.HealthCheck(time.Duration(minioHealthCheckDuration) * time.Second)
	if err != nil {
		return errs.Wrap(err)
	}
	defer cancel()

	if minioClient.IsOffline() {
		return ErrComponentStart.Wrap("Minio server is offline")
	}

	// Check for localhost in API URL and Minio SignEndpoint
	if exactIP(config.Config.Object.ApiURL) == "127.0.0.1" || exactIP(config.Config.Object.Minio.SignEndpoint) == "127.0.0.1" {
		return ErrConfig.Wrap("apiURL or Minio SignEndpoint endpoint contain 127.0.0.1")
	}

	return nil
}

// checkRedis checks the Redis connection
func checkRedis() error {
	// Prioritize environment variables
	address := getEnv("REDIS_ADDRESS", strings.Join(config.Config.Redis.Address, ","))
	username := getEnv("REDIS_USERNAME", config.Config.Redis.Username)
	password := getEnv("REDIS_PASSWORD", config.Config.Redis.Password)

	// Split address to handle multiple addresses for cluster setup
	redisAddresses := strings.Split(address, ",")

	var redisClient redis.UniversalClient
	if len(redisAddresses) > 1 {
		// Use cluster client for multiple addresses
		redisClient = redis.NewClusterClient(&redis.ClusterOptions{
			Addrs:    redisAddresses,
			Username: username,
			Password: password,
		})
	} else {
		// Use regular client for single address
		redisClient = redis.NewClient(&redis.Options{
			Addr:     redisAddresses[0],
			Username: username,
			Password: password,
		})
	}
	defer redisClient.Close()

	// Ping Redis to check connectivity
	_, err := redisClient.Ping(context.Background()).Result()
	if err != nil {
		return errs.Wrap(err)
	}

	return nil
}

// checkZookeeper checks the Zookeeper connection
func checkZookeeper() error {
	// Prioritize environment variables
	schema := getEnv("ZOOKEEPER_SCHEMA", "digest")
	address := getEnv("ZOOKEEPER_ADDRESS", strings.Join(config.Config.Zookeeper.ZkAddr, ","))
	username := getEnv("ZOOKEEPER_USERNAME", config.Config.Zookeeper.Username)
	password := getEnv("ZOOKEEPER_PASSWORD", config.Config.Zookeeper.Password)

	// Split addresses to handle multiple Zookeeper nodes
	zookeeperAddresses := strings.Split(address, ",")

	// Connect to Zookeeper
	c, _, err := zk.Connect(zookeeperAddresses, time.Second) // Adjust the timeout as necessary
	if err != nil {
		return errs.Wrap(err)
	}
	defer c.Close()

	// Set authentication if username and password are provided
	if username != "" && password != "" {
		if err := c.AddAuth(schema, []byte(username+":"+password)); err != nil {
			return errs.Wrap(err)
		}
	}

	// Check if Zookeeper is reachable
	_, _, err = c.Get("/")
	if err != nil {
		return errs.Wrap(err)
	}

	return nil
}

// checkKafka checks the Kafka connection
func checkKafka() error {
	// Prioritize environment variables
	username := getEnv("KAFKA_USERNAME", config.Config.Kafka.Username)
	password := getEnv("KAFKA_PASSWORD", config.Config.Kafka.Password)
	address := getEnv("KAFKA_ADDRESS", strings.Join(config.Config.Kafka.Addr, ","))

	// Split addresses to handle multiple Kafka brokers
	kafkaAddresses := strings.Split(address, ",")

	// Configure Kafka client
	cfg := sarama.NewConfig()
	if username != "" && password != "" {
		cfg.Net.SASL.Enable = true
		cfg.Net.SASL.User = username
		cfg.Net.SASL.Password = password
	}
	// Additional Kafka setup (e.g., TLS configuration) can be added here
	// kafka.SetupTLSConfig(cfg)

	// Create Kafka client
	kafkaClient, err := sarama.NewClient(kafkaAddresses, cfg)
	if err != nil {
		return errs.Wrap(err)
	}
	defer kafkaClient.Close()

	// Verify if necessary topics exist
	topics, err := kafkaClient.Topics()
	if err != nil {
		return errs.Wrap(err)
	}

	requiredTopics := []string{
		config.Config.Kafka.MsgToMongo.Topic,
		config.Config.Kafka.MsgToPush.Topic,
		config.Config.Kafka.LatestMsgToRedis.Topic,
	}

	for _, requiredTopic := range requiredTopics {
		if !isTopicPresent(requiredTopic, topics) {
			return ErrComponentStart.Wrap(fmt.Sprintf("Kafka doesn't contain topic: %v", requiredTopic))
		}
	}

	return nil
}

// isTopicPresent checks if a topic is present in the list of topics
func isTopicPresent(topic string, topics []string) bool {
	for _, t := range topics {
		if t == topic {
			return true
		}
	}
	return false
}

func colorPrint(colorCode int, format string, a ...interface{}) {
	fmt.Printf("\x1b[%dm%s\x1b[0m\n", colorCode, fmt.Sprintf(format, a...))
}

func errorPrint(s string) {
	colorPrint(colorRed, "%v", s)
}

func successPrint(s string) {
	colorPrint(colorGreen, "%v", s)
}

func warningPrint(s string) {
	colorPrint(colorYellow, "Warning: But %v", s)
}