// Copyright (C) 2019-2020 Zilliz. 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 paramtable

import (
	"fmt"
	"os"
	"path"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"syscall"

	"github.com/spf13/cast"
	"github.com/spf13/viper"

	memkv "github.com/milvus-io/milvus/internal/kv/mem"
	"github.com/milvus-io/milvus/internal/log"
	"github.com/milvus-io/milvus/internal/proto/commonpb"
	"github.com/milvus-io/milvus/internal/util/logutil"
	"github.com/milvus-io/milvus/internal/util/typeutil"
)

// UniqueID is type alias of typeutil.UniqueID
type UniqueID = typeutil.UniqueID

const (
	DefaultMinioHost            = "localhost"
	DefaultMinioPort            = "9000"
	DefaultMinioAccessKey       = "minioadmin"
	DefaultMinioSecretAccessKey = "minioadmin"
	DefaultMinioUseSSL          = "false"
	DefaultMinioBucketName      = "a-bucket"
	DefaultPulsarHost           = "localhost"
	DefaultPulsarPort           = "6650"
	DefaultEtcdEndpoints        = "localhost:2379"
	DefaultRocksmqPath          = "/var/lib/milvus/rdb_data"
	DefaultInsertBufferSize     = "16777216"
	DefaultEnvPrefix            = "milvus"
)

var DefaultYaml = "milvus.yaml"

// Base abstracts BaseTable
// TODO: it's never used, consider to substitute BaseTable or to remove it
type Base interface {
	Load(key string) (string, error)
	LoadRange(key, endKey string, limit int) ([]string, []string, error)
	LoadYaml(fileName string) error
	Remove(key string) error
	Save(key, value string) error
	Init()
}

// BaseTable the basics of paramtable
type BaseTable struct {
	once      sync.Once
	params    *memkv.MemoryKV
	configDir string

	RoleName   string
	Log        log.Config
	LogCfgFunc func(log.Config)
}

// GlobalInitWithYaml initializes the param table with the given yaml.
// We will update the global DefaultYaml variable directly, once and for all.
// GlobalInitWithYaml shall be called at the very beginning before initiating the base table.
// GlobalInitWithYaml should be called only in standalone and embedded Milvus.
func (gp *BaseTable) GlobalInitWithYaml(yaml string) {
	gp.once.Do(func() {
		DefaultYaml = yaml
		gp.Init()
	})
}

// Init initializes the param table.
func (gp *BaseTable) Init() {
	gp.params = memkv.NewMemoryKV()
	gp.configDir = gp.initConfPath()
	gp.loadFromYaml(DefaultYaml)
	gp.tryLoadFromEnv()
	gp.InitLogCfg()
}

// GetConfigDir returns the config directory
func (gp *BaseTable) GetConfigDir() string {
	return gp.configDir
}

// LoadFromKVPair saves given kv pair to paramtable
func (gp *BaseTable) LoadFromKVPair(kvPairs []*commonpb.KeyValuePair) error {
	for _, pair := range kvPairs {
		err := gp.Save(pair.Key, pair.Value)
		if err != nil {
			return err
		}
	}
	return nil
}

func (gp *BaseTable) initConfPath() string {
	// check if user set conf dir through env
	configDir, find := syscall.Getenv("MILVUSCONF")
	if !find {
		runPath, err := os.Getwd()
		if err != nil {
			panic(err)
		}
		configDir = runPath + "/configs/"
		if _, err := os.Stat(configDir); err != nil {
			_, fpath, _, _ := runtime.Caller(0)
			// TODO, this is a hack, need to find better solution for relative path
			configDir = path.Dir(fpath) + "/../../../configs/"
		}
	}
	return configDir
}

func (gp *BaseTable) loadFromYaml(file string) {
	if err := gp.LoadYaml(file); err != nil {
		panic(err)
	}
}

func (gp *BaseTable) tryLoadFromEnv() {
	gp.loadEtcdConfig()
	gp.loadMinioConfig()
	gp.loadMQConfig()
	gp.loadDataNodeConfig()
	gp.loadOtherEnvs()
}

// Load loads an object with @key.
func (gp *BaseTable) Load(key string) (string, error) {
	return gp.params.Load(strings.ToLower(key))
}

// Load2 loads an object with multiple @keys, return the first successful value.
// If all keys not exist, return error.
// This is to be compatible with old configuration file.
func (gp *BaseTable) Load2(keys []string) (string, error) {
	for _, key := range keys {
		if str, err := gp.params.Load(strings.ToLower(key)); err == nil {
			return str, nil
		}
	}
	return "", fmt.Errorf("invalid keys: %v", keys)
}

// LoadWithDefault loads an object with @key. If the object does not exist, @defaultValue will be returned.
func (gp *BaseTable) LoadWithDefault(key, defaultValue string) string {
	return gp.params.LoadWithDefault(strings.ToLower(key), defaultValue)
}

// LoadWithDefault2 loads an object with multiple @keys, return the first successful value.
// If all keys not exist, return @defaultValue.
// This is to be compatible with old configuration file.
func (gp *BaseTable) LoadWithDefault2(keys []string, defaultValue string) string {
	for _, key := range keys {
		if str, err := gp.params.Load(strings.ToLower(key)); err == nil {
			return str
		}
	}
	return defaultValue
}

// LoadRange loads objects with range @startKey to @endKey with @limit number of objects.
func (gp *BaseTable) LoadRange(key, endKey string, limit int) ([]string, []string, error) {
	return gp.params.LoadRange(strings.ToLower(key), strings.ToLower(endKey), limit)
}

func (gp *BaseTable) LoadYaml(fileName string) error {
	config := viper.New()
	configFile := gp.configDir + fileName
	if _, err := os.Stat(configFile); err != nil {
		panic("cannot access config file: " + configFile)
	}

	config.SetConfigFile(configFile)
	if err := config.ReadInConfig(); err != nil {
		panic(err)
	}

	for _, key := range config.AllKeys() {
		val := config.Get(key)
		str, err := cast.ToStringE(val)
		if err != nil {
			switch val := val.(type) {
			case []interface{}:
				str = str[:0]
				for _, v := range val {
					ss, err := cast.ToStringE(v)
					if err != nil {
						panic(err)
					}
					if str == "" {
						str = ss
					} else {
						str = str + "," + ss
					}
				}

			default:
				panic("undefined config type, key=" + key)
			}
		}
		err = gp.params.Save(strings.ToLower(key), str)
		if err != nil {
			panic(err)
		}

	}

	return nil
}

func (gp *BaseTable) Remove(key string) error {
	return gp.params.Remove(strings.ToLower(key))
}

func (gp *BaseTable) Save(key, value string) error {
	return gp.params.Save(strings.ToLower(key), value)
}

func (gp *BaseTable) ParseBool(key string, defaultValue bool) bool {
	valueStr := gp.LoadWithDefault(key, strconv.FormatBool(defaultValue))
	value, err := strconv.ParseBool(valueStr)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseFloat(key string) float64 {
	valueStr, err := gp.Load(key)
	if err != nil {
		panic(err)
	}
	value, err := strconv.ParseFloat(valueStr, 64)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseFloatWithDefault(key string, defaultValue float64) float64 {
	valueStr := gp.LoadWithDefault(key, fmt.Sprintf("%f", defaultValue))
	value, err := strconv.ParseFloat(valueStr, 64)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseInt64(key string) int64 {
	valueStr, err := gp.Load(key)
	if err != nil {
		panic(err)
	}
	value, err := strconv.ParseInt(valueStr, 10, 64)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseInt64WithDefault(key string, defaultValue int64) int64 {
	valueStr := gp.LoadWithDefault(key, strconv.FormatInt(defaultValue, 10))
	value, err := strconv.ParseInt(valueStr, 10, 64)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseInt32(key string) int32 {
	valueStr, err := gp.Load(key)
	if err != nil {
		panic(err)
	}
	value, err := strconv.ParseInt(valueStr, 10, 32)
	if err != nil {
		panic(err)
	}
	return int32(value)
}

func (gp *BaseTable) ParseInt32WithDefault(key string, defaultValue int32) int32 {
	valueStr := gp.LoadWithDefault(key, strconv.FormatInt(int64(defaultValue), 10))
	value, err := strconv.ParseInt(valueStr, 10, 32)
	if err != nil {
		panic(err)
	}
	return int32(value)
}

func (gp *BaseTable) ParseInt(key string) int {
	valueStr, err := gp.Load(key)
	if err != nil {
		panic(err)
	}
	value, err := strconv.Atoi(valueStr)
	if err != nil {
		panic(err)
	}
	return value
}

func (gp *BaseTable) ParseIntWithDefault(key string, defaultValue int) int {
	valueStr := gp.LoadWithDefault(key, strconv.FormatInt(int64(defaultValue), 10))
	value, err := strconv.Atoi(valueStr)
	if err != nil {
		panic(err)
	}
	return value
}

// package methods

// ConvertRangeToIntRange converts a range of strings to a range of ints.
func ConvertRangeToIntRange(rangeStr, sep string) []int {
	items := strings.Split(rangeStr, sep)
	if len(items) != 2 {
		panic("Illegal range ")
	}

	startStr := items[0]
	endStr := items[1]
	start, err := strconv.Atoi(startStr)
	if err != nil {
		panic(err)
	}
	end, err := strconv.Atoi(endStr)
	if err != nil {
		panic(err)
	}

	if start < 0 || end < 0 {
		panic("Illegal range value")
	}
	if start > end {
		panic("Illegal range value, start > end")
	}
	return []int{start, end}
}

// ConvertRangeToIntSlice convert given @rangeStr & @sep to a slice of ints.
func ConvertRangeToIntSlice(rangeStr, sep string) []int {
	rangeSlice := ConvertRangeToIntRange(rangeStr, sep)
	start, end := rangeSlice[0], rangeSlice[1]
	var ret []int
	for i := start; i < end; i++ {
		ret = append(ret, i)
	}
	return ret
}

// InitLogCfg init log of the base table
func (gp *BaseTable) InitLogCfg() {
	gp.Log = log.Config{}
	format, err := gp.Load("log.format")
	if err != nil {
		panic(err)
	}
	gp.Log.Format = format
	level, err := gp.Load("log.level")
	if err != nil {
		panic(err)
	}
	gp.Log.Level = level
	gp.Log.File.MaxSize = gp.ParseInt("log.file.maxSize")
	gp.Log.File.MaxBackups = gp.ParseInt("log.file.maxBackups")
	gp.Log.File.MaxDays = gp.ParseInt("log.file.maxAge")
}

// SetLogConfig set log config of the base table
func (gp *BaseTable) SetLogConfig() {
	gp.LogCfgFunc = func(cfg log.Config) {
		logutil.SetupLogger(&cfg)
		defer log.Sync()
	}
}

// SetLogger sets the logger file by given id
func (gp *BaseTable) SetLogger(id UniqueID) {
	rootPath, err := gp.Load("log.file.rootPath")
	if err != nil {
		panic(err)
	}
	if rootPath != "" {
		if id < 0 {
			gp.Log.File.Filename = path.Join(rootPath, gp.RoleName+".log")
		} else {
			gp.Log.File.Filename = path.Join(rootPath, gp.RoleName+"-"+strconv.FormatInt(id, 10)+".log")
		}
	} else {
		gp.Log.File.Filename = ""
	}

	if gp.LogCfgFunc != nil {
		gp.LogCfgFunc(gp.Log)
	}
}

func (gp *BaseTable) loadPulsarConfig() {
	pulsarAddress := os.Getenv("PULSAR_ADDRESS")
	if pulsarAddress == "" {
		pulsarHost := gp.LoadWithDefault("pulsar.address", DefaultPulsarHost)
		port := gp.LoadWithDefault("pulsar.port", DefaultPulsarPort)
		pulsarAddress = "pulsar://" + pulsarHost + ":" + port
	}

	gp.Save("_PulsarAddress", pulsarAddress)
}

func (gp *BaseTable) loadRocksMQConfig() {
	rocksmqPath := os.Getenv("ROCKSMQ_PATH")
	if rocksmqPath == "" {
		rocksmqPath = gp.LoadWithDefault("rocksmq.path", DefaultRocksmqPath)
	}
	gp.Save("_RocksmqPath", rocksmqPath)
}

func (gp *BaseTable) loadMQConfig() {
	gp.loadPulsarConfig()
	gp.loadRocksMQConfig()
}

func (gp *BaseTable) loadEtcdConfig() {
	etcdEndpoints := os.Getenv("ETCD_ENDPOINTS")
	if etcdEndpoints == "" {
		etcdEndpoints = gp.LoadWithDefault("etcd.endpoints", DefaultEtcdEndpoints)
	}
	gp.Save("_EtcdEndpoints", etcdEndpoints)
}

func (gp *BaseTable) loadMinioConfig() {
	minioAddress := os.Getenv("MINIO_ADDRESS")
	if minioAddress == "" {
		minioHost := gp.LoadWithDefault("minio.address", DefaultMinioHost)
		port := gp.LoadWithDefault("minio.port", DefaultMinioPort)
		minioAddress = minioHost + ":" + port
	}
	gp.Save("_MinioAddress", minioAddress)

	minioAccessKey := os.Getenv("MINIO_ACCESS_KEY")
	if minioAccessKey == "" {
		minioAccessKey = gp.LoadWithDefault("minio.accessKeyID", DefaultMinioAccessKey)
	}
	gp.Save("_MinioAccessKeyID", minioAccessKey)

	minioSecretKey := os.Getenv("MINIO_SECRET_KEY")
	if minioSecretKey == "" {
		minioSecretKey = gp.LoadWithDefault("minio.secretAccessKey", DefaultMinioSecretAccessKey)
	}
	gp.Save("_MinioSecretAccessKey", minioSecretKey)

	minioUseSSL := os.Getenv("MINIO_USE_SSL")
	if minioUseSSL == "" {
		minioUseSSL = gp.LoadWithDefault("minio.useSSL", DefaultMinioUseSSL)
	}
	gp.Save("_MinioUseSSL", minioUseSSL)

	minioBucketName := os.Getenv("MINIO_BUCKET_NAME")
	if minioBucketName == "" {
		minioBucketName = gp.LoadWithDefault("minio.bucketName", DefaultMinioBucketName)
	}
	gp.Save("_MinioBucketName", minioBucketName)
}

func (gp *BaseTable) loadDataNodeConfig() {
	insertBufferFlushSize := os.Getenv("DATA_NODE_IBUFSIZE")
	if insertBufferFlushSize == "" {
		insertBufferFlushSize = gp.LoadWithDefault("datanode.flush.insertBufSize", DefaultInsertBufferSize)
	}
	gp.Save("_DATANODE_INSERTBUFSIZE", insertBufferFlushSize)
}

func (gp *BaseTable) loadOtherEnvs() {
	// try to load environment start with ENV_PREFIX
	for _, e := range os.Environ() {
		parts := strings.SplitN(e, "=", 2)
		if strings.Contains(parts[0], DefaultEnvPrefix) {
			parts := strings.SplitN(e, "=", 2)
			// remove the ENV PREFIX and use the rest as key
			keyParts := strings.SplitAfterN(parts[0], ".", 2)
			// mem kv throw no errors
			gp.Save(keyParts[1], parts[1])
		}
	}
}