package TDengineDB

import (
	"compress/gzip"
	"encoding/base64"
	"fmt"
	jsonitor "github.com/json-iterator/go"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"
	"time"
)

const (
	TSDB_DATA_TYPE_NULL       = 0  // 1 bytes
	TSDB_DATA_TYPE_BOOL       = 1  // 1 bytes
	TSDB_DATA_TYPE_TINYINT    = 2  // 1 byte
	TSDB_DATA_TYPE_SMALLINT   = 3  // 2 bytes
	TSDB_DATA_TYPE_INT        = 4  // 4 bytes
	TSDB_DATA_TYPE_BIGINT     = 5  // 8 bytes
	TSDB_DATA_TYPE_FLOAT      = 6  // 4 bytes
	TSDB_DATA_TYPE_DOUBLE     = 7  // 8 bytes
	TSDB_DATA_TYPE_BINARY     = 8  // string
	TSDB_DATA_TYPE_TIMESTAMP  = 9  // 8 bytes
	TSDB_DATA_TYPE_NCHAR      = 10 // unicode string
	TSDB_DATA_TYPE_UTINYINT   = 11 // 1 byte
	TSDB_DATA_TYPE_USMALLINT  = 12 // 2 bytes
	TSDB_DATA_TYPE_UINT       = 13 // 4 bytes
	TSDB_DATA_TYPE_UBIGINT    = 14 // 8 bytes
	TSDB_DATA_TYPE_JSON       = 15
	TSDB_DATA_TYPE_VARBINARY  = 16
	TSDB_DATA_TYPE_DECIMAL    = 17
	TSDB_DATA_TYPE_BLOB       = 18
	TSDB_DATA_TYPE_MEDIUMBLOB = 19
	TSDB_DATA_TYPE_MAX        = 20
)
const (
	TSDB_DATA_TYPE_NULL_Str      = "NULL"
	TSDB_DATA_TYPE_BOOL_Str      = "BOOL"
	TSDB_DATA_TYPE_TINYINT_Str   = "TINYINT"
	TSDB_DATA_TYPE_SMALLINT_Str  = "SMALLINT"
	TSDB_DATA_TYPE_INT_Str       = "INT"
	TSDB_DATA_TYPE_BIGINT_Str    = "BIGINT"
	TSDB_DATA_TYPE_FLOAT_Str     = "FLOAT"
	TSDB_DATA_TYPE_DOUBLE_Str    = "DOUBLE"
	TSDB_DATA_TYPE_BINARY_Str    = "VARCHAR"
	TSDB_DATA_TYPE_TIMESTAMP_Str = "TIMESTAMP"
	TSDB_DATA_TYPE_NCHAR_Str     = "NCHAR"
	TSDB_DATA_TYPE_UTINYINT_Str  = "TINYINT UNSIGNED"
	TSDB_DATA_TYPE_USMALLINT_Str = "SMALLINT UNSIGNED"
	TSDB_DATA_TYPE_UINT_Str      = "INT UNSIGNED"
	TSDB_DATA_TYPE_UBIGINT_Str   = "BIGINT UNSIGNED"
	TSDB_DATA_TYPE_JSON_Str      = "JSON"
)
var TypeNameMap = map[int]string{
	TSDB_DATA_TYPE_NULL:      TSDB_DATA_TYPE_NULL_Str,
	TSDB_DATA_TYPE_BOOL:      TSDB_DATA_TYPE_BOOL_Str,
	TSDB_DATA_TYPE_TINYINT:   TSDB_DATA_TYPE_TINYINT_Str,
	TSDB_DATA_TYPE_SMALLINT:  TSDB_DATA_TYPE_SMALLINT_Str,
	TSDB_DATA_TYPE_INT:       TSDB_DATA_TYPE_INT_Str,
	TSDB_DATA_TYPE_BIGINT:    TSDB_DATA_TYPE_BIGINT_Str,
	TSDB_DATA_TYPE_FLOAT:     TSDB_DATA_TYPE_FLOAT_Str,
	TSDB_DATA_TYPE_DOUBLE:    TSDB_DATA_TYPE_DOUBLE_Str,
	TSDB_DATA_TYPE_BINARY:    TSDB_DATA_TYPE_BINARY_Str,
	TSDB_DATA_TYPE_TIMESTAMP: TSDB_DATA_TYPE_TIMESTAMP_Str,
	TSDB_DATA_TYPE_NCHAR:     TSDB_DATA_TYPE_NCHAR_Str,
	TSDB_DATA_TYPE_UTINYINT:  TSDB_DATA_TYPE_UTINYINT_Str,
	TSDB_DATA_TYPE_USMALLINT: TSDB_DATA_TYPE_USMALLINT_Str,
	TSDB_DATA_TYPE_UINT:      TSDB_DATA_TYPE_UINT_Str,
	TSDB_DATA_TYPE_UBIGINT:   TSDB_DATA_TYPE_UBIGINT_Str,
	TSDB_DATA_TYPE_JSON:      TSDB_DATA_TYPE_JSON_Str,
}

var NameTypeMap = map[string]int{
	TSDB_DATA_TYPE_NULL_Str:      TSDB_DATA_TYPE_NULL,
	TSDB_DATA_TYPE_BOOL_Str:      TSDB_DATA_TYPE_BOOL,
	TSDB_DATA_TYPE_TINYINT_Str:   TSDB_DATA_TYPE_TINYINT,
	TSDB_DATA_TYPE_SMALLINT_Str:  TSDB_DATA_TYPE_SMALLINT,
	TSDB_DATA_TYPE_INT_Str:       TSDB_DATA_TYPE_INT,
	TSDB_DATA_TYPE_BIGINT_Str:    TSDB_DATA_TYPE_BIGINT,
	TSDB_DATA_TYPE_FLOAT_Str:     TSDB_DATA_TYPE_FLOAT,
	TSDB_DATA_TYPE_DOUBLE_Str:    TSDB_DATA_TYPE_DOUBLE,
	TSDB_DATA_TYPE_BINARY_Str:    TSDB_DATA_TYPE_BINARY,
	TSDB_DATA_TYPE_TIMESTAMP_Str: TSDB_DATA_TYPE_TIMESTAMP,
	TSDB_DATA_TYPE_NCHAR_Str:     TSDB_DATA_TYPE_NCHAR,
	TSDB_DATA_TYPE_UTINYINT_Str:  TSDB_DATA_TYPE_UTINYINT,
	TSDB_DATA_TYPE_USMALLINT_Str: TSDB_DATA_TYPE_USMALLINT,
	TSDB_DATA_TYPE_UINT_Str:      TSDB_DATA_TYPE_UINT,
	TSDB_DATA_TYPE_UBIGINT_Str:   TSDB_DATA_TYPE_UBIGINT,
	TSDB_DATA_TYPE_JSON_Str:      TSDB_DATA_TYPE_JSON,
}
var jsonI = jsonitor.ConfigCompatibleWithStandardLibrary

//TDengineClient 数据库客户端  http://192.168.1.215:6041/rest/sql
type TDengineClient struct {
	url           *url.URL            //数据库地址
	header        map[string][]string //请求头
	httpClient    *http.Client        //客户端
	timeFormat    string              //时间格式
	maxRetryCount int                 //重试次数
}

//NewTDengineClient 初始化客户端
func NewTDengineClient(ipport string,user string,password string,timeout time.Duration,retryCount int) *TDengineClient {
	//请求组织
	client := &TDengineClient{
		maxRetryCount: retryCount,
		httpClient: &http.Client{
			Timeout: timeout,
		},
	}
	client.url = &url.URL{
		Scheme: "http",
		Host:   ipport,
		Path:   "/rest/sql",
	}
	basic := base64.StdEncoding.EncodeToString([]byte(fmt.Sprint(user, ":", password)))
	client.header = map[string][]string{
		"Connection":      {"keep-alive"},
		"Accept-Encoding": {"gzip"},
		"Authorization":   {fmt.Sprintf("Basic %s", basic)},
	}
	return client
}

//Execute 执行SQL
//sqlCmd sql语句
func (c *TDengineClient) Execute(sqlCmd string) (*ExecuteResult,error) {
	retryCount := 0
retry:
	reqBody := ioutil.NopCloser(strings.NewReader(sqlCmd))
	request := &http.Request{
		Method:     http.MethodPost,
		URL:        c.url,
		Proto:      "HTTP/1.1",
		ProtoMajor: 1,
		ProtoMinor: 1,
		Header:     c.header,
		Body:       reqBody,
		Host:       c.url.Host,
	}
	response, err := c.httpClient.Do(request)
	if err != nil {
		if urlErr, ok := err.(*url.Error); ok {
			if urlErr.Timeout() {
				retryCount++
				if retryCount <= c.maxRetryCount {
					time.Sleep(time.Microsecond) //休眠放弃cpu,等待下一次时间片
					goto retry
				}
			}
		}
		return nil, err
	}
	defer response.Body.Close()
	//请求状态
	if response.StatusCode != http.StatusOK {
		if response.StatusCode == http.StatusGatewayTimeout || response.StatusCode == http.StatusRequestTimeout {
			retryCount++
			if retryCount <= c.maxRetryCount {
				time.Sleep(time.Microsecond) //休眠放弃cpu,等待下一次时间片
				goto retry
			}
		}
		body, err := ioutil.ReadAll(response.Body)
		if err != nil {
			return nil, fmt.Errorf("Read body err: %s - %s - %s ", response.Status, err, string(body))
		}
		return nil, fmt.Errorf("server response: %s - %s ", response.Status, string(body))
	}
	respBody := response.Body
	//解压
	if response.Header.Get("Content-Encoding") == "gzip" {
		respBody, err = gzip.NewReader(respBody)
		if err != nil {
			return nil, err
		}
	}
	bodyByte, err := ioutil.ReadAll(respBody)
	if err != nil {
		return nil, fmt.Errorf("Read body err: %s - %s ", err, string(bodyByte))
	}
	result, err := c.marshalBody(bodyByte)
	if err != nil {
		return nil, fmt.Errorf("marshal body err: %s - %s ", err, string(bodyByte))
	}
	return result, nil
}

var(
	//时间格式 v3.0 使用  time.RFC3339Nano 格式
	timeFormats = []string{ time.RFC3339Nano,"2006-01-02 15:04:05.999999999"}
)

//marshalBody 反序列化 jsonStr 到 对象
func (c *TDengineClient) marshalBody(body []byte) (*ExecuteResult, error) {
	var result ExecuteResult
	iter := jsonI.BorrowIterator(body)
	defer jsonI.ReturnIterator(iter)
	iter.ReadObjectCB(func(iter *jsonitor.Iterator, s string) bool {
		switch s {
		case "code":
			result.Code = iter.ReadInt()
		case "desc":
			result.Desc = iter.ReadString()
		case "column_meta":
			iter.ReadArrayCB(func(iter *jsonitor.Iterator) bool {
				index := 0
				iter.ReadArrayCB(func(iter *jsonitor.Iterator) bool {
					switch index {
					case 0:
						result.ColNames = append(result.ColNames, iter.ReadString())
						index = 1
					case 1:
						valueType := iter.WhatIsNext()
						if valueType == jsonitor.NumberValue { //v2.0.17
							if c.timeFormat == "" {
								c.timeFormat = timeFormats[1] //时间格式
							}
							result.ColTypes = append(result.ColTypes, iter.ReadInt())
						} else { //v3.0
							if c.timeFormat == "" {
								c.timeFormat = timeFormats[0] //时间格式
							}
							typeStr := iter.ReadString()
							t, exist := NameTypeMap[typeStr]
							if exist {
								result.ColTypes = append(result.ColTypes, t)
							} else {
								iter.ReportError("unsupported type in column_meta", typeStr)
							}
						}
						index = 2
					case 2:
						result.ColLength = append(result.ColLength, iter.ReadInt64())
						index = 0
					}
					return true
				})
				return true
			})
		case "data":
			columnCount := len(result.ColTypes)
			column := 0
			iter.ReadArrayCB(func(iter *jsonitor.Iterator) bool {
				column = 0
				var row = make([]interface{}, columnCount)
				iter.ReadArrayCB(func(iter *jsonitor.Iterator) bool {
					defer func() {
						column += 1
					}()
					columnType := result.ColTypes[column]
					if columnType == TSDB_DATA_TYPE_JSON {
						row[column] = iter.SkipAndReturnBytes()
						return true
					}
					if iter.ReadNil() {
						row[column] = nil
						return true
					}
					var err error
					switch columnType {
					case TSDB_DATA_TYPE_NULL:
						iter.Skip()
						row[column] = nil
					case TSDB_DATA_TYPE_BOOL:
						row[column] = iter.ReadAny().ToBool()
					case TSDB_DATA_TYPE_TINYINT:
						row[column] = iter.ReadInt8()
					case TSDB_DATA_TYPE_SMALLINT:
						row[column] = iter.ReadInt16()
					case TSDB_DATA_TYPE_INT:
						row[column] = iter.ReadInt32()
					case TSDB_DATA_TYPE_BIGINT:
						row[column] = iter.ReadInt64()
					case TSDB_DATA_TYPE_FLOAT:
						row[column] = iter.ReadFloat32()
					case TSDB_DATA_TYPE_DOUBLE:
						row[column] = iter.ReadFloat64()
					case TSDB_DATA_TYPE_BINARY:
						row[column] = iter.ReadString()
					case TSDB_DATA_TYPE_TIMESTAMP:
						b := iter.ReadString()
						row[column], err = time.Parse(c.timeFormat, b)
						if err != nil {
							iter.ReportError("parse time", err.Error())
						}
					case TSDB_DATA_TYPE_NCHAR:
						row[column] = iter.ReadString()
					case TSDB_DATA_TYPE_UTINYINT:
						row[column] = iter.ReadUint8()
					case TSDB_DATA_TYPE_USMALLINT:
						row[column] = iter.ReadUint16()
					case TSDB_DATA_TYPE_UINT:
						row[column] = iter.ReadUint32()
					case TSDB_DATA_TYPE_UBIGINT:
						row[column] = iter.ReadUint64()
					default:
						row[column] = nil
						iter.Skip()
					}
					return iter.Error == nil
				})
				if iter.Error != nil {
					return false
				}
				result.Data = append(result.Data, row)
				return true
			})
		case "rows":
			result.Rows = iter.ReadInt()
		default:
			iter.Skip()
		}
		return iter.Error == nil
	})
	if iter.Error != nil && iter.Error != io.EOF {
		return nil, iter.Error
	}
	return &result, nil
}