package main

import (
	"bytes"
	"database/sql"
	"fmt"
	"github.com/ClickHouse/clickhouse-go/v2"
	"log"
	"reflect"
	"strings"
	"time"
)

type Ck struct {
	Address      string  //数据库地址:端口
	UserName     string  //用户名
	PassWord     string  //密码
	DBName       string  //数据库名
	DB           *sql.DB //数据库连接池对象
	MaxOpenConns int     //用于设置最大打开的连接数，默认值为0表示不限制。
	MaxIdleConns int     //用于设置闲置的连接数。
}

func (c *Ck) Init() {
	if c.MaxOpenConns <= 0 {
		c.MaxOpenConns = 20
	}
	if c.MaxIdleConns <= 0 {
		c.MaxIdleConns = 20
	}
	c.DB = clickhouse.OpenDB(&clickhouse.Options{
		Addr: strings.Split(c.Address, ","),
		Auth: clickhouse.Auth{
			Database: c.DBName,
			Username: c.UserName,
			Password: c.PassWord,
		},
		//TLS: &tls.Config{
		//	InsecureSkipVerify: true,
		//},
		//Settings: clickhouse.Settings{
		//	"max_execution_time": 60,
		//},
		DialTimeout: time.Second * 30,
		//Compression: &clickhouse.Compression{
		//	Method: clickhouse.CompressionLZ4,
		//},
		//Debug:                true,
		BlockBufferSize:      10,
		MaxCompressionBuffer: 10240,
		//ClientInfo: clickhouse.ClientInfo{
		//	Products: []struct {
		//		Name    string
		//		Version string
		//	}{
		//		{Name: "my-app", Version: "0.1"},
		//	},
		//},
	})
	c.DB.SetMaxIdleConns(c.MaxIdleConns)
	c.DB.SetMaxOpenConns(c.MaxOpenConns)
	c.DB.SetConnMaxLifetime(time.Hour)

}

func (m *Ck) FindOne(tableName string, query map[string]interface{}, fields, order string) *map[string]interface{} {
	list := m.Find(tableName, query, fields, order, 0, 1)
	if list != nil && len(*list) == 1 {
		temp := (*list)[0]
		return &temp
	}
	return nil
}

func (m *Ck) Find(tableName string, query map[string]interface{}, fields, order string, start, pageSize int) *[]map[string]interface{} {
	fs := []string{}
	vs := []interface{}{}
	for k, v := range query {
		rt := reflect.TypeOf(v)
		rv := reflect.ValueOf(v)
		if rt.Kind() == reflect.Map {
			for _, rv_k := range rv.MapKeys() {
				if rv_k.String() == "ne" {
					fs = append(fs, fmt.Sprintf("%s!=?", k))
					vs = append(vs, rv.MapIndex(rv_k).Interface())
				}
				if rv_k.String() == "notin" {
					if len(rv.MapIndex(rv_k).Interface().([]interface{})) > 0 {
						for _, v := range rv.MapIndex(rv_k).Interface().([]interface{}) {
							fs = append(fs, fmt.Sprintf("%s!=?", k))
							vs = append(vs, v)
						}
					}
				}
				if rv_k.String() == "in" {
					if len(rv.MapIndex(rv_k).Interface().([]interface{})) > 0 {
						_fs := fmt.Sprintf("%s in (?", k)
						for k, v := range rv.MapIndex(rv_k).Interface().([]interface{}) {
							if k > 0 {
								_fs += ",?"
							}
							vs = append(vs, v)
						}
						_fs += ")"
						fs = append(fs, _fs)
					}
				}
			}
		} else {
			if v == "$isNull" {
				fs = append(fs, fmt.Sprintf("%s is null", k))
			} else if v == "$isNotNull" {
				fs = append(fs, fmt.Sprintf("%s is not null", k))
			} else {
				fs = append(fs, fmt.Sprintf("%s=?", k))
				vs = append(vs, v)
			}
		}
	}
	var buffer bytes.Buffer
	buffer.WriteString("select ")
	if fields == "" {
		buffer.WriteString("*")
	} else {
		buffer.WriteString(fields)
	}
	buffer.WriteString(" from ")
	buffer.WriteString(tableName)
	if len(fs) > 0 {
		buffer.WriteString(" where ")
		buffer.WriteString(strings.Join(fs, " and "))
	}
	if order != "" {
		buffer.WriteString(" order by ")
		buffer.WriteString(order)
	}
	if start > -1 && pageSize > 0 {
		buffer.WriteString(" limit ")
		buffer.WriteString(fmt.Sprint(start))
		buffer.WriteString(",")
		buffer.WriteString(fmt.Sprint(pageSize))
	}
	q := buffer.String()
	//log.Println(q, vs)
	return m.SelectBySql(q, vs...)
}

func (m *Ck) SelectBySql(q string, args ...interface{}) *[]map[string]interface{} {
	return m.SelectBySqlByTx(nil, q, args...)
}
func (m *Ck) SelectBySqlByTx(tx *sql.Tx, q string, args ...interface{}) *[]map[string]interface{} {
	return m.Select(0, nil, tx, q, args...)
}

func (m *Ck) Select(bath int, f func(l *[]map[string]interface{}), tx *sql.Tx, q string, args ...interface{}) *[]map[string]interface{} {
	var err error
	rows, err := m.DB.Query(q, args...)
	if err != nil {
		log.Println(err)
		return nil
	}
	if rows != nil {
		defer rows.Close()
	}
	columns, err := rows.Columns()
	if err != nil {
		log.Println(err)
		return nil
	}
	list := []map[string]interface{}{}
	for rows.Next() {
		scanArgs := make([]interface{}, len(columns))
		values := make([]interface{}, len(columns))
		ret := make(map[string]interface{})
		for k, _ := range values {
			scanArgs[k] = &values[k]
		}
		err = rows.Scan(scanArgs...)
		if err != nil {
			log.Println(err)
			break
		}
		for i, col := range values {
			if v, ok := col.([]uint8); ok {
				ret[columns[i]] = string(v)
			} else {
				ret[columns[i]] = col
			}
		}
		list = append(list, ret)
		if bath > 0 && len(list) == bath {
			f(&list)
			list = []map[string]interface{}{}
		}
	}
	if bath > 0 && len(list) > 0 {
		f(&list)
		list = []map[string]interface{}{}
	}
	return &list
}