package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"

	"github.com/zeromicro/ddl-parser/parser"

	"golang.org/x/text/cases"
	"golang.org/x/text/language"
)

var ddlDir = "ddl"
var genDir = "model/gmodel_gen"

func toPascalCase(s string) string {
	words := strings.Split(s, "_")
	for i, word := range words {
		words[i] = cases.Title(language.English).String(strings.ToLower(word))
	}
	return strings.Join(words, "")
}

func main() {
	var name string // 需要序列化的单独文件名
	var gdir string // 需要修改的序列化路径 model
	var ddir string // 需要修改的序列化路径 ddl
	flag.StringVar(&name, "name", "", "输入需要序列化的ddl文件名, 不需要后缀.ddl")
	flag.StringVar(&gdir, "mdir", "", "输入需要生成model的Go文件所在目录")
	flag.StringVar(&ddir, "ddir", "", "输入需要生成ddl的Go文件所在目录")
	flag.Parse()

	if gdir != "" {
		genDir = gdir
	}

	if ddir != "" {
		ddlDir = ddir
	}

	if name != "" {
		name = fmt.Sprintf("%s/%s.sql", ddlDir, name)
		GenFromPath(name)
	} else {
		matches, err := filepath.Glob(fmt.Sprintf("%s/*.sql", ddlDir))
		if err != nil {
			panic(err)
		}

		for _, pth := range matches {
			GenFromPath(pth)
		}
	}
}

func GenFromPath(pth string) {
	p, err := filepath.Abs(pth)
	if err != nil {
		panic(err)
	}

	ddlfilestr, err := ioutil.ReadFile(pth)
	if err != nil {
		panic(err)
	}
	// PRIMARY KEY (`guest_id`) USING BTREE
	re := regexp.MustCompile("PRIMARY\\s+KEY\\s+\\(\\s*`([^`]+)`\\s*\\)|`([^`]+)` [^\n]+PRIMARY\\s+KEY\\s+")

	matches := re.FindStringSubmatch(string(ddlfilestr))
	PrimaryStr := ""
	if len(matches) > 0 {
		PrimaryStr = matches[1]
	}

	var importstr = "import (\"gorm.io/gorm\"\n"

	// 匹配到主键定义
	parser.NewParser()
	result, err := parser.NewParser().From(p)
	if err != nil {
		panic(err)
	}

	fcontent := "package model\n"

	for _, table := range result {
		structstr := "type %s struct {%s\n}\n"

		tableName := toPascalCase(table.Name)

		fieldstr := ""
		for _, col := range table.Columns {
			fieldName := toPascalCase(col.Name)
			typeName := SQLTypeToGoTypeMap[col.DataType.Type()]
			if typeName == "*time.Time" {
				importstr += "\"time\"\n"
			}
			tagstr := "`gorm:"
			if col.Name == PrimaryStr {
				tagstr += "\"primary_key\""
				typeName = typeName[1:]
			} else {
				tagstr += "\"-\""
			}
			tagstr += fmt.Sprintf(" json:\"%s\"`", col.Name)

			fieldColStr := fmt.Sprintf("\n%s %s %s// %s", fieldName, typeName, tagstr, col.Constraint.Comment)

			fieldstr += fieldColStr

		}

		fcontent += importstr + ")\n"
		fcontent += fmt.Sprintf(structstr, tableName, fieldstr)
		modelstr := fmt.Sprintf(`type %sModel struct {db *gorm.DB}`, tableName)
		fcontent += modelstr
		fcontent += "\n"

		newfuncstr := fmt.Sprintf(`func New%sModel(db *gorm.DB) *%sModel {return &%sModel{db}}`, tableName, tableName, tableName)
		fcontent += newfuncstr
		fcontent += "\n"

		genGoFileName := fmt.Sprintf("%s/%s_gen.go", genDir, table.Name)
		f, err := os.OpenFile(genGoFileName, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
		if err != nil {
			panic(err)
		}
		f.WriteString(fcontent)
		err = f.Close()
		if err != nil {
			panic(err)
		}
		err = exec.Command("gofmt", "-w", genGoFileName).Run()
		if err != nil {
			panic(err)
		}

		fcontent = "package model\n// TODO: 使用model的属性做你想做的"
		genGoLogicFileName := fmt.Sprintf("%s/%s_logic.go", genDir, table.Name)

		// 使用 os.Stat 函数获取文件信息
		_, err = os.Stat(genGoLogicFileName)
		// 判断文件是否存在并输出结果
		if os.IsNotExist(err) {
			f2, err := os.OpenFile(genGoLogicFileName, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
			if err != nil {
				panic(err)
			}
			f2.WriteString(fcontent)
			err = f2.Close()
			if err != nil {
				panic(err)
			}
			fmt.Println(genGoLogicFileName, "create!")
		} else {
			fmt.Println(genGoLogicFileName, "exists")
		}

	}
}

const (
	_ int = iota
	LongVarBinary
	LongVarChar
	GeometryCollection
	GeomCollection
	LineString
	MultiLineString
	MultiPoint
	MultiPolygon
	Point
	Polygon
	Json
	Geometry
	Enum
	Set
	Bit
	Time
	Timestamp
	DateTime
	Binary
	VarBinary
	Blob
	Year
	Decimal
	Dec
	Fixed
	Numeric
	Float
	Float4
	Float8
	Double
	Real
	TinyInt
	SmallInt
	MediumInt
	Int
	Integer
	BigInt
	MiddleInt
	Int1
	Int2
	Int3
	Int4
	Int8
	Date
	TinyBlob
	MediumBlob
	LongBlob
	Bool
	Boolean
	Serial
	NVarChar
	NChar
	Char
	Character
	VarChar
	TinyText
	Text
	MediumText
	LongText
)

var SQLTypeToGoTypeMap = map[int]string{
	LongVarBinary: "[]byte",
	Binary:        "[]byte",
	VarBinary:     "[]byte",
	Blob:          "[]byte",
	TinyBlob:      "[]byte",
	MediumBlob:    "[]byte",
	LongBlob:      "[]byte",

	LongVarChar: "*string",
	NVarChar:    "*string",
	NChar:       "*string",
	Char:        "*string",
	Character:   "*string",
	VarChar:     "*string",
	TinyText:    "*string",
	Text:        "*string",
	MediumText:  "*string",
	LongText:    "*string",

	Time:      "*time.Time",
	Timestamp: "*time.Time",
	DateTime:  "*time.Time",
	Date:      "*time.Time",

	Year:      "*int64",
	TinyInt:   "*int64",
	SmallInt:  "*int64",
	MediumInt: "*int64",
	Int:       "*int64",
	Integer:   "*int64",
	BigInt:    "*int64",
	MiddleInt: "*int64",
	Int1:      "*int64",
	Int2:      "*int64",
	Int3:      "*int64",
	Int4:      "*int64",
	Int8:      "*int64",
	Serial:    "*int64",

	Decimal: "*float64",
	Dec:     "*float64",
	Fixed:   "*float64",
	Numeric: "*float64",
	Float:   "*float64",
	Float4:  "*float64",
	Float8:  "*float64",
	Double:  "*float64",
	Real:    "*float64",

	Bool:    "*bool",
	Boolean: "*bool",
}