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 targerDir = "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
	flag.StringVar(&name, "name", "", "输入需要序列化的ddl文件名, 不需要后缀.ddl")
	flag.Parse()

	if name != "" {
		name = fmt.Sprintf("%s/%s.sql", targerDir, name)
		GenFromPath(name)
	} else {
		matches, err := filepath.Glob(fmt.Sprintf("%s/*.sql", targerDir))
		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)
		}
		// log.Println(fcontent)
	}
}