/*
Tool for generating the frontend definition of the role model
It generates a typescript file containing the full role, but without functions
*/
package main

import (
	"flag"
	"fmt"
	"io"
	"os"
	"regexp"
	"strings"
	"unicode"

	"gitlab.com/mstarongitlab/goutils/sliceutils"
)

var findRoleStructRegex = regexp.MustCompile(`type Role struct \{([\s\S]+)\}\n\n/\*`)

var (
	flagInputFile  = flag.String("input", "", "Specify the input file. If empty, read from stdin")
	flagOutputFile = flag.String(
		"output",
		"",
		"Specify the output file. If empty, writes to stdout",
	)
)

func main() {
	flag.Parse()
	var input io.Reader
	var output io.Writer

	if *flagInputFile == "" {
		input = os.Stdin
	} else {
		file, err := os.Open(*flagInputFile)
		if err != nil {
			panic(err)
		}
		defer file.Close()
		input = file
	}
	if *flagOutputFile == "" {
		output = os.Stdout
	} else {
		file, err := os.Create(*flagOutputFile)
		if err != nil {
			panic(err)
		}
		defer file.Close()
		output = file
	}

	data, err := io.ReadAll(input)
	if err != nil {
		panic(err)
	}
	if !findRoleStructRegex.Match(data) {
		panic("Input doesn't contain role struct")
	}
	content := findRoleStructRegex.FindStringSubmatch(string(data))[1]
	lines := strings.Split(content, "\n")
	lines = sliceutils.Map(lines, func(t string) string { return strings.TrimSpace(t) })
	importantLines := sliceutils.Filter(lines, func(t string) bool {
		if strings.HasPrefix(t, "//") {
			return false
		}
		if strings.Contains(t, "gorm.Model") {
			return false
		}
		data := sliceutils.Filter(strings.Split(t, " "), func(t string) bool { return t != "" })
		if len(data) < 2 {
			return false
		}
		if !strings.HasPrefix(data[1], "*") && !strings.HasPrefix(data[1], "[]") {
			return false
		}
		return true
	})
	nameTypeMap := map[string]string{}
	for _, line := range importantLines {
		parts := sliceutils.Filter(strings.Split(line, " "), func(t string) bool { return t != "" })
		nameTypeMap[parts[0]] = parts[1]
	}

	outBuilder := strings.Builder{}
	outBuilder.WriteString(`// Code generated by cmd/RolesApiTypeGenerator DO NOT EDIT.
// If you need to refresh the content, run go generate again
`)
	outBuilder.WriteString("import Model, { attr } from '@ember-data/model';\n\n")

	outBuilder.WriteString("export default class Role extends Model {\n")
	outBuilder.WriteString(`  @attr() declare createdAt: Date
  @attr() declare updatedAt: Date
  @attr() declare name: string
  @attr() declare priority: number
  @attr() declare isUserRole: boolean
  @attr() declare isBuiltIn: boolean

`)

	for n, t := range nameTypeMap {
		outBuilder.WriteString(fNT(n, t))
	}

	outBuilder.WriteString("}\n\n")
	outBuilder.WriteString(`declare module 'ember-data/types/registries/model' {
  export default interface ModelRegistry {
    role: Role
  }
}`)
	fmt.Fprint(output, outBuilder.String())
}

func convertGoTypeToTS(t string) string {
	switch t {
	case "string", "*string":
		return "string"
	case "time.Time":
		return "Date"
	case "uint",
		"uint8",
		"uint16",
		"uint32",
		"uint64",
		"int",
		"int8",
		"int16",
		"int32",
		"int64",
		"float32",
		"float64",
		"byte",
		"*uint",
		"*uint8",
		"*uint16",
		"*uint32",
		"*uint64",
		"*int",
		"*int8",
		"*int16",
		"*int32",
		"*int64",
		"*float32",
		"*float64",
		"*byte":
		return "number"
	case "bool", "*bool":
		return "boolean"
	case "[]string":
		return "Array<string>"
	default:
		panic(fmt.Sprintf("Unknown type: %s", t))
	}
}

func convertGoNameToTS(name string) string {
	buffer := []rune{}
	isFirst := true
	for _, char := range name {
		if isFirst {
			buffer = append(buffer, unicode.ToLower(char))
			isFirst = false
		} else {
			buffer = append(buffer, char)
		}
	}
	return string(buffer)
}

func fNT(name, valType string) string {
	return fmt.Sprintf(
		"  @attr() declare %s?: %s\n",
		convertGoNameToTS(name),
		convertGoTypeToTS(valType),
	)
}