main.go

package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"strings"

	"github.com/maxwelbm/gojson/pkg/gojson"
)

var (
	name       = flag.String("name", "AutoGenerated", "the name of the struct")
	pkg        = flag.String("pkg", "", "the name of the package for the generated code")
	inputName  = flag.String("input", "", "the name of the input file containing JSON (if input not provided via STDIN)")
	outputName = flag.String("o", "", "the name of the file to write the output to (outputs to STDOUT by default)")
	format     = flag.String("fmt", "json", "the format of the input data (json or yaml, defaults to json)")
	tags       = flag.String("tags", "fmt", "comma separated list of the tags to put on the struct, default is the same as fmt")
	// forceFloats = flag.Bool("forcefloats", false, "[experimental] force float64 type for integral values")
	subStruct = flag.Bool("subStruct", false, "create types for sub-structs (default is false)")
)

func main() {
	flag.Parse()

	if *format != "json" && *format != "yaml" {
		flag.Usage()
		fmt.Fprintln(os.Stderr, "fmt must be json or yaml")
		os.Exit(1)
	}

	tagList := make([]string, 0)
	if tags == nil || *tags == "" || *tags == "fmt" {
		tagList = append(tagList, *format)
	} else {
		tagList = strings.Split(*tags, ",")
	}

	if isInteractive() && *inputName == "" {
		flag.Usage()
		fmt.Fprintln(os.Stderr, "Expects input on stdin")
		os.Exit(1)
	}

	var input io.Reader
	input = os.Stdin

	if *inputName != "" {
		f, err := os.Open(*inputName)
		if err != nil {
			log.Fatalf("reading input file: %s", err)
		}

		defer f.Close()
		input = f
	}

	var convertFloats bool

	var parser gojson.Parser

	switch *format {
	case "json":
		parser = gojson.ParseJSON
		convertFloats = true
	case "yaml":
		parser = gojson.ParseYaml
	}

	if output, err := gojson.Generate(input, parser, *name, *pkg, tagList, *subStruct, convertFloats); err != nil {
		fmt.Fprintln(os.Stderr, "error parsing", err)
		os.Exit(1)
	} else {
		if *outputName != "" {
			err := os.WriteFile(*outputName, output, 0644)
			if err != nil {
				log.Fatalf("writing output: %s", err)
			}
		} else {
			fmt.Print(string(output))
		}
	}
}

// Return true if os.Stdin appears to be interactive
func isInteractive() bool {
	fileInfo, err := os.Stdin.Stat()
	if err != nil {
		return false
	}

	return fileInfo.Mode()&(os.ModeCharDevice) != 0
}