package main

import "os"
import "fmt"
import "strings"
import "path/filepath"
import "git.tebibyte.media/sashakoshka/hopp/generate"

func main() {
	name := os.Args[0]
	if len(os.Args) != 3 {
		fmt.Fprintf(os.Stderr, "Usage: %s SOURCE DESTINATION\n", name)
		os.Exit(2)
	}
	source      := os.Args[1]
	destination := os.Args[2]

	input, err := os.Open(source)
	handleErr(1, err)
	defer input.Close()
	protocol, err := generate.ParseReader(input)
	handleErr(1, err)

	absDestination, err := filepath.Abs(destination)
	handleErr(1, err)
	packageName := cleanPackageName(strings.ReplaceAll(
		strings.ToLower(filepath.Base(absDestination)),
		" ", "_"))
	destination = filepath.Join(os.Args[2], "generated.go")

	output, err := os.Create(destination)
	handleErr(1, err)
	err = protocol.Generate(output, packageName)
	handleErr(1, err)
	fmt.Fprintf(os.Stderr, "%s: OK\n", name)
}

func handleErr(code int, err error) {
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s: %v\n", os.Args[0], err)
		os.Exit(code)
	}
}

func cleanPackageName(str string) string {
	buffer := []byte(str)
	j := 0
	for _, b := range buffer {
		if ('a' <= b && b <= 'z') ||
			('A' <= b && b <= 'Z') ||
			('0' <= b && b <= '9') ||
			b == '_' || b == ' ' {
			buffer[j] = b
			j++
		}
	}
	return string(buffer[:j])
}