package main

import (
	"code.icb4dc0.de/prskr/go-pwgen"
	"flag"
	"fmt"
	"log"
	"os"
	"strings"
)

// although there might be terminals where it's less, let's be pessimistic
const tabWidth = 8

var (
	length           uint
	count            int
	letters          uint
	lowercase        uint
	uppercase        uint
	digits           uint
	specials         uint
	specialsAlphabet string
)

func main() {
	flags := flag.NewFlagSet("pwgen", flag.ExitOnError)
	flags.IntVar(&count, "count", 20, "Number of passwords to generate")
	flags.UintVar(&length, "length", 20, "Length of each password to generate")
	flags.UintVar(&letters, "letters", 0, "Number of letters to include at least")
	flags.UintVar(&lowercase, "lowercase", 3, "Number of lowercase characters to include at least")
	flags.UintVar(&uppercase, "uppercase", 3, "Number of uppercase characters to include at least")
	flags.UintVar(&digits, "digits", 3, "Number of digits to include at least")
	flags.UintVar(&specials, "specials", 0, "Number of special characters to include at least")
	flags.StringVar(&specialsAlphabet, "specials-alphabet", pwgen.DefaultSpecialsAlphabet, "Special characters to include as special characters")

	if err := flags.Parse(os.Args[1:]); err != nil {
		log.Fatalf("Failed to parse arguments: %v", err)
	}

	terminalWidth := getWidth()

	passwordsPerRow := int(terminalWidth / (length + tabWidth))

	builder := strings.Builder{}
	for i := 0; i < count; i += passwordsPerRow {
		for j := 0; j < passwordsPerRow && i+j < count; j++ {
			pw, err := pwgen.Generate(
				pwgen.WithLength(length),
				pwgen.WithLetters(letters),
				pwgen.WithLowercase(lowercase),
				pwgen.WithUppercase(uppercase),
				pwgen.WithDigits(digits),
				pwgen.WithSpecials(specials),
				pwgen.WithSpecialsAlphabet(specialsAlphabet),
			)
			if err != nil {
				log.Fatalf("Error occurred generating password: %v", err)
			}

			builder.WriteString(pw)
			builder.WriteRune('\t')
		}

		fmt.Println(strings.TrimSuffix(builder.String(), "\t"))
		builder.Reset()
	}
}