package pwgen_test

import (
	"code.icb4dc0.de/prskr/go-pwgen"
	"errors"
	"testing"
)

func FuzzDefaultGenerator_Generate(f *testing.F) {

	f.Add(uint(0), uint(2), uint(2), uint(2), uint(2))
	f.Add(uint(5), uint(2), uint(2), uint(2), uint(2))
	f.Add(uint(3), uint(2), uint(2), uint(2), uint(2))
	f.Add(uint(3), uint(2), uint(2), uint(2), uint(0))
	f.Add(uint(3), uint(2), uint(2), uint(2), uint(5))
	f.Add(uint(10), uint(2), uint(2), uint(2), uint(5))

	f.Fuzz(func(t *testing.T, letters, digits, uppercase, lowercase, specials uint) {
		password, err := pwgen.Default.Generate(
			pwgen.WithLetters(letters),
			pwgen.WithDigits(digits),
			pwgen.WithUppercase(uppercase),
			pwgen.WithLowercase(lowercase),
			pwgen.WithSpecials(specials),
		)

		if err != nil {
			if errors.Is(err, pwgen.ErrLengthOverflow) {
				t.Logf("pwgen.ErrLengthOverflow")
				return
			}
			t.Fatal(err)
		}

		if matchesCriteria[rune]([]rune(password), containsDigit) < digits {
			t.Errorf("password %q does not contain %d digits", password, digits)
		}

		if matchesCriteria[rune]([]rune(password), containsLetter) < letters {
			t.Errorf("password %q does not contain %d letters", password, letters)
		}

		if matchesCriteria[rune]([]rune(password), containsUppercase) < uppercase {
			t.Errorf("password %q does not contain %d uppercase", password, uppercase)
		}

		if matchesCriteria[rune]([]rune(password), containsLowercase) < lowercase {
			t.Errorf("password %q does not contain %d lowercase", password, lowercase)
		}

		if matchesCriteria[rune]([]rune(password), containsSpecials) < specials {
			t.Errorf("password %q does not contain %d specials", password, specials)
		}
	})
}

func matchesCriteria[T any](s []T, criteria func(T) bool) uint {
	var found uint
	for i := range s {
		if criteria(s[i]) {
			found += 1
		}
	}
	return found
}

func containsLetter(r rune) bool {
	return r >= 'A' && r <= 'z'
}

func containsDigit(r rune) bool {
	return r >= '0' && r <= '9'
}

func containsSpecials(r rune) bool {
	for i := range pwgen.DefaultSpecialsAlphabet {
		if r == rune(pwgen.DefaultSpecialsAlphabet[i]) {
			return true
		}
	}

	return false
}

func containsLowercase(r rune) bool {
	return r >= 'a' && r <= 'z'
}

func containsUppercase(r rune) bool {
	return r >= 'A' && r <= 'Z'
}