package go_pgp

import (
	"crypto"

	"github.com/ProtonMail/go-crypto/openpgp/packet"
)

const (
	// The minimal number of RSA bits
	MinRSABits = 3072
)

type createOption func(cfg *packet.Config)

func HashOption(h crypto.Hash) createOption {
	if !h.Available() {
		h = 0
	}
	return func(cfg *packet.Config) {
		cfg.DefaultHash = h
	}
}

func CipherOption(cipher packet.CipherFunction) createOption {
	if !cipher.IsSupported() {
		cipher = 0
	}
	return func(cfg *packet.Config) {
		cfg.DefaultCipher = cipher
	}
}

func RSABitsOption(numBits int) createOption {
	if numBits < MinRSABits {
		numBits = MinRSABits
	}
	return func(cfg *packet.Config) {
		cfg.RSABits = numBits
	}
}

type CompressionLevel int

const (
	DefaultCompression CompressionLevel = iota - 1
	NoCompression
	CompressionLevel1
	CompressionLevel2
	CompressionLevel3
	CompressionLevel4
	CompressionLevel5
	CompressionLevel6
	CompressionLevel7
	CompressionLevel8
	CompressionLevel9
	compressionLevelOutOfRange
)

const CompressionLevelMax = compressionLevelOutOfRange - 1

func CompressionOption(level CompressionLevel) createOption {
	if level < DefaultCompression || level > CompressionLevelMax {
		level = CompressionLevel5
	}
	return func(cfg *packet.Config) {
		cfg.CompressionConfig = &packet.CompressionConfig{
			Level: int(level),
		}
	}
}