//go:build pkcs11
// +build pkcs11

/*
Copyright IBM Corp. All Rights Reserved.

SPDX-License-Identifier: Apache-2.0
*/

package factory

import (
	"encoding/hex"

	"github.com/hyperledger/fabric-lib-go/bccsp"
	"github.com/hyperledger/fabric-lib-go/bccsp/pkcs11"
	"github.com/hyperledger/fabric-lib-go/bccsp/sw"
	"github.com/pkg/errors"
)

const (
	// PKCS11BasedFactoryName is the name of the factory of the hsm-based BCCSP implementation
	PKCS11BasedFactoryName = "PKCS11"
)

// PKCS11Factory is the factory of the HSM-based BCCSP.
type PKCS11Factory struct{}

// Name returns the name of this factory
func (f *PKCS11Factory) Name() string {
	return PKCS11BasedFactoryName
}

// Get returns an instance of BCCSP using Opts.
func (f *PKCS11Factory) Get(config *FactoryOpts) (bccsp.BCCSP, error) {
	// Validate arguments
	if config == nil || config.PKCS11 == nil {
		return nil, errors.New("Invalid config. It must not be nil.")
	}

	p11Opts := *config.PKCS11
	ks := sw.NewDummyKeyStore()
	mapper := skiMapper(p11Opts)

	return pkcs11.New(p11Opts, ks, pkcs11.WithKeyMapper(mapper))
}

func skiMapper(p11Opts pkcs11.PKCS11Opts) func([]byte) []byte {
	keyMap := map[string]string{}
	for _, k := range p11Opts.KeyIDs {
		keyMap[k.SKI] = k.ID
	}

	return func(ski []byte) []byte {
		keyID := hex.EncodeToString(ski)
		if id, ok := keyMap[keyID]; ok {
			return []byte(id)
		}
		if p11Opts.AltID != "" {
			return []byte(p11Opts.AltID)
		}
		return ski
	}
}
