/*
Copyright IBM Corp. 2017 All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package mocks

import (
	"bytes"
	"crypto"
	"errors"
	"hash"
	"reflect"

	"github.com/hyperledger/fabric/bccsp"
)

type MockBCCSP struct {
	SignArgKey    bccsp.Key
	SignDigestArg []byte
	SignOptsArg   bccsp.SignerOpts

	SignValue []byte
	SignErr   error

	VerifyValue bool
	VerifyErr   error

	ExpectedSig []byte

	KeyImportValue bccsp.Key
	KeyImportErr   error

	EncryptError error
	DecryptError error

	HashVal []byte
	HashErr error
}

func (*MockBCCSP) KeyGen(opts bccsp.KeyGenOpts) (bccsp.Key, error) {
	panic("Not yet implemented")
}

func (*MockBCCSP) KeyDeriv(k bccsp.Key, opts bccsp.KeyDerivOpts) (bccsp.Key, error) {
	panic("Not yet implemented")
}

func (m *MockBCCSP) KeyImport(raw interface{}, opts bccsp.KeyImportOpts) (bccsp.Key, error) {
	return m.KeyImportValue, m.KeyImportErr
}

func (*MockBCCSP) GetKey(ski []byte) (bccsp.Key, error) {
	panic("Not yet implemented")
}

func (m *MockBCCSP) Hash(msg []byte, opts bccsp.HashOpts) ([]byte, error) {
	return m.HashVal, m.HashErr
}

func (*MockBCCSP) GetHash(opts bccsp.HashOpts) (hash.Hash, error) {
	panic("Not yet implemented")
}

func (b *MockBCCSP) Sign(k bccsp.Key, digest []byte, opts bccsp.SignerOpts) ([]byte, error) {
	if !reflect.DeepEqual(b.SignArgKey, k) {
		return nil, errors.New("invalid key")
	}
	if !reflect.DeepEqual(b.SignDigestArg, digest) {
		return nil, errors.New("invalid digest")
	}
	if !reflect.DeepEqual(b.SignOptsArg, opts) {
		return nil, errors.New("invalid opts")
	}

	return b.SignValue, b.SignErr
}

func (b *MockBCCSP) Verify(k bccsp.Key, signature, digest []byte, opts bccsp.SignerOpts) (bool, error) {
	// we want to mock a success
	if b.VerifyValue {
		return b.VerifyValue, nil
	}

	// we want to mock a failure because of an error
	if b.VerifyErr != nil {
		return b.VerifyValue, b.VerifyErr
	}

	// in neither case, compare the signature with the expected one
	return bytes.Equal(b.ExpectedSig, signature), nil
}

func (m *MockBCCSP) Encrypt(k bccsp.Key, plaintext []byte, opts bccsp.EncrypterOpts) ([]byte, error) {
	if m.EncryptError == nil {
		return plaintext, nil
	} else {
		return nil, m.EncryptError
	}
}

func (m *MockBCCSP) Decrypt(k bccsp.Key, ciphertext []byte, opts bccsp.DecrypterOpts) ([]byte, error) {
	if m.DecryptError == nil {
		return ciphertext, nil
	} else {
		return nil, m.DecryptError
	}
}

type MockKey struct {
	BytesValue []byte
	BytesErr   error
	Symm       bool
	PK         bccsp.Key
	PKErr      error
	Pvt        bool
}

func (m *MockKey) Bytes() ([]byte, error) {
	return m.BytesValue, m.BytesErr
}

func (*MockKey) SKI() []byte {
	panic("Not yet implemented")
}

func (m *MockKey) Symmetric() bool {
	return m.Symm
}

func (m *MockKey) Private() bool {
	return m.Pvt
}

func (m *MockKey) PublicKey() (bccsp.Key, error) {
	return m.PK, m.PKErr
}

type SignerOpts struct {
	HashFuncValue crypto.Hash
}

func (o *SignerOpts) HashFunc() crypto.Hash {
	return o.HashFuncValue
}

type KeyGenOpts struct {
	EphemeralValue bool
}

func (*KeyGenOpts) Algorithm() string {
	return "Mock KeyGenOpts"
}

func (o *KeyGenOpts) Ephemeral() bool {
	return o.EphemeralValue
}

type KeyStore struct {
	GetKeyValue bccsp.Key
	GetKeyErr   error
	StoreKeyErr error
}

func (*KeyStore) ReadOnly() bool {
	panic("Not yet implemented")
}

func (ks *KeyStore) GetKey(ski []byte) (bccsp.Key, error) {
	return ks.GetKeyValue, ks.GetKeyErr
}

func (ks *KeyStore) StoreKey(k bccsp.Key) error {
	return ks.StoreKeyErr
}

type KeyImportOpts struct{}

func (*KeyImportOpts) Algorithm() string {
	return "Mock KeyImportOpts"
}

func (*KeyImportOpts) Ephemeral() bool {
	panic("Not yet implemented")
}

type (
	EncrypterOpts struct{}
	DecrypterOpts struct{}
)

type HashOpts struct{}

func (HashOpts) Algorithm() string {
	return "Mock HashOpts"
}

type KeyDerivOpts struct {
	EphemeralValue bool
}

func (*KeyDerivOpts) Algorithm() string {
	return "Mock KeyDerivOpts"
}

func (o *KeyDerivOpts) Ephemeral() bool {
	return o.EphemeralValue
}