/*
   Copyright Docker attest authors

   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 tlog

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	"github.com/secure-systems-lab/go-securesystemslib/dsse"
	"github.com/sigstore/rekor/pkg/generated/models"
)

const (
	UseMockTL = true

	TestEntry = `{"body":"eyJhcGlWZXJzaW9uIjoiMC4wLjEiLCJraW5kIjoiaGFzaGVkcmVrb3JkIiwic3BlYyI6eyJkYXRhIjp7Imhhc2giOnsiYWxnb3JpdGhtIjoic2hhMjU2IiwidmFsdWUiOiI5Zjg2ZDA4MTg4NGM3ZDY1OWEyZmVhYTBjNTVhZDAxNWEzYmY0ZjFiMmIwYjgyMmNkMTVkNmMxNWIwZjAwYTA4In19LCJzaWduYXR1cmUiOnsiY29udGVudCI6Ik1FUUNJQUlyVUZGUzBIYmNzZjc5L08yajVXdHl2R2Vvd1NVSXpZcDlBM2IwWnREVUFpQVQxZU42ZjFyVmVWa011REFlN3dxWkJ2bE5LY2VsajNVVDNmaWhyQjZSY2c9PSIsInB1YmxpY0tleSI6eyJjb250ZW50IjoiTFMwdExTMUNSVWRKVGlCRFJWSlVTVVpKUTBGVVJTMHRMUzB0Q2sxSlNVSlZla05DSzJGQlJFRm5SVU5CWjBWQ1RVRnZSME5EY1VkVFRUUTVRa0ZOUTAxQk9IaEVWRUZNUW1kT1ZrSkJUVlJDU0ZKc1l6TlJkMGhvWTA0S1RXcE5lRTFxU1ROTlZHdDVUWHBWTlZkb1kwNU5hbEY0VFdwSk1rMVVhM2xOZWxVMVYycEJVRTFSTUhkRGQxbEVWbEZSUkVWM1VqQmFXRTR3VFVacmR3cEZkMWxJUzI5YVNYcHFNRU5CVVZsSlMyOWFTWHBxTUVSQlVXTkVVV2RCUlVRMFZpdFNSV2g0SzJGeFYwZzNlV3hOVFVSSVlXaE9UVzVOVEZOUFNsQXZDamxyUVcwNWJIQXJNMjF4V1ZSQmFGVlNjbUUyVDBRMVVYZzRXbUprSzJWMVVIbFFhemw1SzNjdloxZEhSRUk1ZW00dlNXd3hTMDVIVFVWUmQwUm5XVVFLVmxJd1VFRlJTQzlDUVZGRVFXZGxRVTFDVFVkQk1WVmtTbEZSVFUxQmIwZERRM05IUVZGVlJrSjNUVVJOUVhkSFFURlZaRVYzUlVJdmQxRkRUVUZCZHdwRWQxbEVWbEl3VWtKQlozZENiMGxGWkVkV2VtUkVRVXRDWjJkeGFHdHFUMUJSVVVSQlowNUtRVVJDUjBGcFJVRTNOMjFFTDFSbVJtRlJVemxrWlhRMENqbFhaRk41YURKT1VTOUZiMVJtYVVGdFFtaHVWblpEVTNSUVowTkpVVU1yZDNSdllpOU9iMUp4T0c5cU4wZDNibTVKYUZKVGRDOVJNbmtyVXpoUkwzSUthRkpVYW5GaE9HZExRVDA5Q2kwdExTMHRSVTVFSUVORlVsUkpSa2xEUVZSRkxTMHRMUzBLIn19fX0=","integratedTime":1703705039,"logID":"c0d23d6ad406973f9559f3ba2d1ca01f84147d8ffc5b8445c224f98b9591801d","logIndex":59674396,"verification":{"inclusionProof":{"checkpoint":"rekor.sigstore.dev - 2605736670972794746\n55510966\nJCi1O53Xmdi9lXnui4Q5SQ+MJSMnWr1Bxn+Q2Qf22tU=\nTimestamp: 1703705040158839214\n\n— rekor.sigstore.dev wNI9ajBFAiAXgtjFDVqCSgiSP04TQzELrz4+EyBwyYVL2EEULTCy0AIhAI9peLU76ZUD1tvU8qvzBJBo77IYD1rc+A1MPc35AeVK\n","hashes":["fb77ee213b48f4b18dc81c6e634c570abf99b257713561f174f2e0f4c039af67","6cb113bbefadecbbb8b89b1c08232438a6125071790b6a062cff8c1ccfdcb91e","6fbe1424e264e4590ca502d671b7a036c87f7a90d1f57534b98eb781144160bf","077b606720a6478200f6c3ed08a68e9b01b1cae192cb120888ddcc95521601bd","b6f8e8bc21ae0cde82b92422a4b4f37b28a43185821e468a4e65b6c79ed8f5b7","89332533fac54e9bc68c7353c42f6ebb9fe38039f67910332ff95082072068d4","0814d6f707a75fb3334bab14ab5466bd8b9a64ae7be7cd4d53a428c64932bc66","e883e826f10329c63a4a2ed21156037a050df43b9d74079296beac6968ed4150","d79230703257b7e4a8a61b032b6980d1a0bdbc7ae96ca838b525b3751785fe48","2f4a77e5288462cd3b75084d37f1502dcbe0943d18dd95cb247fc1ebbabc0aad","38562c253d3536d0d00e3547c880b6b0251a25ac69605b50c9eaa1a27186cc7a","9dea192350ff8b3c0f5ccda38261cb38ebd61869281c3928912332d1144e0a04","2c4d25ba59aa573ab2c79c2d3cd9e1d74789b10632432724d63112ce50b44874","98c486feb5d87092a78a46c4b5be04868654900affc2e86ffb20074dc73a883a","6969c49bd73f19bf28a5eaeabd331ddd60502defb2cd3d96e17b741c80adec6c"],"logIndex":55510965,"rootHash":"2428b53b9dd799d8bd9579ee8b8439490f8c2523275abd41c67f90d907f6dad5","treeSize":55510966},"signedEntryTimestamp":"MEUCIQCG9PRI8PcvtJyE9pbcculZipze6NEWR1Nk8EYocto3BwIgYu5gqgjW80HMjSjUxUNJLp0wlVTesnJCeByUBySc59w="}}`
)

func GetMockTL() TransparencyLog {
	return &MockTransparencyLog{
		UploadLogEntryFunc: func(_ context.Context, _ string, _ []byte, _ []byte, _ dsse.SignerVerifier) (*DockerTLExtension, error) {
			return &DockerTLExtension{
				Kind: "Mock",
				Data: json.RawMessage(TestEntry),
			}, nil
		},
		VerifyLogEntryFunc: func(_ context.Context, ext *DockerTLExtension, _, _ []byte) (time.Time, error) {
			// return the integrated time in the log entry without any checking
			entry := new(models.LogEntryAnon)
			entryBytes, err := json.Marshal(ext.Data)
			if err != nil {
				return time.Time{}, fmt.Errorf("error failed to marshal TL entry: %w", err)
			}
			err = entry.UnmarshalBinary(entryBytes)
			if err != nil {
				return time.Time{}, fmt.Errorf("error failed to unmarshal TL entry: %w", err)
			}
			if entry.IntegratedTime == nil {
				return time.Time{}, fmt.Errorf("error missing integrated time in TL entry")
			}
			return time.Unix(*entry.IntegratedTime, 0), nil
		},
	}
}

type MockTransparencyLog struct {
	UploadLogEntryFunc func(ctx context.Context, subject string, payload, signature []byte, signer dsse.SignerVerifier) (*DockerTLExtension, error)
	VerifyLogEntryFunc func(ctx context.Context, ext *DockerTLExtension, payload, publicKey []byte) (time.Time, error)
}

func (tl *MockTransparencyLog) UploadEntry(ctx context.Context, subject string, payload, signature []byte, signer dsse.SignerVerifier) (*DockerTLExtension, error) {
	if tl.UploadLogEntryFunc != nil {
		return tl.UploadLogEntryFunc(ctx, subject, payload, signature, signer)
	}
	return nil, nil
}

func (tl *MockTransparencyLog) VerifyEntry(ctx context.Context, ext *DockerTLExtension, payload, publicKey []byte) (time.Time, error) {
	if tl.VerifyLogEntryFunc != nil {
		return tl.VerifyLogEntryFunc(ctx, ext, payload, publicKey)
	}
	return time.Time{}, nil
}