From 22cb4a27b1404093a279ecff4c5a27abd860b7d4 Mon Sep 17 00:00:00 2001
From: Callum <cmwaters19@gmail.com>
Date: Tue, 28 Apr 2020 12:53:26 +0200
Subject: [PATCH] create evidence pool mock

---
 evidence/mock/pool_mock.go | 124 +++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 evidence/mock/pool_mock.go

diff --git a/evidence/mock/pool_mock.go b/evidence/mock/pool_mock.go
new file mode 100644
index 000000000..9ba15807f
--- /dev/null
+++ b/evidence/mock/pool_mock.go
@@ -0,0 +1,124 @@
+package mock
+
+import (
+	"time"
+
+	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
+)
+
+// A quick and easy in-memory mock implementation of the evidence pool configured with both the standard exposed
+// functions and extra helper function to set up, operate and ultimately imitate the evidence pool in a testing
+// environment. Note: this mock does no validation. Do not test with large amounts of evidence
+type EvidencePool struct {
+	PendingEvidenceList   []types.Evidence
+	CommittedEvidenceList []types.Evidence
+	ExpirationAgeTime     time.Duration
+	ExpirationAgeBlock    int64
+	BlockHeight           int64
+	BlockTime             time.Time
+}
+
+// ------------------------ INSTANTIATION METHODS --------------------------------------
+
+func NewEvidencePool(height, expiryHeight int64, currentTime time.Time, expiryTime time.Duration) *EvidencePool {
+	return &EvidencePool{
+		[]types.Evidence{},
+		[]types.Evidence{},
+		expiryTime,
+		expiryHeight,
+		height,
+		currentTime,
+	}
+}
+
+func NewDefaultEvidencePool() *EvidencePool {
+	return NewEvidencePool(1, 1, time.Now(), time.Millisecond)
+}
+
+// ----------------------- EVIDENCE POOL PUBLIC METHODS --------------------------------
+
+func (p *EvidencePool) PendingEvidence(maxNum int64) []types.Evidence {
+	if maxNum == -1 || maxNum >= int64(len(p.PendingEvidenceList)) {
+		return p.PendingEvidenceList
+	}
+	return p.PendingEvidenceList[:maxNum]
+}
+
+func (p *EvidencePool) AddEvidence(evidence types.Evidence) error {
+	p.PendingEvidenceList = append(p.PendingEvidenceList, evidence)
+	return nil
+}
+
+func (p *EvidencePool) Update(block *types.Block, state sm.State) {
+	p.BlockHeight = block.Height
+	p.BlockTime = block.Time
+	p.MarkEvidenceAsCommitted(block.Height, block.Time, block.Evidence.Evidence)
+	p.RemoveExpiredEvidence()
+}
+
+func (p *EvidencePool) MarkEvidenceAsCommitted(height int64, lastBlockTime time.Time, evidence []types.Evidence) {
+	for _, ev := range evidence {
+		if p.IsPending(ev) {
+			p.RemovePendingEvidence(ev)
+		}
+		p.CommittedEvidenceList = append(p.CommittedEvidenceList, ev)
+	}
+}
+
+func (p *EvidencePool) IsPending(evidence types.Evidence) bool {
+	for _, ev := range p.PendingEvidenceList {
+		if ev.Equal(evidence) {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *EvidencePool) IsCommitted(evidence types.Evidence) bool {
+	for _, ev := range p.CommittedEvidenceList {
+		if ev.Equal(evidence) {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *EvidencePool) IsExpired(evidence types.Evidence) bool {
+	return evidence.Height()+p.ExpirationAgeBlock < p.BlockHeight &&
+		evidence.Time().Add(p.ExpirationAgeTime).Before(p.BlockTime)
+}
+
+// ------------------------------- HELPER METHODS --------------------------------------
+
+func (p *EvidencePool) RemovePendingEvidence(evidence types.Evidence) {
+	for idx, ev := range p.PendingEvidenceList {
+		if ev.Equal(evidence) {
+			p.PendingEvidenceList[idx] = p.PendingEvidenceList[len(p.PendingEvidenceList)-1]
+			p.PendingEvidenceList = p.PendingEvidenceList[:len(p.PendingEvidenceList)-1]
+			return
+		}
+	}
+}
+
+func (p *EvidencePool) RemoveExpiredEvidence() {
+	for _, evidence := range p.PendingEvidenceList {
+		if p.IsExpired(evidence) {
+			p.RemovePendingEvidence(evidence)
+		}
+	}
+}
+
+func (p *EvidencePool) AddMockEvidence(height int64, address []byte) types.Evidence {
+	mock := types.MockEvidence{
+		EvidenceHeight:  height,
+		EvidenceTime:    p.BlockTime,
+		EvidenceAddress: address,
+	}
+	_ = p.AddEvidence(mock)
+	return mock
+}
+
+func (p *EvidencePool) CommitEvidence(evidence types.Evidence) {
+	p.MarkEvidenceAsCommitted(evidence.Height(), evidence.Time(), []types.Evidence{evidence})
+}