From 186e862c8c58a8d06ae0948a0393da7ffd544a7a Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Thu, 21 Nov 2024 12:15:26 -0600
Subject: [PATCH] feat: expose previous block hash in block interface

Fixes #797
---
 ledger/allegra/allegra.go |  4 ++++
 ledger/alonzo/alonzo.go   |  4 ++++
 ledger/babbage/babbage.go |  8 ++++++++
 ledger/block.go           |  1 +
 ledger/byron/byron.go     | 16 ++++++++++++++++
 ledger/conway/conway.go   |  4 ++++
 ledger/mary/mary.go       |  4 ++++
 ledger/shelley/shelley.go |  8 ++++++++
 8 files changed, 49 insertions(+)

diff --git a/ledger/allegra/allegra.go b/ledger/allegra/allegra.go
index fb5084e9..ae45b1f3 100644
--- a/ledger/allegra/allegra.go
+++ b/ledger/allegra/allegra.go
@@ -68,6 +68,10 @@ func (b *AllegraBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *AllegraBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *AllegraBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
diff --git a/ledger/alonzo/alonzo.go b/ledger/alonzo/alonzo.go
index 2823e16d..345a1128 100644
--- a/ledger/alonzo/alonzo.go
+++ b/ledger/alonzo/alonzo.go
@@ -71,6 +71,10 @@ func (b *AlonzoBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *AlonzoBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *AlonzoBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
diff --git a/ledger/babbage/babbage.go b/ledger/babbage/babbage.go
index d8402f43..d52852bc 100644
--- a/ledger/babbage/babbage.go
+++ b/ledger/babbage/babbage.go
@@ -72,6 +72,10 @@ func (b *BabbageBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *BabbageBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *BabbageBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
@@ -174,6 +178,10 @@ func (h *BabbageBlockHeader) Hash() string {
 	return h.hash
 }
 
+func (h *BabbageBlockHeader) PrevHash() string {
+	return h.Body.PrevHash.String()
+}
+
 func (h *BabbageBlockHeader) BlockNumber() uint64 {
 	return h.Body.BlockNumber
 }
diff --git a/ledger/block.go b/ledger/block.go
index 967bb47a..be21a8a8 100644
--- a/ledger/block.go
+++ b/ledger/block.go
@@ -29,6 +29,7 @@ type Block interface {
 
 type BlockHeader interface {
 	Hash() string
+	PrevHash() string
 	BlockNumber() uint64
 	SlotNumber() uint64
 	IssuerVkey() IssuerVkey
diff --git a/ledger/byron/byron.go b/ledger/byron/byron.go
index 042d27d4..9a07d5a5 100644
--- a/ledger/byron/byron.go
+++ b/ledger/byron/byron.go
@@ -101,6 +101,10 @@ func (h *ByronMainBlockHeader) Hash() string {
 	return h.hash
 }
 
+func (h *ByronMainBlockHeader) PrevHash() string {
+	return h.PrevBlock.String()
+}
+
 func (h *ByronMainBlockHeader) BlockNumber() uint64 {
 	// Byron blocks don't store the block number in the block
 	return 0
@@ -525,6 +529,10 @@ func (h *ByronEpochBoundaryBlockHeader) Hash() string {
 	return h.hash
 }
 
+func (h *ByronEpochBoundaryBlockHeader) PrevHash() string {
+	return h.PrevBlock.String()
+}
+
 func (h *ByronEpochBoundaryBlockHeader) BlockNumber() uint64 {
 	// Byron blocks don't store the block number in the block
 	return 0
@@ -569,6 +577,10 @@ func (b *ByronMainBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *ByronMainBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *ByronMainBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
@@ -623,6 +635,10 @@ func (b *ByronEpochBoundaryBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *ByronEpochBoundaryBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *ByronEpochBoundaryBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
diff --git a/ledger/conway/conway.go b/ledger/conway/conway.go
index 5c2e7b7c..de39e9cf 100644
--- a/ledger/conway/conway.go
+++ b/ledger/conway/conway.go
@@ -71,6 +71,10 @@ func (b *ConwayBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *ConwayBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *ConwayBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
diff --git a/ledger/mary/mary.go b/ledger/mary/mary.go
index 7d2ced51..967f4cd4 100644
--- a/ledger/mary/mary.go
+++ b/ledger/mary/mary.go
@@ -70,6 +70,10 @@ func (b *MaryBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *MaryBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *MaryBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
diff --git a/ledger/shelley/shelley.go b/ledger/shelley/shelley.go
index 226dafe4..3de1e6b2 100644
--- a/ledger/shelley/shelley.go
+++ b/ledger/shelley/shelley.go
@@ -67,6 +67,10 @@ func (b *ShelleyBlock) Hash() string {
 	return b.Header.Hash()
 }
 
+func (b *ShelleyBlock) PrevHash() string {
+	return b.Header.PrevHash()
+}
+
 func (b *ShelleyBlock) BlockNumber() uint64 {
 	return b.Header.BlockNumber()
 }
@@ -158,6 +162,10 @@ func (h *ShelleyBlockHeader) Hash() string {
 	return h.hash
 }
 
+func (h *ShelleyBlockHeader) PrevHash() string {
+	return h.Body.PrevHash.String()
+}
+
 func (h *ShelleyBlockHeader) BlockNumber() uint64 {
 	return h.Body.BlockNumber
 }