feat(query): add block by hash query

migrations/20250505144856_headers.sql

@@ -1,7 +1,7 @@
 -- Add migration script here
 CREATE TABLE IF NOT EXISTS headers (
   slot INT PRIMARY KEY,
-  hash VARCHAR NOT NULL,
+  hash VARCHAR NOT NULL UNIQUE,
   parent VARCHAR NOT NULL,
   parent_state_root VARCHAR NOT NULL,
   extrinsic_hash VARCHAR NOT NULL,

src/models/block.rs

@@ -127,6 +127,12 @@ impl Block {
         Ok(Block { slot })
     }
 
+    /// Get the block data by hash from the database.
+    pub async fn get_by_hash(pool: &PgPool, hash: &str) -> Result<Self> {
+        let slot = Header::hash_to_slot(pool, hash).await?;
+        Ok(Block { slot })
+    }
+
     /// Get the raw block data from the database.
     pub async fn raw(pool: &PgPool, slot: i32) -> Result<String> {
         let raw = query_scalar!("SELECT raw FROM blocks WHERE slot=$1", slot)

src/models/header.rs

@@ -89,6 +89,15 @@ impl Header {
         Ok(data)
     }
 
+    /// Get the slot id for block by hash
+    pub async fn hash_to_slot(pool: &PgPool, hash: &str) -> Result<i32> {
+        let data = query_scalar!("SELECT slot FROM headers WHERE hash=$1", hash)
+            .fetch_one(pool)
+            .await?;
+
+        Ok(data)
+    }
+
     pub async fn insert(
         pool: &PgPool,
         slot: i32,

src/schema/root.rs

@@ -53,10 +53,22 @@ impl QueryRoot {
     }
 
     /// Get the block data from the database.
-    async fn block(&self, ctx: &Context<'_>, slot: i32) -> Result<Option<Block>> {
+    async fn block(
+        &self,
+        ctx: &Context<'_>,
+        slot: Option<i32>,
+        hash: Option<String>,
+    ) -> Result<Option<Block>> {
         let pool = &ctx.data::<Manager>()?.pg;
-        let block = Block::get(pool, slot).await.ok();
-        Ok(block)
+        if let Some(slot) = slot {
+            return Ok(Block::get(pool, slot).await.ok());
+        }
+
+        if let Some(hash) = hash {
+            return Ok(Block::get_by_hash(pool, &hash).await.ok());
+        }
+
+        Ok(None)
     }
 
     /// Get the epoch by id