first commit of refactor

backend/models/AddressCheckpointModel.js

@@ -0,0 +1,76 @@
+import pool from '../infra/database.js';
+
+
+/**
+ * Get the last checked block number for an address
+ * @param {number} addressId - Address ID from the addresses table
+ * @returns {Promise<number|null>} Last checked block number, or null if never checked
+ */
+export async function getLastCheckedBlock(addressId) {
+  const result = await pool.query(
+    `SELECT last_checked_block
+     FROM address_checkpoints
+     WHERE address_id = $1`,
+    [addressId]
+  );
+  
+  return result.rows[0]?.last_checked_block || null;
+}
+
+/**
+ * Update the last checked block number for an address
+ * Creates a new checkpoint record if one doesn't exist
+ * @param {number} addressId - Address ID from the addresses table
+ * @param {number} blockNumber - Block number that was just checked
+ * @returns {Promise<Object>} Updated checkpoint record
+ */
+export async function updateLastCheckedBlock(addressId, blockNumber) {
+  const result = await pool.query(
+    `INSERT INTO address_checkpoints (address_id, last_checked_block, last_checked_at)
+     VALUES ($1, $2, NOW())
+     ON CONFLICT (address_id)
+     DO UPDATE SET
+       last_checked_block = $2,
+       last_checked_at = NOW()
+     RETURNING address_id, last_checked_block, last_checked_at`,
+    [addressId, blockNumber]
+  );
+  
+  return result.rows[0];
+}
+
+/**
+ * Get all address checkpoints (useful for debugging/monitoring)
+ * @returns {Promise<Array>} Array of checkpoint objects
+ */
+export async function listAll() {
+  const result = await pool.query(
+    `SELECT 
+       ac.address_id,
+       a.address,
+       a.label,
+       ac.last_checked_block,
+       ac.last_checked_at
+     FROM address_checkpoints ac
+     JOIN addresses a ON a.id = ac.address_id
+     ORDER BY ac.last_checked_at DESC`
+  );
+  
+  return result.rows;
+}
+
+/**
+ * Delete checkpoint for an address (useful when address is removed)
+ * Note: This should happen automatically via CASCADE when address is deleted
+ * @param {number} addressId - Address ID
+ * @returns {Promise<boolean>} True if deleted, false if not found
+ */
+export async function remove(addressId) {
+  const result = await pool.query(
+    `DELETE FROM address_checkpoints WHERE address_id = $1`,
+    [addressId]
+  );
+  
+  return result.rowCount > 0;
+}
+