feat(store): add migration_log table for PARA migration tracking

Author: devwhodevs

src/store.rs

@@ -47,6 +47,18 @@ pub struct EdgeStats {
     pub isolated_file_count: usize,
 }
 
+/// A record of a PARA migration operation (batch file moves).
+#[derive(Debug, Clone)]
+pub struct MigrationEntry {
+    pub id: i64,
+    pub migration_id: String,
+    pub old_path: String,
+    pub new_path: String,
+    pub category: String,
+    pub confidence: f64,
+    pub migrated_at: String,
+}
+
 /// A record representing a CLI event (for observability/analytics).
 #[derive(Debug, Clone)]
 pub struct CliEvent {
@@ -322,6 +334,20 @@ impl Store {
             CREATE INDEX IF NOT EXISTS idx_unresolved_source ON unresolved_links(source_file);",
         )?;
 
+        // Migration log table — records PARA migration batch operations.
+        self.conn.execute_batch(
+            "CREATE TABLE IF NOT EXISTS migration_log (
+                id           INTEGER PRIMARY KEY,
+                migration_id TEXT NOT NULL,
+                old_path     TEXT NOT NULL,
+                new_path     TEXT NOT NULL,
+                category     TEXT NOT NULL,
+                confidence   REAL NOT NULL,
+                migrated_at  TEXT NOT NULL DEFAULT (datetime('now'))
+            );
+            CREATE INDEX IF NOT EXISTS idx_migration_id ON migration_log(migration_id);",
+        )?;
+
         Ok(())
     }
 
@@ -1504,6 +1530,68 @@ impl Store {
         Ok(results)
     }
 
+    // ── Migration Log ────────────────────────────────────────────
+
+    /// Record a single file move as part of a named migration batch.
+    pub fn log_migration(
+        &self,
+        migration_id: &str,
+        old_path: &str,
+        new_path: &str,
+        category: &str,
+        confidence: f64,
+    ) -> Result<()> {
+        self.conn.execute(
+            "INSERT INTO migration_log (migration_id, old_path, new_path, category, confidence)
+             VALUES (?1, ?2, ?3, ?4, ?5)",
+            params![migration_id, old_path, new_path, category, confidence],
+        )?;
+        Ok(())
+    }
+
+    /// Retrieve all entries for a migration, ordered by insertion order.
+    pub fn get_migration(&self, migration_id: &str) -> Result<Vec<MigrationEntry>> {
+        let mut stmt = self.conn.prepare(
+            "SELECT id, migration_id, old_path, new_path, category, confidence, migrated_at
+             FROM migration_log WHERE migration_id = ?1 ORDER BY id ASC",
+        )?;
+        let rows = stmt.query_map(params![migration_id], |row| {
+            Ok(MigrationEntry {
+                id: row.get(0)?,
+                migration_id: row.get(1)?,
+                old_path: row.get(2)?,
+                new_path: row.get(3)?,
+                category: row.get(4)?,
+                confidence: row.get(5)?,
+                migrated_at: row.get(6)?,
+            })
+        })?;
+        let results: Result<Vec<_>, _> = rows.collect();
+        Ok(results?)
+    }
+
+    /// Return the migration_id of the most recently created migration, if any.
+    pub fn get_last_migration_id(&self) -> Result<Option<String>> {
+        let result = self
+            .conn
+            .query_row(
+                "SELECT migration_id FROM migration_log ORDER BY migrated_at DESC, id DESC LIMIT 1",
+                [],
+                |row| row.get::<_, String>(0),
+            )
+            .optional()?;
+        Ok(result)
+    }
+
+    /// Delete all entries for a migration (for undo / rollback support).
+    pub fn delete_migration(&self, migration_id: &str) -> Result<()> {
+        self.conn.execute(
+            "DELETE FROM migration_log WHERE migration_id = ?1",
+            params![migration_id],
+        )?;
+        Ok(())
+    }
+
     // ── Helpers ─────────────────────────────────────────────────
 
     pub fn next_vector_id(&self) -> Result<u64> {
@@ -3310,4 +3398,31 @@ mod tests {
             .unwrap();
         assert_eq!(store.count_files_with_dates().unwrap(), 2);
     }
+
+    #[test]
+    fn test_migration_log_insert_and_query() {
+        let store = Store::open_memory().unwrap();
+        store.log_migration("mig-001", "old/note.md", "01-Projects/note.md", "project", 0.9).unwrap();
+        store.log_migration("mig-001", "old/ref.md", "03-Resources/ref.md", "resource", 0.85).unwrap();
+        let entries = store.get_migration("mig-001").unwrap();
+        assert_eq!(entries.len(), 2);
+        assert_eq!(entries[0].old_path, "old/note.md");
+    }
+
+    #[test]
+    fn test_migration_log_get_last() {
+        let store = Store::open_memory().unwrap();
+        store.log_migration("mig-001", "a.md", "01-Projects/a.md", "project", 0.9).unwrap();
+        store.log_migration("mig-002", "b.md", "02-Areas/b.md", "area", 0.8).unwrap();
+        let last_id = store.get_last_migration_id().unwrap();
+        assert_eq!(last_id.as_deref(), Some("mig-002"));
+    }
+
+    #[test]
+    fn test_migration_log_delete() {
+        let store = Store::open_memory().unwrap();
+        store.log_migration("mig-001", "a.md", "01-Projects/a.md", "project", 0.9).unwrap();
+        store.delete_migration("mig-001").unwrap();
+        assert!(store.get_migration("mig-001").unwrap().is_empty());
+    }
 }