feat: sqlite migration

.gitignore

@@ -10,4 +10,11 @@ nimcache/
 *.a
 
 # OS
-.DS_Store 
+.DS_Store
+
+# Temporary files
+*.db
+
+# Compiled files
+chat_sdk/*
+!*.nim

chat_sdk.nimble

@@ -16,3 +16,6 @@ task buildSharedLib, "Build shared library for C bindings":
 
 task buildStaticLib, "Build static library for C bindings":
   exec "nim c --app:staticLib --out:../library/c-bindings/libchatsdk.a chat_sdk/chat_sdk.nim" 
+
+task migrate, "Run database migrations":
+  exec "nim c -r chat_sdk/migration.nim"

chat_sdk/migration.nim

@@ -0,0 +1,40 @@
+import os, osproc, sequtils, algorithm
+import db_connector/db_sqlite
+
+proc ensureMigrationTable(db: DbConn) =
+  db.exec(sql"""
+    CREATE TABLE IF NOT EXISTS schema_migrations (
+      filename TEXT PRIMARY KEY,
+      applied_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    )
+  """)
+
+proc hasMigrationRun(db: DbConn, filename: string): bool =
+  for row in db.fastRows(sql"SELECT 1 FROM schema_migrations WHERE filename = ?", filename):
+    return true
+  return false
+
+proc markMigrationRun(db: DbConn, filename: string) =
+  db.exec(sql"INSERT INTO schema_migrations (filename) VALUES (?)", filename)
+
+proc runMigrations*(db: DbConn, dir = "migrations") =
+  ensureMigrationTable(db)
+  let files = walkFiles(dir / "*.sql").toSeq().sorted()
+  for file in files:
+    if hasMigrationRun(db, file):
+      echo "Already applied: ", file
+    else:
+      echo "Applying: ", file
+      let sql = readFile(file)
+      db.exec(sql(sql))
+      markMigrationRun(db, file)
+
+proc main() =
+  let db = open("test.db", "", "", "")
+  try:
+    runMigrations(db)
+  finally:
+    db.close()
+
+when isMainModule:
+  main()

migrations/README.md

@@ -0,0 +1,9 @@
+## Database Migrations
+
+This directory contains SQL migration files for the Nim Chat SDK. 
+
+Each migration file should be named in the format `NNN_description.sql`, where `NNN` is a zero-padded number indicating the order of the migration. For example, `001_create_user_table.sql` is the first migration.
+
+## Running Migrations
+
+If you want to install a test sqlite database with tables setup, you can run `nimble migrate` from the command line. This will execute all migration files in order, ensuring that your database schema is up to date.