added BaseIntrospector and reorganized connections

app/src/data/connection/BaseIntrospector.ts

@@ -0,0 +1,75 @@
+import {
+   type DatabaseMetadata,
+   type DatabaseMetadataOptions,
+   type Kysely,
+   type KyselyPlugin,
+   type RawBuilder,
+   type TableMetadata,
+   type DatabaseIntrospector,
+   type SchemaMetadata,
+   ParseJSONResultsPlugin,
+   DEFAULT_MIGRATION_TABLE,
+   DEFAULT_MIGRATION_LOCK_TABLE,
+} from "kysely";
+import { KyselyPluginRunner } from "data/plugins/KyselyPluginRunner";
+import type { IndexMetadata } from "data/connection/Connection";
+
+export type TableSpec = TableMetadata & {
+   indices: IndexMetadata[];
+};
+export type SchemaSpec = TableSpec[];
+
+export type BaseIntrospectorConfig = {
+   excludeTables?: string[];
+   plugins?: KyselyPlugin[];
+};
+
+export abstract class BaseIntrospector implements DatabaseIntrospector {
+   readonly _excludeTables: string[] = [];
+   readonly _plugins: KyselyPlugin[];
+
+   constructor(
+      protected readonly db: Kysely<any>,
+      config: BaseIntrospectorConfig = {},
+   ) {
+      this._excludeTables = config.excludeTables ?? [];
+      this._plugins = config.plugins ?? [new ParseJSONResultsPlugin()];
+   }
+
+   abstract getSchemaSpec(): Promise<SchemaSpec>;
+   abstract getSchemas(): Promise<SchemaMetadata[]>;
+
+   protected getExcludedTableNames(): string[] {
+      return [...this._excludeTables, DEFAULT_MIGRATION_TABLE, DEFAULT_MIGRATION_LOCK_TABLE];
+   }
+
+   protected async executeWithPlugins<T>(query: RawBuilder<any>): Promise<T> {
+      const result = await query.execute(this.db);
+      const runner = new KyselyPluginRunner(this._plugins ?? []);
+      return (await runner.transformResultRows(result.rows)) as unknown as T;
+   }
+
+   async getMetadata(options?: DatabaseMetadataOptions): Promise<DatabaseMetadata> {
+      return {
+         tables: await this.getTables(options),
+      };
+   }
+
+   async getIndices(tbl_name?: string): Promise<IndexMetadata[]> {
+      const schema = await this.getSchemaSpec();
+      return schema
+         .flatMap((table) => table.indices)
+         .filter((index) => !tbl_name || index.table === tbl_name);
+   }
+
+   async getTables(
+      options: DatabaseMetadataOptions = { withInternalKyselyTables: false },
+   ): Promise<TableMetadata[]> {
+      const schema = await this.getSchemaSpec();
+      return schema.map((table) => ({
+         name: table.name,
+         isView: table.isView,
+         columns: table.columns,
+      }));
+   }
+}