From 02b478733c74b99fbc8a39345a72a53fb5c22ddc Mon Sep 17 00:00:00 2001
From: Yann Amsellem <yann@agnostic.engineering>
Date: Thu, 16 Oct 2025 18:05:19 +0200
Subject: [PATCH] chore: parse schema from url

---
 src/lib/olap-engine/engine-remote.ts | 32 ++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/lib/olap-engine/engine-remote.ts b/src/lib/olap-engine/engine-remote.ts
index 9398c98..40034a7 100644
--- a/src/lib/olap-engine/engine-remote.ts
+++ b/src/lib/olap-engine/engine-remote.ts
@@ -4,6 +4,9 @@ import type { Events, ExecOptions, OLAPEngine, OLAPResponse, Table } from './ind
 import CLICKHOUSE_GET_SCHEMA from './queries/clickhouse_get_schema.sql?raw';
 import CLICKHOUSE_GET_UDFS from './queries/clickhouse_get_udfs.sql?raw';
 
+const TABLE_PATTERN =
+	/^(?:[a-zA-Z_]+:[a-zA-Z_]+=[a-zA-Z()0-9]+(?:,[a-zA-Z_]+=[a-zA-Z()0-9]+)*;)*[a-zA-Z_]+:[a-zA-Z_]+=[a-zA-Z()0-9]+(?:,[a-zA-Z_]+=[a-zA-Z()0-9]+)*$/;
+
 export class RemoteEngine extends InternalEventEmitter<Events> implements OLAPEngine {
 	readonly isAbortable = true;
 
@@ -31,9 +34,10 @@ export class RemoteEngine extends InternalEventEmitter<Events> implements OLAPEn
 	}
 
 	async getSchema() {
+		const customs = this.getCustomSchemaFromUrl();
 		const response = await this.exec(CLICKHOUSE_GET_SCHEMA, {}, false);
-		if (!response) return [];
-		return response.data as Table[];
+		if (!response) return customs;
+		return customs.concat(response.data as Table[]);
 	}
 
 	async getUDFs() {
@@ -42,6 +46,30 @@ export class RemoteEngine extends InternalEventEmitter<Events> implements OLAPEn
 
 		return response.data.map((row) => row.name as string);
 	}
+
+	private getCustomSchemaFromUrl(): Table[] {
+		const schema = new URLSearchParams(window.location.search).get('schema');
+		if (!schema) return [];
+		if (!TABLE_PATTERN.test(schema)) {
+			console.warn('Bad schema passed');
+			return [];
+		}
+
+		return schema.split(';').map((raw) => {
+			const [name, _columns] = raw.split(':');
+
+			return {
+				engine: 'custom',
+				name,
+				short: name,
+				url: '',
+				columns: _columns.split(',').map((_column) => {
+					const [name, type] = _column.split('=');
+					return { name, type };
+				})
+			};
+		});
+	}
 }
 
 interface RemoteEngineException {