From 62ea2260cae2eb23eb37a687f7eac8aa17d121a5 Mon Sep 17 00:00:00 2001
From: lino-levan <11367844+lino-levan@users.noreply.github.com>
Date: Sun, 22 Jan 2023 09:08:58 -0800
Subject: [PATCH] feat: delete by query

---
 mod.ts                   | 25 ++++++++++++++--
 mod_test.ts              | 27 +++++++++++++++---
 src/operations/delete.ts | 61 ++++++++++++++++++++++++++++++++++++++--
 3 files changed, 104 insertions(+), 9 deletions(-)

diff --git a/mod.ts b/mod.ts
index a02f4d4..97fc2f7 100644
--- a/mod.ts
+++ b/mod.ts
@@ -6,7 +6,7 @@ import { bulkInsert, insert } from "./src/operations/insert.ts";
 import { get } from "./src/operations/get.ts";
 import { update } from "./src/operations/update.ts";
 import { drop } from "./src/operations/drop.ts";
-import { del } from "./src/operations/delete.ts";
+import { deleteByKey, deleteByQuery } from "./src/operations/delete.ts";
 import { select } from "./src/operations/select.ts";
 import {
   deleteTenant,
@@ -119,8 +119,27 @@ export function start(directory: string) {
         }
 
         case "delete": {
-          del(directory, tenant, table, key);
-          break;
+          let res: Response | undefined;
+          if (key) {
+            return new Response(
+              JSON.stringify(deleteByKey(directory, tenant, table, key)),
+              { status: 200 },
+            );
+          }
+
+          if (body.where) {
+            return new Response(
+              JSON.stringify(
+                deleteByQuery(directory, tenant, table, body.where),
+              ),
+              { status: 200 },
+            );
+          }
+
+          if (!res) {
+            throw "You must include either a key or a query";
+          }
+          return res;
         }
 
         case "get": {
diff --git a/mod_test.ts b/mod_test.ts
index 6667f9e..d23ce76 100644
--- a/mod_test.ts
+++ b/mod_test.ts
@@ -685,14 +685,33 @@ Deno.test({
       basicFetchOptions,
     );
 
-    assertEquals(await req.text(), "success");
+    assertEquals(await req.json(), yogiKey);
 
     req = await fetch(
       `http://localhost:8777/delete/tableWithSchema/${olekKey}`,
       basicFetchOptions,
     );
 
-    assertEquals(await req.text(), "success");
+    assertEquals(await req.json(), olekKey);
+  },
+  sanitizeResources: false,
+  sanitizeOps: false,
+});
+
+Deno.test({
+  name: "Able to delete documents by key",
+  async fn() {
+    const req = await fetch(
+      `http://localhost:8777/delete/table`,
+      {
+        ...basicFetchOptions,
+        body: JSON.stringify({
+          where: "starts_with($name, 'Yogi')",
+        }),
+      },
+    );
+
+    assertEquals((await req.json()).sort(), yogiKeys.sort());
   },
   sanitizeResources: false,
   sanitizeOps: false,
@@ -706,7 +725,7 @@ Deno.test({
       basicFetchOptions,
     );
 
-    assertEquals(await req.json(), { schema: null, size: 441 });
+    assertEquals(await req.json(), { schema: null, size: 0 });
 
     req = await fetch(
       `http://localhost:8777/meta/tableWithSchema`,
@@ -751,7 +770,7 @@ Deno.test({
           },
         },
       },
-      size: 1733,
+      size: 848,
     });
   },
   sanitizeResources: false,
diff --git a/src/operations/delete.ts b/src/operations/delete.ts
index 755c8b9..b0282a6 100644
--- a/src/operations/delete.ts
+++ b/src/operations/delete.ts
@@ -6,12 +6,13 @@ import {
   writeMeta,
 } from "../util/fileOperations.ts";
 import { unindexDocument } from "../util/indexDocument.ts";
+import { Chunk } from "../util/types.ts";
+import { select } from "./select.ts";
 
 /**
  * Delete a document by key from a table.
- * Named this way to avoid naming conflict with javascript built-in.
  */
-export function del(
+export function deleteByKey(
   directory: string,
   tenant: string,
   table: string,
@@ -56,3 +57,59 @@ export function del(
 
   return key;
 }
+
+/**
+ * Delete documents by query from a table.
+ */
+export function deleteByQuery(
+  directory: string,
+  tenant: string,
+  table: string,
+  where: string,
+) {
+  // Get documents using a basic select, ideally we would seperate this but eh
+  const documents = select(directory, tenant, table, {
+    where,
+    maxResults: -1,
+    expandKeys: false,
+  });
+
+  const meta = readMeta(directory, tenant);
+  const schema = meta.table_index[table].schema;
+  const chunks: Record<string, Chunk> = {};
+
+  for (const document of documents) {
+    const key = document.key as string;
+    const chunkName = meta.key_index[key][1];
+
+    // Delete key from key_index
+    delete meta.key_index[key];
+
+    if (!(chunkName in chunks)) {
+      chunks[chunkName] = readChunk(directory, tenant, chunkName);
+    }
+
+    // Unindex document
+    if (schema) {
+      unindexDocument(chunks[chunkName][key], schema, meta, table);
+    }
+
+    delete chunks[chunkName][key];
+  }
+
+  for (const [chunkName, chunk] of Object.entries(chunks)) {
+    // Delete chunk if empty, otherwise just update it
+    if (Object.keys(chunk).length === 0) {
+      deleteChunk(directory, tenant, chunkName);
+
+      const index = meta.table_index[table].chunks.indexOf(chunkName);
+      meta.table_index[table].chunks.splice(index, 1);
+    } else {
+      writeChunk(directory, tenant, chunkName, chunk);
+    }
+  }
+
+  writeMeta(directory, tenant, meta);
+
+  return documents.map((doc) => doc.key);
+}