Feature/inv 122 템플릿 CRUD 메서드 구현 (#38)

* feat: implement list templates api

* feat: 템플릿 단건 조회 api 구현

* feat: 템플릿 update api 구현

* feat: 템플릿 삭제 api 구현

* feat: 템플릿 생성 api 구현

src/lib/db/schema/templates.query.ts

@@ -0,0 +1,87 @@
+"use server";
+import { eq } from "drizzle-orm";
+import { nanoid } from "nanoid";
+
+import { db } from "~/lib/db";
+import { templates } from "~/lib/db/schema/templates";
+
+type CreateTemplateParams = {
+  title: string;
+  description?: string;
+  customFields?: Record<string, any>; // JSON data
+};
+
+type UpdateTemplateParams = {
+  id: string;
+  title?: string;
+  description?: string;
+  customFields?: Record<string, any>; // JSON data
+};
+
+export async function getAllTemplates() {
+  const result = await db.select().from(templates);
+  return result;
+}
+
+export async function getById(id: string) {
+  const result = await db.select().from(templates).where(eq(templates.id, id));
+  return result[0];
+}
+
+async function updateTemplate(params: UpdateTemplateParams) {
+  const { id, ...updates } = params;
+
+  if (!id) {
+    throw new Error("ID is required to update a template");
+  }
+
+  const currentTimestamp = new Date();
+
+  try {
+    await db
+      .update(templates)
+      .set({
+        ...updates,
+        updatedAt: currentTimestamp,
+      })
+      .where(eq(templates.id, id));
+  } catch (error) {
+    console.error("Error updating template:", error);
+    throw new Error("Could not update template");
+  }
+}
+
+async function deleteTemplate(id: string): Promise<void> {
+  if (!id) {
+    throw new Error("ID is required to delete a template");
+  }
+
+  try {
+    await db.delete(templates).where(eq(templates.id, id));
+  } catch (error) {
+    console.error("Error deleting template:", error);
+    throw new Error("Could not delete template");
+  }
+}
+
+async function createTemplate(params: CreateTemplateParams): Promise<void> {
+  const { title, description, customFields } = params;
+
+  const id = nanoid();
+
+  const currentTimestamp = new Date();
+
+  try {
+    await db.insert(templates).values({
+      id,
+      title,
+      description,
+      customFields,
+      createdAt: currentTimestamp,
+      updatedAt: currentTimestamp,
+    });
+  } catch (error) {
+    console.error("Error creating template:", error);
+    throw new Error("Could not create template");
+  }
+}