Add name conflict checking API

backend/src/check/check.controller.ts

@@ -1,4 +1,26 @@
-import { Controller } from "@nestjs/common";
+import { Controller, Post } from "@nestjs/common";
+import { CheckService } from "./check.service";
+import { CheckNameConflictDto } from "./dto/check-name-conflict.dto";
+import { CheckNameConflicReponse } from "./types/check-name-conflict-response.type";
+import { Public } from "src/utils/decorators/auth.decorator";
+import { ApiBody, ApiOkResponse, ApiOperation, ApiTags } from "@nestjs/swagger";
 
+@ApiTags("Check")
 @Controller("check")
-export class CheckController {}
+export class CheckController {
+	constructor(private checkService: CheckService) {}
+
+	@Public()
+	@Post("name-conflicts")
+	@ApiOperation({
+		summary: "Check Whether The Name Conflicts with Username or Title of Workspace.",
+		description: "If the name is conflict, it returns true.",
+	})
+	@ApiBody({ type: CheckNameConflictDto })
+	@ApiOkResponse({ type: CheckNameConflicReponse })
+	async checkNameConflict(
+		checkNameConflictDto: CheckNameConflictDto
+	): Promise<CheckNameConflicReponse> {
+		return this.checkService.checkNameConflict(checkNameConflictDto.name);
+	}
+}

backend/src/check/check.module.ts

@@ -1,9 +1,10 @@
 import { Module } from "@nestjs/common";
 import { CheckService } from "./check.service";
 import { CheckController } from "./check.controller";
+import { PrismaService } from "src/db/prisma.service";
 
 @Module({
-	providers: [CheckService],
+	providers: [CheckService, PrismaService],
 	controllers: [CheckController],
 })
 export class CheckModule {}

backend/src/check/check.service.ts

@@ -1,4 +1,25 @@
 import { Injectable } from "@nestjs/common";
+import { PrismaService } from "src/db/prisma.service";
+import { CheckNameConflicReponse } from "./types/check-name-conflict-response.type";
 
 @Injectable()
-export class CheckService {}
+export class CheckService {
+	constructor(private prismaService: PrismaService) {}
+
+	async checkNameConflict(name: string): Promise<CheckNameConflicReponse> {
+		const conflictUserList = await this.prismaService.user.findMany({
+			where: {
+				nickname: name,
+			},
+		});
+		const conflictWorkspaceList = await this.prismaService.workspace.findMany({
+			where: {
+				title: name,
+			},
+		});
+
+		return {
+			conflict: Boolean(conflictUserList.length + conflictWorkspaceList.length),
+		};
+	}
+}

backend/src/check/dto/check-name-conflict.dto.ts

@@ -0,0 +1,6 @@
+import { ApiProperty } from "@nestjs/swagger";
+
+export class CheckNameConflictDto {
+	@ApiProperty({ type: String, description: "Name to check conflict" })
+	name: string;
+}

backend/src/check/types/check-name-conflict-response.type.ts

@@ -0,0 +1,6 @@
+import { ApiProperty } from "@nestjs/swagger";
+
+export class CheckNameConflicReponse {
+	@ApiProperty({ type: Boolean, description: "Whether the name is conflict" })
+	conflict: boolean;
+}