feat: add snippet search API

app/api/snippets/route.ts

@@ -4,6 +4,7 @@ import { SnippetRepository } from "./snippet.repository";
 import { OwnershipMiddleware } from "./ownership.middleware";
 import { ZodError } from "zod";
 import { rateLimit } from "@/lib/rateLimiter";
+import { SearchSnippetsOptions } from "./snippet.repository";
 
 // Default pagination settings
 const DEFAULT_LIMIT = 20;
@@ -15,21 +16,67 @@ const RATE_LIMIT_MAX_REQUESTS = 10;
 const repository = new SnippetRepository();
 const service = new SnippetService(repository);
 
+function parseBoundedInteger(
+  value: string | null,
+  fallback: number,
+  min: number,
+  max: number,
+) {
+  const parsed = Number.parseInt(value ?? "", 10);
+
+  if (Number.isNaN(parsed)) {
+    return fallback;
+  }
+
+  return Math.min(Math.max(parsed, min), max);
+}
+
+function parseSearchOptions(req: NextRequest): SearchSnippetsOptions {
+  const { searchParams } = new URL(req.url);
+  const rawTags = searchParams.get("tags");
+
+  return {
+    limit: parseBoundedInteger(searchParams.get("limit"), DEFAULT_LIMIT, 1, MAX_LIMIT),
+    offset: parseBoundedInteger(searchParams.get("offset"), 0, 0, Number.MAX_SAFE_INTEGER),
+    title: searchParams.get("title")?.trim() || undefined,
+    language: searchParams.get("language")?.trim() || undefined,
+    keyword: searchParams.get("keyword")?.trim() || undefined,
+    tags:
+      rawTags
+        ?.split(",")
+        .map((tag) => tag.trim())
+        .filter(Boolean) || undefined,
+  };
+}
+
+function hasSearchFilters(options: SearchSnippetsOptions) {
+  return Boolean(
+    options.title ||
+      options.language ||
+      options.keyword ||
+      (options.tags && options.tags.length > 0),
+  );
+}
+
 export async function GET(req: NextRequest) {
   try {
-    const { searchParams } = new URL(req.url);
-
-    // Parse pagination parameters with validation
-    const limit = Math.min(
-      Math.max(parseInt(searchParams.get("limit") || String(DEFAULT_LIMIT), 10),
-      MAX_LIMIT
-    );
-    const offset = Math.max(parseInt(searchParams.get("offset") || "0", 10), 0);
+    const options = parseSearchOptions(req);
+    const result = hasSearchFilters(options)
+      ? await service.searchSnippets(options)
+      : await service.getAllSnippets({
+          limit: options.limit,
+          offset: options.offset,
+        });
 
-    // Handle backward compatibility: if no pagination params, return all (first page)
-    const result = await service.getAllSnippets({ limit, offset });
-
-    return NextResponse.json(result);
+    return NextResponse.json({
+      ...result,
+      filters: {
+        title: options.title ?? null,
+        language: options.language ?? null,
+        tags: options.tags ?? [],
+        keyword: options.keyword ?? null,
+      },
+    });
   } catch (error) {
     console.error("[API] Error fetching snippets:", error);
     return NextResponse.json(
@@ -91,4 +138,4 @@ export async function POST(req: NextRequest) {
       { status: 500 },
     );
   }
-}
+}

app/api/snippets/snippet.repository.ts

@@ -8,6 +8,13 @@ export interface PaginationOptions {
   offset: number;
 }
 
+export interface SearchSnippetsOptions extends PaginationOptions {
+  title?: string;
+  language?: string;
+  tags?: string[];
+  keyword?: string;
+}
+
 // Paginated result interface
 export interface PaginatedResult<T> {
   data: T[];
@@ -51,6 +58,67 @@ export class SnippetRepository {
     };
   }
 
+  async search(options: SearchSnippetsOptions) {
+    const limit = options.limit;
+    const offset = options.offset;
+    const title = options.title?.trim() || null;
+    const titlePattern = title ? `%${title}%` : null;
+    const language = options.language?.trim() || null;
+    const keyword = options.keyword?.trim() || null;
+    const tags = options.tags?.length ? options.tags : null;
+    const tagsJson = tags ? JSON.stringify(tags) : null;
+
+    const countResult = await this.sql`
+      SELECT COUNT(*) AS total
+      FROM snippets
+      WHERE (${title}::text IS NULL OR title ILIKE ${titlePattern})
+        AND (${language}::text IS NULL OR LOWER(language) = LOWER(${language}))
+        AND (${tagsJson}::jsonb IS NULL OR tags @> ${tagsJson}::jsonb)
+        AND (
+          ${keyword}::text IS NULL
+          OR (
+            setweight(to_tsvector('simple', COALESCE(title, '')), 'A') ||
+            setweight(to_tsvector('simple', COALESCE(description, '')), 'B') ||
+            setweight(to_tsvector('simple', COALESCE(code, '')), 'C') ||
+            setweight(to_tsvector('simple', COALESCE(language, '')), 'B') ||
+            setweight(jsonb_to_tsvector('simple', COALESCE(tags, '[]'::jsonb), '["string"]'), 'B')
+          ) @@ websearch_to_tsquery('simple', ${keyword})
+        )
+    `;
+
+    const total = Number(countResult[0]?.total ?? 0);
+
+    const result = await this.sql`
+      SELECT *
+      FROM snippets
+      WHERE (${title}::text IS NULL OR title ILIKE ${titlePattern})
+        AND (${language}::text IS NULL OR LOWER(language) = LOWER(${language}))
+        AND (${tagsJson}::jsonb IS NULL OR tags @> ${tagsJson}::jsonb)
+        AND (
+          ${keyword}::text IS NULL
+          OR (
+            setweight(to_tsvector('simple', COALESCE(title, '')), 'A') ||
+            setweight(to_tsvector('simple', COALESCE(description, '')), 'B') ||
+            setweight(to_tsvector('simple', COALESCE(code, '')), 'C') ||
+            setweight(to_tsvector('simple', COALESCE(language, '')), 'B') ||
+            setweight(jsonb_to_tsvector('simple', COALESCE(tags, '[]'::jsonb), '["string"]'), 'B')
+          ) @@ websearch_to_tsquery('simple', ${keyword})
+        )
+      ORDER BY created_at DESC
+      LIMIT ${limit} OFFSET ${offset}
+    `;
+
+    const data = result as any[];
+
+    return {
+      data,
+      total,
+      limit,
+      offset,
+      hasMore: offset + data.length < total,
+    };
+  }
+
   async findById(id: string) {
     const result = await this.sql`
       SELECT * FROM snippets WHERE id = ${id}

app/api/snippets/snippet.service.ts

@@ -1,4 +1,9 @@
-import { SnippetRepository, PaginationOptions, PaginatedResult } from "./snippet.repository";
+import {
+  SnippetRepository,
+  PaginationOptions,
+  PaginatedResult,
+  SearchSnippetsOptions,
+} from "./snippet.repository";
 import { createSnippetSchema, updateSnippetSchema } from "./snippet.validator";
 
 export class SnippetService {
@@ -13,6 +18,15 @@ export class SnippetService {
     }
   }
 
+  async searchSnippets(options: SearchSnippetsOptions): Promise<PaginatedResult<any>> {
+    try {
+      return await this.snippetRepository.search(options);
+    } catch (error) {
+      console.error("[Service] Error searching snippets:", error);
+      throw new Error("Failed to search snippets");
+    }
+  }
+
   async getSnippetById(id: string) {
     try {
       const snippet = await this.snippetRepository.findById(id);

lib/snippet.service.test.ts

@@ -4,6 +4,7 @@ import { SnippetRepository } from "../app/api/snippets/snippet.repository";
 // Mock the repository
 const mockRepository = {
   findAll: jest.fn(),
+  search: jest.fn(),
   findById: jest.fn(),
   create: jest.fn(),
   update: jest.fn(),
@@ -48,6 +49,42 @@ describe("SnippetService", () => {
     });
   });
 
+  describe("searchSnippets", () => {
+    it("should return filtered snippets", async () => {
+      const filters = {
+        title: "React",
+        language: "typescript",
+        tags: ["frontend"],
+        keyword: "hooks",
+        limit: 10,
+        offset: 0,
+      };
+      const mockResult = {
+        data: [{ id: "1", title: "React Hooks" }],
+        total: 1,
+        limit: 10,
+        offset: 0,
+        hasMore: false,
+      };
+
+      (mockRepository.search as jest.Mock).mockResolvedValue(mockResult);
+
+      const result = await service.searchSnippets(filters);
+      expect(result).toEqual(mockResult);
+      expect(mockRepository.search).toHaveBeenCalledWith(filters);
+    });
+
+    it("should throw error when search fails", async () => {
+      (mockRepository.search as jest.Mock).mockRejectedValue(
+        new Error("DB error"),
+      );
+
+      await expect(
+        service.searchSnippets({ limit: 10, offset: 0, keyword: "react" }),
+      ).rejects.toThrow("Failed to search snippets");
+    });
+  });
+
   describe("getSnippetById", () => {
     it("should return snippet by id", async () => {
       const mockSnippet = { id: "1", title: "Test Snippet" };

scripts/add-snippet-search-indexes.sql

@@ -0,0 +1,14 @@
+CREATE EXTENSION IF NOT EXISTS pg_trgm;
+
+CREATE INDEX IF NOT EXISTS idx_snippets_lower_language ON snippets(LOWER(language));
+CREATE INDEX IF NOT EXISTS idx_snippets_title_trgm ON snippets USING GIN (title gin_trgm_ops);
+CREATE INDEX IF NOT EXISTS idx_snippets_tags_gin ON snippets USING GIN (tags jsonb_path_ops);
+CREATE INDEX IF NOT EXISTS idx_snippets_search_vector ON snippets USING GIN (
+  (
+    setweight(to_tsvector('simple', COALESCE(title, '')), 'A') ||
+    setweight(to_tsvector('simple', COALESCE(description, '')), 'B') ||
+    setweight(to_tsvector('simple', COALESCE(code, '')), 'C') ||
+    setweight(to_tsvector('simple', COALESCE(language, '')), 'B') ||
+    setweight(jsonb_to_tsvector('simple', COALESCE(tags, '[]'::jsonb), '["string"]'), 'B')
+  )
+);

scripts/init-db.sql

@@ -1,6 +1,8 @@
 -- Drop tables if they exist (for fresh setup)
 DROP TABLE IF EXISTS snippets CASCADE;
 
+CREATE EXTENSION IF NOT EXISTS pg_trgm;
+
 -- Create snippets table
 CREATE TABLE snippets (
   id UUID PRIMARY KEY,
@@ -16,4 +18,16 @@ CREATE TABLE snippets (
 
 -- Create indexes for better query performance
 CREATE INDEX IF NOT EXISTS idx_snippets_language ON snippets(language);
+CREATE INDEX IF NOT EXISTS idx_snippets_lower_language ON snippets(LOWER(language));
 CREATE INDEX IF NOT EXISTS idx_snippets_created_at ON snippets(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_snippets_title_trgm ON snippets USING GIN (title gin_trgm_ops);
+CREATE INDEX IF NOT EXISTS idx_snippets_tags_gin ON snippets USING GIN (tags jsonb_path_ops);
+CREATE INDEX IF NOT EXISTS idx_snippets_search_vector ON snippets USING GIN (
+  (
+    setweight(to_tsvector('simple', COALESCE(title, '')), 'A') ||
+    setweight(to_tsvector('simple', COALESCE(description, '')), 'B') ||
+    setweight(to_tsvector('simple', COALESCE(code, '')), 'C') ||
+    setweight(to_tsvector('simple', COALESCE(language, '')), 'B') ||
+    setweight(jsonb_to_tsvector('simple', COALESCE(tags, '[]'::jsonb), '["string"]'), 'B')
+  )
+);