feat: impl duckduckgo search tool

components/tool/duckduckgo/README.md

@@ -0,0 +1,98 @@
+# DuckDuckGo Search Tool
+
+English | [简体中文](README_zh.md)
+
+A DuckDuckGo search tool implementation for [Eino](https://github.com/cloudwego/eino) that implements the `InvokableTool` interface. This enables seamless integration with Eino's ChatModel interaction system and `ToolsNode` for enhanced search capabilities.
+
+## Features
+
+- Implements `github.com/cloudwego/eino/components/tool.InvokableTool`
+- Easy integration with Eino's tool system
+- Configurable search parameters
+
+## Installation
+
+```bash
+go get github.com/cloudwego/eino-ext/components/tool/duckduckgo
+```
+
+## Quick Start
+
+```go
+package main
+
+import (
+    "context"
+    "log"
+
+    "github.com/cloudwego/eino-ext/components/tool/duckduckgo"
+    "github.com/cloudwego/eino-ext/components/tool/duckduckgo/ddgsearch"
+    "github.com/cloudwego/eino/components/tool"
+)
+
+func main() {
+    // Create tool config
+    cfg := &duckduckgo.Config{ // All of these parameters are default values, for demonstration purposes only
+        ToolName:   "duckduckgo_search",
+        ToolDesc:   "search web for information by duckduckgo",
+        Region:     ddgsearch.RegionWT,
+        Retries:    3,
+        Timeout:    10,
+        MaxResults: 10,
+    }
+
+    // Create the search tool
+    searchTool, err := duckduckgo.NewTool(context.Background(), cfg)
+    if err != nil {
+        log.Fatal(err)
+    }
+
+    // Use with Eino's ToolsNode
+    tools := []tool.BaseTool{searchTool}
+    // ... configure and use with ToolsNode
+}
+```
+
+## Configuration
+
+The tool can be configured using the `Config` struct:
+
+```go
+type Config struct {
+    ToolName    string           // Tool name for LLM interaction (default: "duckduckgo_search")
+    ToolDesc    string           // Tool description (default: "search web for information by duckduckgo")
+    Region      ddgsearch.Region // Search region (default: "wt-wt" of no specified region)
+    Retries     int             // Number of retries (default: 3)
+    Timeout     int             // Max timeout in seconds (default: 10)
+    MaxResults  int             // Maximum results per search (default: 10)
+    Proxy       string          // Optional proxy URL
+}
+```
+
+## Search
+
+### Request Schema
+```go
+type SearchRequest struct {
+    Query string `json:"query" jsonschema_description:"The query to search the web for"`
+    Page  int    `json:"page" jsonschema_description:"The page number to search for, default: 1"`
+}
+```
+
+### Response Schema
+```go
+type SearchResponse struct {
+    Results []SearchResult `json:"results" jsonschema_description:"The results of the search"`
+}
+
+type SearchResult struct {
+    Title       string `json:"title" jsonschema_description:"The title of the search result"`
+    Description string `json:"description" jsonschema_description:"The description of the search result"`
+    Link        string `json:"link" jsonschema_description:"The link of the search result"`
+}
+```
+
+## For More Details
+
+- [DuckDuckGo Search Library Documentation](ddgsearch/README.md)
+- [Eino Documentation](https://github.com/cloudwego/eino)

components/tool/duckduckgo/README_zh.md

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+# DuckDuckGo 搜索工具
+
+[English](README.md) | 简体中文
+
+这是一个为 [Eino](https://github.com/cloudwego/eino) 实现的 DuckDuckGo 搜索工具。该工具实现了 `InvokableTool` 接口，可以与 Eino 的 ChatModel 交互系统和 `ToolsNode` 无缝集成。
+
+## 特性
+
+- 实现了 `github.com/cloudwego/eino/components/tool.InvokableTool` 接口
+- 易于与 Eino 工具系统集成
+- 可配置的搜索参数
+
+## 安装
+
+```bash
+go get github.com/cloudwego/eino-ext/components/tool/duckduckgo
+```
+
+## 快速开始
+
+```go
+package main
+
+import (
+    "context"
+    "log"
+
+    "github.com/cloudwego/eino-ext/components/tool/duckduckgo"
+    "github.com/cloudwego/eino-ext/components/tool/duckduckgo/ddgsearch"
+    "github.com/cloudwego/eino/components/tool"
+)
+
+func main() {
+    // 创建工具配置
+    cfg := &duckduckgo.Config{ // 下面所有这些参数都是默认值，仅作用法展示
+        ToolName:   "duckduckgo_search",
+        ToolDesc:   "search web for information by duckduckgo",
+        Region:     ddgsearch.RegionWT,
+        Retries:    3,
+        Timeout:    10,
+        MaxResults: 10,
+    }
+
+    // 创建搜索工具
+    searchTool, err := duckduckgo.NewTool(context.Background(), cfg)
+    if err != nil {
+        log.Fatal(err)
+    }
+
+    // 与 Eino 的 ToolsNode 一起使用
+    tools := []tool.BaseTool{searchTool}
+    // ... 配置并使用 ToolsNode
+}
+```
+
+## 配置
+
+工具可以通过 `Config` 结构体进行配置：
+
+```go
+type Config struct {
+    ToolName    string           // 用于 LLM 交互的工具名称（默认："duckduckgo_search"）
+    ToolDesc    string           // 工具描述（默认："search web for information by duckduckgo"）
+    Region      ddgsearch.Region // 搜索地区（默认："wt-wt"）
+    Retries     int             // 重试次数（默认：3）
+    Timeout     int             // 最大超时时间（秒）（默认：10）
+    MaxResults  int             // 每次搜索的最大结果数（默认：10）
+    Proxy       string          // 可选的代理 URL
+}
+```
+
+## Search
+
+### 请求 Schema
+```go
+type SearchRequest struct {
+    Query string `json:"query" jsonschema_description:"要搜索的查询内容"`
+    Page  int    `json:"page" jsonschema_description:"要搜索的页码，默认：1"`
+}
+```
+
+### 响应 Schema
+```go
+type SearchResponse struct {
+    Results []SearchResult `json:"results" jsonschema_description:"搜索结果列��"`
+}
+
+type SearchResult struct {
+    Title       string `json:"title" jsonschema_description:"搜索结果的标题"`
+    Description string `json:"description" jsonschema_description:"搜索结果的描述"`
+    Link        string `json:"link" jsonschema_description:"搜索结果的链接"`
+}
+```
+
+## 更多详情
+
+- [DuckDuckGo 搜索库文档](ddgsearch/README_zh.md)
+- [Eino 文档](https://github.com/cloudwego/eino) 

components/tool/duckduckgo/ddgsearch/README.md

@@ -0,0 +1,149 @@
+# DDGSearch
+
+English | [简体中文](README_zh.md)
+
+A native Go library for DuckDuckGo search functionality. This library provides a simple and efficient way to perform searches using DuckDuckGo's search engine.
+
+## Why DuckDuckGo?
+
+DuckDuckGo offers several advantages:
+- **No Authentication Required**: Unlike other search engines, DuckDuckGo's API can be used without any API keys or authentication
+- Privacy-focused search results
+- No rate limiting for reasonable usage
+- Support for multiple regions and languages
+- Clean and relevant search results
+
+## Features
+
+- Clean and idiomatic Go implementation
+- Comprehensive error handling
+- Configurable search parameters
+- In-memory caching with TTL
+- Support for:
+  - Multiple regions (us-en, uk-en, de-de, etc.)
+  - Safe search levels (strict, moderate, off)
+  - Time-based filtering (day, week, month, year)
+  - Result pagination
+  - Custom HTTP headers
+  - Proxy configuration
+
+## Installation
+
+```bash
+go get github.com/cloudwego/eino-ext/components/tool/duckduckgo
+```
+
+## Quick Start
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "log"
+    "time"
+
+    "github.com/cloudwego/eino-ext/components/tool/duckduckgo/ddgsearch"
+)
+
+func main() {
+    // Create a new client with configuration
+    cfg := &ddgsearch.Config{
+        Timeout:    30 * time.Second,
+        MaxRetries: 3,
+        Cache:      true,
+    }
+    client, err := ddgsearch.New(cfg)
+    if err != nil {
+        log.Fatal(err)
+    }
+
+    // Configure search parameters
+    params := &ddgsearch.SearchParams{
+        Query:      "what is golang",
+        Region:     ddgsearch.RegionUSEN,
+        SafeSearch: ddgsearch.SafeSearchModerate,
+        TimeRange:  ddgsearch.TimeRangeMonth,
+        MaxResults: 10,
+    }
+
+    // Perform search
+    response, err := client.Search(context.Background(), params)
+    if err != nil {
+        log.Fatal(err)
+    }
+
+    // Print results
+    for i, result := range response.Results {
+        fmt.Printf("%d. %s\n   URL: %s\n   Description: %s\n\n", 
+            i+1, result.Title, result.URL, result.Description)
+    }
+}
+```
+
+## Advanced Usage
+
+### Configuration
+
+```go
+// Create client with custom configuration
+cfg := &ddgsearch.Config{
+    Timeout:    20 * time.Second,
+    MaxRetries: 3,
+    Proxy:      "http://proxy:8080",
+    Cache:      true,
+    Headers: map[string]string{
+        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36",
+    },
+}
+client, err := ddgsearch.New(cfg)
+```
+
+### Search Parameters
+
+```go
+params := &ddgsearch.SearchParams{
+    Query:      "golang tutorial",       // Search query
+    Region:     ddgsearch.RegionUS,    // Region for results (us-en, uk-en, etc.)
+    SafeSearch: ddgsearch.SafeSearchModerate, // Safe search level
+    TimeRange:  ddgsearch.TimeRangeWeek, // Time filter
+    MaxResults: 10,                      // Maximum results to return
+}
+```
+
+Available regions:
+- RegionUS (United States)
+- RegionUK (United Kingdom)
+- RegionDE (Germany)
+- RegionFR (France)
+- RegionJP (Japan)
+- RegionCN (China)
+- RegionRU (Russia)
+
+Safe search levels:
+- SafeSearchStrict
+- SafeSearchModerate
+- SafeSearchOff
+
+Time range options:
+- TimeRangeDay
+- TimeRangeWeek
+- TimeRangeMonth
+- TimeRangeYear
+
+### Proxy Support
+
+```go
+// HTTP proxy
+cfg := &ddgsearch.Config{
+    Proxy: "http://proxy:8080",
+}
+client, err := ddgsearch.New(cfg)
+
+// SOCKS5 proxy
+cfg := &ddgsearch.Config{
+    Proxy: "socks5://proxy:1080",
+}
+client, err := ddgsearch.New(cfg)
+```