/duckduck.go

// Package goduckgo provides the functionality for using
// DuckDuckGo API. For the description of the API, visit
// http://duckduckgo.com/api.html.
package goduckgo

import (
	"fmt"
	"net/url"
	"encoding/json"
	"net/http"
	"io/ioutil"
	"io"
	"os"
)

// Type Message is a structure containing all the information returned by
// DDG for a query.
type Message struct {
	Definition string
	DefinitionSource string
	Heading string
	AbstractText string
	Abstract string
	AbstractSource string
	Image string
	Type string
	AnswerType string
	Redirect string
	DefinitionURL string
	Answer string
	AbstractURL string
	Results Results
	RelatedTopics RelatedTopics
}

type Result struct {
	Result string
	FirstURL string
	Text string
}

// Method Show of struct Result writes Result to standard output
func (result *Result) Show(prefix string) {
	result.Fshow(os.Stdout, prefix)
}

func (result *Result) Fshow(w io.Writer, prefix string) {
	fmt.Fprintln(w, prefix, "Result:", result.Result)
	fmt.Fprintln(w, prefix, "First URL:", result.FirstURL)
	fmt.Fprintln(w, prefix, "Text:", result.Text)
}


type Results []Result

type RelatedTopics []RelatedTopic

type RelatedTopic struct {
	Result string
	Icon Icon
	FirstURL string
	Text string
}

func (topic *RelatedTopic) Show(prefix string) {
	topic.Fshow(os.Stdout, prefix)
}

func (topic *RelatedTopic) Fshow(w io.Writer, prefix string) {
	fmt.Fprintln(w, prefix, "Result:", topic.Result)
	fmt.Fprintln(w, prefix, "Icon:")
	topic.Icon.Fshow(w, prefix + prefix)
	fmt.Fprintln(w, prefix, "FirstURL:", topic.FirstURL)
	fmt.Fprintln(w, prefix, "Text:", topic.Text)
}

type Icon struct {
	URL string
	Height interface{} // can be string or number ("16" or 16)
	Width interface{} // can be string or number ("16" or 16)
}

func (icon *Icon) Show(prefix string) {
	icon.Fshow(os.Stdout, prefix)
}

func (icon *Icon) Fshow(w io.Writer, prefix string) {
	fmt.Fprintln(w, prefix, "URL:", icon.URL)
	fmt.Fprintln(w, prefix, "Height:", icon.Height)
	fmt.Fprintln(w, prefix, "Width:", icon.Width)
}

func Query(query string) (*Message, error) {
	query_enc := url.QueryEscape(query)
	ddgurl := fmt.Sprintf("http://api.duckduckgo.com?q=%s&format=json&pretty=1", query_enc)
	resp, err := http.Get(ddgurl)
	if err != nil {
		return nil, err
	}
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	var message *Message = &Message{}

	if err = json.Unmarshal(body, message); err != nil {
		return nil, err
	}
	return message, nil
}