wuxing.go

// Package p contains an HTTP Cloud Function.
package p

import (
	"encoding/json"
	"fmt"
	"net/http"
	"sort"
	"strings"

	"github.com/PuerkitoBio/goquery"
)

// Char used to decode JSON request
type Char struct {
	Word string
}

// XingCount holds Xing and its count
type XingCount struct {
	Xing  string
	Count int
}

// XingList A list of XingCount used for sorting
type XingList []XingCount

func (p XingList) Len() int           { return len(p) }
func (p XingList) Less(i, j int) bool { return p[i].Count < p[j].Count }
func (p XingList) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }

func topWuxing(m map[string]int) string {
	if len(m) == 0 {
		return ""
	}
	xl := make(XingList, len(m))
	i := 0
	for k, v := range m {
		xl[i] = XingCount{k, v}
		i++
	}
	sort.Sort(sort.Reverse(xl))

	ret := xl[0].Xing
	for idx, v := range xl {
		if idx > 0 && (xl[0].Count < v.Count*2) && v.Count > 1 {
			ret = ret + v.Xing
		}
	}
	return ret
}

// WuxingHandler accepts requests with json data {"char": "天"} and returns wuxing for the given character
func WuxingHandler(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case "GET":
		message := `Example POST data {word: 天}`
		j, _ := json.Marshal(message)
		w.Write(j)
	case "POST":
		var char Char
		err := json.NewDecoder(r.Body).Decode(&char)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}
		res, _ := http.Get("http://www.zdic.net/hans/" + char.Word)
		counts := make(map[string]int)
		doc, _ := goquery.NewDocumentFromReader(res.Body)

		wuxing := "金木水火土"
		doc.Find(".definitions").Each(func(i int, s *goquery.Selection) {
			def := s.Text()
			for _, xing := range wuxing {
				count := strings.Count(def, string(xing))
				counts[string(xing)] = count + counts[string(xing)]
			}
		})
		ret := topWuxing(counts)
		j, _ := json.Marshal(ret)
		w.Write(j)
	default:
		fmt.Fprintf(w, "Not Supported")
	}
}