package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"go/doc"
	"log"
	"net/http"
	"os"
	"sort"
	"strings"
)

const url = "http://api.urbandictionary.com/v0/define?term="
const usage = "ud: confirm that the term you're thinking of has already been added to urban dictionary\n\nusage: ud <term>\n"

var all bool

func init() {
	flag.BoolVar(&all, "all", false, "more than one")
	flag.BoolVar(&all, "a", false, "more than one")
}

type response struct {
	Results []result `json:"list"`
}

type result struct {
	Definition string `json:"definition"`
	Example    string `json:"example"`
	Link       string `json:"permalink"`
	Author     string `json:"author"`

	Up   int `json:"thumbs_up"`
	Down int `json:"thumbs_down"`
}

// ByVotes aids in sorting result based on votes
type ByVotes []result

func (bv ByVotes) Len() int {
	return len(bv)
}

func (bv ByVotes) Swap(i, j int) {
	bv[i], bv[j] = bv[j], bv[i]
}

func (bv ByVotes) Less(i, j int) bool {
	return float64(bv[i].Up-bv[i].Down) > float64(bv[j].Up-bv[j].Down)
}

func main() {
	flag.Parse()
	if len(flag.Args()) < 1 {
		fmt.Fprintf(os.Stderr, "%s\n", usage)
		os.Exit(1)
	}

	u := fmt.Sprintf("%s%s", url, strings.Join(flag.Args(), "+"))

	resp, err := http.Get(u)
	if err != nil {
		log.Fatal(err)
	}
	data := response{}
	err = json.NewDecoder(resp.Body).Decode(&data)
	resp.Body.Close()
	if err != nil {
		log.Fatal(err)
	}

	sort.Sort(ByVotes(data.Results))

	if !all {
		if len(data.Results) > 0 {
			data.Results = data.Results[:1]
		}
	}

	for i, res := range data.Results {
		if i > 0 {
			fmt.Printf("\n\n")
		}
		if all {
			fmt.Printf(
				"Definition %d:\n",
				i+1,
			)
		}
		doc.ToText(os.Stdout, res.Definition, "", "", 80)
		res.Example = strings.Replace(res.Example, "\r\n", "\n", -1)
		res.Example = strings.Replace(res.Example, "\n", "\n  ", -1)
		fmt.Printf("\n\n  Example:\n  %s\n", res.Example)
		fmt.Printf(
			"\nSource: %s\nUp: %d, Down: %d\nAuthor: %s\n",
			res.Link,
			res.Up,
			res.Down,
			res.Author,
		)
	}
}