package main

import (
	"os"
	"io"
	"bufio"
	"strings"
	"sort"
	"strconv"
	"github.com/gonum/plot"
	"github.com/gonum/plot/plotter"
	"github.com/gonum/plot/plotutil"
	"github.com/gonum/plot/vg"
)

type sortedMap struct {
	m map[int]int
	s []int
}

func (sm *sortedMap) Len() int {
	return len(sm.m)
}
func (sm *sortedMap) Less(i, j int) bool {
	return sm.m[sm.s[i]] > sm.m[sm.s[j]]
}
func (sm *sortedMap) Swap(i, j int) {
	sm.s[i], sm.s[j] = sm.s[j], sm.s[i]
}

// sortedKeys returns the slice []int which is sorted by the count in map.
// Eventually, we should hold the sorted slice []int, it's enough to sort.
// func (sm *sortedMap) sortedKeys(m map[int]int) []int {
func sortedKeys(m map[int]int) []int {
	sm := new(sortedMap)
	sm.m = m
	sm.s = make([]int, len(m))
	i := 0
	for key, _ := range m {
		sm.s[i] = key
		i++
	}

	sort.Sort(sm)

	return sm.s
}

func drawBarChart(val []float64, label []string) {
	group := plotter.Values(val)

	p, err := plot.New()
	if err != nil {
		panic(err)
	}
	p.Title.Text = "The Relationship of Frequency and Word count"
	p.X.Label.Text = "Frequency"
	p.Y.Label.Text = "Word count"

	w := vg.Points(1)

	bars, err := plotter.NewBarChart(group, w)
	if err != nil {
		panic(err)
	}

	bars.LineStyle.Width = vg.Length(0)
	bars.Color = plotutil.Color(0)

	p.Add(bars)
	p.NominalX(label...) // gonum/plot does NOT support Japanse.

	if err := p.Save(5*vg.Inch, 3*vg.Inch, "q38.png"); err != nil {
		panic(err)
	}
}


func main()  {
	f, err := os.Open("../data/neko.txt.mecab")
	defer f.Close()
	if err != nil {
		panic(err)
	}

	r := bufio.NewReader(f)

	sents := make([][]map[string]string, 0)
	sent := make([]map[string]string, 0)

	for {
		b, _, err := r.ReadLine()
		if err == io.EOF {
			break
		}

		// store morpheme which is not "EOS" into maps
		if string(b) != "EOS" {
			// split by tab and comma
			tmp := strings.Split(string(b), "\t")
			m := append(tmp[:1], strings.Split(tmp[1], ",")...)

			morpheme := make(map[string]string)

		 	morpheme["surface"] = m[0]
			morpheme["base"]    = m[7]
			morpheme["pos"]     = m[1]
			morpheme["pos1"]    = m[2]

			sent = append(sent, morpheme)
		} else { // if we find "EOS", store sentence to sentences and initialize the sent
			if len(sent) > 0 { // for appearing "EOS" continuously
				sents = append(sents, sent)
				sent = make([]map[string]string, 0)
			}
		}

	}

	// count the number of the morpheme has same base
	freq := make(map[string]int)
	for _, sent := range sents {
		for _, m := range sent {
			freq[m["base"]]++
		}
	}

	// count the number of the kind of word
	hist := make(map[int]int)

	for _, v := range freq {
		hist[v]++
	}

	// draw Hist chart
	res := sortedKeys(hist)
	var val []float64
	var label []string
	for _, v := range res {
		val = append(val, float64(hist[v]))

		// print label of x axis only a nice round number
		if v == 10 || v == 30 || v == 100 {
			// fmt.Println(strconv.Itoa(v))
			label = append(label, strconv.Itoa(v))
		} else {
			label = append(label, "")
		}
	}
	drawBarChart(val, label)

}