package models

import (
	"bytes"
	"io/ioutil"
	"strconv"
	"strings"

	"github.com/spf13/viper"
)

type EntryFrequency struct {
	Times int
	Entry string
}

func (ef *EntryFrequency) ToBytes() []byte {
	var ret []byte
	ret = append(ret, []byte(strconv.Itoa(ef.Times))...)
	ret = append(ret, byte('\t'))
	ret = append(ret, []byte(ef.Entry)...)
	return ret
}

func FromBytes(bts []byte) (*EntryFrequency, error) {
	fields := bytes.Split(bts, []byte{'\t'})
	times, err := strconv.Atoi(string(fields[0]))
	if err != nil {
		return nil, err
	}
	return &EntryFrequency{
		Times: times,
		Entry: string(fields[1]),
	}, nil
}

type Frequencies struct {
	Entries []*EntryFrequency
}

func LoadFrequencies() (*Frequencies, error) {
	fl := viper.ConfigFileUsed()
	fl = fl[:strings.LastIndex(fl, "/")+1] + "freq"
	req := &Frequencies{}
	b, err := ioutil.ReadFile(fl)
	if err != nil {
		err = req.Save()
		if err != nil {
			return nil, err
		}
		return req, nil
	}
	lines := bytes.Split(b, []byte{'\n'})
	for i := range lines {
		var ef *EntryFrequency
		ef, err = FromBytes(lines[i])
		if err == nil {
			req.AddEntry(ef)
		}
	}
	return req, nil
}

func (f *Frequencies) AddEntry(ef *EntryFrequency) {
	f.Entries = append(f.Entries, ef)
}

func (f *Frequencies) GetTimes(entry string) int {
	for i := range f.Entries {
		if f.Entries[i].Entry == entry {
			return f.Entries[i].Times
		}
	}
	return 0
}

func (f *Frequencies) IncrementEntry(entry string) {
	for i := range f.Entries {
		if f.Entries[i].Entry == entry {
			f.Entries[i].Times++
			return
		}
	}
	f.Entries = append(f.Entries, &EntryFrequency{
		Times: 1,
		Entry: entry,
	})
}

func (f *Frequencies) Save() error {
	fl := viper.ConfigFileUsed()
	fl = fl[:strings.LastIndex(fl, "/")+1] + "freq"
	var b []byte
	for _, e := range f.Entries {
		b = append(b, e.ToBytes()...)
		b = append(b, byte('\n'))
	}
	return ioutil.WriteFile(fl, b, 0600)
}