package compareID

import (
	"bytes"
	"encoding/json"
	"fmt"
	"github.com/agext/levenshtein"
	"io/ioutil"
	"net/http"
	"strings"
	"time"
)

//Anime contains the essentials for being able to compare anidb to meikan
type Anime struct {
	ID        int
	Type      string
	Episodes  int
	Title     string
	StartDate time.Time
	EndDate   time.Time
}

//Result is the way the json received is structured
//It contains a collection of animes made up of AnimeRes
type Result struct {
	Total int        `json:"total"`
	Anime []AnimeRes `json:"data"`
}

//AnimeRes is how the search results from meikan are built up in the JSON
type AnimeRes struct {
	EndDate   string `json:"end_date"`
	Episodes  int    `json:"episodes"`
	ID        int    `json:"id"`
	Rating    string `json:"rating"`
	StartDate string `json:"start_date"`
	State     string `json:"state"`
	Title     string `json:"title"`
	Type      string `json:"type"`
}

//Animes is a collection of animes
type Animes []MatchedAnime

//MatchedAnime contains all the neccessary information after matching two animes
type MatchedAnime struct {
	MeikanTitle string
	AnidbTitle  string
	MeikanID    int
	AnidbID     int
	Score       int
}

//check does a default error check
func check(e error) {
	if e != nil {
		panic(e)
	}
}

//lessType makes types when comparing less specific
//So missmatches like OVA == Specials don't happen.
func LessType(Type string) string {
	switch Type {
	case "TV", "ONA":
		return "Shows"
	case "OVA", "Specials":
		return "Extra"
	}

	return Type
}

//fixType changes the types anidb uses to ones that match with meikan specifications.
func FixType(Type string) string {
	switch Type {
	case "TV Series":
		return "TV"
	case "TV Special":
		return "Special"
	case "Web":
		return "ONA"
	}
	return Type
}

//fixMeikanDates takes two strings and tries to parse them returning two Time structs
func FixMeikanDates(Date, Date2 string) (date, date2 time.Time) {
	if Date != "" {
		date, _ = time.Parse(`2006-01-02`, Date)
	}
	if Date2 != "" {
		date2, _ = time.Parse(`2006-01-02`, Date)
	}
	return date, date2
}

//subAnimeDates subtracts one date from the other.
//Returning an integer that is added onto the total score when comparing.
func SubAnimeDates(Date, Date2 time.Time) (total int) {
	if Date.Year() == 1 && Date2.Year() == 1 {
		return 0
	}
	diff := Date.Sub(Date2)
	if diff < 0 {
		diff = diff * -1
	}
	if diff <= 2190*time.Hour {
		return 50
	}
	return -150
}

//checkResults takes an Anime struct and a channel.
//It compares the supplied anime to all the search results returned from searching the title.
//If the score is over 100 it should be a match.
func CheckResults(anime Anime, c chan MatchedAnime) {
	fmt.Println(`Searching anime`, anime.ID)
	var highest, hI int
	var err error
	anime.Title = strings.Replace(strings.Replace(anime.Title, `\`, `\\`, -1), `"`, `\"`, -1)
	var search = bytes.NewBuffer([]byte(`{"title":"` + anime.Title + `", "show_r18": true}`))
	resp, err := http.Post("https://api.meikan.moe/v1/anime?incl=start_date,end_date", "application/json", search)
	check(err)
	fmt.Println(`Completed meikan search for`, anime.ID)
	// nolint: errcheck
	defer resp.Body.Close()
	var result Result
	body, err := ioutil.ReadAll(resp.Body)
	check(err)
	_ = json.NewDecoder(bytes.NewReader(body)).Decode(&result)
	anime.Type = FixType(anime.Type)
	if anime.Episodes < 1 {
		anime.Episodes = 1
	}
	for i := 0; i < len(result.Anime); i++ {
		var total int
		meikan := result.Anime[i]
		stDate, enDate := FixMeikanDates(meikan.StartDate, meikan.EndDate)
		if meikan.Type == anime.Type {
			total += 25
		} else {
			MType := LessType(meikan.Type)
			AType := LessType(anime.Type)
			if MType == AType {
				total += 12
			}
		}
		score := levenshtein.Match(meikan.Title, anime.Title, nil)
		if score > 0.95 {
			total += 50
		}
		if meikan.Episodes == anime.Episodes {
			total += 25
		}
		total += SubAnimeDates(stDate, anime.StartDate)
		if anime.Episodes != 1 {
			total += SubAnimeDates(enDate, anime.EndDate)
		}
		if total > highest {
			highest = total
			hI = i
		}
	}
	//return highest, hI
	if len(result.Anime) != 0 {
		c <- MatchedAnime{
			MeikanTitle: result.Anime[hI].Title,
			AnidbTitle:  anime.Title,
			MeikanID:    result.Anime[hI].ID,
			AnidbID:     anime.ID,
			Score:       highest,
		}
	}
}

func main() {
	http.DefaultTransport = &http.Transport{MaxIdleConnsPerHost: 50, MaxIdleConns: 50}
}