package api

import (
	"encoding/json"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
	"unicode"

	"github.com/gin-gonic/gin"

	"golang.org/x/text/transform"
	"golang.org/x/text/unicode/norm"
)

type IDFMStation struct {
	DatasetID string `json:"datasetid"`
	RecordIDs string `json:"recordid"`
	Fields    struct {
		Id            string    `json:"id"`
		PointGeo      []float64 `json:"pointgeo"`
		StopId        string    `json:"stop_id"`
		StopName      string    `json:"stop_name"`
		OperatorName  string    `json:"operatorname"`
		NomCommune    string    `json:"nom_commune"`
		RouteLongName string    `json:"route_long_name"`
		StopLat       string    `json:"stop_lat"`
		StopLon       string    `json:"stop_lon"`
		CodeINSEE     string    `json:"code_insee"`
	} `json:"fields"`
	Geometry struct {
		Type        string    `json:"type"`
		Coordinates []float64 `json:"coordinates"`
	} `json:"geometry"`
}

func (s *IDFMStation) ComputeSlug() string {
	isMn := func(r rune) bool {
		return unicode.Is(unicode.Mn, r) // Mn: nonspacing marks
	}
	t := transform.Chain(norm.NFD, transform.RemoveFunc(isMn), norm.NFC)

	r, _ := ioutil.ReadAll(transform.NewReader(strings.NewReader(s.Fields.StopName), t))

	return strings.ToLower(strings.Replace(strings.Replace(strings.Replace(string(r), " ", "+", -1), "'", "+", -1), "-", "+", -1))
}

type PGStation struct {
	Id   string `json:"slug"`
	Name string `json:"name"`
}

var IDFMStations []IDFMStation

func init() {
	fd, err := os.Open("arrets-lignes.json")
	if err != nil {
		log.Fatal("Unable to open `arrets-lignes.json`:", err.Error())
	}
	defer fd.Close()

	dec := json.NewDecoder(fd)
	if err = dec.Decode(&IDFMStations); err != nil {
		log.Fatal("Unable to decode `arrets-lignes.json`:", err.Error())
	}
}

func searchStation(code, station string) ([]string, error) {
	code = "IDFM:" + strings.TrimPrefix(code, "line:IDFM:")

	var res []string
	for _, st := range IDFMStations {
		if st.Fields.Id == code && st.ComputeSlug() == station {
			if strings.HasPrefix(st.Fields.StopId, "IDFM:monomodalStopPlace:") {
				res = append(res, "STIF:StopArea:SP:"+strings.TrimPrefix(strings.TrimPrefix(st.Fields.StopId, "IDFM:"), "monomodalStopPlace:")+":")
			} else {
				res = append(res, "STIF:StopPoint:Q:"+strings.TrimPrefix(st.Fields.StopId, "IDFM:")+":")
			}
		}
	}

	if len(res) == 0 {
		return []string{station}, nil
	} else {
		return res, nil
	}
}

func declareStationsRoutes(router *gin.RouterGroup) {
	router.GET("/stations/:type/:code", func(c *gin.Context) {
		code := convertLineCode(string(c.Param("code")))

		var stations []PGStation
		for _, station := range IDFMStations {
			if station.Fields.Id == "IDFM:"+code {
				pgstation := PGStation{
					Id:   station.ComputeSlug(),
					Name: station.Fields.StopName,
				}

				stations = append(stations, pgstation)
			}
		}

		c.JSON(http.StatusOK, APIResult(c, map[string][]PGStation{
			"stations": stations,
		}))
	})
}