package stations

import (
	"bytes"
	"encoding/xml"
	"fmt"

	"git.fjla.uk/owlboard/go-types/pkg/database"
	"git.fjla.uk/owlboard/go-types/pkg/upstreamApi"
	"git.fjla.uk/owlboard/timetable-mgr/dbAccess"
)

// Parses n number of XML byte arrays
func parseData(data ...[]byte) ([]database.Station, error) {
	var stations []upstreamApi.Station
	for _, d := range data {
		parsedStations, err := parseXML(d)
		if err != nil {
			return nil, err
		}
		stations = append(stations, parsedStations...)
	}

	var output []database.Station
	for _, s := range stations {
		outputStation, err := convertApiToDatabase(s)
		if err != nil {
			return nil, err
		}
		output = append(output, outputStation)
	}
	return output, nil
}

// Parses XML and converts to struct
func parseXML(data []byte) ([]upstreamApi.Station, error) {
	var stationList upstreamApi.StationList

	reader := bytes.NewReader(data)
	decoder := xml.NewDecoder(reader)
	err := decoder.Decode(&stationList)
	if err != nil {
		return nil, fmt.Errorf("error parsing XML: %v", err)
	}

	return stationList.Stations, nil
}

// Convert API type to Database type ready for insertion
func convertApiToDatabase(data upstreamApi.Station) (database.Station, error) {
	if data.CrsCode == "" {
		return database.Station{}, fmt.Errorf("CRS code is required but missing")
	}

	tiploc, err := dbAccess.GetTiplocFromCrs(data.CrsCode)
	if err != nil {
		return database.Station{}, err
	}

	stanox, err := dbAccess.GetStanoxFromCrs(data.CrsCode)
	if err != nil {
		return database.Station{}, err
	}

	output := database.Station{
		CRS:     data.CrsCode,
		TIPLOC:  tiploc,
		STANOX:  stanox,
		NLCDESC: data.Name,
		Location: database.GeoJson{
			Type: "Point",
			Coordinates: []float64{
				data.Longitude,
				data.Latitude,
			},
		},
		Operator: data.StationOperator,
	}

	return output, nil
}