cities5000.go

package geonames

import (
	"strconv"
	"strings"
	"time"

	"github.com/remizovm/geonames/models"
)

const cities5000URL = `cities5000.zip`

// Cities5000 returns all cities with the population >5000
func (c *Client) Cities5000() (map[int]*models.Feature, error) {
	var err error
	result := make(map[int]*models.Feature)

	zipped, err := c.httpGet(geonamesURL + cities5000URL)
	if err != nil {
		return nil, err
	}

	f, err := unzip(zipped)
	if err != nil {
		return nil, err
	}

	data, err := getZipData(f, "cities5000.txt")
	if err != nil {
		return nil, err
	}

	parse(data, 0, func(raw [][]byte) bool {
		if len(raw) != 19 {
			return true
		}

		geonameID, _ := strconv.Atoi(string(raw[0]))

		alternateNames := strings.Split(string(raw[3]), ",")
		for i := range alternateNames {
			alternateNames[i] = strings.TrimSpace(alternateNames[i])
			if alternateNames[i] == "" {
				alternateNames = append(alternateNames[:i], alternateNames[i+1:]...)
			}
		}

		latitude, _ := strconv.ParseFloat(string(raw[4]), 64)
		longitude, _ := strconv.ParseFloat(string(raw[5]), 64)

		var population *int
		if string(raw[14]) != "" {
			populationInt, err := strconv.Atoi(string(raw[14]))
			if err == nil {
				population = &populationInt
			}
		}

		var elevation *int
		if string(raw[15]) != "" {
			elevationInt, err := strconv.Atoi(string(raw[15]))
			if err == nil {
				elevation = &elevationInt
			}
		}

		dem, _ := strconv.Atoi(string(raw[16]))
		modificationDate, _ := time.Parse("2006-02-01", string(raw[18]))

		result[geonameID] = &models.Feature{
			GeonameID:        geonameID,
			Name:             string(raw[1]),
			ASCIIName:        string(raw[2]),
			AlternateNames:   alternateNames,
			Latitude:         latitude,
			Longitude:        longitude,
			Class:            string(raw[6]),
			Code:             string(raw[7]),
			CountryCode:      string(raw[8]),
			Cc2:              string(raw[9]),
			Admin1Code:       string(raw[10]),
			Admin2Code:       string(raw[11]),
			Admin3Code:       string(raw[12]),
			Admin4Code:       string(raw[13]),
			Population:       population,
			Elevation:        elevation,
			Dem:              dem,
			TimeZone:         string(raw[17]),
			ModificationDate: modificationDate,
		}

		return true
	})

	return result, nil
}