package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strconv"
	"strings"

	"github.com/cabify/gotoprom"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"github.com/robfig/cron/v3"
)

var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")

type OntCovidData struct {
	Help    string `json:"help"`
	Success bool   `json:"success"`
	Result  struct {
		Sort         string `json:"sort"`
		IncludeTotal bool   `json:"include_total"`
		ResourceID   string `json:"resource_id"`
		Fields       []struct {
			Type string `json:"type"`
			ID   string `json:"id"`
			Info struct {
				Notes        string `json:"notes"`
				TypeOverride string `json:"type_override"`
				Label        string `json:"label"`
			} `json:"info,omitempty"`
		} `json:"fields"`
		RecordsFormat string `json:"records_format"`
		Records       []struct {
			ID                                     int    `json:"_id"`
			ReportDate                             string `json:"report_date"`
			PreviousDayDosesAdministered           string `json:"previous_day_doses_administered"`
			TotalDosesAdministered                 string `json:"total_doses_administered"`
			TotalDosesInFullyVaccinatedIndividuals string `json:"total_doses_in_fully_vaccinated_individuals"`
			TotalIndividualsFullyVaccinated        string `json:"total_individuals_fully_vaccinated"`
		} `json:"records"`
		Limit int `json:"limit"`
		Links struct {
			Start string `json:"start"`
			Next  string `json:"next"`
		} `json:"_links"`
		Total int `json:"total"`
	} `json:"result"`
}

var metrics struct {
	TotalDosesAdministered       func() prometheus.Gauge `name:"total_doses_administered" help:"Total Doses Administered"`
	PreviousDayDosesAdministered func() prometheus.Gauge `name:"previous_day_doses_administered" help:"Previous Day Doses Administered"`
	DaysLeft                     func() prometheus.Gauge `name:"days_left" help:"Days Left"`
}

func init() {
	gotoprom.MustInit(&metrics, "ont_covid_data")
}

func updateMetrics() {
	data_url := "https://data.ontario.ca/api/3/action/datastore_search?sort=report_date+desc&limit=1&resource_id=8a89caa9-511c-4568-af89-7f2174b4378c"
	population := int64(11971129)
	resp, getErr := http.Get(data_url)
	if getErr != nil {
		log.Fatalln(getErr)
	}
	body, readErr := ioutil.ReadAll(resp.Body)
	if readErr != nil {
		log.Fatalln(readErr)
	}
	data := OntCovidData{}
	err := json.Unmarshal(body, &data)
	if err != nil {
		fmt.Println(err)
	}
	totalString := strings.Replace(data.Result.Records[0].TotalDosesAdministered, ",", "", -1)
	total, _ := strconv.ParseInt(totalString, 0, 64)
	prevDayString := strings.Replace(data.Result.Records[0].PreviousDayDosesAdministered, ",", "", -1)
	prevDay, _ := strconv.ParseInt(prevDayString, 0, 64)
	// reportDate := data.Result.Records[0].ReportDate

	days := (population - total) / prevDay

	metrics.TotalDosesAdministered().Set(float64(total))
	metrics.PreviousDayDosesAdministered().Set(float64(prevDay))
	metrics.DaysLeft().Set(float64(days))
}

func main() {
	c := cron.New()
	c.AddFunc("@hourly", func() { updateMetrics() })
	c.Start()

	updateMetrics()

	flag.Parse()
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}