package httpcall

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"math"
	"net/http"

	"git.cryptic.systems/fh-trier/go-flucky/pkg/config"

	stypes "git.cryptic.systems/fh-trier/go-flucky-server/pkg/types"
)

// SendTemperatures remote servers
func SendTemperatures(temperatures []*stypes.Temperature, configDir string) error {

	cnf, err := config.Read(configDir)
	if err != nil {
		return err
	}

	// split temperatures in blocks to reduce server data size in single request
	blockSize := 500
	temperatureBlocks := make(map[int][]*stypes.Temperature)
	length := int(math.Ceil(float64(len(temperatures)) / float64(blockSize)))
	for i := 0; i < length; i++ {
		start := i * blockSize
		end := (i + 1) * blockSize

		if end > len(temperatures) {
			end = len(temperatures)
		}

		temperatureBlocks[i] = temperatures[start:end]
	}

	for _, remote := range cnf.Remotes {

		if remote.Enabled {

			for _, temperatureBlock := range temperatureBlocks {

				temperaturesAsBytes, err := json.Marshal(temperatureBlock)
				if err != nil {
					return fmt.Errorf("Can not marshal temperatures to JSON: %v", err)
				}

				temperaturesAsReader := bytes.NewReader(temperaturesAsBytes)

				requestURL := fmt.Sprintf("%s%s", remote.Address, "/temperatures")
				req, err := http.NewRequest("POST", requestURL, temperaturesAsReader)
				if err != nil {
					return err
				}

				client := http.Client{}
				resp, err := client.Do(req)
				if err != nil {
					return err
				}
				defer resp.Body.Close()

				if resp.StatusCode < 200 || resp.StatusCode > 299 {
					b, err := ioutil.ReadAll(resp.Body)
					if err != nil {
						return fmt.Errorf("Invalid HTTP-Statuscode - expected 200, got %d - can not read response body: %v", resp.StatusCode, err)
					}
					return fmt.Errorf("Invalid HTTP-Statuscode - expected 200, got %d: %v", resp.StatusCode, string(b))
				}
			}
		}
	}

	return nil

}