package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"math"
	"net/http"
	"strconv"
	"strings"
	"time"
)

const api_url = "https://proxy1.lpn.swisscom.ch/thingpark/lrc/rest"

func MakePost(url string) {
	req, err := http.NewRequest("POST", url, nil)
	if err != nil {
		log.Fatal("Error reading request. ", err)
	}

	// Set headers
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	// Set client timeout
	client := &http.Client{Timeout: time.Second * 10}

	// Send request
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal("Error reading response. ", err)
	}
	defer resp.Body.Close()

	fmt.Println("response Status:", resp.Status)
	fmt.Println("response Headers:", resp.Header)

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal("Error reading body. ", err)
	}

	fmt.Printf("%s\n", body)
}

func ResetNodeToZero(deveui string, w1_0 int32, w2_0 int32) {
	fmt.Printf("Called ResetNodeToZero for deveui %s\n", deveui)
	valstr := fmt.Sprintf("%08X%08X%08X%08X", uint32(w1_0), uint32(w2_0), 0, 0)
	s := fmt.Sprintf("%s/downlink?DevEUI=%s&FPort=1&Payload=00%s", api_url, deveui, valstr)
	MakePost(s)
	SetDownlinkCommand(deveui, "do_nothing")
}

func CalibrateScale(deveui string, downlink_command string, w1 int32, w2 int32) {
	fmt.Printf("Called CalibrateScale for deveui %s, downlink_command: %s\n", deveui, downlink_command)
	var cur_cal_settings CalSettings
	cur_cal_settings = GetCurrentCalibrationSettings(deveui)
	var calibration_weight_gram int32
	var calibration_weight2_gram int32
	tokens := strings.Split(downlink_command, " ")
	if len(tokens) < 2 {
		// no value in gram included!
		fmt.Printf("Error: invalid downlink_command: %s, examples: \"tare_a 10000\", \"tare_b 10000\", \"tare 10000 10000\" devuid: %s\n", downlink_command, deveui)
		return
	}
	n, err := strconv.ParseInt(tokens[1], 10, 32)
	if err == nil {
		calibration_weight_gram = int32(n)
	} else {
		fmt.Printf("Error: cannot get tare weight in gram: %s, deveui: %s\n", downlink_command, deveui)
		return
	}

	if len(tokens) > 2 {
		n, err := strconv.ParseInt(tokens[2], 10, 32)
		if err == nil {
			calibration_weight2_gram = int32(n)
		} else {
			fmt.Printf("Error: cannot get tare weight2 in gram: %s, deveui: %s\n", downlink_command, deveui)
			return
		}
	}

	if tokens[0] == "tare_a" {
		new_w1_c := float32(w1-cur_cal_settings.w1_0) / float32(calibration_weight_gram)
		valstr := fmt.Sprintf("%08X%08X%08X%08X", uint32(cur_cal_settings.w1_0), uint32(cur_cal_settings.w2_0), math.Float32bits(new_w1_c), math.Float32bits(cur_cal_settings.w2_c))
		s := fmt.Sprintf("%s/downlink?DevEUI=%s&FPort=1&Payload=01%s", api_url, deveui, valstr)
		MakePost(s)
		SetDownlinkCommand(deveui, "do_nothing")
	} else if tokens[0] == "tare_b" {
		new_w2_c := float32(w2-cur_cal_settings.w2_0) / float32(calibration_weight_gram)
		valstr := fmt.Sprintf("%08X%08X%08X%08X", uint32(cur_cal_settings.w1_0), uint32(cur_cal_settings.w2_0), math.Float32bits(cur_cal_settings.w1_c), math.Float32bits(new_w2_c))
		s := fmt.Sprintf("%s/downlink?DevEUI=%s&FPort=1&Payload=01%s", api_url, deveui, valstr)
		MakePost(s)
		SetDownlinkCommand(deveui, "do_nothing")
	} else if tokens[0] == "tare" {
		new_w1_c := float32(w1-cur_cal_settings.w1_0) / float32(calibration_weight_gram)
		new_w2_c := float32(w2-cur_cal_settings.w2_0) / float32(calibration_weight2_gram)
		valstr := fmt.Sprintf("%08X%08X%08X%08X", uint32(cur_cal_settings.w1_0), uint32(cur_cal_settings.w2_0), math.Float32bits(new_w1_c), math.Float32bits(new_w2_c))
		s := fmt.Sprintf("%s/downlink?DevEUI=%s&FPort=1&Payload=01%s", api_url, deveui, valstr)
		MakePost(s)
		SetDownlinkCommand(deveui, "do_nothing")
	} else {
		fmt.Printf("Error: either use tare_a or tare_b or tare; deveui %s\n", deveui)
	}
}

func UpdateCalibrationSettingsFromNode(deveui string, w1_0 int32, w2_0 int32, w1_c float32, w2_c float32) {
	fmt.Printf("Called UpdateCalibrationSettingsFromNode for deveui %s\n", deveui)
	var cur_cal_settings CalSettings
	var new_cal_settings CalSettings

	cur_cal_settings = GetCurrentCalibrationSettings(deveui)

	new_cal_settings.w1_0 = w1_0
	new_cal_settings.w2_0 = w2_0
	new_cal_settings.w1_c = w1_c
	new_cal_settings.w2_c = w2_c

	if (new_cal_settings.w1_0 != cur_cal_settings.w1_0) ||
		(new_cal_settings.w2_0 != cur_cal_settings.w2_0) ||
		(new_cal_settings.w1_c != cur_cal_settings.w1_c) ||
		(new_cal_settings.w2_c != cur_cal_settings.w2_c) {
		SetCurrentCalibrationSettings(deveui, new_cal_settings)
		// since something has changed and is reflected in the local config, we don't do anything any more...
		SetDownlinkCommand(deveui, "do_nothing")
	} else {
		fmt.Printf("Info: no change in calibration settings for deveui %s\n", deveui)
	}
}