package main

import (
  "fmt"
  "strings"
  "net/http"
  "io/ioutil"
)

func main() {

  url := "https://api.swep.net/calculateSinglePhase"
  method := "POST"

  payload := strings.NewReader(`{`+"
"+`
  "inputs": {`+"
"+`
    "calculationMethod": "Design",`+"
"+`
    "selectedFluidSide1": {`+"
"+`
      "fluidId": 53,`+"
"+`
      "isGas": false,`+"
"+`
      "inputValue": null`+"
"+`
    },`+"
"+`
    "selectedFluidSide2": {`+"
"+`
      "fluidId": 53,`+"
"+`
      "isGas": false,`+"
"+`
      "inputValue": null`+"
"+`
    },`+"
"+`
    "coCurrent": false,`+"
"+`
    "selectedHeatExchangers": [`+"
"+`
      {`+"
"+`
        "heatExchangerInputType": "Parent",`+"
"+`
        "id": 1`+"
"+`
      }`+"
"+`
    ],`+"
"+`
    "heatLoad": {`+"
"+`
      "amount": 1500,`+"
"+`
      "unit": "HeatLoadUnit.Kilowatt"`+"
"+`
    },`+"
"+`
    "inletTemperatureSide1": {`+"
"+`
      "amount": 80,`+"
"+`
      "unit": "TemperatureUnit.DegreeCelsius"`+"
"+`
    },`+"
"+`
    "inletTemperatureSide2": {`+"
"+`
      "amount": 20,`+"
"+`
      "unit": "TemperatureUnit.DegreeCelsius"`+"
"+`
    },`+"
"+`
    "outletTemperatureSide1": {`+"
"+`
      "amount": 40,`+"
"+`
      "unit": "TemperatureUnit.DegreeCelsius"`+"
"+`
    },`+"
"+`
    "outletTemperatureSide2": {`+"
"+`
      "amount": 50,`+"
"+`
      "unit": "TemperatureUnit.DegreeCelsius"`+"
"+`
    },`+"
"+`
    "flowSide1": null,`+"
"+`
    "flowSide2": null,`+"
"+`
    "maxPressureDropSide1": {`+"
"+`
      "amount": 20000,`+"
"+`
      "unit": "PressureUnit.Pascal"`+"
"+`
    },`+"
"+`
    "maxPressureDropSide2": {`+"
"+`
      "amount": 20000,`+"
"+`
      "unit": "PressureUnit.Pascal"`+"
"+`
    },`+"
"+`
    "numberOfPasses": null,`+"
"+`
    "numberOfPlates": null,`+"
"+`
    "numberOfPlatesStack1": null,`+"
"+`
    "numberOfPlatesStack2": null,`+"
"+`
    "oversurface": null,`+"
"+`
    "portSwitch": true,`+"
"+`
    "autoperformance": false`+"
"+`
  }`+"
"+`
}`)

  client := &http.Client {
  }
  req, err := http.NewRequest(method, url, payload)

  if err != nil {
    fmt.Println(err)
    return
  }
  req.Header.Add("X-API-KEY", "YOUR_API_KEY")
  req.Header.Add("Content-Type", "application/json")

  res, err := client.Do(req)
  if err != nil {
    fmt.Println(err)
    return
  }
  defer res.Body.Close()

  body, err := ioutil.ReadAll(res.Body)
  if err != nil {
    fmt.Println(err)
    return
  }
  fmt.Println(string(body))
}