package itglue

import (
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
)

func check(err error) {
	if err != nil {
		log.Fatal(err)
	}
}

//ITGAPI contains the ITG API URL for North America, as well as the API key.
//Think of it as an instance of the API client
type ITGAPI struct {
	Site   string //Full URL ITG API
	APIKey string //API Key
}

//NewITGAPI expects the API key to be passed to it
//Returns a pointer to an ITGAPI struct
func NewITGAPI(apiKey string) *ITGAPI {
	return &ITGAPI{Site: "https://api.itglue.com", APIKey: apiKey}
}

func getHTTPResponseBody(resp *http.Response) []byte {
	if resp.StatusCode != http.StatusOK {

		out := fmt.Sprintf("ITG returned HTTP status code %s\n%s", resp.Status, resp.Body)
		log.Fatal(out)
		return make([]byte, 0) //TBD: Don't hack
	}

	body, err := ioutil.ReadAll(resp.Body)
	check(err)

	return body
}

//BuildURL expects a restaction to be passed to it
//Returns the full request URL containing the ITG API domain prepended to the rest action
func (itg *ITGAPI) BuildURL(restAction string) *url.URL {
	var itgurl *url.URL
	itgurl, err := url.Parse(itg.Site)
	check(err)
	itgurl.Path += restAction
	return itgurl
}

//GetRequest allows a custom GET request to the API to be made.
//Also used internally by this package by the binding functions
//Expects URL to be passed
//Returns the response body as a byte slice
func (itg *ITGAPI) GetRequest(itgurl *url.URL) []byte {
	client := &http.Client{}
	req, err := http.NewRequest("GET", itgurl.String(), nil)
	check(err)
	req.Header.Set("Content-Type", "application/vnd.api+json")
	req.Header.Set("x-api-key", itg.APIKey)
	req.Header.Set("cache-control", "no-cache")
	response, err := client.Do(req)
	check(err)
	defer response.Body.Close()

	return getHTTPResponseBody(response)
}

//PostRequest allows a custom POST request tot he API to be made
//Also used internally by this package by the binding functions
//Expects a URL and a body to be passed
//Returns the response body as a byte slice
func (itg *ITGAPI) PostRequest(itgurl *url.URL, body io.Reader) []byte {
	client := &http.Client{}
	req, err := http.NewRequest("POST", itgurl.String(), body)
	check(err)
	req.Header.Set("Content-Type", "application/vnd.api+json")
	req.Header.Set("x-api-key", itg.APIKey)
	req.Header.Set("cache-control", "no-cache")
	response, err := client.Do(req)
	check(err)
	defer response.Body.Close()

	return getHTTPResponseBody(response)

}

//PatchRequest allows a custom PATCH request tot he API to be made
//Also used internally by this package by the binding functions
//Expects a URL and a body to be passed
//Returns the response body as a byte slice
func (itg *ITGAPI) PatchRequest(itgurl *url.URL, body io.Reader) []byte {
	client := &http.Client{}
	req, err := http.NewRequest("PATCH", itgurl.String(), body)
	check(err)
	req.Header.Set("Content-Type", "application/vnd.api+json")
	req.Header.Set("x-api-key", itg.APIKey)
	req.Header.Set("cache-control", "no-cache")
	response, err := client.Do(req)
	check(err)
	defer response.Body.Close()

	return getHTTPResponseBody(response)

}