package main

import (
	"fmt"
	"log"
	"net/http"
	"strconv"
	"strings"
)

const validNumberOfURLParams = 5
const sizeParamIndex = 3
const countParamIndex = 4
const validNumberOfSizeParams = 2

const (
	invalidURL                    = "URL is not valid"
	invalidNumberOfParamsError    = "Number of params not correct, expected /WIDTHxLENGTH/count"
	invalidNumberOfSizeParamError = "Size not correct, expected /WIDTHxLENGTH/count"
	invalidParamsType             = "Params should be numbers"
)

func errorResponse(w http.ResponseWriter, errType string) {
	fmt.Fprintf(w, errType)
}

func diecutHandler(w http.ResponseWriter, r *http.Request) {
	if params := strings.Split(r.URL.Path, "/"); len(params) == validNumberOfURLParams {
		if size := strings.Split(params[sizeParamIndex], "x"); len(size) == validNumberOfSizeParams {
			count := params[countParamIndex]

			width, wOk := strconv.ParseInt(size[0], 10, 32)
			height, hOk := strconv.ParseInt(size[1], 10, 32)
			countNumber, cOk := strconv.ParseInt(count, 10, 32)

			if wOk != nil || hOk != nil || cOk != nil {
				errorResponse(w, invalidParamsType)
			} else {
				fmt.Fprintf(w, "%dx%d | %d", width, height, countNumber)

			}

		} else {
			errorResponse(w, invalidNumberOfSizeParamError)
		}
	} else {
		errorResponse(w, invalidNumberOfParamsError)
	}
}

func defaultHandler(w http.ResponseWriter, r *http.Request) {
	errorResponse(w, invalidURL)
}

func main() {
	http.HandleFunc("/prices/diecut/", diecutHandler)
	http.HandleFunc("/", defaultHandler)

	fmt.Println("Server running on localhost:8080")
	log.Fatal(http.ListenAndServe(":8080", nil))
}