main.go

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
)

type Flags struct{
	PNG string `json:"png"`
}

// Struktur for data fra REST Countries API
type CountryInfo struct {
	Name struct {
		Common   string         `json:"common"`
		Official string         `json:"official"`
	}                           `json:"name"`
	Capital   []string          `json:"capital"`
	Languages map[string]string `json:"languages"`
	Continents []string          `json:"continents"`
	Borders    []string         `json:"borders"`
	Population int              `json:"population"`
	Flags Flags                `json:"flags"`
	Cities []string             `json:"cities"`
}


// Struktur for kombinert respons
type CombinedInfo struct {
	Name       string            `json:"name"`
	Continents   []string         `json:"continenents"`
	Population int               `json:"population"`
	Languages  map[string]string `json:"languages"`
	Borders    []string          `json:"borders"`
	Flags      string            `json:"flags"`
	Capital    string            `json:"capital"`
	Cities     string          `json:"cities"`
}

// Henter landdata fra REST Countries API
func getCountryDataByCode(countryCode string) (*CountryInfo, error) {
	url := fmt.Sprintf("http://129.241.150.113:8080/v3.1/alpha/%s", countryCode)
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("error retrieving country data, status code: %d", resp.StatusCode)
	}

	var countries []CountryInfo
	if err := json.NewDecoder(resp.Body).Decode(&countries); err != nil {
		return nil, err
	}

	if len(countries) == 0 {
		return nil, fmt.Errorf("country not found for code: %s", countryCode)
	}

	return &countries[0], nil
}


// Handler som kombinerer data fra begge API-er
func countryInfoHandler(w http.ResponseWriter, r *http.Request) {
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 5 {
		http.Error(w, "Invalid format. Use: /countryinfo/v1/info/{countryCode}", http.StatusBadRequest)
		return
	}
	countryCode := parts[4]

	// Hent data fra begge API-er
	country, err := getCountryDataByCode(countryCode)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	

	// Bygg kombinert respons
	response := CombinedInfo{
		Name:       country.Name.Common,
		Continents:     country.Continents,
		Population: country.Population,
		Languages:  country.Languages,
		Borders:    country.Borders,
		Flags:      country.Flags.PNG,
		Capital:    "",
		Cities:     "",
	}


	if len(country.Capital) > 0 {
		response.Capital = country.Capital[0]
	}

	if len(country.Cities) > 0 {
		response.Cities = country.Cities[0]
	}


	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func main() {
	http.HandleFunc("/", homeHandler)
	http.HandleFunc("/countryinfo/v1/info/", countryInfoHandler)

	fmt.Println("Server running on port 8080...")
	if err := http.ListenAndServe(":8080", nil); err != nil {
		fmt.Printf("Server failed to start: %s\n", err)
	}
}

func homeHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	response := map[string]interface{}{
		"WELCOME": "Welcome to the Country Info API",
		"endpoints": map[string]interface{}{
			"Get Country Info": map[string]string{
				"Description": "Get country details including cities, population, and more.",
				"URL":         "http://localhost:8080/countryinfo/v1/info/{country_code}",
				"Example":     "http://localhost:8080/countryinfo/v1/info/NO",
			},
		},
	}

	json.NewEncoder(w).Encode(response)
}