package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"

	azlog "github.com/Azure/azure-sdk-for-go/sdk/azcore/log"
	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
	"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob"

	"github.com/gorilla/handlers"
)

var (
	host string = ""
	port int    = 5000
)

var (
	subscription       string = "******************************"
	resourceGroupName  string = "******************************"
	storageAccountName string = "******************************"
)

func GetCredential() (*azidentity.DefaultAzureCredential, error) {

	cred, err := azidentity.NewDefaultAzureCredential(nil)
	if err != nil {
		return nil, fmt.Errorf("azidentity.NewDefaultAzureCredential is error: %w", err)
	}

	return cred, nil
}

func ListContainer(ctx context.Context, cred *azidentity.DefaultAzureCredential) ([]string, error) {

	serviceClient, err := azblob.NewServiceClient(fmt.Sprintf("https://%v.blob.core.windows.net", storageAccountName), cred, nil)
	if err != nil {
		return nil, err
	}
	pager := serviceClient.ListContainers(nil)

	ret := []string{}
	for pager.NextPage(ctx) {
		resp := pager.PageResponse()

		for _, v := range resp.ContainerItems {
			ret = append(ret, *v.Name)
		}
	}

	return ret, nil
}

func setAzLogging() {
	azlog.SetListener(func(cls azlog.Event, msg string) {
		log.Println(msg) // printing log out to the console
	})
	azlog.SetEvents(azlog.EventRequest, azlog.EventResponse)
}

func main() {
	http.HandleFunc("/msicheck", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/plain")
		cred, err := GetCredential()
		if err != nil {
			m := fmt.Sprintf("GetCredential error: %v", err)
			log.Println(m)
			http.Error(w, m, http.StatusInternalServerError)
		}
		c, err := ListContainer(r.Context(), cred)
		for _, v := range c {
			w.Write([]byte(v))
			w.Write([]byte("\n"))
		}
	})

	addr := fmt.Sprintf("%v:%v", host, port)
	log.Printf("Listen %v\n", addr)
  
	setAzLogging()

	err := http.ListenAndServe(addr, handlers.LoggingHandler(os.Stdout, http.DefaultServeMux))
	if err != nil {
		log.Fatal("ListenAndServe: ", err)
	}
}