package main

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

/*
Tips: The important thing to point out here is that healthcheckHandler is implemented as a method
on our application struct. This is an effective and idiomatic way to make dependencies available
to our handlers without resorting to global variables or closures - any dependency that the
healthcheckHandler needs can simply be included as a field in the application struct when we
initialize it in main()
*/
func (app *application) healthcheckHandler(w http.ResponseWriter, r *http.Request) {
	// Create a map which holds the information that we want to send in the response.
	data := map[string]string{
		"status":      "available",
		"environment": app.config.env,
		"version":     version,
	}

	/*
		Pass the map to the json.Marshal() function. This returns a []byte slice
		containing the encoded JSON. If there was an error, we log it and send the client
		a generic error message.
	*/
	js, err := json.Marshal(data)
	if err != nil {
		app.logger.Error(err.Error())
		http.Error(w, "The server encountered a problem and could not process your request.", http.StatusInternalServerError)
	}

	// Append a newline to the JSON. This is just a small nicety to make it easier to
	// view in terminal applications.
	js = append(js, '\n')

	// At this point, we know that encoding the data worked without any problem, so we
	// can safely set any necessary HTTP headers for a successful response.
	w.Header().Set("Content-Type", "application/json")

	// Use w.Write() to send the []byte slice containing the JSON as the response body.
	w.Write(js)
}