package main

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

type envelope map[string]any

// This was the original function signature without enveloping
// func (app *application) writeJSON(w http.ResponseWriter, status int, data any, headers http.Header) error {

func (app *application) writeJSON(w http.ResponseWriter, status int, data envelope, headers http.Header) error {
	// TODO set a flag for wether to indent or not. Indenting cost CPU time, more memory, and more allocs
	// approximately 65% more time 30% more mem.
	//js, err := json.Marshal(data)

	// Use the json.MarshalIndent() function so that whitespace is added to the encoded
	// JSON. Here we use no line prefix ("") and tab indents ("\t") for each element.
	js, err := json.MarshalIndent(data, "", "\t")

	if err != nil {
		return err
	}

	js = append(js, '\n')

	// At this point, we know that we won't encounter any more errors before writing the
	// response, so it's safe to add any headers that we want to include. We loop
	// through the header map and add each header to the http.ResponseWriter header map.
	// Note that it's OK if the provided header map is nil. Go doesn't throw an error
	// if you try to range over (or generally, read from) a nil map.
	for key, value := range headers {
		w.Header()[key] = value
	}

	// Add the "Content-Type: application/json" header, then write the status code and
	// JSON response.
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	w.Write(js)

	return nil
}