package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"os"
)

type app struct {
	ClientId     string `json:"client_id"`
	ClientSecret string `json:"client_secret"`
}

type user struct {
	Username    string `json:"username"`
	Instance    string `json:"instance"`
	AccessToken string `json:"access_token"`
}

var BASE_URL = "https://awoo.fai.st"
var DEFAULT_REDIRECT_URI = "urn:ietf:wg:oauth:2.0:oob"

func main() {
	// Get the `client_id` and the `client_secret` values
	app, err := getAppCredentials(BASE_URL)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(getTokenUrl(BASE_URL, app))

	// Read the token
	fmt.Print("Enter token: ")
	reader := bufio.NewReader(os.Stdin)
	token, err := reader.ReadString('\n')
	if err != nil {
		log.Fatal(err)
	}
	token = token[:len(token)-1]
	fmt.Println(token)
}

func getTokenUrl(instance string, app *app) string {
	return fmt.Sprintf("%s/oauth/authorize?response_type=code&client_id=%s&redirect_uri=%s", BASE_URL, app.ClientId, DEFAULT_REDIRECT_URI)
}

func getAppCredentials(instance string) (*app, error) {
	// We try to read the file `credentials.json` to read
	// the application's credentials
	// If it doesn't exist, we generate a new application
	contents, err := os.ReadFile("credentials.json")
	if err != nil {
		return createApp(instance)
	}

	// The file's contents are unmarshalled into a map
	var credentials app
	err = json.Unmarshal(contents, &credentials)
	if err != nil {
		return nil, err
	}

	return &credentials, nil
}

func createApp(instance string) (*app, error) {
	// Define the values to the request for creating the app
	data := url.Values{
		"client_name":   {"grames"},
		"redirect_uris": {DEFAULT_REDIRECT_URI},
	}

	// Send request to create app
	resp, err := http.PostForm(instance+"/api/v1/apps", data)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	// Read the body's JSON response into `contents` as []byte
	contents, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	// Unmarshal the JSON data into an app struct
	var credentials app
	err = json.Unmarshal(contents, &credentials)
	if err != nil {
		return nil, err
	}

	// Marshal the app into JSON data
	b, err := json.MarshalIndent(credentials, "", "  ")
	if err != nil {
		return nil, err
	}

	// Write the JSON data into the file `credentials.json`
	err = os.WriteFile("credentials.json", b, 0644)
	if err != nil {
		return nil, err
	}

	return &credentials, nil
}