package main

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"log"
	"net/http"
	"sync"

	"github.com/zalando/go-keyring"
)

var simklJwt SimklJWT

// simklKeyringService is the OS keyring service name all AniTrack secrets
// live under (same wallet the 99designs/keyring build used).
const simklKeyringService = "AniTrack"

func simklRingSet(key string, data []byte) error {
	if err := keyring.Set(simklKeyringService, key, string(data)); err != nil {
		log.Printf("simkl: save %s failed: %s", key, err)
		return err
	}
	return nil
}

var simklCtxShutdown, simklCancel = context.WithCancel(context.Background())

func (a *App) CheckIfSimklLoggedIn() bool {
	if (SimklJWT{} == simklJwt) {
		tokenType, tokenTypeErr := keyring.Get(simklKeyringService, "SimklTokenType")
		accessToken, accessTokenErr := keyring.Get(simklKeyringService, "SimklAccessToken")
		scope, scopeErr := keyring.Get(simklKeyringService, "SimklScope")
		if (tokenTypeErr != nil || accessTokenErr != nil || scopeErr != nil) || len(accessToken) == 0 {
			return false
		} else {
			simklJwt.TokenType = tokenType
			simklJwt.AccessToken = accessToken
			simklJwt.Scope = scope
			return true
		}
	} else {
		return true
	}
}

func (a *App) SimklLogin() {
	if !a.CheckIfSimklLoggedIn() {
		tokenType, tokenTypeErr := keyring.Get(simklKeyringService, "SimklTokenType")
		accessToken, accessTokenErr := keyring.Get(simklKeyringService, "SimklAccessToken")
		scope, scopeErr := keyring.Get(simklKeyringService, "SimklScope")
		if (tokenTypeErr != nil || accessTokenErr != nil || scopeErr != nil) || len(accessToken) == 0 {
			getSimklCodeUrl := "https://simkl.com/oauth/authorize?response_type=code&client_id=" + Environment.SIMKL_CLIENT_ID + "&redirect_uri=" + Environment.SIMKL_CALLBACK_URI
			if err := a.app.Browser.OpenURL(getSimklCodeUrl); err != nil {
				log.Printf("simkl: failed to open browser: %s", err)
				return
			}

			serverDone := &sync.WaitGroup{}
			serverDone.Add(1)
			a.handleSimklCallback(serverDone)
			serverDone.Wait()
		} else {
			simklJwt.TokenType = tokenType
			simklJwt.AccessToken = accessToken
			simklJwt.Scope = scope
		}
	}
}

func (a *App) handleSimklCallback(wg *sync.WaitGroup) {
	mux := http.NewServeMux()
	srv := &http.Server{Addr: ":6734", Handler: mux}
	mux.HandleFunc("/callback", func(w http.ResponseWriter, r *http.Request) {
		select {
		case <-simklCtxShutdown.Done():
			fmt.Println("Shutting down...")
			return
		default:
		}
		content := r.FormValue("code")

		if content != "" {
			simklJwt = getSimklAuthorizationToken(content)
			_ = simklRingSet("SimklTokenType", []byte(simklJwt.TokenType))
			_ = simklRingSet("SimklAccessToken", []byte(simklJwt.AccessToken))
			_ = simklRingSet("SimklScope", []byte(simklJwt.Scope))
			a.app.Dialog.Info().
				SetTitle("Simkl Authorization").
				SetMessage("It is now safe to close your browser tab").
				Show()
			fmt.Println("Shutting down...")
			simklCancel()
			if err := srv.Shutdown(context.Background()); err != nil {
				log.Println("server.Shutdown:", err)
			}
		} else {
			_, err := fmt.Fprintf(w, "Getting code failed.")
			if err != nil {
				return
			}
		}
	})

	go func() {
		defer wg.Done()
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			log.Printf("Server error: %s\n", err)
		}
		fmt.Println("Shutting down...")
	}()
}

func getSimklAuthorizationToken(content string) SimklJWT {
	data := struct {
		GrantType    string `json:"grant_type"`
		ClientID     string `json:"client_id"`
		ClientSecret string `json:"client_secret"`
		RedirectURI  string `json:"redirect_uri"`
		Code         string `json:"code"`
	}{
		GrantType:    "authorization_code",
		ClientID:     Environment.SIMKL_CLIENT_ID,
		ClientSecret: Environment.SIMKL_CLIENT_SECRET,
		RedirectURI:  Environment.SIMKL_CALLBACK_URI,
		Code:         content,
	}
	jsonData, err := json.Marshal(data)
	if err != nil {
		log.Printf("Failed to marshal data: %s\n", err)
		return SimklJWT{}
	}

	response, err := http.NewRequest("POST", "https://api.simkl.com/oauth/token", bytes.NewBuffer(jsonData))
	if err != nil {
		log.Printf("Failed at response, %s\n", err)
	}
	response.Header.Add("Content-Type", "application/json")

	client := &http.Client{}
	res, resErr := client.Do(response)
	if resErr != nil {
		log.Printf("Failed at res, %s\n", err)
	}

	defer res.Body.Close()

	returnedBody, err := io.ReadAll(res.Body)
	if err != nil {
		log.Printf("Could not read returned body, %s\n.", err)
	}

	var post SimklJWT
	err = json.Unmarshal(returnedBody, &post)
	if err != nil {
		log.Printf("Failed at unmarshal, %s\n", err)
	}

	return post
}

func (a *App) GetSimklLoggedInUser() SimklUser {
	a.SimklLogin()

	client := &http.Client{}

	req, _ := http.NewRequest("POST", "https://api.simkl.com/users/settings", nil)

	req.Header.Add("Content-Type", "application/json")
	req.Header.Add("Authorization", "Bearer "+simklJwt.AccessToken)
	req.Header.Add("simkl-api-key", Environment.SIMKL_CLIENT_ID)

	response, err := client.Do(req)
	if err != nil {
		log.Printf("Failed at request, %s\n", err)
		return SimklUser{}
	}

	defer response.Body.Close()

	respBody, _ := io.ReadAll(response.Body)

	var errCheck struct {
		Error   string `json:"error"`
		Message string `json:"message"`
	}

	err = json.Unmarshal(respBody, &errCheck)
	if err != nil {
		log.Printf("Failed at unmarshal, %s\n", err)
	}

	if errCheck.Error != "" {
		a.LogoutSimkl()
		return SimklUser{}
	}

	var user SimklUser

	err = json.Unmarshal(respBody, &user)
	if err != nil {
		log.Printf("Failed at unmarshal, %s\n", err)
	}

	return user
}

func (a *App) LogoutSimkl() string {
	if (SimklJWT{} != simklJwt) {
		tokenTypeErr := keyring.Delete(simklKeyringService, "SimklTokenType")
		accessTokenErr := keyring.Delete(simklKeyringService, "SimklAccessToken")
		scopeErr := keyring.Delete(simklKeyringService, "SimklScope")

		if tokenTypeErr != nil || accessTokenErr != nil || scopeErr != nil {
			log.Printf("simkl: logout cleanup failed (type=%v access=%v scope=%v)", tokenTypeErr, accessTokenErr, scopeErr)
		}
		simklJwt = SimklJWT{}
	}

	return "Simkl Logged Out Successfully"
}