package logic

import (
	"context"
	"encoding/base64"
	"fmt"
	"git.anthrove.art/Anthrove/gorse-playground/internal/config"
	"github.com/anthrove/openapi-e621-go"
	"github.com/caarlos0/env/v11"
	"golang.org/x/time/rate"
	"log"
	"net/http"

	_ "github.com/joho/godotenv/autoload"
)

var e621Config config.E621
var rateLimit *rate.Limiter
var apiClient *openapi.APIClient

func init() {
	err := env.Parse(&e621Config)

	if err != nil {
		log.Panic(err)
	}

	rateLimit = rate.NewLimiter(1, 2)

	apiClient, err = newE621Client(e621Config)

	if err != nil {
		log.Panic(err)
	}

}

func newE621Client(cfg config.E621) (*openapi.APIClient, error) {
	e621Config := openapi.NewConfiguration()
	e621Config.DefaultHeader["Authorization"] = "Basic " + base64.StdEncoding.EncodeToString([]byte(cfg.Username+":"+cfg.ApiKey))
	e621Config.UserAgent = fmt.Sprintf("gorse-playground-scraper used by %s | (made by the Anthrove Team)", cfg.Username)
	e621Config.Debug = false

	client := http.DefaultClient
	client.Transport = newRateMiddleware(&http.Transport{})

	e621Config.HTTPClient = client

	return openapi.NewAPIClient(e621Config), nil
}

func GetAllFavorites(ctx context.Context, userID int) ([]openapi.Post, error) {
	posts := make([]openapi.Post, 0)

	page := 1
	for {
		currentFavs, err := GetFavoritePage(ctx, userID, page)

		if err != nil {
			return nil, err
		}

		if len(currentFavs) == 0 {
			break
		}

		posts = append(posts, currentFavs...)
		page++
	}

	return posts, nil
}

func GetFavoritePage(ctx context.Context, userId int, pageIdentifier int) ([]openapi.Post, error) {
	favorites, _, err := apiClient.FavoritesAPI.ListFavorites(ctx).Page(int32(pageIdentifier)).UserId(int32(userId)).Execute()
	if err != nil {
		return make([]openapi.Post, 0), err
	}

	return favorites.Posts, nil
}

func newRateMiddleware(transport *http.Transport) http.RoundTripper {
	return &rateMiddleware{
		transport: transport,
	}
}

type rateMiddleware struct {
	transport *http.Transport
}

func (r rateMiddleware) RoundTrip(request *http.Request) (*http.Response, error) {
	err := rateLimit.Wait(request.Context())

	if err != nil {
		return nil, err
	}

	return r.transport.RoundTrip(request)
}