package logic

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

	_ "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 SubmitItems(ctx context.Context) error {
	currentDate := time.Now().Format("2006-01-02")
	err := utils.DownloadE6Data(ctx, "posts-"+currentDate+".csv.gz", "post-file.csv")

	if err != nil {
		return err
	}

	fileReader, err := os.Open("post-file.csv")

	if err != nil {
		return err
	}

	inputE621PostChannel := make(chan e621.Post)
	outputAnthrovePostChannel := make(chan models.GorseItem)
	postChan := utils.GetStreamingData[e621.Post](ctx, fileReader)

	go func() {
		defer close(inputE621PostChannel)
		for post := range postChan {
			inputE621PostChannel <- post
		}
		log.Println("Loading ended")
	}()

	go func() {
		defer close(outputAnthrovePostChannel)
		err := postToItem(inputE621PostChannel, outputAnthrovePostChannel)
		if err != nil { //TODO: DEADLOCK
			log.Println(err)
		}
		log.Println("Convert ended")
	}()

	log.Println("Start with comparison check")

	items := make([]models.GorseItem, 0)
	length := 0

	for item := range outputAnthrovePostChannel {
		timeDate, err := time.Parse(time.DateTime, item.Timestamp)

		if err != nil {
			log.Println(err)
			continue
		}

		if !timeDate.After(time.Date(2024, 1, 1, 1, 1, 1, 0, time.UTC)) {
			continue
		}

		items = append(items, item)

		if length%20_000 == 0 && length > 0 {
			log.Println("Worked ", length, " items")
			err := UpsertItems(ctx, items)

			if err != nil {
				return err
			}

			items = make([]models.GorseItem, 0)
		}

		length++
	}

	err = UpsertItems(ctx, items)

	if err != nil {
		return err
	}

	return 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)
}

func postToItem(input chan e621.Post, output chan models.GorseItem) error {
	for e6Post := range input {

		tagParts := strings.Split(e6Post.TagString, " ")

		output <- models.GorseItem{
			Comment:   e6Post.Description,
			IsHidden:  e6Post.IsDeleted,
			ItemId:    strconv.Itoa(e6Post.ID),
			Labels:    tagParts,
			Timestamp: e6Post.CreatedAt,
		}
	}
	return nil
}