package service

import (
	"context"
	"fmt"
	"rockhu-bot/local/model"
	"rockhu-bot/local/repository"
	"rockhu-bot/local/utl/common"
	"strconv"
	"time"

	"github.com/gocolly/colly"
	"gorm.io/datatypes"
)

type ConcertService struct {
	repository *repository.ConcertRepository
}

func NewConcertService(repository *repository.ConcertRepository) *ConcertService {
	return &ConcertService{
		repository: repository,
	}
}

// GetFirst
// Gets first row from Concert table.
//
//	   	Args:
//	   		context.Context: Application context
//		Returns:
//			string: Application version
func (as ConcertService) GetAll(ctx context.Context) *[]model.ConcertModel {
	return as.repository.GetAll(ctx)
}

func (as ConcertService) CheckAndUpdateConcerts(ctx context.Context) []model.ConcertModel {
	cm := as.GetAll(ctx)
	fmt.Printf("Currently there are %d concerts\n", len(*cm))
	NewConcerts := scrapeData(ctx)
	fmt.Printf("There are %d new concerts\n", len(*NewConcerts))
	forInsert, forDelete, _ := partitionConcerts(*cm, *NewConcerts)

	tx := as.repository.CreateTransaction()
	defer tx.Rollback()

	if len(forDelete) > 0 {
		tx.Delete(forDelete)
	}
	if len(forInsert) > 0 {
		tx.Create(forInsert)
	}

	tx.Commit()

	return forInsert
}

func scrapeData(ctx context.Context) *[]model.ConcertModel {
	c := colly.NewCollector()
	concerts := new([]model.ConcertModel)

	// Find and visit all links
	c.OnHTML(".event_box", func(e *colly.HTMLElement) {
		currentDate := time.Now()
		currentMonth := currentDate.Month()
		month, err := common.GetMonthFromLocalized(e.ChildText(".event_date>.month"))
		if err != nil {
			panic(err)
		}
		dayText := e.ChildText(".event_date>.day")
		day, err := strconv.Atoi(dayText)
		if err != nil {
			panic(err)
		}

		year := currentDate.Year()
		if month < int(currentMonth) {
			year = year + 1
		}

		eventDate := time.Date(year, time.Month(month), day, 0, 0, 0, 0, time.UTC)
		concert := new(model.ConcertModel)
		concert.Name = e.ChildText(".event_title")
		concert.StartDate = datatypes.Date(eventDate)
		*concerts = append(*concerts, *concert)
	})

	c.OnRequest(func(r *colly.Request) {
		fmt.Println("Visiting", r.URL)
	})

	c.Visit("https://jegy.rock1.hu/")

	return concerts
}

func concertKey(concert model.ConcertModel) string {
	cc := concert.Name + (time.Time)(concert.StartDate).Format("2006-01-02")
	fmt.Println(cc)
	return cc
}

func partitionConcerts(previous, current []model.ConcertModel) (newConcerts, deletedConcerts, unchangedConcerts []model.ConcertModel) {
	// Create a map of previous concerts for quick lookup
	fmt.Println("Previous concerts\n")
	previousMap := make(map[string]model.ConcertModel)
	for _, concert := range previous {
		previousMap[concertKey(concert)] = concert
	}

	fmt.Println("New concerts\n")
	// Create a map of current concerts for quick lookup
	currentMap := make(map[string]model.ConcertModel)
	for _, concert := range current {
		currentMap[concertKey(concert)] = concert
	}

	// Identify new and unchanged concerts
	for _, concert := range current {
		if _, exists := previousMap[concertKey(concert)]; exists {
			unchangedConcerts = append(unchangedConcerts, concert)
		} else {
			newConcerts = append(newConcerts, concert)
			fmt.Printf("New concert %s\n", concert.Name)
		}
	}

	// Identify deleted concerts
	for _, concert := range previous {
		if _, exists := currentMap[concertKey(concert)]; !exists {
			deletedConcerts = append(deletedConcerts, concert)
			fmt.Printf("Deleted concert %s\n", concert.Name)
		}
	}

	return newConcerts, deletedConcerts, unchangedConcerts
}