package discord

import (
	"context"
	"fmt"
	"sync"
	"time"

	"gitea.dwysokinski.me/twhelp/dcbot/internal/domain"
	"github.com/bwmarrin/discordgo"
	"go.uber.org/zap"
)

const (
	executeMonitorsJobTimeout = 2 * time.Minute
	colorGreen                = 0x00ff00
	colorRed                  = 0xff0000
)

type executeMonitorsJob struct {
	s      *discordgo.Session
	svc    MonitorService
	logger *zap.Logger
}

func (e *executeMonitorsJob) Run() {
	ctx, cancel := context.WithTimeout(context.Background(), executeMonitorsJobTimeout)
	defer cancel()

	start := time.Now()
	notifications, err := e.svc.Execute(ctx)
	if err != nil {
		e.logger.Error("something went wrong while executing monitors", zap.Error(err))
		return
	}

	var wg sync.WaitGroup

	for ch, embeds := range ennoblementNotificationsToEmbeds(notifications) {
		wg.Add(1)

		go func(ch string, embeds []*discordgo.MessageEmbed) {
			defer wg.Done()
			for _, embed := range embeds {
				_, _ = e.s.ChannelMessageSendEmbed(ch, embed)
			}
		}(ch, embeds)
	}

	wg.Wait()

	e.logger.Info(
		"notifications sent",
		zap.Int("notifications", len(notifications)),
		zap.Duration("duration", time.Since(start)),
	)
}

func ennoblementNotificationsToEmbeds(ns []domain.EnnoblementNotification) map[string][]*discordgo.MessageEmbed {
	m := make(map[string]map[domain.EnnoblementNotificationType][]*discordgo.MessageEmbed)
	timestamp := formatTimestamp(time.Now())
	for _, n := range ns {
		if _, ok := m[n.ChannelID]; !ok {
			m[n.ChannelID] = make(map[domain.EnnoblementNotificationType][]*discordgo.MessageEmbed)
		}

		embeds := m[n.ChannelID][n.Type]

		str := buildEnnoblementNotificationDescription(n)
		if l := len(embeds); l == 0 || len(embeds[l-1].Description)+len(str) > embedDescriptionCharLimit {
			embeds = append(embeds, &discordgo.MessageEmbed{
				Color:     ennoblementNotificationTypeToColor(n.Type),
				Type:      discordgo.EmbedTypeRich,
				Timestamp: timestamp,
			})
		}
		if len(embeds[len(embeds)-1].Description) > 0 {
			str = "\n" + str
		}
		embeds[len(embeds)-1].Description += str

		m[n.ChannelID][n.Type] = embeds
	}

	res := make(map[string][]*discordgo.MessageEmbed, len(m))
	for ch, innerMap := range m {
		cnt := 0
		for _, embeds := range innerMap {
			cnt += len(embeds)
		}

		res[ch] = make([]*discordgo.MessageEmbed, 0, cnt)
		for _, embeds := range innerMap {
			res[ch] = append(res[ch], embeds...)
		}
	}

	return res
}

func buildEnnoblementNotificationDescription(n domain.EnnoblementNotification) string {
	return fmt.Sprintf(
		"%s has taken %s (Old owner: %s)",
		nullPlayerMetaToMarkdown(n.Ennoblement.NewOwner),
		buildLink(n.Ennoblement.Village.FullName, n.Ennoblement.Village.ProfileURL),
		nullPlayerMetaToMarkdown(n.Ennoblement.OldOwner),
	)
}

func nullPlayerMetaToMarkdown(p domain.NullPlayerMeta) string {
	if !p.Valid {
		return "Barbarians"
	}

	tag := p.Player.Tribe.Tribe.Tag
	if tag == "" {
		tag = "-"
	}

	return buildLink(p.Player.Name, p.Player.ProfileURL) +
		" [" +
		buildLink(tag, p.Player.Tribe.Tribe.ProfileURL) +
		"]"
}

func ennoblementNotificationTypeToColor(t domain.EnnoblementNotificationType) int {
	switch t {
	case domain.EnnoblementNotificationTypeGain:
		return colorGreen
	case domain.EnnoblementNotificationTypeLoss:
		fallthrough
	default:
		return colorRed
	}
}