package main

import (
	"fmt"
	"log"
	"strings"
	"sync"
	"time"

	"github.com/bwmarrin/discordgo"
)

type StatusMonitor struct {
	mu          sync.Mutex
	session     *discordgo.Session
	channelID   string
	host        string
	port        int
	interval    time.Duration
	messageID   string
	onlineSince time.Time
}

func NewStatusMonitor(s *discordgo.Session, cfg *Config) *StatusMonitor {
	return &StatusMonitor{
		session:   s,
		channelID: cfg.ChannelID,
		host:      cfg.ServerHost,
		port:      cfg.ServerPort,
		interval:  time.Duration(cfg.UpdateInterval) * time.Second,
	}
}

func (m *StatusMonitor) Start() {
	m.updateStatus()

	m.findExistingMessage()

	ticker := time.NewTicker(m.interval)
	go func() {
		for range ticker.C {
			m.updateStatus()
		}
	}()
}

func (m *StatusMonitor) findExistingMessage() {
	msgs, err := m.session.ChannelMessages(m.channelID, 50, "", "", "")
	if err != nil {
		log.Printf("Error fetching messages: %v", err)
		return
	}
	for _, msg := range msgs {
		if msg.Author.ID == m.session.State.User.ID {
			m.mu.Lock()
			m.messageID = msg.ID
			m.mu.Unlock()
			return
		}
	}
}

func (m *StatusMonitor) buildEmbed(status *ServerStatus) *discordgo.MessageEmbed {
	embed := &discordgo.MessageEmbed{
		Color: 0x808080,
		Title: "NikoCraft",
		URL:   "https://mc.n1ko.dev",
	}

	if !status.Online {
		embed.Description = "**Сервер оффлайн** 🔴"
		embed.Color = 0xFF0000
		return embed
	}

	var b strings.Builder
	b.WriteString("**Игроки:**\n```\n")
	if len(status.Players) == 0 {
		b.WriteString("Никого нет")
	} else {
		for i, name := range status.Players {
			if i > 0 {
				b.WriteString("\n")
			}
			b.WriteString(name)
		}
	}
	b.WriteString("```")

	embed.Description = b.String()

	uptime := time.Since(m.onlineSince)
	var uptimeStr string
	hours := uptime.Hours()
	if hours < 1 {
		uptimeStr = fmt.Sprintf("%.0f мин.", uptime.Minutes())
	} else {
		uptimeStr = fmt.Sprintf("%.1f ч.", hours)
	}

	embed.Fields = []*discordgo.MessageEmbedField{
		{
			Name:   ":busts_in_silhouette: Игроков",
			Value:  fmt.Sprintf("%d/%d", status.OnlineCount, status.MaxPlayers),
			Inline: true,
		},
		{
			Name:   ":repeat: Аптайм",
			Value:  uptimeStr,
			Inline: true,
		},
	}

	return embed
}

func (m *StatusMonitor) updateStatus() {
	status, err := queryServer(m.host, m.port)

	m.mu.Lock()
	defer m.mu.Unlock()

	if err != nil {
		log.Printf("Server query failed: %v", err)
		m.onlineSince = time.Time{}
		status = &ServerStatus{Online: false}
	} else {
		if m.onlineSince.IsZero() {
			m.onlineSince = time.Now()
		}
	}

	embed := m.buildEmbed(status)

	if m.messageID != "" {
		_, err := m.session.ChannelMessageEditComplex(&discordgo.MessageEdit{
			Channel: m.channelID,
			ID:      m.messageID,
			Embeds:  &[]*discordgo.MessageEmbed{embed},
		})
		if err != nil {
			log.Printf("Error editing embed (will create new): %v", err)
			m.messageID = ""
		}
	}

	if m.messageID == "" {
		msg, err := m.session.ChannelMessageSendEmbed(m.channelID, embed)
		if err != nil {
			log.Printf("Error sending embed: %v", err)
			return
		}
		m.messageID = msg.ID
	}
}