package events

import (
	"context"
	"log"
	"strconv"
	"strings"

	"velox-bot/internal/db/services"

	"github.com/bwmarrin/discordgo"
)

// HandleGuildMemberAdd sends a configurable welcome message in a guild channel
// and an optional configurable DM to the joining user.
func HandleGuildMemberAdd(s *discordgo.Session, m *discordgo.GuildMemberAdd, svc *services.Services) {
	if s == nil || m == nil || svc == nil || svc.Welcome == nil {
		return
	}
	if m.User == nil {
		return
	}

	ctx := context.Background()
	guildID := mustParseInt64(m.GuildID)

	settings, err := svc.Welcome.GetSettings(ctx, guildID)
	if err != nil {
		log.Printf("welcome: failed to load settings for guild %s: %v", m.GuildID, err)
		return
	}
	if settings == nil || settings.ChannelID == 0 {
		// No welcome channel configured; nothing to do.
		return
	}

	memberMention := m.User.Mention()

	// Resolve guild/server name and user avatar for placeholders / visuals.
	guildName := ""
	userAvatarURL := ""
	if g, err := s.State.Guild(m.GuildID); err == nil && g != nil {
		guildName = g.Name
	} else if g, err := s.Guild(m.GuildID); err == nil && g != nil {
		guildName = g.Name
	}
	if m.User.Avatar != "" {
		userAvatarURL = discordgo.EndpointUserAvatar(m.User.ID, m.User.Avatar)
	}

	// Build guild welcome message.
	channelID := strconv.FormatInt(settings.ChannelID, 10)
	welcomeMsg := strings.TrimSpace(settings.WelcomeMessage)
	if welcomeMsg == "" {
		// Default message when none configured.
		// "<user>! Welcome to <server>! Have fun!"
		welcomeMsg = "<user>! Welcome to <server>! Have fun!"
	}
	welcomeMsg = strings.ReplaceAll(welcomeMsg, "{user}", memberMention)
	if guildName != "" {
		welcomeMsg = strings.ReplaceAll(welcomeMsg, "{server}", guildName)
		welcomeMsg = strings.ReplaceAll(welcomeMsg, "<server>", guildName)
	}
	welcomeMsg = strings.ReplaceAll(welcomeMsg, "<user>", memberMention)

	embed := &discordgo.MessageEmbed{
		Title:       "👋 Welcome!",
		Description: welcomeMsg,
		Color:       0xFFA500,
		Footer: &discordgo.MessageEmbedFooter{
			Text: "ID: " + m.User.ID,
		},
	}
	if userAvatarURL != "" {
		embed.Author = &discordgo.MessageEmbedAuthor{
			Name:    m.User.Username,
			IconURL: userAvatarURL,
		}
		embed.Thumbnail = &discordgo.MessageEmbedThumbnail{
			URL: userAvatarURL,
		}
	}
	gif := strings.TrimSpace(settings.WelcomeGIFURL)
	if gif == "" {
		// Default GIF when none configured.
		gif = "https://images-ext-1.discordapp.net/external/uJ6XfdK2WwDnei3RmNWUqSiOVboC4mK9r78TtgVE_9g/https/media.giphy.com/media/XD9o33QG9BoMis7iM4/giphy.gif"
	}
	embed.Image = &discordgo.MessageEmbedImage{URL: gif}

	if _, err := s.ChannelMessageSendComplex(channelID, &discordgo.MessageSend{
		Content: memberMention,
		Embed:   embed,
	}); err != nil {
		log.Printf("welcome: failed to send channel welcome in guild %s: %v", m.GuildID, err)
	}

	// Optional DM.
	dmText := strings.TrimSpace(settings.WelcomeDM)
	if dmText == "" {
		// Default DM when none configured.
		// "Welcome to <server>! Have fun!"
		dmText = "Welcome to <server>! Have fun!"
	}
	dmText = strings.ReplaceAll(dmText, "{user}", memberMention)
	if guildName != "" {
		dmText = strings.ReplaceAll(dmText, "{server}", guildName)
		dmText = strings.ReplaceAll(dmText, "<server>", guildName)
	}

	dmCh, err := s.UserChannelCreate(m.User.ID)
	if err != nil {
		log.Printf("welcome: failed to create DM channel for user %s: %v", m.User.ID, err)
		return
	}
	if _, err := s.ChannelMessageSend(dmCh.ID, dmText); err != nil {
		log.Printf("welcome: failed to send DM welcome to user %s: %v", m.User.ID, err)
	}
}