package public

import (
	"context"
	"fmt"
	"log"
	"strconv"
	"strings"
	"time"

	"velox-bot/internal/db/services"

	"github.com/bwmarrin/discordgo"
)

// Everything else /config needs so that no setting depends on a dashboard:
// seeing the settings, clearing one, switching Twitch alerts on and off,
// listing streamers, and the server owner's beta features switch.

var clearChoices = []string{"welcome-channel", "welcome-message", "welcome-dm", "welcome-gif", "default-role", "log-channel"}

func extraOptions() []*discordgo.ApplicationCommandOption {
	clear := &discordgo.ApplicationCommandOption{
		Type: discordgo.ApplicationCommandOptionString, Name: "setting", Description: "What to clear", Required: true,
	}
	for _, c := range clearChoices {
		clear.Choices = append(clear.Choices, &discordgo.ApplicationCommandOptionChoice{Name: c, Value: c})
	}
	return []*discordgo.ApplicationCommandOption{
		{Type: discordgo.ApplicationCommandOptionSubCommand, Name: "view", Description: "Show the welcome, role, logging and Twitch settings"},
		{Type: discordgo.ApplicationCommandOptionSubCommand, Name: "clear", Description: "Clear a welcome, role or log setting", Options: []*discordgo.ApplicationCommandOption{clear}},
		{
			Type: discordgo.ApplicationCommandOptionSubCommand, Name: "toggletwitch", Description: "Turn Twitch live notifications on or off",
			Options: []*discordgo.ApplicationCommandOption{{Type: discordgo.ApplicationCommandOptionBoolean, Name: "enabled", Description: "On or off", Required: true}},
		},
		{Type: discordgo.ApplicationCommandOptionSubCommand, Name: "streamers", Description: "List the Twitch streamers being watched"},
		{
			Type: discordgo.ApplicationCommandOptionSubCommand, Name: "beta-features",
			Description: "Let testers use beta features here. Only the server owner can change it",
			Options:     []*discordgo.ApplicationCommandOption{{Type: discordgo.ApplicationCommandOptionBoolean, Name: "enabled", Description: "On or off. Leave out to see the state"}},
		},
	}
}

func guildInt(i *discordgo.InteractionCreate) int64 {
	n, _ := strconv.ParseInt(i.GuildID, 10, 64)
	return n
}

func ownerOf(s *discordgo.Session, guildID string) (string, error) {
	if g, err := s.State.Guild(guildID); err == nil && g != nil && g.OwnerID != "" {
		return g.OwnerID, nil
	}
	g, err := s.Guild(guildID)
	if err != nil {
		return "", err
	}
	return g.OwnerID, nil
}

// handleExtra runs the subcommands above. It reports whether it handled name.
func handleExtra(s *discordgo.Session, i *discordgo.InteractionCreate, sub *discordgo.ApplicationCommandInteractionDataOption) bool {
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	g := guildInt(i)
	svc := services.Global
	args := map[string]*discordgo.ApplicationCommandInteractionDataOption{}
	for _, o := range sub.Options {
		args[o.Name] = o
	}
	fail := func(err error) {
		respondEphemeral(s, i, "Something went wrong. Try again in a moment.")
		log.Printf("config %s: %v", sub.Name, err)
	}

	switch sub.Name {
	case "view":
		var b strings.Builder
		if w, err := svc.Welcome.GetSettings(ctx, g); err == nil {
			fmt.Fprintf(&b, "**Welcome**\nChannel: %s\nMessage: %s\nDM: %s\nGIF: %s\n", mention("#", w.ChannelID), textOr(w.WelcomeMessage), textOr(w.WelcomeDM), textOr(w.WelcomeGIFURL))
		}
		if r, err := svc.DefaultRole.GetRole(ctx, g); err == nil {
			fmt.Fprintf(&b, "**Default role:** %s\n", mention("@&", r))
		}
		if l, err := svc.LogSettings.GetSettings(ctx, g); err == nil && l != nil {
			state := "off"
			if l.IsEnabled {
				state = "on"
			}
			fmt.Fprintf(&b, "**Logging:** %s, channel %s\n", state, mention("#", l.ChannelID))
		} else {
			b.WriteString("**Logging:** off\n")
		}
		if on, err := svc.Twitch.IsEnabled(ctx, g); err == nil {
			ch, _, _ := svc.Twitch.GetNotificationChannel(ctx, g)
			users, _ := svc.Twitch.ListUsersForGuild(ctx, g)
			state := "off"
			if on {
				state = "on"
			}
			fmt.Fprintf(&b, "**Twitch alerts:** %s, channel %s, %d streamer(s)\n", state, mention("#", ch), len(users))
		}
		respondEphemeral(s, i, clipConfig(b.String(), 1900))
	case "clear":
		var err error
		setting := args["setting"].StringValue()
		switch setting {
		case "welcome-channel":
			err = svc.Welcome.SetChannel(ctx, g, 0)
		case "welcome-message":
			err = svc.Welcome.SetMessage(ctx, g, "")
		case "welcome-dm":
			err = svc.Welcome.SetDM(ctx, g, "")
		case "welcome-gif":
			err = svc.Welcome.SetGIF(ctx, g, "")
		case "default-role":
			err = svc.DefaultRole.SetRole(ctx, g, 0)
		case "log-channel":
			err = svc.LogSettings.SetChannel(ctx, g, 0)
		default:
			respondEphemeral(s, i, "Unknown setting.")
			return true
		}
		if err != nil {
			fail(err)
			return true
		}
		respondEphemeral(s, i, "Cleared **"+setting+"**.")
	case "toggletwitch":
		on := args["enabled"].BoolValue()
		if err := svc.Twitch.SetEnabled(ctx, g, on); err != nil {
			fail(err)
			return true
		}
		if on {
			if ch, ok, _ := svc.Twitch.GetNotificationChannel(ctx, g); !ok || ch == 0 {
				respondEphemeral(s, i, "Twitch alerts are **on**, but there is no channel yet. Set one with `/config settwitchnotificationchannel`.")
				return true
			}
			respondEphemeral(s, i, "Twitch alerts are **on**.")
		} else {
			respondEphemeral(s, i, "Twitch alerts are **off**.")
		}
	case "streamers":
		users, err := svc.Twitch.ListUsersForGuild(ctx, g)
		if err != nil {
			fail(err)
			return true
		}
		if len(users) == 0 {
			respondEphemeral(s, i, "No streamers yet. Add one with `/config addstreamer`.")
			return true
		}
		respondEphemeral(s, i, clipConfig("Watching: "+strings.Join(users, ", "), 1900))
	case "beta-features":
		on, err := svc.BetaSettings.IsOptedIn(ctx, g)
		if err != nil {
			fail(err)
			return true
		}
		state := "off"
		if on {
			state = "on"
		}
		want, ok := args["enabled"]
		if !ok {
			respondEphemeral(s, i, "Beta features are **"+state+"** in this server. Testers can use them here when this is on. Only the server owner can change it.")
			return true
		}
		owner, err := ownerOf(s, i.GuildID)
		if err != nil {
			fail(err)
			return true
		}
		if i.Member == nil || i.Member.User == nil || i.Member.User.ID != owner {
			respondEphemeral(s, i, "Only the server owner can change this. Beta features can act on the whole server.")
			return true
		}
		by, _ := strconv.ParseInt(owner, 10, 64)
		if err := svc.BetaSettings.SetOptedIn(ctx, g, by, want.BoolValue()); err != nil {
			fail(err)
			return true
		}
		if want.BoolValue() {
			respondEphemeral(s, i, "Beta features are **on**. Beta commands appear here within a minute, for testers only.")
		} else {
			respondEphemeral(s, i, "Beta features are **off**. Beta commands disappear from this server within a minute.")
		}
	default:
		return false
	}
	return true
}

func mention(prefix string, id int64) string {
	if id == 0 {
		return "not set"
	}
	return fmt.Sprintf("<%s%d>", prefix, id)
}

func textOr(v string) string {
	if strings.TrimSpace(v) == "" {
		return "not set"
	}
	return "`" + clipConfig(v, 120) + "`"
}

func clipConfig(s string, n int) string {
	if r := []rune(s); len(r) > n {
		return string(r[:n-1]) + "…"
	}
	return s
}