package public

import (
	"context"
	"fmt"
	"strings"
	"time"

	"github.com/bwmarrin/discordgo"
)

// Looking at who is banned and who is timed out, so unbanning and ending a
// timeout never needs a dashboard to find the person first.

func listOptions() []*discordgo.ApplicationCommandOption {
	return []*discordgo.ApplicationCommandOption{
		{Type: discordgo.ApplicationCommandOptionSubCommand, Name: "bans", Description: "List banned users, to use with /moderation unban"},
		{Type: discordgo.ApplicationCommandOptionSubCommand, Name: "timeouts", Description: "List members who are timed out right now"},
	}
}

const listShown = 20

func handleBans(s *discordgo.Session, i *discordgo.InteractionCreate) {
	if !hasPerm(i, discordgo.PermissionBanMembers) {
		respondEphemeral(s, i, "You need **Ban Members** for this command.")
		return
	}
	bans, err := s.GuildBans(i.GuildID, 1000, "", "")
	if err != nil {
		respondEphemeral(s, i, "I couldn't read the ban list. I need the **Ban Members** permission.")
		return
	}
	if len(bans) == 0 {
		respondEphemeral(s, i, "Nobody is banned.")
		return
	}
	var b strings.Builder
	fmt.Fprintf(&b, "**Banned users (%d)**\n", len(bans))
	for n, ban := range bans {
		if n == listShown {
			fmt.Fprintf(&b, "…and %d more.\n", len(bans)-listShown)
			break
		}
		name := "unknown"
		id := ""
		if ban.User != nil {
			name, id = ban.User.Username, ban.User.ID
		}
		reason := strings.TrimSpace(ban.Reason)
		if reason == "" {
			reason = "no reason"
		}
		fmt.Fprintf(&b, "• %s (`%s`): %s\n", escape(name), id, escape(clip(reason, 80)))
	}
	b.WriteString("Unban with `/moderation unban user_id:<id>`.")
	respondEphemeral(s, i, clip(b.String(), 1950))
}

func handleTimeouts(s *discordgo.Session, i *discordgo.InteractionCreate) {
	if !hasPerm(i, discordgo.PermissionModerateMembers) {
		respondEphemeral(s, i, "You need **Moderate Members** for this command.")
		return
	}
	_, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	members, err := s.GuildMembers(i.GuildID, "", 1000)
	if err != nil {
		respondEphemeral(s, i, "I couldn't read the member list.")
		return
	}
	now := time.Now()
	var out []*discordgo.Member
	for _, m := range members {
		if m.CommunicationDisabledUntil != nil && m.CommunicationDisabledUntil.After(now) {
			out = append(out, m)
		}
	}
	if len(out) == 0 {
		respondEphemeral(s, i, "Nobody is timed out (among the first 1000 members).")
		return
	}
	var b strings.Builder
	fmt.Fprintf(&b, "**Timed out (%d)**\n", len(out))
	for n, m := range out {
		if n == listShown {
			fmt.Fprintf(&b, "…and %d more.\n", len(out)-listShown)
			break
		}
		fmt.Fprintf(&b, "• <@%s> until <t:%d:f>\n", m.User.ID, m.CommunicationDisabledUntil.Unix())
	}
	b.WriteString("End one with `/moderation untimeout`.")
	respondEphemeral(s, i, clip(b.String(), 1950))
}

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

// escape keeps names and reasons from becoming markdown or mentions.
func escape(s string) string {
	return strings.NewReplacer("`", "'", "*", "", "_", " ", "~", "", "@", "@​", "|", "/").Replace(s)
}