package help

import (
	"log"
	"unicode/utf8"

	"github.com/bwmarrin/discordgo"
)

var Help = &discordgo.ApplicationCommand{
	Name:        "help",
	Description: "Get help with the bot",
}

// A message's embeds share a limit of 6000 characters, and one embed holds at
// most 25 fields of 1024 characters. The reference is longer than that, so it
// is sent as a few messages.
const (
	maxEmbedChars = 5000
	maxFieldChars = 1024
)

func fields() []*discordgo.MessageEmbedField {
	return []*discordgo.MessageEmbedField{
		{
			Name: "Fun",
			Value: "" +
				"`/ping` — Pong!\n" +
				"`/joke [type]` — Random joke (optional category)\n" +
				"`/coinflip` — Flip a coin\n" +
				"`/dice <expr>` — Roll dice (e.g. `d20`, `2d20+1`, `2#d20+1`)\n" +
				"`/rps <hand>` — Rock Paper Scissors (server only)\n" +
				"`/rpsstats` — Your RPS score (server only)\n" +
				"`/rpsleaderboard` — Top RPS scores (server only)",
		},
		{
			Name: "Music (requires **DJ** role)",
			Value: "" +
				"`/play <query>` — Play a song (search or URL)\n" +
				"`/queue` — Show the current queue\n" +
				"`/volume <0-150>` — Set playback volume\n" +
				"`/music skip|pause|resume|stop` — Control playback\n" +
				"`/music repeat <off|song|queue>`, `/music remove <n>`, `/music move <from> <to>` — Repeat and reorder\n" +
				"`/music toggle` — Turn music on or off (**Manage Server**)",
		},
		{
			Name: "Scheduling (1:1 sessions)",
			Value: "" +
				"`/schedule create user:@someone datetime:\"YYYY-MM-DD HH:MM\" [description]` — Create a session\n" +
				"`/schedule list` — List your upcoming sessions\n" +
				"`/schedule reschedule id:<id> datetime:\"YYYY-MM-DD HH:MM\"` — Request a new time\n\n" +
				"Invites are sent via DM; react with ✅ / ❌ / 🔁 to respond.",
		},
		{
			Name: "Timezone",
			Value: "" +
				"`/timezone set <IANA>` — Set your timezone (e.g. `Europe/Lisbon`)\n" +
				"`/timezone show` — Show your timezone",
		},
		{
			Name: "Projects",
			Value: "" +
				"`/projects list` — List active projects\n" +
				"`/projects create name:\"...\" [description]` — Create a project (**Manage Server**)\n" +
				"`/projects add-helper project-id:<id> user:@someone` — Add helper (**Manage Server**)",
		},
		{
			Name: "Tickets",
			Value: "" +
				"Open a ticket from the panel: you get a private thread with the staff.\n" +
				"`/ticket add user:@someone` — Add someone to your ticket\n" +
				"`/ticket close [reason]` — Close the ticket (opener or staff)\n" +
				"`/ticket claim`, `/ticket remove user:@someone` — Staff only\n" +
				"`/tickets setup`, `/tickets settings`, `/tickets category add|edit|remove|list`, `/tickets panel`, `/tickets list` — Set up (**Manage Server**)",
		},
		{
			Name: "Security (anti-raid & anti-nuke)",
			Value: "" +
				"`/security status`, `/security settings`, `/security history` — What's on, every setting, what happened\n" +
				"`/security toggle` — Join Gate, raid mode, anti-nuke, heat on/off (off: owner or trusted)\n" +
				"`/security joingate`, `words`, `raid`, `antinuke`, `heat`, `alert-dms` — Tune thresholds and filters (owner or trusted)\n" +
				"`/security alerts`, `/security quarantine-role`, `/security release`, `/security end-raid` — Owner or trusted\n" +
				"`/security trust add|remove` — Owner only\n" +
				"`/security snapshot` — Save roles and channels; `/security restore` — Rebuild what a nuke deleted (owner or trusted)\n" +
				"`/lockdown channel|server|joins`, `/unlock …` (unlock: owner or trusted)",
		},
		{
			Name: "Meetings (**Manage Server**)",
			Value: "" +
				"`/meeting add-lobby channel:#voice` — Add a voice lobby that creates meetings (up to 10)\n" +
				"`/meeting remove-lobby channel:#voice` — Stop using a voice lobby\n" +
				"`/meeting lobbies` — List the voice lobbies\n" +
				"`/meeting lock` — Lock your meeting room\n" +
				"`/meeting lock-private` — Lock + hide your meeting room\n" +
				"`/meeting unlock` — Unlock your meeting room\n" +
				"`/meeting invite user:@someone` — Allow a user to join\n" +
				"`/meeting uninvite user:@someone` — Remove a user's permission",
		},
		{
			Name: "Moderation (focused tools)",
			Value: "" +
				"`/moderation purge amount:<1-100>` — Delete recent messages (**Manage Messages**)\n" +
				"`/moderation timeout user:@someone duration:<10m|1h|...> [reason]` — Timeout member (**Moderate Members**)\n" +
				"`/moderation kick user:@someone [reason]` — Kick member (**Kick Members**)\n" +
				"`/moderation ban user:@someone [delete_days] [reason]` — Ban member (**Ban Members**)\n" +
				"`/moderation unban user_id:<id> [reason]` — Unban by user ID (**Ban Members**)\n" +
				"`/moderation untimeout user:@someone [reason]` — Remove timeout (**Moderate Members**)\n" +
				"`/moderation slowmode channel:#channel seconds:<0-21600>` — Set slowmode (**Manage Channels**)\n" +
				"`/moderation bans`, `/moderation timeouts` — Who is banned, who is timed out",
		},
		{
			Name: "Leveling",
			Value: "" +
				"`/slvl toggle` — Enable/disable leveling (**Manage Server**)\n" +
				"`/slvl set user:@someone level:<n>` — Set user level (**Manage Server**)\n" +
				"`/slvl set-channel channel:#channel` — Level-up message channel (**Manage Server**)\n" +
				"`/slvl set-message message:\"...\"` — Custom level-up message (**Manage Server**)\n" +
				"`/slvl set-reward level:<n> role:@role`, `/slvl remove-reward level:<n>` — Role rewards (**Manage Server**)\n" +
				"`/slvl status` — Show the leveling settings (**Manage Server**)\n" +
				"`/rank [user]` — Your rank card (server only)\n" +
				"`/leaderboard` — Top levels (server only)\n" +
				"`/rewards` — List configured rewards (server only)",
		},
		{
			Name: "Twitch live notifications (**Manage Server**)",
			Value: "" +
				"`/config addstreamer username:<twitch-name>` — Add a streamer\n" +
				"`/config removestreamer username:<twitch-name>` — Remove a streamer\n" +
				"`/config settwitchnotificationchannel channel:#channel` — Set notification channel\n" +
				"`/config toggletwitch enabled:<bool>`, `/config streamers` — Turn alerts on or off, list streamers",
		},
		{
			Name: "Welcome / onboarding (**Manage Server**)",
			Value: "" +
				"`/config setwelcomechannel channel:#channel` — Channel for welcome messages\n" +
				"`/config setwelcomemessage message:\"...\"` — Welcome text (supports `{user}`, `{server}`)\n" +
				"`/config setwelcomedm message:\"...\"` — DM template (supports `{user}`, `{server}`)\n" +
				"`/config setwelcomegif url:<image-url>` — GIF/image used in welcome embed\n" +
				"`/config setdefaultrole role:@role` — Role granted to new members\n" +
				"`/config view`, `/config clear setting:<...>` — See or clear these settings",
		},
		{
			Name: "Logging (**Manage Server**)",
			Value: "" +
				"`/config setlogchannel channel:#channel` — Set log output channel\n" +
				"`/config enablelogging` — Enable event/moderation logging\n" +
				"`/config disablelogging` — Disable event/moderation logging",
		},
		{
			Name: "Beta features",
			Value: "" +
				"`/config beta-features [enabled]` — Let testers use beta features here (server owner only)\n" +
				"Bot owner: `/beta` in a DM with the bot — set the beta server and role, list or remove servers",
		},
		{
			Name:  "Other",
			Value: "`/help` — Show this help in DMs",
		},
	}
}

func fieldSize(f *discordgo.MessageEmbedField) int {
	return utf8.RuneCountInString(f.Name) + utf8.RuneCountInString(f.Value)
}

// embeds splits the reference into embeds that fit Discord's limits.
func embeds(author *discordgo.MessageEmbedAuthor) []*discordgo.MessageEmbed {
	var out []*discordgo.MessageEmbed
	cur := &discordgo.MessageEmbed{
		Title:       "Velox Bot Help",
		Description: "Command reference. Some commands require server permissions or roles.",
		Color:       0xFFA500,
		Author:      author,
	}
	size := utf8.RuneCountInString(cur.Title) + utf8.RuneCountInString(cur.Description) + utf8.RuneCountInString(author.Name)
	for _, f := range fields() {
		if size+fieldSize(f) > maxEmbedChars || len(cur.Fields) >= 25 {
			out = append(out, cur)
			cur = &discordgo.MessageEmbed{Title: "Velox Bot Help (continued)", Color: 0xFFA500}
			size = utf8.RuneCountInString(cur.Title)
		}
		cur.Fields = append(cur.Fields, f)
		size += fieldSize(f)
	}
	return append(out, cur)
}

func HelpHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
	s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
		Type: discordgo.InteractionResponseChannelMessageWithSource,
		Data: &discordgo.InteractionResponseData{
			Content: "Check your DMs for help.",
			Flags:   discordgo.MessageFlagsEphemeral,
		},
	})

	userID := ""

	// check if command is run in a guild
	if i.Member != nil {
		userID = i.Member.User.ID
	} else {
		userID = i.Interaction.User.ID
	}

	dmChannel, err := s.UserChannelCreate(userID)
	if err != nil {
		log.Printf("Error creating DM channel: %v", err)
		return
	}

	author := discordgo.MessageEmbedAuthor{
		Name: "Velox Bot",
		URL:  "https://gitea.fernandovideira.com/FernandoJVideira/velox-bot",
	}

	for _, e := range embeds(&author) {
		if _, err := s.ChannelMessageSendEmbed(dmChannel.ID, e); err != nil {
			log.Printf("Error sending help: %v", err)
			return
		}
	}
}