Rewrite from TypeScript to Go

Complete rewrite of the Freebee Matrix bot as GogoBee using mautrix-go.

- E2EE with goolm (pure Go, no CGo/libolm) and cross-signing bootstrap
- 35+ plugins with dependency injection and ordered registration
- SQLite storage via modernc.org/sqlite (no CGo)
- Scheduler via robfig/cron for WOTD, holidays, birthdays, releases, etc.
- Optional LLM integration (Ollama) for sentiment, profanity, roasts, vibes
- Threaded trivia, three-tier profanity tracking, WOTD usage verification
- Multi-country holiday support with deduplication
- Quadratic XP curve, configurable bot display name, encrypted DMs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/plugin/welcome.go

@@ -0,0 +1,206 @@
+package plugin
+
+import (
+	"database/sql"
+	"fmt"
+	"log/slog"
+	"os"
+	"strings"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix"
+)
+
+// WelcomeRegistry is the interface for retrieving all registered commands (for !help).
+type WelcomeRegistry interface {
+	GetCommands() []CommandDef
+}
+
+// WelcomePlugin detects new users and provides the !help command.
+type WelcomePlugin struct {
+	Base
+	xp       *XPPlugin
+	registry WelcomeRegistry
+}
+
+// NewWelcomePlugin creates a new welcome plugin.
+func NewWelcomePlugin(client *mautrix.Client, xp *XPPlugin, registry WelcomeRegistry) *WelcomePlugin {
+	return &WelcomePlugin{
+		Base:     NewBase(client),
+		xp:       xp,
+		registry: registry,
+	}
+}
+
+func (p *WelcomePlugin) Name() string { return "welcome" }
+
+func (p *WelcomePlugin) Commands() []CommandDef {
+	return []CommandDef{
+		{Name: "help", Description: "DM you a list of all bot commands", Usage: "!help", Category: "Info"},
+	}
+}
+
+func (p *WelcomePlugin) Init() error { return nil }
+
+func (p *WelcomePlugin) OnReaction(_ ReactionContext) error { return nil }
+
+func (p *WelcomePlugin) OnMessage(ctx MessageContext) error {
+	if p.IsCommand(ctx.Body, "help") {
+		return p.handleHelp(ctx)
+	}
+
+	// Passive: detect new users by checking for "welcome_wagon" achievement
+	p.checkNewUser(ctx)
+
+	return nil
+}
+
+func (p *WelcomePlugin) checkNewUser(ctx MessageContext) {
+	d := db.Get()
+
+	var exists int
+	err := d.QueryRow(
+		`SELECT 1 FROM achievements WHERE user_id = ? AND achievement_id = 'welcome_wagon'`,
+		string(ctx.Sender),
+	).Scan(&exists)
+
+	if err == nil {
+		// Already has the achievement, not a new user
+		return
+	}
+	if err != sql.ErrNoRows {
+		slog.Error("welcome: check achievement", "err", err)
+		return
+	}
+
+	// New user! Grant achievement
+	_, err = d.Exec(
+		`INSERT OR IGNORE INTO achievements (user_id, achievement_id) VALUES (?, 'welcome_wagon')`,
+		string(ctx.Sender),
+	)
+	if err != nil {
+		slog.Error("welcome: grant achievement", "err", err)
+		return
+	}
+
+	// Grant 25 XP
+	if p.xp != nil {
+		p.xp.GrantXP(ctx.Sender, 25, "welcome")
+	}
+
+	// Send welcome message
+	botName := os.Getenv("BOT_DISPLAY_NAME")
+	if botName == "" {
+		botName = "GogoBee"
+	}
+	welcome := fmt.Sprintf(
+		"Welcome to the community, %s! I'm %s, your friendly community bot.\n\n"+
+			"Here are some things you can do:\n"+
+			"  - !help — see all available commands\n"+
+			"  - !rank — check your XP and level\n"+
+			"  - !streak — see your activity streak\n"+
+			"  - !trivia — play trivia games\n\n"+
+			"You've been awarded 25 XP as a welcome gift! Have fun!",
+		string(ctx.Sender), botName,
+	)
+	if err := p.SendMessage(ctx.RoomID, welcome); err != nil {
+		slog.Error("welcome: send message", "err", err)
+	}
+}
+
+// categoryOrder defines the display order for help categories.
+var categoryOrder = []string{
+	"Fun & Games",
+	"Leveling & Stats",
+	"Entertainment",
+	"Lookup & Reference",
+	"LLM & Sentiment",
+	"Personal",
+	"Holidays",
+	"Reactions",
+	"Info",
+}
+
+// categoryEmojis maps categories to display emojis.
+var categoryEmojis = map[string]string{
+	"Fun & Games":        "🎲",
+	"Leveling & Stats":   "📊",
+	"Entertainment":      "🎬",
+	"Lookup & Reference": "📖",
+	"LLM & Sentiment":    "🧠",
+	"Personal":           "👤",
+	"Holidays":           "🎉",
+	"Reactions":          "😎",
+	"Info":               "ℹ️",
+	"Admin":              "🔧",
+}
+
+func (p *WelcomePlugin) handleHelp(ctx MessageContext) error {
+	cmds := p.registry.GetCommands()
+	if len(cmds) == 0 {
+		return p.SendReply(ctx.RoomID, ctx.EventID, "No commands available.")
+	}
+
+	// Group by category
+	grouped := make(map[string][]CommandDef)
+	var adminCmds []CommandDef
+	for _, cmd := range cmds {
+		if cmd.AdminOnly {
+			adminCmds = append(adminCmds, cmd)
+			continue
+		}
+		cat := cmd.Category
+		if cat == "" {
+			cat = "Other"
+		}
+		grouped[cat] = append(grouped[cat], cmd)
+	}
+
+	var sb strings.Builder
+	helpBotName := os.Getenv("BOT_DISPLAY_NAME")
+	if helpBotName == "" {
+		helpBotName = "GogoBee"
+	}
+	sb.WriteString(fmt.Sprintf("%s Commands\n", helpBotName))
+
+	for _, cat := range categoryOrder {
+		cmds, ok := grouped[cat]
+		if !ok || len(cmds) == 0 {
+			continue
+		}
+		emoji := categoryEmojis[cat]
+		sb.WriteString(fmt.Sprintf("\n%s %s\n", emoji, cat))
+		for _, cmd := range cmds {
+			sb.WriteString(fmt.Sprintf("  %s — %s\n", cmd.Usage, cmd.Description))
+		}
+		delete(grouped, cat)
+	}
+
+	// Any uncategorized leftovers
+	for cat, cmds := range grouped {
+		if len(cmds) == 0 {
+			continue
+		}
+		sb.WriteString(fmt.Sprintf("\n%s\n", cat))
+		for _, cmd := range cmds {
+			sb.WriteString(fmt.Sprintf("  %s — %s\n", cmd.Usage, cmd.Description))
+		}
+	}
+
+	if p.IsAdmin(ctx.Sender) && len(adminCmds) > 0 {
+		emoji := categoryEmojis["Admin"]
+		sb.WriteString(fmt.Sprintf("\n%s Admin\n", emoji))
+		for _, cmd := range adminCmds {
+			sb.WriteString(fmt.Sprintf("  %s — %s\n", cmd.Usage, cmd.Description))
+		}
+	}
+
+	// DM the help message
+	if err := p.SendDM(ctx.Sender, sb.String()); err != nil {
+		slog.Error("welcome: send help DM", "err", err)
+		return p.SendReply(ctx.RoomID, ctx.EventID, "Failed to send help DM. Do you have DMs enabled?")
+	}
+
+	return p.SendReply(ctx.RoomID, ctx.EventID, "Help sent to your DMs!")
+}