feat: basic schedule

internal/events/schedule_reminders.go

@@ -0,0 +1,92 @@
+package events
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	"velox-bot/internal/db/services"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+// StartScheduleReminderLoop runs a background loop that periodically checks for
+// upcoming sessions and sends DM reminders to all participants.
+func StartScheduleReminderLoop(s *discordgo.Session, svc *services.Services) {
+	if svc == nil || svc.Schedule == nil || s == nil {
+		return
+	}
+
+	const (
+		interval       = time.Minute      // check every minute
+		remindBefore   = 10 * time.Minute // remind 10 minutes before
+		initialDelay   = 10 * time.Second
+	)
+
+	go func() {
+		// small delay so the bot can fully start
+		time.Sleep(initialDelay)
+
+		ticker := time.NewTicker(interval)
+		defer ticker.Stop()
+
+		for range ticker.C {
+			now := time.Now().UTC()
+			ctx := context.Background()
+
+			// Find all sessions that start in the next `remindBefore` window and haven't been reminded.
+			schedules, err := svc.Schedule.ListDueForReminder(ctx, now, remindBefore)
+			if err != nil {
+				log.Printf("schedule: reminder query failed: %v", err)
+				continue
+			}
+			for _, sch := range schedules {
+				if sch == nil {
+					continue
+				}
+
+				// Build reminder text
+				whenStr := sch.ScheduledAt.UTC().Format("2006-01-02 15:04")
+				base := fmt.Sprintf("Reminder: you have a scheduled session at %s UTC with <@%d>.", whenStr, sch.InviteeID)
+				desc := sch.Description
+				if desc != "" {
+					base += "\nTopic: " + desc
+				}
+
+				// Notify requester
+				if err := dmUser(s, sch.RequesterID, base); err != nil {
+					log.Printf("schedule: failed to DM requester reminder: %v", err)
+				}
+
+				// Notify invitee (mirror text with requester mention)
+				baseInvitee := fmt.Sprintf("Reminder: you have a scheduled session at %s UTC with <@%d>.", whenStr, sch.RequesterID)
+				if desc != "" {
+					baseInvitee += "\nTopic: " + desc
+				}
+				if err := dmUser(s, sch.InviteeID, baseInvitee); err != nil {
+					log.Printf("schedule: failed to DM invitee reminder: %v", err)
+				}
+
+				if err := svc.Schedule.MarkReminded(ctx, sch.ID); err != nil {
+					log.Printf("schedule: failed to mark reminder sent for id=%d: %v", sch.ID, err)
+				}
+			}
+		}
+	}()
+}
+
+func dmUser(s *discordgo.Session, userID int64, content string) error {
+	if s == nil || userID == 0 {
+		return nil
+	}
+	uid := strconv.FormatInt(userID, 10)
+	ch, err := s.UserChannelCreate(uid)
+	if err != nil {
+		return err
+	}
+	_, err = s.ChannelMessageSend(ch.ID, content)
+	return err
+}
+