Merge pull request 'develop' (#35) from develop into main

Reviewed-on: goffee/core#35

config.go

@@ -1,10 +1,13 @@
 // Copyright 2021 Harran Ali <harran.m@gmail.com>. All rights reserved.
 // Copyright (c) 2024 Zeni Kim <zenik@smarteching.com>
+// Copyright (c) 2026 Jose Cely <me@jacs.guru>
 // Use of this source code is governed by MIT-style
 // license that can be found in the LICENSE file.
 
 package core
 
+import "time"
+
 type EnvFileConfig struct {
 	UseDotEnvFile bool
 }
@@ -28,6 +31,12 @@ type QueueConfig struct {
 	Queues      map[string]int
 }
 
+type SchedulerConfig struct {
+	EnableScheduler    bool
+	SchedulerInterval  time.Duration
+	SchedulerRateLimit int
+}
+
 type CacheConfig struct {
 	EnableCache bool
 }

go.mod

@@ -16,8 +16,9 @@ require (
 	github.com/hibiken/asynq v0.26.0
 	github.com/joho/godotenv v1.5.1
 	github.com/julienschmidt/httprouter v1.3.0
-	github.com/redis/go-redis/v9 v9.19.0
+	github.com/redis/go-redis/v9 v9.21.0
-	golang.org/x/crypto v0.50.0
+	golang.org/x/crypto v0.53.0
+	golang.org/x/text v0.38.0
 	gorm.io/driver/mysql v1.6.0
 	gorm.io/driver/postgres v1.6.0
 	gorm.io/driver/sqlite v1.6.0
@@ -29,17 +30,17 @@ require (
 	github.com/SparkPost/gosparkpost v0.2.0 // indirect
 	github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
-	github.com/go-chi/chi/v5 v5.2.5 // indirect
+	github.com/go-chi/chi/v5 v5.3.0 // indirect
 	github.com/go-sql-driver/mysql v1.10.0 // indirect
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
-	github.com/jackc/pgx/v5 v5.9.2 // indirect
+	github.com/jackc/pgx/v5 v5.10.0 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/mailgun/errors v0.5.0 // indirect
+	github.com/mailgun/errors v0.6.0 // indirect
 	github.com/mailgun/mailgun-go/v4 v4.23.0 // indirect
-	github.com/mattn/go-sqlite3 v1.14.44 // indirect
+	github.com/mattn/go-sqlite3 v1.14.47 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
@@ -48,11 +49,10 @@ require (
 	github.com/sendgrid/sendgrid-go v3.16.1+incompatible // indirect
 	github.com/spf13/cast v1.10.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
-	golang.org/x/image v0.39.0 // indirect
+	golang.org/x/image v0.43.0 // indirect
-	golang.org/x/net v0.53.0 // indirect
+	golang.org/x/net v0.56.0 // indirect
-	golang.org/x/sync v0.20.0 // indirect
+	golang.org/x/sync v0.21.0 // indirect
-	golang.org/x/sys v0.43.0 // indirect
+	golang.org/x/sys v0.46.0 // indirect
-	golang.org/x/text v0.36.0 // indirect
 	golang.org/x/time v0.15.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )

go.sum

@@ -27,6 +27,8 @@ github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHk
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/go-chi/chi/v5 v5.2.5 h1:Eg4myHZBjyvJmAFjFvWgrqDTXFyOzjj7YIm3L3mu6Ug=
 github.com/go-chi/chi/v5 v5.2.5/go.mod h1:X7Gx4mteadT3eDOMTsXzmI4/rwUpOwBHLpAfupzFJP0=
+github.com/go-chi/chi/v5 v5.3.0 h1:halUjDxhshgXHMrao5bB8eNBXo/rnzwr8m5m36glehM=
+github.com/go-chi/chi/v5 v5.3.0/go.mod h1:R+tYY2hNuVUUjxoPtqUdgBqevM9s9njzkTLutVsOCto=
 github.com/go-ozzo/ozzo-validation v3.6.0+incompatible h1:msy24VGS42fKO9K1vLz82/GeYW1cILu7Nuuj1N3BBkE=
 github.com/go-ozzo/ozzo-validation v3.6.0+incompatible/go.mod h1:gsEKFIVnabGBt6mXmxK0MoFy+cZoTJY6mu5Ll3LVLBU=
 github.com/go-sql-driver/mysql v1.10.0 h1:Q+1LV8DkHJvSYAdR83XzuhDaTykuDx0l6fkXxoWCWfw=
@@ -52,6 +54,8 @@ github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7Ulw
 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
 github.com/jackc/pgx/v5 v5.9.2 h1:3ZhOzMWnR4yJ+RW1XImIPsD1aNSz4T4fyP7zlQb56hw=
 github.com/jackc/pgx/v5 v5.9.2/go.mod h1:mal1tBGAFfLHvZzaYh77YS/eC6IX9OWbRV1QIIM0Jn4=
+github.com/jackc/pgx/v5 v5.10.0 h1:VhSvgU2jSli8o3AqIEOTJr7rZwAEUVo4E4XhR94Zfr0=
+github.com/jackc/pgx/v5 v5.10.0/go.mod h1:mal1tBGAFfLHvZzaYh77YS/eC6IX9OWbRV1QIIM0Jn4=
 github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
 github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/jaytaylor/html2text v0.0.0-20190408195923-01ec452cbe43/go.mod h1:CVKlgaMiht+LXvHG173ujK6JUhZXKb2u/BQtjPDIvyk=
@@ -76,11 +80,15 @@ github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mailgun/errors v0.5.0 h1:pLQo8uhAdORsjN69mGixSr0pGs46z/BW/FQXd8HG1VM=
 github.com/mailgun/errors v0.5.0/go.mod h1:+2nrgY77E0vDkG4ErehpcpbSkMLkseJzKbrva89WeSs=
+github.com/mailgun/errors v0.6.0 h1:IWmzIGwXCSN/Q60JT/lXvam3xRAgTUJSX88KwKJ7hss=
+github.com/mailgun/errors v0.6.0/go.mod h1:+2nrgY77E0vDkG4ErehpcpbSkMLkseJzKbrva89WeSs=
 github.com/mailgun/mailgun-go/v4 v4.23.0 h1:jPEMJzzin2s7lvehcfv/0UkyBu18GvcURPr2+xtZRbk=
 github.com/mailgun/mailgun-go/v4 v4.23.0/go.mod h1:imTtizoFtpfZqPqGP8vltVBB6q9yWcv6llBhfFeElZU=
 github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
 github.com/mattn/go-sqlite3 v1.14.44 h1:3VSe+xafpbzsLbdr2AWlAZk9yRHiBhTBakioXaCKTF8=
 github.com/mattn/go-sqlite3 v1.14.44/go.mod h1:pjEuOr8IwzLJP2MfGeTb0A35jauH+C2kbHKBr7yXKVQ=
+github.com/mattn/go-sqlite3 v1.14.47 h1:jOBI62gS7nKeZv+as1oGEy0+1qISgXwH/QBlR6KbfIo=
+github.com/mattn/go-sqlite3 v1.14.47/go.mod h1:6JTjA44L93a0QCyJef5YvlPoKXntQPjzWv5gtm9sB6w=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -94,6 +102,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/redis/go-redis/v9 v9.19.0 h1:XPVaaPSnG6RhYf7p+rmSa9zZfeVAnWsH5h3lxthOm/k=
 github.com/redis/go-redis/v9 v9.19.0/go.mod h1:v/M13XI1PVCDcm01VtPFOADfZtHf8YW3baQf57KlIkA=
+github.com/redis/go-redis/v9 v9.21.0 h1:FPBE4hhbAke+TLmcY3WkpbDffJEomdqPn3HYiqAtL9E=
+github.com/redis/go-redis/v9 v9.21.0/go.mod h1:v/M13XI1PVCDcm01VtPFOADfZtHf8YW3baQf57KlIkA=
 github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
 github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
@@ -122,20 +132,32 @@ go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
 golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
+golang.org/x/crypto v0.53.0 h1:QZ4Muo8THX6CizN2vPPd5fBGHyogrdK9fG4wLPFUsto=
+golang.org/x/crypto v0.53.0/go.mod h1:DNLU434OwVakk9PzuwV8w62mAJpRJL3vsgcfp4Qnsio=
 golang.org/x/image v0.39.0 h1:skVYidAEVKgn8lZ602XO75asgXBgLj9G/FE3RbuPFww=
 golang.org/x/image v0.39.0/go.mod h1:sIbmppfU+xFLPIG0FoVUTvyBMmgng1/XAMhQ2ft0hpA=
+golang.org/x/image v0.43.0 h1:FLxcP4ec2350nTfOC8ysKtqYSIFbk/QGjw1ZHNP4tsY=
+golang.org/x/image v0.43.0/go.mod h1:rrpelvGFt+kLPAjPM4HeWPgrl0FtafueU//e5N0qk/Q=
 golang.org/x/net v0.0.0-20190724013045-ca1201d0de80/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
 golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
+golang.org/x/net v0.56.0 h1:Rw8j/hFzGvJUZwNBXnAtf5sVDVt+65SK2C7IxCxZt5o=
+golang.org/x/net v0.56.0/go.mod h1:D3Ku6r+V6JROoZK144D2XfMHFcMq/0zSfLelVTCFKec=
 golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
 golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/sync v0.21.0 h1:HLII4xRRTtCRkxYp4HNFF0Js/Og6q2i++KXbg0gHCwM=
+golang.org/x/sync v0.21.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
 golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
+golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
 golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
+golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
+golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

scheduler.go

@@ -0,0 +1,157 @@
+// Copyright (c) 2026 Jose Cely <me@jacs.guru>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package core
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"git.smarteching.com/goffee/core/logger"
+	"git.smarteching.com/goffee/core/scheduler"
+)
+
+// Default values for SchedulerConfig
+var DefaultSchedulerInterval = 10 * time.Second
+var DefaultSchedulerRateLimit = 10
+
+// globalSchedulerMux holds the active Schedulermux instance so controllers
+// can access it without requiring a direct import chain.
+var globalSchedulerMux *Schedulermux
+
+// Schedulermux wraps the scheduler Registry and manages the lifecycle
+// of a simple database-backed task scheduler.
+type Schedulermux struct {
+	registry  *scheduler.Registry
+	store     *scheduler.Store
+	semaphore *scheduler.PersistedSemaphore
+	sched     *scheduler.Scheduler
+}
+
+// SchedulerInit initializes the scheduler internals (registry).
+// The store must be set separately via SetStore before starting.
+// The semaphore is created lazily during RunScheduler once the DB is available.
+func (s *Schedulermux) SchedulerInit() {
+	s.registry = scheduler.NewRegistry()
+	globalSchedulerMux = s
+}
+
+// SetStore sets the store (backed by *gorm.DB) on the scheduler.
+// This also runs AutoMigrate for the queue_items and processed_items tables.
+func (s *Schedulermux) SetStore(st *scheduler.Store) {
+	s.store = st
+}
+
+// AddWork registers a task handler function for a given task type.
+func (s *Schedulermux) AddWork(taskType string, handler scheduler.HandlerFunc) {
+	s.registry.Register(taskType, handler)
+}
+
+// GetStore returns the scheduler store, or nil if not initialized.
+func (s *Schedulermux) GetStore() *scheduler.Store {
+	return s.store
+}
+
+// RunScheduler starts the scheduler loop with the given configuration.
+// It auto-migrates the scheduler_meta table, recovers the persisted semaphore
+// state, creates the in-memory semaphore, and launches the scheduler goroutine.
+func (s *Schedulermux) RunScheduler(config SchedulerConfig) {
+	if s.store == nil {
+		log.Fatal("scheduler: store is not set — call SetStore before RunScheduler")
+	}
+
+	interval := config.SchedulerInterval
+	if interval <= 0 {
+		interval = DefaultSchedulerInterval
+	}
+
+	rateLimit := config.SchedulerRateLimit
+	if rateLimit < 0 {
+		rateLimit = DefaultSchedulerRateLimit
+	}
+
+	ctx := context.Background()
+
+	// Auto-migrate the scheduler_meta table for semaphore persistence.
+	_ = s.store.DB().AutoMigrate(&scheduler.SchedulerMeta{})
+
+	// Recover the persisted semaphore state (defaults to green).
+	wasGreen := s.store.GetSemaphore(ctx)
+	s.semaphore = scheduler.NewPersistedSemaphore(s.store, wasGreen)
+	logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] semaphore recovered: %s", map[bool]string{true: "green", false: "red"}[wasGreen]))
+
+	// Recover stuck items from a previous crash before starting.
+	recovered, err := s.store.RecoverStuck(ctx)
+	if err != nil {
+		logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] recover stuck error: %v", err))
+	} else if recovered > 0 {
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] recovered %d stuck task(s) back to pending", recovered))
+	}
+
+	s.sched = scheduler.NewScheduler(
+		scheduler.SchedulerConfig{
+			Interval:  interval,
+			RateLimit: rateLimit,
+		},
+		s.semaphore,
+		s.store,
+		s.registry,
+	)
+
+	s.sched.Start(ctx)
+}
+
+// StopScheduler gracefully stops the scheduler loop.
+func (s *Schedulermux) StopScheduler() {
+	if s.sched != nil {
+		s.sched.Stop()
+	}
+}
+
+// SemaphoreSetGreen allows task execution to proceed.
+func (s *Schedulermux) SemaphoreSetGreen() {
+	if s.semaphore != nil {
+		s.semaphore.SetGreen()
+	}
+}
+
+// SemaphoreSetRed blocks task execution.
+func (s *Schedulermux) SemaphoreSetRed() {
+	if s.semaphore != nil {
+		s.semaphore.SetRed()
+	}
+}
+
+// ResolveSchedulerStore returns the store from the global scheduler mux instance.
+// Returns nil if the scheduler was never initialized.
+func ResolveSchedulerStore() *scheduler.Store {
+	if globalSchedulerMux == nil {
+		return nil
+	}
+	return globalSchedulerMux.GetStore()
+}
+
+// SchedulerSemaphoreSetGreen enables task execution by setting the semaphore to green.
+func SchedulerSemaphoreSetGreen() {
+	if globalSchedulerMux != nil {
+		globalSchedulerMux.SemaphoreSetGreen()
+	}
+}
+
+// SchedulerSemaphoreSetRed blocks task execution by setting the semaphore to red.
+func SchedulerSemaphoreSetRed() {
+	if globalSchedulerMux != nil {
+		globalSchedulerMux.SemaphoreSetRed()
+	}
+}
+
+// SchedulerSemaphoreIsGreen returns whether the scheduler semaphore is currently green.
+func SchedulerSemaphoreIsGreen() bool {
+	if globalSchedulerMux == nil || globalSchedulerMux.semaphore == nil {
+		return false
+	}
+	return globalSchedulerMux.semaphore.IsGreen()
+}

scheduler/scheduler.go

@@ -0,0 +1,689 @@
+// Copyright (c) 2026 Jose Cely <me@jacs.guru>
+// Use of this source code is governed by MIT-style
+// license that can be found in the LICENSE file.
+
+package scheduler
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"time"
+
+	"git.smarteching.com/goffee/core/logger"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// ─── Status types ────────────────────────────────────────────────────────────
+
+// QueueStatus represents the lifecycle state of a queued item.
+type QueueStatus string
+
+const (
+	StatusPending    QueueStatus = "pending"
+	StatusProcessing QueueStatus = "processing" // claimed by a scheduler tick
+)
+
+// ProcessedStatus is the final outcome recorded in processed_items.
+type ProcessedStatus string
+
+const (
+	ProcessedOK    ProcessedStatus = "ok"
+	ProcessedError ProcessedStatus = "error"
+)
+
+// ─── Models ──────────────────────────────────────────────────────────────────
+
+// QueueItem is a task waiting to be executed.
+// Any external program can insert a row into this table to enqueue work.
+//
+//	INSERT INTO queue_items (task_type, payload, priority, max_runs, thread) VALUES (?, ?, ?, ?, ?);
+type QueueItem struct {
+	ID        uint        `gorm:"primaryKey;autoIncrement"`
+	TaskType  string      `gorm:"not null;index"` // e.g. "send_email", "sync_records"
+	Payload   string      `gorm:"type:text"`      // JSON or plain string, interpreted by the handler
+	Status    QueueStatus `gorm:"not null;default:'pending';index"`
+	Priority  int         `gorm:"not null;default:0;index"` // higher = runs first within a tick
+	MaxRuns   int         `gorm:"not null;default:1"`       // 1 = run once, -1 = repeat indefinitely, N = run N times
+	Thread    int         `gorm:"not null;default:0"`       // 0 = sequential, 1 = concurrent per type
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+// TableName overrides the GORM default.
+func (QueueItem) TableName() string { return "queue_items" }
+
+// ProcessedItem is an immutable record of a completed execution.
+// Rows are never updated — only inserted.
+type ProcessedItem struct {
+	ID          uint            `gorm:"primaryKey;autoIncrement"`
+	QueueItemID uint            `gorm:"not null;index"` // FK → queue_items.id (soft ref)
+	TaskType    string          `gorm:"not null;index"`
+	Payload     string          `gorm:"type:text"`
+	Status      ProcessedStatus `gorm:"not null;index"`
+	ErrorMsg    string          `gorm:"type:text"` // empty when Status == "ok"
+	StartedAt   time.Time       `gorm:"not null"`
+	FinishedAt  time.Time       `gorm:"not null"`
+	DurationMs  int64           `gorm:"not null"` // FinishedAt - StartedAt in ms
+	CreatedAt   time.Time
+}
+
+// TableName overrides the GORM default.
+func (ProcessedItem) TableName() string { return "processed_items" }
+
+// SchedulerMeta stores key-value metadata for the scheduler, such as the
+// semaphore state. This table persists across restarts so the scheduler can
+// recover its previous state.
+type SchedulerMeta struct {
+	Key   string `gorm:"primaryKey;size:64"`
+	Value string `gorm:"size:16;not null"`
+}
+
+// TableName overrides the GORM default.
+func (SchedulerMeta) TableName() string { return "scheduler_meta" }
+
+// ─── Handler ─────────────────────────────────────────────────────────────────
+
+// HandlerFunc processes a single queue item.
+// Return a non-nil error to mark the item as processed with error status.
+type HandlerFunc func(ctx context.Context, item *QueueItem) error
+
+// Registry maps task types to their handlers.
+// Register all handlers before calling Scheduler.Start.
+type Registry struct {
+	handlers map[string]HandlerFunc
+}
+
+// NewRegistry creates an empty handler registry.
+func NewRegistry() *Registry {
+	return &Registry{handlers: make(map[string]HandlerFunc)}
+}
+
+// Register associates a task type with a handler.
+// Panics on duplicate registration to catch misconfiguration at startup.
+func (r *Registry) Register(taskType string, h HandlerFunc) {
+	if _, exists := r.handlers[taskType]; exists {
+		panic(fmt.Sprintf("scheduler: handler already registered for task type %q", taskType))
+	}
+	r.handlers[taskType] = h
+}
+
+// get returns the handler for a task type, or a fallback error handler.
+func (r *Registry) get(taskType string) HandlerFunc {
+	if h, ok := r.handlers[taskType]; ok {
+		return h
+	}
+	return func(_ context.Context, item *QueueItem) error {
+		return fmt.Errorf("no handler registered for task type %q", item.TaskType)
+	}
+}
+
+// ─── Store ───────────────────────────────────────────────────────────────────
+
+// Store handles all database operations for the scheduler.
+type Store struct {
+	db *gorm.DB
+}
+
+// NewStore creates a Store.
+// Tables (queue_items, processed_items)
+func NewStore(db *gorm.DB) (*Store, error) {
+	if db == nil {
+		return nil, fmt.Errorf("scheduler: db is nil")
+	}
+	return &Store{db: db}, nil
+}
+
+// DB returns the underlying *gorm.DB used by the store.
+func (s *Store) DB() *gorm.DB {
+	return s.db
+}
+
+// Enqueue inserts a new pending task.
+// maxRuns controls how many times the task executes: 1 = once (default), -1 = repeat indefinitely.
+// thread controls concurrency: 0 = sequential per type, 1 = concurrent per type.
+// Any value of maxRuns < -1 is clamped to 1.
+func (s *Store) Enqueue(ctx context.Context, taskType, payload string, priority, maxRuns, thread int) (*QueueItem, error) {
+	if maxRuns < -1 {
+		maxRuns = 1
+	}
+	item := &QueueItem{
+		TaskType: taskType,
+		Payload:  payload,
+		Status:   StatusPending,
+		Priority: priority,
+		MaxRuns:  maxRuns,
+		Thread:   thread,
+	}
+	if err := s.db.WithContext(ctx).Create(item).Error; err != nil {
+		return nil, fmt.Errorf("enqueue %s: %w", taskType, err)
+	}
+	return item, nil
+}
+
+// ClaimBatch atomically claims up to `limit` pending tasks and marks them
+// as "processing" so that concurrent scheduler instances never double-execute.
+func (s *Store) ClaimBatch(ctx context.Context, limit int) ([]*QueueItem, error) {
+	var items []*QueueItem
+
+	err := s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		query := tx.
+			Clauses(clause.Locking{Strength: "UPDATE", Options: "SKIP LOCKED"}).
+			Where("status = ?", StatusPending).
+			Order("priority DESC, id ASC").
+			Limit(limit).
+			Find(&items)
+
+		if query.Error != nil {
+			return query.Error
+		}
+		if len(items) == 0 {
+			return nil
+		}
+
+		ids := make([]uint, len(items))
+		for i, it := range items {
+			ids[i] = it.ID
+		}
+
+		return tx.Model(&QueueItem{}).
+			Where("id IN ?", ids).
+			Update("status", StatusProcessing).
+			Error
+	})
+
+	if err != nil {
+		return nil, fmt.Errorf("claim batch: %w", err)
+	}
+	return items, nil
+}
+
+// RecordResult writes a ProcessedItem, then either deletes the QueueItem (if
+// MaxRuns is exhausted) or decrements MaxRuns and resets the status to pending
+// for re-execution on the next tick. A maxRuns of -1 means repeat indefinitely.
+func (s *Store) RecordResult(ctx context.Context, item *QueueItem, startedAt time.Time, execErr error) error {
+	finishedAt := time.Now()
+
+	status := ProcessedOK
+	errMsg := ""
+	if execErr != nil {
+		status = ProcessedError
+		errMsg = execErr.Error()
+	}
+
+	processed := &ProcessedItem{
+		QueueItemID: item.ID,
+		TaskType:    item.TaskType,
+		Payload:     item.Payload,
+		Status:      status,
+		ErrorMsg:    errMsg,
+		StartedAt:   startedAt,
+		FinishedAt:  finishedAt,
+		DurationMs:  finishedAt.Sub(startedAt).Milliseconds(),
+	}
+
+	return s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		// 1. Insert the immutable result record.
+		if err := tx.Create(processed).Error; err != nil {
+			return fmt.Errorf("insert processed_item: %w", err)
+		}
+
+		// 2. Decide: delete the queue item or re-queue it.
+		// MaxRuns == 1 means "run once" — delete.
+		// MaxRuns == -1 means "repeat indefinitely" — always re-queue.
+		// MaxRuns > 1 means "run N times" — decrement and re-queue.
+		if item.MaxRuns == 1 {
+			// Exhausted — delete.
+			if err := tx.Delete(&QueueItem{}, item.ID).Error; err != nil {
+				return fmt.Errorf("delete queue_item %d: %w", item.ID, err)
+			}
+		} else {
+			// Decrement MaxRuns (if not -1/infinite) and set back to pending.
+			newMaxRuns := item.MaxRuns
+			if newMaxRuns > 1 {
+				newMaxRuns--
+			}
+			if err := tx.Model(&QueueItem{}).
+				Where("id = ?", item.ID).
+				Updates(map[string]interface{}{
+					"status":   StatusPending,
+					"max_runs": newMaxRuns,
+				}).Error; err != nil {
+				return fmt.Errorf("re-queue queue_item %d: %w", item.ID, err)
+			}
+		}
+
+		return nil
+	})
+}
+
+// SemaphoreKey is the key used in scheduler_meta for the semaphore state.
+const SemaphoreKey = "semaphore"
+
+// SemaphoreValueGreen is the stored value for a green semaphore.
+const SemaphoreValueGreen = "green"
+
+// SemaphoreValueRed is the stored value for a red semaphore.
+const SemaphoreValueRed = "red"
+
+// SetSemaphore persists the semaphore state to the database.
+func (s *Store) SetSemaphore(ctx context.Context, green bool) error {
+	value := SemaphoreValueRed
+	if green {
+		value = SemaphoreValueGreen
+	}
+	return s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		var count int64
+		tx.Model(&SchedulerMeta{}).Where("key = ?", SemaphoreKey).Count(&count)
+		if count == 0 {
+			return tx.Create(&SchedulerMeta{Key: SemaphoreKey, Value: value}).Error
+		}
+		return tx.Model(&SchedulerMeta{}).
+			Where("key = ?", SemaphoreKey).
+			Update("value", value).Error
+	})
+}
+
+// GetSemaphore reads the persisted semaphore state from the database.
+// Returns true if green, false if red or not found.
+func (s *Store) GetSemaphore(ctx context.Context) bool {
+	var meta SchedulerMeta
+	err := s.db.WithContext(ctx).Where("key = ?", SemaphoreKey).First(&meta).Error
+	if err != nil || meta.Value != SemaphoreValueGreen {
+		return false
+	}
+	return true
+}
+
+// PendingCount returns the number of tasks currently in pending or processing state.
+func (s *Store) PendingCount(ctx context.Context) (int64, error) {
+	var count int64
+	err := s.db.WithContext(ctx).
+		Model(&QueueItem{}).
+		Where("status IN ?", []QueueStatus{StatusPending, StatusProcessing}).
+		Count(&count).Error
+	return count, err
+}
+
+// RecentProcessed returns the last `n` processed items ordered by newest first.
+func (s *Store) RecentProcessed(ctx context.Context, n int) ([]*ProcessedItem, error) {
+	var items []*ProcessedItem
+	err := s.db.WithContext(ctx).
+		Order("id DESC").
+		Limit(n).
+		Find(&items).Error
+	return items, err
+}
+
+// RecoverStuck resets any items stuck in "processing" state (e.g. after a
+// crash) back to "pending" so they can be re-claimed on the next tick.
+// Call this once at startup.
+func (s *Store) RecoverStuck(ctx context.Context) (int64, error) {
+	result := s.db.WithContext(ctx).
+		Model(&QueueItem{}).
+		Where("status = ?", StatusProcessing).
+		Update("status", StatusPending)
+	return result.RowsAffected, result.Error
+}
+
+// ─── Semaphore ───────────────────────────────────────────────────────────────
+
+// Semaphore is the interface for the scheduler kill switch.
+// Green (true) means tasks can run; Red (false) means tasks are blocked.
+type Semaphore interface {
+	SetGreen()
+	SetRed()
+	IsGreen() bool
+}
+
+// inMemorySemaphore is the default channel-based implementation.
+type inMemorySemaphore struct {
+	green chan bool
+}
+
+// NewSemaphore creates a Semaphore. Pass true to start green, false to start red.
+func NewSemaphore(startGreen bool) Semaphore {
+	s := &inMemorySemaphore{green: make(chan bool, 1)}
+	s.green <- startGreen
+	return s
+}
+
+func (s *inMemorySemaphore) SetGreen() {
+	<-s.green
+	s.green <- true
+}
+
+func (s *inMemorySemaphore) SetRed() {
+	<-s.green
+	s.green <- false
+}
+
+func (s *inMemorySemaphore) IsGreen() bool {
+	val := <-s.green
+	s.green <- val
+	return val
+}
+
+// PersistedSemaphore implements Semaphore and persists every state change to
+// the database via the Store, so the state survives application restarts.
+type PersistedSemaphore struct {
+	inner Semaphore
+	store *Store
+	ctx   context.Context
+}
+
+// NewPersistedSemaphore creates a PersistedSemaphore with an initial state.
+func NewPersistedSemaphore(store *Store, startGreen bool) *PersistedSemaphore {
+	return &PersistedSemaphore{
+		inner: NewSemaphore(startGreen),
+		store: store,
+		ctx:   context.Background(),
+	}
+}
+
+// SetGreen allows task execution and persists the state.
+func (ps *PersistedSemaphore) SetGreen() {
+	ps.inner.SetGreen()
+	_ = ps.store.SetSemaphore(ps.ctx, true)
+}
+
+// SetRed blocks task execution and persists the state.
+func (ps *PersistedSemaphore) SetRed() {
+	ps.inner.SetRed()
+	_ = ps.store.SetSemaphore(ps.ctx, false)
+}
+
+// IsGreen reports whether execution is currently allowed.
+func (ps *PersistedSemaphore) IsGreen() bool {
+	return ps.inner.IsGreen()
+}
+
+// ─── Scheduler ───────────────────────────────────────────────────────────────
+
+// Scheduler polls the database every interval and executes pending tasks.
+type Scheduler struct {
+	interval  time.Duration
+	rateLimit int // max tasks per tick; 0 = unlimited
+	semaphore Semaphore
+	store     *Store
+	registry  *Registry
+
+	stop chan struct{}
+	done chan struct{}
+}
+
+// SchedulerConfig holds constructor options.
+type SchedulerConfig struct {
+	Interval  time.Duration
+	RateLimit int // 0 = unlimited
+}
+
+// NewScheduler creates a Scheduler.
+func NewScheduler(cfg SchedulerConfig, sem Semaphore, st *Store, reg *Registry) *Scheduler {
+	return &Scheduler{
+		interval:  cfg.Interval,
+		rateLimit: cfg.RateLimit,
+		semaphore: sem,
+		store:     st,
+		registry:  reg,
+		stop:      make(chan struct{}),
+		done:      make(chan struct{}),
+	}
+}
+
+// Start launches the scheduler goroutine.
+func (s *Scheduler) Start(ctx context.Context) {
+	go s.run(ctx)
+}
+
+// Stop signals the scheduler and waits for it to exit cleanly.
+func (s *Scheduler) Stop() {
+	close(s.stop)
+	<-s.done
+}
+
+// run is the main event loop.
+func (s *Scheduler) run(ctx context.Context) {
+	defer close(s.done)
+
+	ticker := time.NewTicker(s.interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			logger.ResolveLogger().Info("[scheduler] context cancelled, shutting down")
+			return
+		case <-s.stop:
+			logger.ResolveLogger().Info("[scheduler] stop requested, shutting down")
+			return
+		case t := <-ticker.C:
+			s.tick(ctx, t)
+		}
+	}
+}
+
+// tick runs on every ticker event.
+func (s *Scheduler) tick(ctx context.Context, t time.Time) {
+	ts := t.Format(time.TimeOnly)
+
+	if !s.semaphore.IsGreen() {
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] tick %s — semaphore RED, skipping", ts))
+		return
+	}
+
+	limit := s.rateLimit
+	if limit == 0 {
+		limit = 1000
+	}
+
+	items, err := s.store.ClaimBatch(ctx, limit)
+	if err != nil {
+		logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] tick %s — claim error: %v", ts, err))
+		return
+	}
+	if len(items) == 0 {
+		return
+	}
+
+	logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] tick %s — executing %d task(s)", ts, len(items)))
+
+	// Split items into sequential vs concurrent groups.
+	var sequential []*QueueItem
+	concurrentGroups := make(map[string][]*QueueItem) // taskType -> items
+
+	for _, item := range items {
+		if item.Thread != 0 {
+			concurrentGroups[item.TaskType] = append(concurrentGroups[item.TaskType], item)
+		} else {
+			sequential = append(sequential, item)
+		}
+	}
+
+	// Execute sequential items one at a time.
+	for i, item := range sequential {
+		s.execute(ctx, item, i+1, len(items))
+	}
+
+	// Execute concurrent groups in parallel per type.
+	for _, group := range concurrentGroups {
+		s.executeGroup(ctx, group, len(items))
+	}
+
+	if remaining, err := s.store.PendingCount(ctx); err == nil {
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] tick %s — done (%d task(s) still queued)", ts, remaining))
+	}
+}
+
+// execute runs a task's handler one or more times within the same tick.
+// When Thread=0 (sequential), runs execute one after another in a loop.
+// When Thread=1 (concurrent), runs fire simultaneously in goroutines.
+// The number of runs per tick is capped by the rate limit, and the item
+// is re-queued with remaining runs or deleted when exhausted.
+func (s *Scheduler) execute(ctx context.Context, item *QueueItem, pos, total int) {
+	// Determine how many runs to fire this tick.
+	desiredRuns := item.MaxRuns
+	if desiredRuns < 1 {
+		desiredRuns = 1 // -1 (infinite): one batch per tick
+	}
+
+	// Cap by the rate limit so one item cannot exhaust the tick budget.
+	budget := s.rateLimit
+	if budget <= 0 {
+		budget = 1000
+	}
+	if desiredRuns > budget {
+		desiredRuns = budget
+	}
+
+	remainingRuns := 0
+	if item.MaxRuns == -1 {
+		remainingRuns = -1
+	} else {
+		remainingRuns = item.MaxRuns - desiredRuns
+		if remainingRuns < 0 {
+			remainingRuns = 0
+		}
+	}
+
+	isConcurrent := item.Thread != 0
+	if isConcurrent {
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d type=%s firing %d/%d concurrent run(s)", pos, total, item.ID, item.TaskType, desiredRuns, item.MaxRuns))
+	} else {
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d type=%s firing %d/%d sequential run(s)", pos, total, item.ID, item.TaskType, desiredRuns, item.MaxRuns))
+	}
+
+	if isConcurrent {
+		// ── Concurrent: all runs in parallel goroutines ──
+		var wg sync.WaitGroup
+		wg.Add(desiredRuns)
+
+		for i := 0; i < desiredRuns; i++ {
+			go func(runIdx int) {
+				defer wg.Done()
+				startedAt := time.Now()
+				handler := s.registry.get(item.TaskType)
+				execErr := handler(ctx, item)
+
+				finishedAt := time.Now()
+				elapsed := finishedAt.Sub(startedAt).Milliseconds()
+
+				status := ProcessedOK
+				errMsg := ""
+				if execErr != nil {
+					status = ProcessedError
+					errMsg = execErr.Error()
+				}
+
+				processed := &ProcessedItem{
+					QueueItemID: item.ID,
+					TaskType:    item.TaskType,
+					Payload:     item.Payload,
+					Status:      status,
+					ErrorMsg:    errMsg,
+					StartedAt:   startedAt,
+					FinishedAt:  finishedAt,
+					DurationMs:  elapsed,
+				}
+				if err := s.store.db.WithContext(ctx).Create(processed).Error; err != nil {
+					logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] failed to record processed_item for id=%d run=%d: %v", pos, total, item.ID, runIdx+1, err))
+				}
+
+				if execErr != nil {
+					logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] task id=%d run=%d FAILED after %dms: %v", pos, total, item.ID, runIdx+1, elapsed, execErr))
+				} else {
+					logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d run=%d OK (%dms)", pos, total, item.ID, runIdx+1, elapsed))
+				}
+			}(i)
+		}
+
+		wg.Wait()
+	} else {
+		// ── Sequential: all runs one after another ──
+		for i := 0; i < desiredRuns; i++ {
+			startedAt := time.Now()
+			handler := s.registry.get(item.TaskType)
+			execErr := handler(ctx, item)
+
+			finishedAt := time.Now()
+			elapsed := finishedAt.Sub(startedAt).Milliseconds()
+
+			status := ProcessedOK
+			errMsg := ""
+			if execErr != nil {
+				status = ProcessedError
+				errMsg = execErr.Error()
+			}
+
+			processed := &ProcessedItem{
+				QueueItemID: item.ID,
+				TaskType:    item.TaskType,
+				Payload:     item.Payload,
+				Status:      status,
+				ErrorMsg:    errMsg,
+				StartedAt:   startedAt,
+				FinishedAt:  finishedAt,
+				DurationMs:  elapsed,
+			}
+			if err := s.store.db.WithContext(ctx).Create(processed).Error; err != nil {
+				logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] failed to record processed_item for id=%d run=%d: %v", pos, total, item.ID, i+1, err))
+			}
+
+			if execErr != nil {
+				logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] task id=%d run=%d FAILED after %dms: %v", pos, total, item.ID, i+1, elapsed, execErr))
+			} else {
+				logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d run=%d OK (%dms)", pos, total, item.ID, i+1, elapsed))
+			}
+		}
+	}
+
+	// ── After all runs: decide the queue item's fate ──
+	if remainingRuns == -1 {
+		if err := s.store.db.WithContext(ctx).
+			Model(&QueueItem{}).
+			Where("id = ?", item.ID).
+			Updates(map[string]interface{}{
+				"status":   StatusPending,
+				"max_runs": -1,
+			}).Error; err != nil {
+			logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] failed to re-queue infinite item id=%d: %v", pos, total, item.ID, err))
+		}
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d re-queued for next tick (infinite)", pos, total, item.ID))
+	} else if remainingRuns > 0 {
+		if err := s.store.db.WithContext(ctx).
+			Model(&QueueItem{}).
+			Where("id = ?", item.ID).
+			Updates(map[string]interface{}{
+				"status":   StatusPending,
+				"max_runs": remainingRuns,
+			}).Error; err != nil {
+			logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] failed to re-queue item id=%d with %d remaining runs: %v", pos, total, item.ID, remainingRuns, err))
+		}
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d re-queued with %d run(s) remaining", pos, total, item.ID, remainingRuns))
+	} else {
+		if err := s.store.db.WithContext(ctx).Delete(&QueueItem{}, item.ID).Error; err != nil {
+			logger.ResolveLogger().Error(fmt.Sprintf("[scheduler] [%d/%d] failed to delete finished item id=%d: %v", pos, total, item.ID, err))
+		}
+		logger.ResolveLogger().Info(fmt.Sprintf("[scheduler] [%d/%d] task id=%d all runs exhausted, deleted", pos, total, item.ID))
+	}
+}
+
+// executeGroup runs all items in a group concurrently using goroutines.
+// Each item's result is recorded independently.
+func (s *Scheduler) executeGroup(ctx context.Context, items []*QueueItem, total int) {
+	var wg sync.WaitGroup
+	wg.Add(len(items))
+
+	for _, item := range items {
+		item := item // capture range variable
+		go func() {
+			defer wg.Done()
+			// Find the item's position among all items for logging context.
+			// Since we don't have global position here, use a local index.
+			s.execute(ctx, item, 0, total)
+		}()
+	}
+
+	wg.Wait()
+}