[feature] Implement backfilling statuses thru scheduled_at (#3685)

* Implement backfilling statuses thru scheduled_at

* Forbid mentioning others in backfills

* Update error messages & codes

* Add new tests for backfilled statuses

* Test that backfilling doesn't timeline or notify

* Fix check for absence of notification

* Test that backfills do not cause federation

* Fix type of apimodel.StatusCreateRequest.ScheduledAt in tests

* Add config file switch and min date check

4 files changed, 28 insertions, 0 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index 33003d0f9..8ce2105b4 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -91,6 +91,7 @@ type Configuration struct {
 	InstanceSubscriptionsProcessFrom  string             `name:"instance-subscriptions-process-from" usage:"Time of day from which to start running instance subscriptions processing jobs. Should be in the format 'hh:mm:ss', eg., '15:04:05'."`
 	InstanceSubscriptionsProcessEvery time.Duration      `name:"instance-subscriptions-process-every" usage:"Period to elapse between instance subscriptions processing jobs, starting from instance-subscriptions-process-from."`
 	InstanceStatsMode                 string             `name:"instance-stats-mode" usage:"Allows you to customize the way stats are served to crawlers: one of '', 'serve', 'zero', 'baffle'. Home page stats remain unchanged."`
+	InstanceAllowBackdatingStatuses   bool               `name:"instance-allow-backdating-statuses" usage:"Allow local accounts to backdate statuses using the scheduled_at param to /api/v1/statuses"`
 
 	AccountsRegistrationOpen         bool `name:"accounts-registration-open" usage:"Allow anyone to submit an account signup request. If false, server will be invite-only."`
 	AccountsReasonRequired           bool `name:"accounts-reason-required" usage:"Do new account signups require a reason to be submitted on registration?"`
diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index 7f66e4209..78a8230d5 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -67,6 +67,7 @@ var Defaults = Configuration{
 	InstanceLanguages:                 make(language.Languages, 0),
 	InstanceSubscriptionsProcessFrom:  "23:00",        // 11pm,
 	InstanceSubscriptionsProcessEvery: 24 * time.Hour, // 1/day.
+	InstanceAllowBackdatingStatuses:   true,
 
 	AccountsRegistrationOpen:         false,
 	AccountsReasonRequired:           true,
diff --git a/internal/config/flags.go b/internal/config/flags.go
index d67085d6d..3a2564c94 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -93,6 +93,7 @@ func (s *ConfigState) AddServerFlags(cmd *cobra.Command) {
 		cmd.Flags().String(InstanceSubscriptionsProcessFromFlag(), cfg.InstanceSubscriptionsProcessFrom, fieldtag("InstanceSubscriptionsProcessFrom", "usage"))
 		cmd.Flags().Duration(InstanceSubscriptionsProcessEveryFlag(), cfg.InstanceSubscriptionsProcessEvery, fieldtag("InstanceSubscriptionsProcessEvery", "usage"))
 		cmd.Flags().String(InstanceStatsModeFlag(), cfg.InstanceStatsMode, fieldtag("InstanceStatsMode", "usage"))
+		cmd.Flags().Bool(InstanceAllowBackdatingStatusesFlag(), cfg.InstanceAllowBackdatingStatuses, fieldtag("InstanceAllowBackdatingStatuses", "usage"))
 
 		// Accounts
 		cmd.Flags().Bool(AccountsRegistrationOpenFlag(), cfg.AccountsRegistrationOpen, fieldtag("AccountsRegistrationOpen", "usage"))
diff --git a/internal/config/helpers.gen.go b/internal/config/helpers.gen.go
index d3ccf16ea..156c19fd5 100644
--- a/internal/config/helpers.gen.go
+++ b/internal/config/helpers.gen.go
@@ -1082,6 +1082,31 @@ func GetInstanceStatsMode() string { return global.GetInstanceStatsMode() }
 // SetInstanceStatsMode safely sets the value for global configuration 'InstanceStatsMode' field
 func SetInstanceStatsMode(v string) { global.SetInstanceStatsMode(v) }
 
+// GetInstanceAllowBackdatingStatuses safely fetches the Configuration value for state's 'InstanceAllowBackdatingStatuses' field
+func (st *ConfigState) GetInstanceAllowBackdatingStatuses() (v bool) {
+	st.mutex.RLock()
+	v = st.config.InstanceAllowBackdatingStatuses
+	st.mutex.RUnlock()
+	return
+}
+
+// SetInstanceAllowBackdatingStatuses safely sets the Configuration value for state's 'InstanceAllowBackdatingStatuses' field
+func (st *ConfigState) SetInstanceAllowBackdatingStatuses(v bool) {
+	st.mutex.Lock()
+	defer st.mutex.Unlock()
+	st.config.InstanceAllowBackdatingStatuses = v
+	st.reloadToViper()
+}
+
+// InstanceAllowBackdatingStatusesFlag returns the flag name for the 'InstanceAllowBackdatingStatuses' field
+func InstanceAllowBackdatingStatusesFlag() string { return "instance-allow-backdating-statuses" }
+
+// GetInstanceAllowBackdatingStatuses safely fetches the value for global configuration 'InstanceAllowBackdatingStatuses' field
+func GetInstanceAllowBackdatingStatuses() bool { return global.GetInstanceAllowBackdatingStatuses() }
+
+// SetInstanceAllowBackdatingStatuses safely sets the value for global configuration 'InstanceAllowBackdatingStatuses' field
+func SetInstanceAllowBackdatingStatuses(v bool) { global.SetInstanceAllowBackdatingStatuses(v) }
+
 // GetAccountsRegistrationOpen safely fetches the Configuration value for state's 'AccountsRegistrationOpen' field
 func (st *ConfigState) GetAccountsRegistrationOpen() (v bool) {
 	st.mutex.RLock()