feat(web): prepare the fluxer.com domain migration (#2952)

fluxer_admin/src/templates/pages/instance_config.rs

@@ -2,7 +2,8 @@
 
 use crate::{
     api::types::{
-        AppPublicConfigResponse, EXPERIMENT_MAX_TARGETED_USERS, ExperimentDeliveryConfigResponse,
+        AppPublicConfigResponse, DOMAIN_MIGRATION_DEFAULT_SALT, DomainMigrationConfigResponse,
+        EXPERIMENT_MAX_TARGETED_USERS, ExperimentDeliveryConfigResponse,
         GatewayRolloutConfigResponse, InstanceConfigResponse, InstanceIntegrationsResponse,
         InstanceMediaResponse, InstancePolicyResponse, InstanceRegistrationResponse,
         LimitConfigResponse, NoiseSuppressionBackend, PUSH_SERVICE_DELIVERY_DEFAULT_SALT,
@@ -149,6 +150,7 @@ pub fn instance_config_page(
                         (gateway_rollout_section(base, csrf_token, &instance_config.gateway_rollout))
                         (voice_noise_suppression_section(base, csrf_token, &instance_config.voice_noise_suppression))
                         (push_service_delivery_section(base, csrf_token, &instance_config.push_service_delivery))
+                        (domain_migration_section(base, csrf_token, &instance_config.domain_migration))
                         (experiment_delivery_section(base, csrf_token, &instance_config.experiment_delivery))
                         @if let Some(limit_config) = limit_config {
                             (limit_config_section(base, limit_config))
@@ -1286,6 +1288,139 @@ fn push_service_delivery_section(
     )
 }
 
+fn domain_migration_section(
+    base: &str,
+    csrf_token: &str,
+    domain_migration: &DomainMigrationConfigResponse,
+) -> Markup {
+    let status = if domain_migration.enabled {
+        ("Live", BadgeVariant::Success)
+    } else {
+        ("Inert", BadgeVariant::Default)
+    };
+    let included_user_ids = domain_migration.included_user_ids.join("\n");
+    let excluded_user_ids = domain_migration.excluded_user_ids.join("\n");
+    section_card_with_description(
+        "Domain Migration",
+        "Moves web clients of the official instance from the legacy web app origin to the new \
+         one. Selected accounts copy their local data across and continue on the new origin. \
+         Clients of other instances read this configuration and ignore it.",
+        html! {
+            form method="post" action={(base) "/instance-config?action=update_domain_migration"} {
+                (csrf_input(csrf_token))
+                div class="space-y-6" {
+                    div class="flex flex-wrap items-center gap-2" {
+                        h3 class="text-sm font-semibold text-neutral-900" { "Master switch" }
+                        (badge(status.0, status.1))
+                        span class="text-xs text-neutral-500" {
+                            "Config version " (domain_migration.config_version)
+                        }
+                    }
+                    (checkbox(
+                        "domain_migration_enabled",
+                        "true",
+                        "Move selected web clients to the new origin",
+                        domain_migration.enabled,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Off is the safe state and the kill switch. With this unchecked no client \
+                         starts a migration and clients that already migrated stop forwarding the \
+                         legacy origin, so the rollout and targeting fields below have no effect at all."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Installed apps" }
+                    (checkbox(
+                        "domain_migration_standalone_forwarding",
+                        "true",
+                        "Forward installed desktop web apps to the new origin",
+                        domain_migration.standalone_forwarding,
+                        true,
+                    ))
+                    p class="text-xs text-neutral-500" {
+                        "Leave this off until the manifest scope extension and the association file \
+                         are live and verified. While it is off, installed Chromium desktop apps copy \
+                         their data across but stay on the legacy origin and offer to install the new \
+                         app. Installed mobile and Safari apps never forward either way."
+                    }
+
+                    h3 class="text-sm font-semibold text-neutral-900" { "Rollout" }
+                    (number_field(
+                        "domain_migration_rollout_basis_points",
+                        "Rollout (basis points)",
+                        &domain_migration.rollout_basis_points.to_string(),
+                        Some(0), Some(10000), "1",
+                        Some("Share of logged-in users bucketed into the migration, in basis points: 0 is nobody, 100 is 1%, 10000 is everybody."),
+                    ))
+                    (number_field(
+                        "domain_migration_anonymous_rollout_basis_points",
+                        "Anonymous rollout (basis points)",
+                        &domain_migration.anonymous_rollout_basis_points.to_string(),
+                        Some(0), Some(10000), "1",
+                        Some("Share of logged-out devices sent to the new origin, in basis points. Each device is bucketed on its own random ID."),
+                    ))
+                    div class="flex flex-col gap-2" {
+                        (text_input(
+                            "domain_migration_rollout_salt",
+                            "Rollout Salt",
+                            &domain_migration.rollout_salt,
+                            DOMAIN_MIGRATION_DEFAULT_SALT,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Seeds the bucketing hash for users and devices. Changing it reshuffles \
+                             which users and devices fall inside the percentages above. Leave it \
+                             alone to keep the current cohort stable."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "domain_migration_included_user_ids",
+                            "Always-on User IDs",
+                            "1500000000000000001\n1500000000000000002",
+                            &included_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            domain_migration.included_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "One snowflake per line, or comma separated. These users are targeted \
+                             regardless of the percentage above. IDs must contain 1 to 20 decimal \
+                             digits. Invalid entries prevent the save. Blank entries and duplicate \
+                             IDs are ignored."
+                        }
+                    }
+                    div class="flex flex-col gap-2" {
+                        (textarea_input(
+                            "domain_migration_excluded_user_ids",
+                            "Never-on User IDs",
+                            "1500000000000000003\n1500000000000000004",
+                            &excluded_user_ids,
+                            4,
+                            false,
+                        ))
+                        (entry_count_hint(
+                            domain_migration.excluded_user_ids.len(),
+                            EXPERIMENT_MAX_TARGETED_USERS,
+                        ))
+                        p class="text-xs text-neutral-500" {
+                            "Same format. Exclusion wins over both the always-on list and the \
+                             percentage. It stops new migrations only. A user who already moved \
+                             stays on the new origin."
+                        }
+                    }
+
+                    (form_actions(html! {
+                        (submit_button("Save Domain Migration Configuration"))
+                    }))
+                }
+            }
+        },
+    )
+}
+
 fn experiment_delivery_section(
     base: &str,
     csrf_token: &str,
@@ -1929,6 +2064,28 @@ mod tests {
         assert!(!markup.contains("at the cap"));
     }
 
+    #[test]
+    fn domain_migration_section_shows_both_rollouts_and_list_counts() {
+        let domain_migration = DomainMigrationConfigResponse {
+            anonymous_rollout_basis_points: 250,
+            included_user_ids: vec!["1500000000000000001".to_owned()],
+            excluded_user_ids: vec![
+                "1500000000000000002".to_owned(),
+                "1500000000000000003".to_owned(),
+            ],
+            ..DomainMigrationConfigResponse::default()
+        };
+        let markup = domain_migration_section("/admin", "csrf", &domain_migration).into_string();
+        assert!(markup.contains("action=update_domain_migration"));
+        assert!(markup.contains("domain_migration_enabled"));
+        assert!(markup.contains("name=\"domain_migration_anonymous_rollout_basis_points\""));
+        assert!(markup.contains("value=\"250\""));
+        assert!(markup.contains("name=\"domain_migration_standalone_forwarding\""));
+        assert!(markup.contains("1 of 1000 stored"));
+        assert!(markup.contains("2 of 1000 stored"));
+        assert!(!markup.contains("at the cap"));
+    }
+
     #[test]
     fn voice_noise_suppression_section_flags_a_list_at_its_cap() {
         let voice_noise_suppression = VoiceNoiseSuppressionConfigResponse {