app: add sidecar sync commands (export, detect, import, resolve, full export/import)

crates/application/tests/app_tests.rs

@@ -3,3 +3,5 @@ mod organization;
 mod storage;
 mod catalog;
 mod sharing;
+mod sidecar;
+mod processing;

crates/application/tests/processing/commands/complete_job.rs

@@ -0,0 +1,76 @@
+use std::sync::Arc;
+use application::testing::{InMemoryJobBatchRepository, InMemoryJobRepository, StubEventPublisher};
+use application::processing::{CompleteJobCommand, CompleteJobHandler};
+use domain::entities::{Job, JobBatch, JobStatus, JobType};
+use domain::events::DomainEvent;
+use domain::ports::{JobBatchRepository, JobRepository};
+use domain::value_objects::StructuredData;
+
+#[tokio::test]
+async fn completes_job() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    job.start().unwrap();
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = CompleteJobHandler::new(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    let result = handler.execute(CompleteJobCommand {
+        job_id,
+        result: StructuredData::new(),
+    }).await.unwrap();
+
+    assert_eq!(result.status, JobStatus::Completed);
+    assert!(result.result_data.is_some());
+}
+
+#[tokio::test]
+async fn completes_job_and_updates_batch() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let batch = JobBatch::new("test-batch", 2);
+    let batch_id = batch.batch_id;
+    batch_repo.save(&batch).await.unwrap();
+
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new())
+        .with_batch(batch_id);
+    job.start().unwrap();
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = CompleteJobHandler::new(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    handler.execute(CompleteJobCommand {
+        job_id,
+        result: StructuredData::new(),
+    }).await.unwrap();
+
+    let updated_batch = batch_repo.find_by_id(&batch_id).await.unwrap().unwrap();
+    assert_eq!(updated_batch.completed_count, 1);
+}
+
+#[tokio::test]
+async fn publishes_event() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    job.start().unwrap();
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = CompleteJobHandler::new(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    handler.execute(CompleteJobCommand {
+        job_id,
+        result: StructuredData::new(),
+    }).await.unwrap();
+
+    let events = event_pub.published().await;
+    assert_eq!(events.len(), 1);
+    assert!(matches!(&events[0], DomainEvent::JobCompleted { job_id: id, .. } if *id == job_id));
+}

crates/application/tests/processing/commands/configure_pipeline.rs

@@ -0,0 +1,48 @@
+use std::sync::Arc;
+use application::testing::{InMemoryPipelineRepository, InMemoryPluginRepository};
+use application::processing::{ConfigurePipelineCommand, ConfigurePipelineHandler, PipelineStepConfig};
+use domain::entities::{Plugin, PluginType};
+use domain::errors::DomainError;
+use domain::ports::PluginRepository;
+use domain::value_objects::{StructuredData, SystemId};
+
+#[tokio::test]
+async fn creates_pipeline() {
+    let pipeline_repo = Arc::new(InMemoryPipelineRepository::new());
+    let plugin_repo = Arc::new(InMemoryPluginRepository::new());
+
+    let p1 = Plugin::new("EXIF", PluginType::MediaProcessor);
+    let p2 = Plugin::new("Thumb", PluginType::MediaProcessor);
+    let p1_id = p1.plugin_id;
+    let p2_id = p2.plugin_id;
+    plugin_repo.save(&p1).await.unwrap();
+    plugin_repo.save(&p2).await.unwrap();
+
+    let handler = ConfigurePipelineHandler::new(pipeline_repo.clone(), plugin_repo.clone());
+    let pipeline = handler.execute(ConfigurePipelineCommand {
+        trigger_event: "asset.ingested".into(),
+        steps: vec![
+            PipelineStepConfig { plugin_id: p1_id, config: StructuredData::new() },
+            PipelineStepConfig { plugin_id: p2_id, config: StructuredData::new() },
+        ],
+    }).await.unwrap();
+
+    assert_eq!(pipeline.trigger_event, "asset.ingested");
+    assert_eq!(pipeline.steps.len(), 2);
+}
+
+#[tokio::test]
+async fn rejects_nonexistent_plugin() {
+    let pipeline_repo = Arc::new(InMemoryPipelineRepository::new());
+    let plugin_repo = Arc::new(InMemoryPluginRepository::new());
+
+    let handler = ConfigurePipelineHandler::new(pipeline_repo.clone(), plugin_repo.clone());
+    let result = handler.execute(ConfigurePipelineCommand {
+        trigger_event: "asset.ingested".into(),
+        steps: vec![
+            PipelineStepConfig { plugin_id: SystemId::new(), config: StructuredData::new() },
+        ],
+    }).await;
+
+    assert!(matches!(result, Err(DomainError::NotFound(_))));
+}

crates/application/tests/processing/commands/enqueue_job.rs

@@ -0,0 +1,65 @@
+use std::sync::Arc;
+use application::testing::{InMemoryJobRepository, StubEventPublisher};
+use application::processing::{EnqueueJobCommand, EnqueueJobHandler};
+use domain::entities::{JobStatus, JobType};
+use domain::events::DomainEvent;
+use domain::value_objects::{StructuredData, SystemId};
+
+#[tokio::test]
+async fn enqueues_job() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+    let handler = EnqueueJobHandler::new(job_repo.clone(), event_pub.clone());
+
+    let job = handler.execute(EnqueueJobCommand {
+        job_type: JobType::ExtractMetadata,
+        priority: 5,
+        payload: StructuredData::new(),
+        target_asset_id: None,
+        batch_id: None,
+    }).await.unwrap();
+
+    assert_eq!(job.status, JobStatus::Queued);
+    assert_eq!(job.priority, 5);
+    assert!(job.target_asset_id.is_none());
+    assert!(job.batch_id.is_none());
+}
+
+#[tokio::test]
+async fn enqueues_with_target_and_batch() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+    let handler = EnqueueJobHandler::new(job_repo.clone(), event_pub.clone());
+
+    let target = SystemId::new();
+    let batch = SystemId::new();
+    let job = handler.execute(EnqueueJobCommand {
+        job_type: JobType::GenerateDerivative,
+        priority: 10,
+        payload: StructuredData::new(),
+        target_asset_id: Some(target),
+        batch_id: Some(batch),
+    }).await.unwrap();
+
+    assert_eq!(job.target_asset_id, Some(target));
+    assert_eq!(job.batch_id, Some(batch));
+}
+
+#[tokio::test]
+async fn publishes_event() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+    let handler = EnqueueJobHandler::new(job_repo.clone(), event_pub.clone());
+
+    let job = handler.execute(EnqueueJobCommand {
+        job_type: JobType::ScanDirectory,
+        priority: 1,
+        payload: StructuredData::new(),
+        target_asset_id: None,
+        batch_id: None,
+    }).await.unwrap();
+
+    let events = event_pub.published().await;
+    assert_eq!(events.len(), 1);
+    assert!(matches!(&events[0], DomainEvent::JobEnqueued { job_id, .. } if *job_id == job.job_id));
+}

crates/application/tests/processing/commands/fail_job.rs

@@ -0,0 +1,95 @@
+use std::sync::Arc;
+use application::testing::{InMemoryJobBatchRepository, InMemoryJobRepository, StubEventPublisher};
+use application::processing::{FailJobCommand, FailJobHandler};
+use domain::entities::{Job, JobBatch, JobStatus, JobType};
+use domain::events::DomainEvent;
+use domain::ports::{JobBatchRepository, JobRepository};
+use domain::value_objects::StructuredData;
+
+fn make_handler(
+    job_repo: Arc<InMemoryJobRepository>,
+    batch_repo: Arc<InMemoryJobBatchRepository>,
+    event_pub: Arc<StubEventPublisher>,
+) -> FailJobHandler {
+    FailJobHandler::new(job_repo, batch_repo, event_pub)
+}
+
+#[tokio::test]
+async fn retries_on_failure() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    let job_id = job.job_id;
+    assert_eq!(job.retry_count, 0);
+    job_repo.save(&job).await.unwrap();
+
+    let handler = make_handler(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    let result = handler.execute(FailJobCommand {
+        job_id,
+        error: "transient error".into(),
+    }).await.unwrap();
+
+    assert_eq!(result.status, JobStatus::Queued);
+    assert_eq!(result.retry_count, 1);
+
+    let events = event_pub.published().await;
+    assert!(matches!(&events[0], DomainEvent::JobEnqueued { .. }));
+}
+
+#[tokio::test]
+async fn fails_permanently_after_max_retries() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    // Exhaust retries (max_retries=3, so fail 3 times)
+    job.fail("err1");
+    job.fail("err2");
+    assert_eq!(job.retry_count, 2);
+    assert_eq!(job.status, JobStatus::Queued); // still retryable
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = make_handler(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    let result = handler.execute(FailJobCommand {
+        job_id,
+        error: "fatal".into(),
+    }).await.unwrap();
+
+    assert_eq!(result.status, JobStatus::Failed);
+    assert_eq!(result.retry_count, 3);
+
+    let events = event_pub.published().await;
+    assert!(matches!(&events[0], DomainEvent::JobFailed { .. }));
+}
+
+#[tokio::test]
+async fn updates_batch_on_permanent_failure() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let event_pub = Arc::new(StubEventPublisher::new());
+
+    let batch = JobBatch::new("test-batch", 2);
+    let batch_id = batch.batch_id;
+    batch_repo.save(&batch).await.unwrap();
+
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new())
+        .with_batch(batch_id);
+    // Exhaust retries
+    job.fail("err1");
+    job.fail("err2");
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = make_handler(job_repo.clone(), batch_repo.clone(), event_pub.clone());
+    handler.execute(FailJobCommand {
+        job_id,
+        error: "permanent failure".into(),
+    }).await.unwrap();
+
+    let updated_batch = batch_repo.find_by_id(&batch_id).await.unwrap().unwrap();
+    assert_eq!(updated_batch.failed_count, 1);
+}

crates/application/tests/processing/commands/manage_plugin.rs

@@ -0,0 +1,61 @@
+use std::sync::Arc;
+use application::testing::InMemoryPluginRepository;
+use application::processing::{ManagePluginCommand, ManagePluginHandler, PluginAction};
+use domain::entities::{Plugin, PluginType};
+use domain::ports::PluginRepository;
+use domain::value_objects::StructuredData;
+
+#[tokio::test]
+async fn creates_plugin() {
+    let plugin_repo = Arc::new(InMemoryPluginRepository::new());
+    let handler = ManagePluginHandler::new(plugin_repo.clone());
+
+    let plugin = handler.execute(ManagePluginCommand {
+        plugin_id: None,
+        action: PluginAction::Create {
+            name: "EXIF Extractor".into(),
+            plugin_type: PluginType::MediaProcessor,
+            config: StructuredData::new(),
+        },
+    }).await.unwrap();
+
+    assert_eq!(plugin.name, "EXIF Extractor");
+    assert_eq!(plugin.plugin_type, PluginType::MediaProcessor);
+    assert!(plugin.is_enabled);
+
+    let saved = plugin_repo.find_by_id(&plugin.plugin_id).await.unwrap();
+    assert!(saved.is_some());
+}
+
+#[tokio::test]
+async fn enables_plugin() {
+    let plugin_repo = Arc::new(InMemoryPluginRepository::new());
+    let mut plugin = Plugin::new("Test", PluginType::ScheduledTask);
+    plugin.disable();
+    let plugin_id = plugin.plugin_id;
+    plugin_repo.save(&plugin).await.unwrap();
+
+    let handler = ManagePluginHandler::new(plugin_repo.clone());
+    let result = handler.execute(ManagePluginCommand {
+        plugin_id: Some(plugin_id),
+        action: PluginAction::Enable,
+    }).await.unwrap();
+
+    assert!(result.is_enabled);
+}
+
+#[tokio::test]
+async fn disables_plugin() {
+    let plugin_repo = Arc::new(InMemoryPluginRepository::new());
+    let plugin = Plugin::new("Test", PluginType::SidecarWriter);
+    let plugin_id = plugin.plugin_id;
+    plugin_repo.save(&plugin).await.unwrap();
+
+    let handler = ManagePluginHandler::new(plugin_repo.clone());
+    let result = handler.execute(ManagePluginCommand {
+        plugin_id: Some(plugin_id),
+        action: PluginAction::Disable,
+    }).await.unwrap();
+
+    assert!(!result.is_enabled);
+}

crates/application/tests/processing/commands/mod.rs

@@ -0,0 +1,6 @@
+mod enqueue_job;
+mod start_job;
+mod complete_job;
+mod fail_job;
+mod manage_plugin;
+mod configure_pipeline;

crates/application/tests/processing/commands/start_job.rs

@@ -0,0 +1,35 @@
+use std::sync::Arc;
+use application::testing::InMemoryJobRepository;
+use application::processing::{StartJobCommand, StartJobHandler};
+use domain::entities::{Job, JobStatus, JobType};
+use domain::errors::DomainError;
+use domain::ports::JobRepository;
+use domain::value_objects::StructuredData;
+
+#[tokio::test]
+async fn starts_queued_job() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = StartJobHandler::new(job_repo.clone());
+    let result = handler.execute(StartJobCommand { job_id }).await.unwrap();
+
+    assert_eq!(result.status, JobStatus::Processing);
+    assert!(result.started_at.is_some());
+}
+
+#[tokio::test]
+async fn rejects_non_queued_job() {
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+    let mut job = Job::new(JobType::ExtractMetadata, 5, StructuredData::new());
+    job.start().unwrap(); // now Processing
+    let job_id = job.job_id;
+    job_repo.save(&job).await.unwrap();
+
+    let handler = StartJobHandler::new(job_repo.clone());
+    let result = handler.execute(StartJobCommand { job_id }).await;
+
+    assert!(matches!(result, Err(DomainError::Conflict(_))));
+}

crates/application/tests/processing/mod.rs

@@ -0,0 +1,2 @@
+mod commands;
+mod queries;

crates/application/tests/processing/queries/mod.rs

@@ -0,0 +1 @@
+mod report_batch_progress;

crates/application/tests/processing/queries/report_batch_progress.rs

@@ -0,0 +1,41 @@
+use std::sync::Arc;
+use application::testing::{InMemoryJobBatchRepository, InMemoryJobRepository};
+use application::processing::{ReportBatchProgressQuery, ReportBatchProgressHandler};
+use domain::entities::{Job, JobBatch, JobType};
+use domain::errors::DomainError;
+use domain::ports::{JobBatchRepository, JobRepository};
+use domain::value_objects::{StructuredData, SystemId};
+
+#[tokio::test]
+async fn returns_progress() {
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+
+    let batch = JobBatch::new("import", 3);
+    let batch_id = batch.batch_id;
+    batch_repo.save(&batch).await.unwrap();
+
+    let j1 = Job::new(JobType::ExtractMetadata, 5, StructuredData::new()).with_batch(batch_id);
+    let j2 = Job::new(JobType::GenerateDerivative, 3, StructuredData::new()).with_batch(batch_id);
+    job_repo.save(&j1).await.unwrap();
+    job_repo.save(&j2).await.unwrap();
+
+    let handler = ReportBatchProgressHandler::new(batch_repo.clone(), job_repo.clone());
+    let progress = handler.execute(ReportBatchProgressQuery { batch_id }).await.unwrap();
+
+    assert_eq!(progress.batch.batch_id, batch_id);
+    assert_eq!(progress.jobs.len(), 2);
+}
+
+#[tokio::test]
+async fn rejects_nonexistent_batch() {
+    let batch_repo = Arc::new(InMemoryJobBatchRepository::new());
+    let job_repo = Arc::new(InMemoryJobRepository::new());
+
+    let handler = ReportBatchProgressHandler::new(batch_repo.clone(), job_repo.clone());
+    let result = handler.execute(ReportBatchProgressQuery {
+        batch_id: SystemId::new(),
+    }).await;
+
+    assert!(matches!(result, Err(DomainError::NotFound(_))));
+}

crates/application/tests/sidecar/commands/detect_external_changes.rs

@@ -0,0 +1,63 @@
+use std::sync::Arc;
+use application::sidecar::{DetectExternalChangesCommand, DetectExternalChangesHandler};
+use application::sidecar::hash_helper::hash_structured_data;
+use application::testing::{InMemorySidecarRepository, InMemorySidecarWriter};
+use domain::entities::{SidecarRecord, SyncStatus};
+use domain::ports::{SidecarRepository, SidecarWriterPort};
+use domain::value_objects::{MetadataValue, StructuredData, SystemId};
+
+#[tokio::test]
+async fn detects_changed_sidecar() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let asset_id = SystemId::new();
+    let path = format!("sidecars/{}.xmp", asset_id);
+
+    // Write original data and create InSync record with its hash
+    let mut original = StructuredData::new();
+    original.insert("title", MetadataValue::String("Old".into()));
+    let hash = hash_structured_data(&original);
+    let mut record = SidecarRecord::new(asset_id, &path);
+    record.mark_synced(hash);
+    sidecar_repo.save(&record).await.unwrap();
+
+    // Simulate external edit: write different data to sidecar file
+    let mut modified = StructuredData::new();
+    modified.insert("title", MetadataValue::String("New".into()));
+    writer.write_sidecar(&modified, &path).await.unwrap();
+
+    let handler = DetectExternalChangesHandler::new(sidecar_repo.clone(), writer);
+    let changed = handler.execute(DetectExternalChangesCommand).await.unwrap();
+
+    assert_eq!(changed, 1);
+    let updated = sidecar_repo.find_by_asset(&asset_id).await.unwrap().unwrap();
+    assert_eq!(updated.sync_status, SyncStatus::PendingRead);
+}
+
+#[tokio::test]
+async fn ignores_unchanged_sidecar() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let asset_id = SystemId::new();
+    let path = format!("sidecars/{}.xmp", asset_id);
+
+    let mut data = StructuredData::new();
+    data.insert("title", MetadataValue::String("Same".into()));
+    let hash = hash_structured_data(&data);
+
+    let mut record = SidecarRecord::new(asset_id, &path);
+    record.mark_synced(hash);
+    sidecar_repo.save(&record).await.unwrap();
+
+    // Write identical data to sidecar file
+    writer.write_sidecar(&data, &path).await.unwrap();
+
+    let handler = DetectExternalChangesHandler::new(sidecar_repo.clone(), writer);
+    let changed = handler.execute(DetectExternalChangesCommand).await.unwrap();
+
+    assert_eq!(changed, 0);
+    let updated = sidecar_repo.find_by_asset(&asset_id).await.unwrap().unwrap();
+    assert_eq!(updated.sync_status, SyncStatus::InSync);
+}

crates/application/tests/sidecar/commands/export_sidecar.rs

@@ -0,0 +1,49 @@
+use std::sync::Arc;
+use application::sidecar::{ExportSidecarCommand, ExportSidecarHandler};
+use application::testing::{InMemoryAssetMetadataRepository, InMemorySidecarRepository, InMemorySidecarWriter};
+use domain::catalog::entities::{AssetMetadata, MetadataSource};
+use domain::entities::SyncStatus;
+use domain::ports::SidecarRepository;
+use domain::value_objects::{MetadataValue, StructuredData, SystemId};
+
+#[tokio::test]
+async fn exports_sidecar_marks_in_sync() {
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let asset_id = SystemId::new();
+    let mut data = StructuredData::new();
+    data.insert("title", MetadataValue::String("Beach".into()));
+    let metadata = AssetMetadata::new(asset_id, MetadataSource::UserEdited, data);
+    use domain::ports::AssetMetadataRepository;
+    meta_repo.save(&metadata).await.unwrap();
+
+    let handler = ExportSidecarHandler::new(meta_repo, sidecar_repo.clone(), writer.clone());
+    let record = handler.execute(ExportSidecarCommand { asset_id }).await.unwrap();
+
+    assert_eq!(record.sync_status, SyncStatus::InSync);
+    assert!(record.last_known_file_hash.is_some());
+
+    let written = writer.get(&record.sidecar_storage_path).await;
+    assert!(written.is_some());
+    assert_eq!(written.unwrap().get_string("title"), Some("Beach"));
+}
+
+#[tokio::test]
+async fn creates_new_record_if_none_exists() {
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let asset_id = SystemId::new();
+
+    let handler = ExportSidecarHandler::new(meta_repo, sidecar_repo.clone(), writer);
+    let record = handler.execute(ExportSidecarCommand { asset_id }).await.unwrap();
+
+    assert_eq!(record.asset_id, asset_id);
+    assert_eq!(record.sync_status, SyncStatus::InSync);
+
+    let saved = sidecar_repo.find_by_asset(&asset_id).await.unwrap();
+    assert!(saved.is_some());
+}

crates/application/tests/sidecar/commands/full_export.rs

@@ -0,0 +1,45 @@
+use std::sync::Arc;
+use application::sidecar::{FullExportCommand, FullExportHandler};
+use application::testing::{
+    InMemoryAssetRepository, InMemoryAssetMetadataRepository,
+    InMemorySidecarRepository, InMemorySidecarWriter,
+};
+use domain::catalog::entities::{Asset, AssetMetadata, AssetType, MetadataSource, SourceReference};
+use domain::ports::AssetRepository;
+use domain::value_objects::{Checksum, MetadataValue, StructuredData, SystemId};
+
+fn make_asset(owner: SystemId) -> Asset {
+    let source = SourceReference {
+        volume_id: SystemId::new(),
+        relative_path: "photos/img.jpg".into(),
+        checksum: Checksum::new("a".repeat(64)).unwrap(),
+    };
+    Asset::new(source, AssetType::Image, "image/jpeg", 1024, owner)
+}
+
+#[tokio::test]
+async fn exports_all_user_assets() {
+    let asset_repo = Arc::new(InMemoryAssetRepository::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let owner = SystemId::new();
+    let a1 = make_asset(owner);
+    let a2 = make_asset(owner);
+    asset_repo.save(&a1).await.unwrap();
+    asset_repo.save(&a2).await.unwrap();
+
+    let mut data = StructuredData::new();
+    data.insert("title", MetadataValue::String("Sunset".into()));
+    use domain::ports::AssetMetadataRepository;
+    meta_repo.save(&AssetMetadata::new(a1.asset_id, MetadataSource::UserEdited, data)).await.unwrap();
+
+    let handler = FullExportHandler::new(asset_repo, meta_repo, sidecar_repo, writer.clone());
+    let count = handler.execute(FullExportCommand { owner_id: owner }).await.unwrap();
+
+    assert_eq!(count, 2);
+
+    let written = writer.get(&format!("sidecars/{}.xmp", a1.asset_id)).await;
+    assert!(written.is_some());
+}

crates/application/tests/sidecar/commands/full_import.rs

@@ -0,0 +1,65 @@
+use std::sync::Arc;
+use application::sidecar::{FullImportCommand, FullImportHandler};
+use application::testing::{
+    InMemoryAssetRepository, InMemoryAssetMetadataRepository,
+    InMemorySidecarRepository, InMemorySidecarWriter,
+};
+use domain::catalog::entities::{Asset, AssetType, MetadataSource, SourceReference};
+use domain::entities::SidecarRecord;
+use domain::ports::{AssetMetadataRepository, AssetRepository, SidecarRepository, SidecarWriterPort};
+use domain::value_objects::{Checksum, MetadataValue, StructuredData, SystemId};
+
+fn make_asset(owner: SystemId) -> Asset {
+    let source = SourceReference {
+        volume_id: SystemId::new(),
+        relative_path: "photos/img.jpg".into(),
+        checksum: Checksum::new("b".repeat(64)).unwrap(),
+    };
+    Asset::new(source, AssetType::Image, "image/jpeg", 2048, owner)
+}
+
+#[tokio::test]
+async fn imports_from_existing_sidecars() {
+    let asset_repo = Arc::new(InMemoryAssetRepository::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let owner = SystemId::new();
+    let asset = make_asset(owner);
+    asset_repo.save(&asset).await.unwrap();
+
+    let path = format!("sidecars/{}.xmp", asset.asset_id);
+    let record = SidecarRecord::new(asset.asset_id, &path);
+    sidecar_repo.save(&record).await.unwrap();
+
+    let mut data = StructuredData::new();
+    data.insert("lens", MetadataValue::String("50mm".into()));
+    writer.write_sidecar(&data, &path).await.unwrap();
+
+    let handler = FullImportHandler::new(asset_repo, meta_repo.clone(), sidecar_repo, writer);
+    let count = handler.execute(FullImportCommand { owner_id: owner }).await.unwrap();
+
+    assert_eq!(count, 1);
+    let imported = meta_repo.find_by_asset_and_source(&asset.asset_id, MetadataSource::ExifExtracted).await.unwrap();
+    assert!(imported.is_some());
+    assert_eq!(imported.unwrap().data.get_string("lens"), Some("50mm"));
+}
+
+#[tokio::test]
+async fn skips_missing_sidecars() {
+    let asset_repo = Arc::new(InMemoryAssetRepository::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+
+    let owner = SystemId::new();
+    let asset = make_asset(owner);
+    asset_repo.save(&asset).await.unwrap();
+    // No sidecar record, no sidecar file
+
+    let handler = FullImportHandler::new(asset_repo, meta_repo, sidecar_repo, writer);
+    let count = handler.execute(FullImportCommand { owner_id: owner }).await.unwrap();
+
+    assert_eq!(count, 0);
+}

crates/application/tests/sidecar/commands/import_sidecar.rs

@@ -0,0 +1,54 @@
+use std::sync::Arc;
+use application::sidecar::{ImportSidecarCommand, ImportSidecarHandler};
+use application::testing::{InMemoryAssetMetadataRepository, InMemorySidecarRepository, InMemorySidecarWriter};
+use domain::catalog::entities::MetadataSource;
+use domain::entities::{SidecarRecord, SyncStatus};
+use domain::errors::DomainError;
+use domain::ports::{SidecarRepository, SidecarWriterPort};
+use domain::value_objects::{MetadataValue, StructuredData, SystemId};
+
+#[tokio::test]
+async fn imports_pending_read_sidecar() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+
+    let asset_id = SystemId::new();
+    let path = format!("sidecars/{}.xmp", asset_id);
+
+    // Create PendingRead record
+    let mut record = SidecarRecord::new(asset_id, &path);
+    record.mark_pending_read();
+    sidecar_repo.save(&record).await.unwrap();
+
+    // Write sidecar file data
+    let mut data = StructuredData::new();
+    data.insert("camera", MetadataValue::String("Canon".into()));
+    writer.write_sidecar(&data, &path).await.unwrap();
+
+    let handler = ImportSidecarHandler::new(sidecar_repo.clone(), writer, meta_repo);
+    let metadata = handler.execute(ImportSidecarCommand { asset_id }).await.unwrap();
+
+    assert_eq!(metadata.metadata_source, MetadataSource::ExifExtracted);
+    assert_eq!(metadata.data.get_string("camera"), Some("Canon"));
+
+    let updated = sidecar_repo.find_by_asset(&asset_id).await.unwrap().unwrap();
+    assert_eq!(updated.sync_status, SyncStatus::InSync);
+}
+
+#[tokio::test]
+async fn rejects_non_pending_read() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+
+    let asset_id = SystemId::new();
+    let record = SidecarRecord::new(asset_id, "sidecars/x.xmp");
+    // Default status is PendingWrite, not PendingRead
+    sidecar_repo.save(&record).await.unwrap();
+
+    let handler = ImportSidecarHandler::new(sidecar_repo, writer, meta_repo);
+    let result = handler.execute(ImportSidecarCommand { asset_id }).await;
+
+    assert!(matches!(result, Err(DomainError::Validation(_))));
+}

crates/application/tests/sidecar/commands/mod.rs

@@ -0,0 +1,6 @@
+mod export_sidecar;
+mod detect_external_changes;
+mod import_sidecar;
+mod resolve_conflict;
+mod full_export;
+mod full_import;

crates/application/tests/sidecar/commands/resolve_conflict.rs

@@ -0,0 +1,85 @@
+use std::sync::Arc;
+use application::sidecar::{ResolveConflictCommand, ResolveConflictHandler};
+use application::testing::{InMemoryAssetMetadataRepository, InMemorySidecarRepository, InMemorySidecarWriter};
+use domain::catalog::entities::{AssetMetadata, MetadataSource};
+use domain::entities::{ConflictPolicy, SidecarRecord, SyncStatus};
+use domain::errors::DomainError;
+use domain::ports::{AssetMetadataRepository, SidecarRepository, SidecarWriterPort};
+use domain::value_objects::{MetadataValue, StructuredData, SystemId};
+
+fn conflict_record(asset_id: SystemId, path: &str) -> SidecarRecord {
+    let mut r = SidecarRecord::new(asset_id, path);
+    r.mark_conflict();
+    r
+}
+
+#[tokio::test]
+async fn db_wins_re_exports() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+
+    let asset_id = SystemId::new();
+    let path = format!("sidecars/{}.xmp", asset_id);
+
+    sidecar_repo.save(&conflict_record(asset_id, &path)).await.unwrap();
+
+    let mut data = StructuredData::new();
+    data.insert("title", MetadataValue::String("DB Value".into()));
+    meta_repo.save(&AssetMetadata::new(asset_id, MetadataSource::UserEdited, data)).await.unwrap();
+
+    let handler = ResolveConflictHandler::new(sidecar_repo.clone(), writer.clone(), meta_repo);
+    let record = handler.execute(ResolveConflictCommand {
+        asset_id,
+        policy: ConflictPolicy::DbWins,
+    }).await.unwrap();
+
+    assert_eq!(record.sync_status, SyncStatus::InSync);
+    let written = writer.get(&path).await.unwrap();
+    assert_eq!(written.get_string("title"), Some("DB Value"));
+}
+
+#[tokio::test]
+async fn file_wins_re_imports() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+
+    let asset_id = SystemId::new();
+    let path = format!("sidecars/{}.xmp", asset_id);
+
+    sidecar_repo.save(&conflict_record(asset_id, &path)).await.unwrap();
+
+    let mut file_data = StructuredData::new();
+    file_data.insert("title", MetadataValue::String("File Value".into()));
+    writer.write_sidecar(&file_data, &path).await.unwrap();
+
+    let handler = ResolveConflictHandler::new(sidecar_repo.clone(), writer, meta_repo.clone());
+    let record = handler.execute(ResolveConflictCommand {
+        asset_id,
+        policy: ConflictPolicy::FileWins,
+    }).await.unwrap();
+
+    assert_eq!(record.sync_status, SyncStatus::InSync);
+    let imported = meta_repo.find_by_asset_and_source(&asset_id, MetadataSource::ExifExtracted).await.unwrap();
+    assert!(imported.is_some());
+    assert_eq!(imported.unwrap().data.get_string("title"), Some("File Value"));
+}
+
+#[tokio::test]
+async fn user_decision_returns_error() {
+    let sidecar_repo = Arc::new(InMemorySidecarRepository::new());
+    let writer = Arc::new(InMemorySidecarWriter::new());
+    let meta_repo = Arc::new(InMemoryAssetMetadataRepository::new());
+
+    let asset_id = SystemId::new();
+    sidecar_repo.save(&conflict_record(asset_id, "sidecars/x.xmp")).await.unwrap();
+
+    let handler = ResolveConflictHandler::new(sidecar_repo, writer, meta_repo);
+    let result = handler.execute(ResolveConflictCommand {
+        asset_id,
+        policy: ConflictPolicy::RequireUserDecision,
+    }).await;
+
+    assert!(matches!(result, Err(DomainError::Validation(msg)) if msg.contains("Manual")));
+}

crates/application/tests/sidecar/mod.rs

@@ -0,0 +1 @@
+mod commands;