feat(tasks): implement atomic claims and leases

backend-api/internal/repository/sqlite/task_repository.go

@@ -3,6 +3,7 @@ package sqlite
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"strings"
 	"time"
 
@@ -145,7 +146,10 @@ func (s *Store) ListTasks(
 	query.WriteString(`SELECT
 		id, creator_subject, created_by_user_id, source_ref, title, description, sku,
 		image_asset_id, quantity, max_budget_cents, currency, status,
-		version, cancel_reason, canceled_at, created_at, updated_at
+		version, claimed_by_user_id, claimed_by_device_id, claim_generation,
+		claim_token_hash, claim_issued_at, claim_expires_at, cancel_reason,
+		cancel_requested_at, cancel_requested_by_user_id, canceled_at,
+		created_at, updated_at
 	FROM purchase_tasks
 	WHERE creator_subject = ?`)
 	arguments := []any{filter.CreatorSubject}
@@ -242,7 +246,9 @@ func (s *Store) GetTaskDetail(
 	}
 	rows, err := tx.QueryContext(
 		ctx,
-		`SELECT id, task_id, actor_user_id, event_type, message, occurred_at
+		`SELECT
+			id, task_id, actor_user_id, actor_device_id,
+			event_type, message, occurred_at
 		FROM task_events
 		WHERE task_id = ?
 		ORDER BY occurred_at ASC, id ASC`,
@@ -256,11 +262,13 @@ func (s *Store) GetTaskDetail(
 	for rows.Next() {
 		var event domain.TaskEvent
 		var actorUserID sql.NullString
+		var actorDeviceID sql.NullString
 		var occurredAt string
 		if err := rows.Scan(
 			&event.ID,
 			&event.TaskID,
 			&actorUserID,
+			&actorDeviceID,
 			&event.Type,
 			&event.Message,
 			&occurredAt,
@@ -270,6 +278,9 @@ func (s *Store) GetTaskDetail(
 		if actorUserID.Valid {
 			event.ActorUserID = &actorUserID.String
 		}
+		if actorDeviceID.Valid {
+			event.ActorDeviceID = &actorDeviceID.String
+		}
 		event.OccurredAt, err = parseTimestamp(occurredAt)
 		if err != nil {
 			return domain.TaskDetail{}, err
@@ -282,10 +293,31 @@ func (s *Store) GetTaskDetail(
 	if err := rows.Close(); err != nil {
 		return domain.TaskDetail{}, repositoryFailure(err)
 	}
+	execution, err := scanExecution(tx.QueryRowContext(
+		ctx,
+		`SELECT
+			id, task_id, attempt_no, claim_generation, user_id, device_id,
+			current_step, order_submitted, started_at, last_heartbeat_at,
+			finished_at
+		FROM task_executions
+		WHERE task_id = ?
+		ORDER BY attempt_no DESC
+		LIMIT 1`,
+		taskID,
+	))
+	var executionPointer *domain.TaskExecution
+	if errors.Is(err, sql.ErrNoRows) {
+		executionPointer = nil
+	} else if err != nil {
+		return domain.TaskDetail{}, repositoryFailure(err)
+	} else {
+		executionPointer = &execution
+	}
 	detail := domain.TaskDetail{
-		Task:   task,
-		Asset:  asset,
-		Events: events,
+		Task:      task,
+		Asset:     asset,
+		Execution: executionPointer,
+		Events:    events,
 	}
 	if err := tx.Commit(); err != nil {
 		return domain.TaskDetail{}, repositoryFailure(err)
@@ -293,7 +325,7 @@ func (s *Store) GetTaskDetail(
 	return detail, nil
 }
 
-func (s *Store) CancelPendingTask(
+func (s *Store) CancelTask(
 	ctx context.Context,
 	creatorSubject string,
 	taskID string,
@@ -313,25 +345,66 @@ func (s *Store) CancelPendingTask(
 	if !domain.CanCancel(task.Status) {
 		return domain.PurchaseTask{}, usecase.ErrTaskStateConflict
 	}
-	result, err := tx.ExecContext(
-		ctx,
-		`UPDATE purchase_tasks
-		SET status = 'CANCELED',
-			version = version + 1,
-			cancel_reason = NULLIF(?, ''),
-			canceled_at = ?,
-			updated_at = ?
-		WHERE id = ?
-			AND creator_subject = ?
-			AND status = 'PENDING'
-			AND version = ?`,
-		reason,
-		formatTimestamp(canceledAt),
-		formatTimestamp(canceledAt),
-		taskID,
-		creatorSubject,
-		task.Version,
-	)
+	if domain.CanRequestCancel(task.Status) &&
+		task.CancelRequestedAt != nil {
+		if err := tx.Commit(); err != nil {
+			return domain.PurchaseTask{}, repositoryFailure(err)
+		}
+		return task, nil
+	}
+	var result sql.Result
+	if domain.CanAdminCancelImmediately(task.Status) {
+		result, err = tx.ExecContext(
+			ctx,
+			`UPDATE purchase_tasks
+			SET status = 'CANCELED',
+				version = version + 1,
+				claimed_by_user_id = NULL,
+				claimed_by_device_id = NULL,
+				claim_token_hash = NULL,
+				claim_issued_at = NULL,
+				claim_expires_at = NULL,
+				cancel_reason = NULLIF(?, ''),
+				cancel_requested_at = NULL,
+				cancel_requested_by_user_id = NULL,
+				canceled_at = ?,
+				updated_at = ?
+			WHERE id = ?
+				AND creator_subject = ?
+				AND status IN ('PENDING', 'CLAIMED')
+				AND version = ?`,
+			reason,
+			formatTimestamp(canceledAt),
+			formatTimestamp(canceledAt),
+			taskID,
+			creatorSubject,
+			task.Version,
+		)
+	} else {
+		event.Type = "TASK_CANCEL_REQUESTED"
+		event.Message = "task cancellation requested"
+		result, err = tx.ExecContext(
+			ctx,
+			`UPDATE purchase_tasks
+			SET version = version + 1,
+				cancel_reason = NULLIF(?, ''),
+				cancel_requested_at = ?,
+				cancel_requested_by_user_id = ?,
+				updated_at = ?
+			WHERE id = ?
+				AND creator_subject = ?
+				AND status IN ('RUNNING', 'WAITING_CONFIRMATION')
+				AND cancel_requested_at IS NULL
+				AND version = ?`,
+			reason,
+			formatTimestamp(canceledAt),
+			nullableString(event.ActorUserID),
+			formatTimestamp(canceledAt),
+			taskID,
+			creatorSubject,
+			task.Version,
+		)
+	}
 	if err != nil {
 		return domain.PurchaseTask{}, repositoryFailure(err)
 	}
@@ -363,11 +436,13 @@ func insertTaskEvent(
 	_, err := tx.ExecContext(
 		ctx,
 		`INSERT INTO task_events (
-			id, task_id, actor_user_id, event_type, message, occurred_at
-		) VALUES (?, ?, ?, ?, ?, ?)`,
+			id, task_id, actor_user_id, actor_device_id,
+			event_type, message, occurred_at
+		) VALUES (?, ?, ?, ?, ?, ?, ?)`,
 		event.ID,
 		event.TaskID,
 		nullableString(event.ActorUserID),
+		nullableString(event.ActorDeviceID),
 		event.Type,
 		event.Message,
 		formatTimestamp(event.OccurredAt),