Changeset 0.32.0 (#206)

server/store/postgres/tasks.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 
-	"git.gobha.me/xcaliber/chat-switchboard/models"
+	"chat-switchboard/models"
 )
 
 type TaskStore struct{}
@@ -149,8 +149,22 @@ func (s *TaskStore) ListAll(ctx context.Context) ([]models.Task, error) {
 	return s.list(ctx, `ORDER BY created_at DESC`)
 }
 
-func (s *TaskStore) ListDue(ctx context.Context, limit int) ([]models.Task, error) {
-	return s.list(ctx, `WHERE is_active = true AND next_run_at <= NOW() ORDER BY next_run_at ASC LIMIT $1`, limit)
+func (s *TaskStore) ClaimDueTask(ctx context.Context) (*models.Task, error) {
+	t := &models.Task{}
+	row := DB.QueryRowContext(ctx, `
+		UPDATE tasks SET next_run_at = NULL
+		WHERE id = (
+			SELECT id FROM tasks
+			WHERE is_active = true AND next_run_at <= NOW()
+			ORDER BY next_run_at ASC
+			LIMIT 1
+			FOR UPDATE SKIP LOCKED
+		)
+		RETURNING `+taskColumns)
+	if err := scanTask(row, t); err != nil {
+		return nil, err
+	}
+	return t, nil
 }
 
 // ── Scheduler bookkeeping ──────────────────────
@@ -181,6 +195,25 @@ func (s *TaskStore) CreateRun(ctx context.Context, r *models.TaskRun) error {
 	).Scan(&r.ID, &r.StartedAt)
 }
 
+func (s *TaskStore) CreateRunExclusive(ctx context.Context, taskID string) (*models.TaskRun, error) {
+	r := &models.TaskRun{}
+	err := DB.QueryRowContext(ctx, `
+		INSERT INTO task_runs (task_id, status)
+		SELECT $1, 'running'
+		WHERE NOT EXISTS (
+			SELECT 1 FROM task_runs
+			WHERE task_id = $1 AND status IN ('running', 'queued')
+		)
+		RETURNING id, started_at`, taskID,
+	).Scan(&r.ID, &r.StartedAt)
+	if err != nil {
+		return nil, err
+	}
+	r.TaskID = taskID
+	r.Status = "running"
+	return r, nil
+}
+
 func (s *TaskStore) UpdateRun(ctx context.Context, id, status string, tokensUsed, toolCalls, wallClock int, errMsg string) error {
 	_, err := DB.ExecContext(ctx, `
 		UPDATE task_runs SET status = $1, tokens_used = $2, tool_calls = $3,