fix: add additional sanity checks

* Add additional guard rails around preferred_models
* Add additional sanity checks around num_hosts

Author: sadsfae

quads_self_schedule.yml

@@ -21,6 +21,58 @@
           (See examples)
       changed_when: false
 
+    - name: Validate 'num_hosts' if provided
+      when: num_hosts is defined
+      ansible.builtin.assert:
+        that:
+          - num_hosts | int > 0
+        fail_msg: >-
+          'num_hosts' must be a positive integer greater than 0.
+          Got: {{ num_hosts }}
+      changed_when: false
+
+    - name: Validate 'preferred_models' type if provided
+      when:
+        - preferred_models is defined
+        - preferred_models is not string
+      ansible.builtin.assert:
+        that:
+          - preferred_models is iterable
+          - preferred_models is not mapping
+        fail_msg: >-
+          'preferred_models' must be either a list of model names or the string "all".
+          Got type: {{ preferred_models | type_debug }}
+      changed_when: false
+
+    - name: Validate 'preferred_models' is not empty if provided as a list
+      when:
+        - preferred_models is defined
+        - preferred_models is not string
+        - preferred_models is iterable
+        - preferred_models is not mapping
+      ansible.builtin.assert:
+        that:
+          - preferred_models | length > 0
+        fail_msg: >-
+          'preferred_models' is defined as an empty list.
+          Either provide model names in the list or set to "all" for any model.
+      changed_when: false
+
+    - name: Warn about duplicate models in preferred_models
+      when:
+        - preferred_models is defined
+        - preferred_models is not string
+        - preferred_models is iterable
+        - preferred_models is not mapping
+        - preferred_models | length > 0
+        - preferred_models | unique | length < (preferred_models | length)
+      ansible.builtin.debug:
+        msg: >-
+          WARNING: Duplicate models detected in preferred_models list.
+          This will cause redundant API calls.
+          Duplicates: {{ preferred_models | difference(preferred_models | unique) | unique | join(', ') }}
+      changed_when: false
+
     - name: Get current time for timestamping output file
       ansible.builtin.setup:
         filter: ansible_date_time
@@ -130,14 +182,16 @@
         - not list_active_only | default(false)
         - preferred_models is defined
         - preferred_models is not string
+        - preferred_models is iterable
+        - preferred_models is not mapping
       ansible.builtin.uri:
         url: "{{ base_api_url }}/available?can_self_schedule=true&model={{ item | upper }}"
         method: GET
         headers:
           Authorization: "Bearer {{ quads_token }}"
         validate_certs: false
         status_code: 200
-      loop: "{{ preferred_models if preferred_models is not string else [] }}"
+      loop: "{{ preferred_models if (preferred_models is iterable and preferred_models is not string and preferred_models is not mapping) else [] }}"
       loop_control:
         label: "{{ item }}"
       register: available_by_model