- name: check if target is an object
  fail:
    msg: target must be an object
  when: target is not mapping


- name: check if target parameters are defined
  fail:
    msg: some target parameters are invalid or not defined
  when: target.name is not string


- name: fail if prometheus is not present
  debug:
    msg: prometheus host is missing, will not add target
  when: services.prometheus is not defined or services.prometheus.hostname is not defined


- block:
    - name: slurp prometheus config
      slurp:
        path: "{{ hostvars[services.prometheus.hostname]['prometheus_conf_file'] | d(prometheus_conf_file) }}"
      register: slurped_config_file
      delegate_to: "{{ services.prometheus.hostname }}"


    - name: parse config file
      set_fact:
        pm_config_file: "{{ slurped_config_file.content | b64decode | from_yaml }}"


    - name: construct scrape target config snippet
      set_fact:
        pm_target:
          job_name: "{{ target.name if (target.exact_name | d(false) == true) else (target.name ~ '-' ~ inventory_hostname ~ '-' ~ ansible_host) }}"
          scrape_interval: "{{ target.scrape_interval | d(None) }}"
          scrape_timeout: "{{ target.scrape_timeout | d(None) }}"
          metrics_path: "{{ target.url | d('/metrics') }}"
          scheme: "{{ target.scheme | d('http') }}"
          static_configs:
            - targets:
              - "{% if target.use_ip | d(false) == true -%}\
                   {{ target.ip | d(ansible_host) }}\
                 {% else -%}\
                   {{ (target.hostname | d(host_name)) ~ '.' ~ (target.tld | d(host_tld)) }}\
                 {% endif -%}{{ (':' ~ target.port) if target.port is defined else '' }}"


    - name: finalize building scrape snippet
      set_fact:
        pm_target_final: "{{ pm_target | combine(target.extra_params | d({}), recursive=true) | dict2items | rejectattr('value', 'equalto', None) | list | items2dict }}"


    - name: output scrape target config
      debug:
        msg: "{{ pm_target_final }}"


    - name: update prometheus config
      blockinfile:
        path: "{{ hostvars[services.prometheus.hostname]['prometheus_conf_file'] | d(prometheus_conf_file) }}"
        block: "{{ [pm_target_final] | to_nice_yaml(indent=2, width=512) | indent(width=2, first=true) }}"
        insertafter: "--- scrape config begin ---"
        marker: "  # target: {mark}"
        marker_begin: "{{ pm_target_final.job_name }} begin"
        marker_end: "{{ pm_target_final.job_name }} end"
      delegate_to: "{{ services.prometheus.hostname }}"
      register: result


    - name: restart prometheus if its config was changed
      service:
        name: prometheus
        state: restarted
      delegate_to: "{{ services.prometheus.hostname }}"
      when: result.changed

  when: services.prometheus is defined and services.prometheus.hostname is defined