{%- if _ is not defined -%}
    {% macro _(message) -%}
        {{ message }}
    {%- endmacro %}
{%- endif -%}

{# Renders field for bootstrap 4 standards.

    Params:
        field - WTForm field
        kwargs - pass any arguments you want in order to put them into the html attributes.
        There are few exceptions: for - for_, class - class_, class__ - class_

    Example usage:
        {{ horz_form.field(form.email, placeholder='Input email', type='email') }}

    Note:
    A change was made to the below macros to support adding tab indexes to form
    elements. A tab index can be added explicitly as a html attribute when creating a
    field but we wanted to add the tab indexes when a wtform is created using the
    form macro, fields macro or the sections macro.
    Due to the fact that some of these macros can be used multiple times in a template,
    we needed a way to specify the start tab index for each invocation of the macro. We
    do that by passing in the start_tab_index parameter to the form, fields and section
    macros.
    This change could possibly cause tab indexes to be incorrect for existing forms
    if some form fields are being rendered explicity inside a form macro. The tab indexes
    would be incorrect because by default, the start_tab_index in the form macro is set to
    1 and the same index is then used to set the tab index on the form submit buttons. To fix
    the tab indexes, the parameter start_tab_index in the form macro will need to be
    set so to account for all the fields which are being explicitly rendered.
#}

{% macro div_form_group(field) -%}
    <div class="form-group {{ 'required' if field.flags.required }} {{ kwargs.get('class_', '') }}">
        {{ caller(**kwargs) }}
    </div>
{%- endmacro %}

{% macro description(field) -%}
    <small class="form-text text-muted description">
        {% if field.description is callable %}
            {{ field.description()|safe }}
        {% else %}
            {{ field.description|safe }}
        {% endif %}
    </small>
{%- endmacro %}

{% macro field_errors(field) -%}
{# You will need javascript similar to below for validations to work properly.
   Alternatively, remove .was-validated from the form element to disable native client side validations by default.

    var forms = document.getElementsByClassName('needs-validation');
    var validation = Array.prototype.filter.call(forms, function(form) {
      form.addEventListener('submit', function(event) {
        if (form.checkValidity() === false) {
          event.preventDefault();
          event.stopPropagation();
        }
        form.classList.add('was-validated');
      }, false);
    });

     var fields = document.getElementsByClassName('is-invalid');
     Array.prototype.filter.call(fields, function(field) {
        field.setCustomValidity(false);
    });
#}
    <div class="invalid-feedback">
        {% if field.errors %}
            {% for e in field.errors %}
                <p>{{ e }}</p>
            {% endfor %}
        {% elif field.flags.required %}
            <p>This field is required.</p>
        {% endif %}
    </div>
{% endmacro %}

{% macro field(field, label_visible=true) -%}
    {% call div_form_group(field, **kwargs) %}
        {% if (field.type != 'HiddenField' and field.type != 'CSRFTokenField') and label_visible %}
            {{ field.label(class_='control-label') }}
        {% endif %}
        <div class="form-row">
            <div class="col">
                <div class="labeled-group">
                    {{ field_widget(field, **kwargs) }}
                    {% if field.description %}
                        {{ description(field) }}
                    {% endif %}
                </div>
            </div>
        </div>
    {% endcall %}
{%- endmacro %}


{% macro custom_css() %}
<!-- included from keg-elements custom-css macro -->
<style>
    .multi-checkbox > * {
        flex: 1 1 48%;
        margin: 0 1%;
    }

    .multi-checkbox-controls {
        padding: 0.5em 1em;
    }
</style>
{% endmacro %}

{% macro custom_js() %}
<!-- included from keg-elements custom-js macro -->
<script>
    document.querySelectorAll('[multi-checkbox-data^="select-"]').forEach(item => {
        const target_value = item.attributes['multi-checkbox-data'].value.indexOf('select-all') !== -1;
        item.addEventListener('click', event => {
            event.target.parentElement.parentElement.querySelectorAll('.custom-checkbox input').forEach(checkbox => {
                checkbox.checked = target_value;
            });
            event.preventDefault();
        })
    })
</script>
{% endmacro %}

{% macro multi_checkbox(field) %}
    <div class="multi-checkbox-controls">
        <button multi-checkbox-data="select-all">Select All</button>
        <button multi-checkbox-data="select-none">Select None</button>
    </div>
    <div id="{{ field.id }}" class="d-flex flex-row flex-wrap multi-checkbox">
    {% for choice_id, choice in field.choices %}
    <div class="custom-control custom-checkbox">
        <input type="checkbox" name="{{ field.name }}"
            {{ 'checked="checked"' if field.data and choice_id in field.data else "" }}
            class="custom-control-input" value="{{ choice_id }}" id="{{ field.id }}{{choice_id}}">
        <label class="custom-control-label" for="{{ field.id }}{{ choice_id }}">{{choice}}</label>
    </div>
    {% endfor %}
    </div>
{% endmacro %}

{% macro field_widget(field) %}
    {% if field.type == "MultiCheckboxField" %}
        {{ multi_checkbox(field) }}
    {% else %}
        {% if field.flags.disabled %}{% set _dummy = kwargs.update({'disabled': field.flags.disabled}) %}{% endif %}
        {% if field.flags.readonly %}{% set _dummy = kwargs.update({'readonly': field.flags.readonly}) %}{% endif %}
        {{ field(class_='form-control is-invalid' if field.errors else 'form-control', **kwargs) }}
    {% endif %}
    {{ field_errors(field) }}
{% endmacro %}

{# Renders checkbox fields since they are represented differently in bootstrap
    Params:
        field - WTForm field (there are no check, but you should put here only BooleanField.
        kwargs - pass any arguments you want in order to put them into the html attributes.
        There are few exceptions: for - for_, class - class_, class__ - class_

    Example usage:
        {{ horiz_form.checkbox_field(form.remember_me) }}
 #}
{% macro checkbox_field(field) -%}
    {% call div_form_group(field, **kwargs) %}
        <div class="unlabeled-group checkbox form-check custom-control custom-checkbox">
            {{ field(type='checkbox', class_='form-check-input custom-control-input is-invalid' if field.errors else 'form-check-input custom-control-input', **kwargs) }}
            <label class="form-check-label custom-control-label" for="{{ field.id }}">
                {{ field.label }}
            </label>
            {{ field_errors(field) }}
        </div>
        {% if field.description %}
            {{ description(field) }}
        {% endif %}
    {% endcall %}
{%- endmacro %}

{# Renders radio field
    Params:
        field - WTForm field (must have an `iter_choices` method)
        kwargs - pass any arguments you want in order to put them into the html attributes.
        There are few exceptions: for - for_, class - class_, class__ - class_

    Example usage:
        {{ horiz_form.radio_field(form.answers) }}
 #}
{% macro radio_field(field, label_visible=true, tabIndex=1) -%}
    {% call div_form_group(field, **kwargs) %}
        {% if label_visible %}
            {{ field.label(class_='control-label') }}
        {% endif %}
        <div class="labeled-group">
        {% for value, label, checked in field.iter_choices() %}
            <div class="radio">
                <label>
                    <input type="radio"
                           name="{{ field.id }}"
                           id="{{ field.id }}"
                           value="{{ value }}"
                           {{ 'checked' if checked }}
                           {{ 'disabled' if field.flags.disabled or (field.flags.readonly and not checked) }}
                           tabIndex="{{tabIndex}}">
                        {{ label }}
                </label>
            </div>
        {% endfor %}
        {{ field_errors(field) }}
        </div>
        {% if field.description %}
            {{ description(field) }}
        {% endif %}
    {% endcall %}
{%- endmacro %}

{% macro submit_group(action_text='Submit', btn_class='btn btn-primary', cancel_url='', tab_index=1) -%}
    <div class="form-group">
      <div class="unlabeled-group">
        <button type="submit" class="{{ btn_class }}" tabIndex="{{tab_index}}">{{ action_text }} </button>
        {% if cancel_url %}
            <a href="{{cancel_url}}" class="cancel" tabIndex="{{tab_index+1}}">Cancel</a>
        {% endif %}
      </div>
    </div>
{%- endmacro %}

{% macro render_field(f) -%}
    {% if f.type == 'BooleanField' %}
        {{ checkbox_field(f, **kwargs) }}
    {% elif f.type == 'RadioField' %}
        {{ radio_field(f, **kwargs) }}
    {% elif f is none %}
        {# Do nothing b/c the field is None #}
    {% else %}
        {{ field(f, **kwargs) }}
    {% endif %}
{%- endmacro %}


{% macro form_errors(form) -%}
    {% if form.form_errors %}
        <div class="invalid-feedback">
            {% for e in form.form_errors %}
                <p>{{ e }}</p>
            {% endfor %}
        </div>
    {% endif %}
{% endmacro %}


{# Renders WTForm in bootstrap way. There are two ways to call function:
     - as macros: it will render all field forms using cycle to iterate over them
     - as call: it will insert form fields as you specify:
     e.g. {% call macros.render_form(form, action_url=url_for('login_view'), action_text='Login',
                                        class_='login-form') %}
                {{ macros.render_field(form.email, placeholder='Input email', type='email') }}
                {{ macros.render_field(form.password, placeholder='Input password', type='password') }}
                {{ macros.render_checkbox_field(form.remember_me, type='checkbox') }}
            {% endcall %}

     Params:
        form - WTForm class
        action_url - url where to submit this form
        action_text - text of submit button
        class_ - sets a class for form
#}
{% macro form(
    form,
    field_names=None,
    action_url='',
    action_text='Submit',
    class_='form-horizontal',
    btn_class='btn btn-primary',
    cancel_url='',
    form_upload=false,
    dirty_check=false,
    start_tab_index=1
) -%}

    <form method="POST"
          action="{{ action_url }}"
          role="form"
          class="{{ class_ }} {{ 'was-validated needs-validation' if form.errors else 'needs-validation' }}"
          {% if form_upload %}enctype="multipart/form-data"{% endif %}
          {% if dirty_check %}data-dirty-check="on"{% endif %}
          novalidate
    >
        {{ form.hidden_tag() if form.hidden_tag }}
        {% set tab_index=[start_tab_index|int] %}
        {{ form_errors(form) }}

        {% if caller %}
            {{ caller() }}
        {% elif field_names %}
            {{ fields(form, field_names) }}
        {% else %}
            {% for f in form %}
                {% if not f.widget.input_type == 'hidden' %}
                    {# Hidden fields are rendered by the `hidden_tag()` call above #}
                    {{ render_field(f, tabIndex=tab_index.pop()) }}
                    {% if tab_index.append(start_tab_index|int+loop.index) %} {% endif %}
                {% endif %}
            {% endfor %}

        {% endif %}
        {{ submit_group(action_text=action_text, btn_class=btn_class, cancel_url=cancel_url, tab_index=tab_index[0]) }}
    </form>
{%- endmacro %}

{% macro fields(form, field_names, start_tab_index=1) -%}
    {% set tab_index = start_tab_index|int %}
    {% for field_name in field_names %}
        {% set tab_index = tab_index + loop.index0 %}
        {{ render_field(form[field_name], tabIndex=tab_index) }}

    {% endfor %}
{%- endmacro %}

{% macro section(heading, form, field_names, start_tab_index=1) -%}
    <h2>{{heading}}</h2>
    {% if caller %}
        {{ caller() }}
    {% else %}
        {{ fields(form, field_names, start_tab_index) }}
    {% endif %}
{%- endmacro %}
