{% extends "module_base.html" %}
{% load static %}

{% block title %}{{ module_title }}{% endblock %}

{% block content %}
<div class="container-fluid">
    <div class="row">
        <div class="col-12">
            <div class="card">
                <div class="card-header">
                    <h4 class="card-title mb-0">
                        <i class="fas fa-cogs me-2"></i>{{ module_title }}
                    </h4>
                </div>
                <div class="card-body">
                    <form method="post" class="needs-validation" novalidate>
                        {% csrf_token %}

                        <!-- BOM Details -->
                        <div class="row">
                            <div class="col-md-12">
                                <div class="mb-3">
                                    <label for="{{ form.product.id_for_label }}" class="form-label">Product</label>
                                    {{ form.product }}
                                    {% if form.product.errors %}
                                        <div class="invalid-feedback">
                                            {% for error in form.product.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>
                        </div>

                        <div class="row">
                            <div class="col-md-6">
                                <div class="mb-3">
                                    <label for="{{ form.version.id_for_label }}" class="form-label">Version</label>
                                    {{ form.version }}
                                    {% if form.version.errors %}
                                        <div class="invalid-feedback">
                                            {% for error in form.version.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>
                            <div class="col-md-6">
                                <div class="mb-3">
                                    <div class="form-check">
                                        {{ form.is_active }}
                                        <label for="{{ form.is_active.id_for_label }}" class="form-check-label">
                                            Active
                                        </label>
                                    </div>
                                    {% if form.is_active.errors %}
                                        <div class="invalid-feedback">
                                            {% for error in form.is_active.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>
                        </div>

                        <!-- BOM Items Formset -->
                        <div class="card mt-4">
                            <div class="card-header">
                                <h5 class="mb-0">Bill of Materials Items</h5>
                            </div>
                            <div class="card-body">
                                {{ formset.management_form }}

                                <div id="bom-items">
                                    {% for form in formset %}
                                        <div class="bom-item mb-3 p-3 border rounded">
                                            <div class="row">
                                                <div class="col-md-5">
                                                    <label class="form-label">Component</label>
                                                    {{ form.component }}
                                                    {% if form.component.errors %}
                                                        <div class="invalid-feedback">
                                                            {% for error in form.component.errors %}{{ error }}{% endfor %}
                                                        </div>
                                                    {% endif %}
                                                </div>
                                                <div class="col-md-3">
                                                    <label class="form-label">Quantity</label>
                                                    {{ form.quantity }}
                                                    {% if form.quantity.errors %}
                                                        <div class="invalid-feedback">
                                                            {% for error in form.quantity.errors %}{{ error }}{% endfor %}
                                                        </div>
                                                    {% endif %}
                                                </div>
                                                <div class="col-md-3">
                                                    <label class="form-label">Unit of Measure</label>
                                                    {{ form.unit_of_measure }}
                                                    {% if form.unit_of_measure.errors %}
                                                        <div class="invalid-feedback">
                                                            {% for error in form.unit_of_measure.errors %}{{ error }}{% endfor %}
                                                        </div>
                                                    {% endif %}
                                                </div>
                                                <div class="col-md-1">
                                                    <label class="form-label">&nbsp;</label>
                                                    <button type="button" class="btn btn-danger btn-sm remove-item">
                                                        <i class="fas fa-trash"></i>
                                                    </button>
                                                </div>
                                            </div>
                                            {{ form.id }}
                                            <!-- Hide the DELETE checkbox -->
                                            {% if form.DELETE %}
                                                {{ form.DELETE.as_hidden }}
                                            {% endif %}
                                        </div>
                                    {% endfor %}
                                </div>

                                <button type="button" class="btn btn-success btn-sm" id="add-item">
                                    <i class="fas fa-plus me-1"></i>Add Component
                                </button>
                            </div>
                        </div>

                        <!-- Form Actions -->
                        <div class="mt-4">
                            <button type="submit" class="btn btn-primary">
                                <i class="fas fa-save me-2"></i>Save Bill of Material
                            </button>
                            <a href="{% url 'manufacturing:bom_list' %}" class="btn btn-secondary ms-2">
                                <i class="fas fa-times me-2"></i>Cancel
                            </a>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</div>

<script>
document.addEventListener('DOMContentLoaded', function() {
    // Auto-create first form if no forms exist
    const container = document.getElementById('bom-items');
    if (container && container.children.length === 0) {
        const totalForms = document.querySelector('input[name$="-TOTAL_FORMS"]');
        totalForms.value = 1;

        // Create the first form
        const templateForm = document.createElement('div');
        templateForm.className = 'bom-item mb-3 p-3 border rounded';
        templateForm.id = 'bom-item-0';
        templateForm.innerHTML = `
            <div class="row">
                <div class="col-md-5">
                    <label class="form-label">Component</label>
                    <select name="bomitem_set-0-component" class="form-select" required>
                        <option value="">---------</option>
                    </select>
                </div>
                <div class="col-md-3">
                    <label class="form-label">Quantity</label>
                    <input type="number" name="bomitem_set-0-quantity" step="0.01" min="0" class="form-control" required>
                </div>
                <div class="col-md-3">
                    <label class="form-label">Unit of Measure</label>
                    <select name="bomitem_set-0-unit_of_measure" class="form-select" required>
                        <option value="">---------</option>
                    </select>
                </div>
                <div class="col-md-1">
                    <label class="form-label">&nbsp;</label>
                    <button type="button" class="btn btn-danger btn-sm remove-item">
                        <i class="fas fa-trash"></i>
                    </button>
                </div>
            </div>
            <input type="hidden" name="bomitem_set-0-id" id="id_bomitem_set-0-id">
            <input type="hidden" name="bomitem_set-0-DELETE" id="id_bomitem_set-0-DELETE">
        `;
        container.appendChild(templateForm);
        attachFormEvents(templateForm);
    }

    // Add new BOM item functionality
    document.getElementById('add-item').addEventListener('click', function() {
        const totalForms = document.querySelector('input[name$="-TOTAL_FORMS"]');
        const maxForms = document.querySelector('input[name$="-MAX_NUM_FORMS"]');
        const formNum = parseInt(totalForms.value);

        // Check if we've reached the maximum number of forms
        if (maxForms && parseInt(maxForms.value) > 0 && formNum >= parseInt(maxForms.value)) {
            alert('Maximum number of components reached.');
            return;
        }

        // Find the first non-deleted form to clone as template
        const container = document.getElementById('bom-items');
        const forms = container.querySelectorAll('.bom-item:not(.deleted-item)');
        const templateForm = forms.length > 0 ? forms[0] : container.firstElementChild;

        if (!templateForm) {
            console.error('No template form found');
            return;
        }

        const newForm = templateForm.cloneNode(true);

        // Update form indices - replace all occurrences of -0- with the new form number
        newForm.innerHTML = newForm.innerHTML.replace(
            new RegExp(`-0-`, 'g'),
            `-${formNum}-`
        );

        // Update the form ID
        newForm.id = `bom-item-${formNum}`;

        // Clear form values and reset state
        newForm.className = 'bom-item mb-3 p-3 border rounded';
        newForm.querySelectorAll('input, select, textarea').forEach(function(field) {
            field.disabled = false;
            if (field.type === 'checkbox') {
                field.checked = false;
            } else if (field.tagName === 'SELECT') {
                field.selectedIndex = 0;
            } else {
                field.value = '';
            }
            // Re-enable required attribute if it was removed
            if (field.name.includes('component') || field.name.includes('quantity') || field.name.includes('unit_of_measure')) {
                field.setAttribute('required', 'required');
            }
        });

        container.appendChild(newForm);
        totalForms.value = formNum + 1;

        // Re-attach event listeners to the new form
        attachFormEvents(newForm);
    });

    // Auto-populate unit of measure when component is selected
    document.addEventListener('change', function(e) {
        if (e.target.name && e.target.name.includes('component') && e.target.tagName === 'SELECT') {
            const componentSelect = e.target;
            const formItem = componentSelect.closest('.bom-item');
            const uomSelect = formItem.querySelector('select[name*="-unit_of_measure"]');

            if (componentSelect.value && uomSelect) {
                // Get the selected option
                const selectedOption = componentSelect.options[componentSelect.selectedIndex];
                const unitOfMeasureId = selectedOption.getAttribute('data-uom-id');

                if (unitOfMeasureId) {
                    // Set the unit of measure
                    for (let i = 0; i < uomSelect.options.length; i++) {
                        if (uomSelect.options[i].value === unitOfMeasureId) {
                            uomSelect.selectedIndex = i;
                            uomSelect.dispatchEvent(new Event('change'));
                            break;
                        }
                    }
                }
            }
        }
    });

    // Initialize component selects with unit of measure data
    initializeComponentSelects();
});

// Function to attach events to form fields
function attachFormEvents(form) {
    const removeBtn = form.querySelector('.remove-item');
    if (removeBtn) {
        const newBtn = removeBtn.cloneNode(true);
        removeBtn.parentNode.replaceChild(newBtn, removeBtn);
        newBtn.addEventListener('click', function() {
            removeComponent(this);
        });
    }
}

function removeComponent(button) {
    // Show confirmation dialog
    const confirmed = confirm('Are you sure you want to delete this component? This action cannot be undone.');

    if (confirmed) {
        const itemForm = button.closest('.bom-item');
        const deleteCheckbox = itemForm.querySelector('input[name$="-DELETE"]');

        if (deleteCheckbox) {
            // Mark for deletion in the form
            deleteCheckbox.checked = true;

            // Hide the item visually and disable all form inputs
            itemForm.classList.add('d-none', 'deleted-item');
            itemForm.querySelectorAll('input, select, textarea').forEach(function(field) {
                field.disabled = true;
                // Clear required attribute to prevent validation errors
                field.removeAttribute('required');
            });
        }
    }
}

// Initialize component selects with unit of measure data
function initializeComponentSelects() {
    const componentSelects = document.querySelectorAll('select[name*="-component"]');
    componentSelects.forEach(select => {
        if (select.options.length > 0 && !select.options[1].hasAttribute('data-uom-id')) {
            // Add data-uom-id attributes via AJAX
            fetch('/inventory/api/products/')
                .then(response => response.json())
                .then(data => {
                    data.forEach(product => {
                        const option = select.querySelector(`option[value="${product.id}"]`);
                        if (option && product.unit_of_measure) {
                            option.setAttribute('data-uom-id', product.unit_of_measure.id);
                        }
                    });
                })
                .catch(error => {
                    console.log('Could not fetch product data for UOM auto-population', error);
                });
        }
    });
}
</script>
{% endblock %}