{% extends 'base.html' %}
{% load static %}

{% block title %}{{ module_title }} - Manufacturing App{% endblock %}

{% block extra_css %}
<style>
.formset-container {
    border: 1px solid #dee2e6;
    border-radius: 0.375rem;
    padding: 1rem;
    margin-bottom: 1rem;
}

.formset-header {
    background-color: #f8f9fa;
    padding: 0.5rem 1rem;
    margin: -1rem -1rem 1rem -1rem;
    border-bottom: 1px solid #dee2e6;
}

.delete-checkbox {
    margin-top: 2rem;
}
</style>
{% endblock %}

{% block content %}
<div class="container-fluid mt-4">
    <div class="row">
        <div class="col-md-10 offset-md-1">
            <div class="card">
                <div class="card-header">
                    <h4 class="mb-0">
                        {% if is_create %}
                            <i class="fas fa-plus-circle"></i> Create Purchase Order
                        {% else %}
                            <i class="fas fa-edit"></i> Edit Purchase Order
                        {% endif %}
                    </h4>
                </div>
                <div class="card-body">
                    <form method="post" id="po-form">
                        {% csrf_token %}

                        <!-- Purchase Order Header -->
                        <div class="row">
                            <div class="col-md-6">
                                <div class="mb-3">
                                    <label for="{{ form.supplier.id_for_label }}" class="form-label">
                                        {{ form.supplier.label }}{% if form.supplier.field.required %}<span class="text-danger">*</span>{% endif %}
                                    </label>
                                    {{ form.supplier }}
                                    {% if form.supplier.errors %}
                                        <div class="text-danger small">
                                            {% for error in form.supplier.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>

                        <div class="row">
                            <div class="col-md-6">
                                <div class="mb-3">
                                    <label for="{{ form.order_date.id_for_label }}" class="form-label">
                                        {{ form.order_date.label }}{% if form.order_date.field.required %}<span class="text-danger">*</span>{% endif %}
                                    </label>
                                    {{ form.order_date }}
                                    {% if form.order_date.errors %}
                                        <div class="text-danger small">
                                            {% for error in form.order_date.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>

                            <div class="col-md-6">
                                <div class="mb-3">
                                    <label for="{{ form.expected_delivery_date.id_for_label }}" class="form-label">
                                        {{ form.expected_delivery_date.label }}
                                    </label>
                                    {{ form.expected_delivery_date }}
                                    {% if form.expected_delivery_date.errors %}
                                        <div class="text-danger small">
                                            {% for error in form.expected_delivery_date.errors %}{{ error }}{% endfor %}
                                        </div>
                                    {% endif %}
                                </div>
                            </div>
                        </div>

                        <!-- Purchase Order Items -->
                        <div class="formset-container">
                            <div class="formset-header">
                                <h5 class="mb-0">
                                    <i class="fas fa-list"></i> Order Items
                                    <button type="button" class="btn btn-sm btn-outline-primary float-end" id="add-item">
                                        <i class="fas fa-plus"></i> Add Item
                                    </button>
                                </h5>
                            </div>

                            {{ formset.management_form }}

                            <div id="purchase-items-container">
                                {% for item_form in formset %}
                                <div class="item-form mb-3 p-3 border rounded {% if item_form.DELETE.value %}d-none deleted-item{% endif %}"
                                     id="item-form-{{ forloop.counter0 }}">
                                    <div class="row">
                                        <div class="col-md-3">
                                            <label class="form-label">Product</label>
                                            {{ item_form.product }}
                                            {% if item_form.product.errors %}
                                                <div class="text-danger small">
                                                    {% for error in item_form.product.errors %}{{ error }}{% endfor %}
                                                </div>
                                            {% endif %}
                                        </div>

                                        <div class="col-md-3">
                                            <label class="form-label">Quantity</label>
                                            {{ item_form.quantity }}
                                            {% if item_form.quantity.errors %}
                                                <div class="text-danger small">
                                                    {% for error in item_form.quantity.errors %}{{ error }}{% endfor %}
                                                </div>
                                            {% endif %}
                                        </div>

                                        <div class="col-md-3">
                                            <label class="form-label">Unit Price</label>
                                            {{ item_form.unit_price }}
                                            {% if item_form.unit_price.errors %}
                                                <div class="text-danger small">
                                                    {% for error in item_form.unit_price.errors %}{{ error }}{% endfor %}
                                                </div>
                                            {% endif %}
                                        </div>

                                        <div class="col-md-3 d-flex align-items-end">
                                            <div class="mb-3 me-2 flex-grow-1">
                                                <label class="form-label">Total</label>
                                                <div class="form-control-plaintext" id="item-total-{{ forloop.counter0 }}">
                                                    Rp 0,00
                                                </div>
                                            </div>
                                            <div class="d-flex align-items-end">
                                                <button type="button" class="btn btn-danger btn-sm mb-3" style="display: block;">
                                                    <i class="fas fa-trash"></i>
                                                </button>
                                            </div>
                                        </div>
                                    </div>
                                    {{ item_form.id }}
                                    {{ item_form.DELETE }}
                                </div>
                                {% endfor %}
                            </div>
                        </div>

                        <div class="mb-3">
                            <label for="{{ form.notes.id_for_label }}" class="form-label">
                                {{ form.notes.label }}
                            </label>
                            {{ form.notes }}
                            {% if form.notes.errors %}
                                <div class="text-danger small">
                                    {% for error in form.notes.errors %}{{ error }}{% endfor %}
                                </div>
                            {% endif %}
                        </div>

                        <div class="d-flex justify-content-between">
                            <a href="{% url 'purchasing:po_list' %}" class="btn btn-secondary">
                                <i class="fas fa-times"></i> Cancel
                            </a>
                            <button type="submit" class="btn btn-primary">
                                {% if is_create %}
                                    <i class="fas fa-save"></i> Create Purchase Order
                                {% else %}
                                    <i class="fas fa-save"></i> Update Purchase Order
                                {% endif %}
                            </button>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</div>

{% block extra_js %}
<script>
document.addEventListener('DOMContentLoaded', function() {
    // Auto-create first form if no forms exist
    const container = document.getElementById('purchase-items-container');
    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 = 'item-form mb-3 p-3 border rounded';
        templateForm.id = 'item-form-0';
        templateForm.innerHTML = `
            <div class="row">
                <div class="col-md-3">
                    <label class="form-label">Product</label>
                    <select name="form-0-product" class="form-control" required>
                        <option value="">---------</option>
                    </select>
                </div>
                <div class="col-md-3">
                    <label class="form-label">Quantity</label>
                    <input type="number" name="form-0-quantity" class="form-control" step="0.01" min="0" required>
                </div>
                <div class="col-md-3">
                    <label class="form-label">Unit Price</label>
                    <input type="number" name="form-0-unit_price" class="form-control" step="0.01" min="0" required>
                </div>
                <div class="col-md-3 d-flex align-items-end">
                    <div class="mb-3 me-2 flex-grow-1">
                        <label class="form-label">Total</label>
                        <div class="form-control-plaintext" id="item-total-0">Rp 0,00</div>
                    </div>
                    <div class="d-flex align-items-end">
                        <button type="button" class="btn btn-danger btn-sm mb-3" style="display: block;">
                            <i class="fas fa-trash"></i>
                        </button>
                    </div>
                </div>
            </div>
            <input type="hidden" name="form-0-id" id="id_form-0-id">
            <input type="checkbox" name="form-0-DELETE" id="id_form-0-DELETE" style="display: none;">
        `;
        container.appendChild(templateForm);
        attachFormEvents(templateForm);
    }

    // Auto-calculate totals when quantity or unit price changes
    document.addEventListener('input', function(e) {
        if (e.target.matches('input[name$="-quantity"], input[name$="-unit_price"]')) {
            calculateItemTotal(e.target.closest('.item-form'));
        }
    });

    // Add new 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 items reached.');
            return;
        }

        // Find the first non-deleted form to clone as template
        const container = document.getElementById('purchase-items-container');
        const forms = container.querySelectorAll('.item-form: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 = `item-form-${formNum}`;

        // Clear form values and reset state
        newForm.className = 'item-form 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('product') || field.name.includes('quantity') || field.name.includes('unit_price')) {
                field.setAttribute('required', 'required');
            }
        });

        // Reset total display
        const totalDisplay = newForm.querySelector('[id^="item-total-"]');
        if (totalDisplay) {
            totalDisplay.id = `item-total-${formNum}`;
            totalDisplay.textContent = 'Rp 0,00';
        }

        // Always show remove button for added items (never hide it)
        const removeBtn = newForm.querySelector('.btn-danger');
        if (removeBtn) {
            removeBtn.style.display = 'block';
        }

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

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

// Function to attach events to form fields
function attachFormEvents(form) {
    // Remove existing event listeners to prevent duplicates
    form.querySelectorAll('input[name$="-quantity"], input[name$="-unit_price"]').forEach(function(input) {
        const newInput = input.cloneNode(true);
        input.parentNode.replaceChild(newInput, input);
        newInput.addEventListener('input', function() {
            calculateItemTotal(form);
        });
    });

    const removeBtn = form.querySelector('.btn-danger');
    if (removeBtn) {
        const newBtn = removeBtn.cloneNode(true);
        removeBtn.parentNode.replaceChild(newBtn, removeBtn);
        newBtn.addEventListener('click', function() {
            removeItem(this);
        });
    }
}

function calculateItemTotal(form) {
    const quantity = parseFloat(form.querySelector('input[name$="-quantity"]').value) || 0;
    const unitPrice = parseFloat(form.querySelector('input[name$="-unit_price"]').value) || 0;
    const total = quantity * unitPrice;

    // Update the total display
    const totalDisplay = form.querySelector('[id^="item-total-"]');
    if (totalDisplay) {
        totalDisplay.textContent = formatCurrency(total);
    }
}

function formatCurrency(amount) {
    return new Intl.NumberFormat('id-ID', {
        style: 'currency',
        currency: 'IDR',
        minimumFractionDigits: 2
    }).format(amount);
}

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

    if (confirmed) {
        const itemForm = button.closest('.item-form');
        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');
            });
        }
    }
}
</script>
{% endblock %}
{% endblock %}