(function ($) {
    'use strict';

    $(document).ready(function () {

        var $uploadWrap = $('.studiou-fpp-upload-wrap');
        if (!$uploadWrap.length) {
            return;
        }

        var productId = $uploadWrap.data('product-id');
        var maxFileSize = parseInt($uploadWrap.data('max-file-size'), 10) || 50;
        var chunkSize = parseInt(studiouWcfppFront.chunkSize, 10) || 1048576;
        var uploadedAttachmentId = null;
        var uploadedFileRecordId = null;
        var isUploading = false;
        var originalGalleryImages = {}; // Store original src/srcset to restore on remove

        // Upload area elements
        var $dropzone = $uploadWrap.find('#studiou-fpp-dropzone');
        var $fileInput = $uploadWrap.find('#studiou-fpp-file-input');
        var $progress = $uploadWrap.find('.studiou-fpp-progress');
        var $progressFill = $uploadWrap.find('.studiou-fpp-progress-fill');
        var $progressText = $uploadWrap.find('.studiou-fpp-progress-text');
        var $preview = $uploadWrap.find('.studiou-fpp-preview');
        var $previewImg = $preview.find('img');
        var $previewName = $uploadWrap.find('.studiou-fpp-preview-name');
        var $removeBtn = $uploadWrap.find('.studiou-fpp-remove-file');
        var $messages = $uploadWrap.find('.studiou-fpp-messages');

        // Block all add-to-cart actions until photo is uploaded
        // Intercept form submissions
        $(document).on('submit', 'form.cart, form.variations_form', function (e) {
            if (!uploadedAttachmentId) {
                e.preventDefault();
                showMessage(studiouWcfppFront.i18n.uploadFile, 'error');
                scrollToUpload();
                return false;
            }
        });

        // Intercept add-to-cart button clicks (covers AJAX and non-AJAX buttons)
        $(document).on('click', '.single_add_to_cart_button, .add_to_cart_button, button[name="add-to-cart"], input[name="add-to-cart"]', function (e) {
            if (!uploadedAttachmentId) {
                e.preventDefault();
                e.stopImmediatePropagation();
                showMessage(studiouWcfppFront.i18n.uploadFile, 'error');
                scrollToUpload();
                return false;
            }
        });

        // Intercept add-to-cart links (e.g. ?add-to-cart=ID)
        $(document).on('click', 'a[href*="add-to-cart"]', function (e) {
            if (!uploadedAttachmentId) {
                e.preventDefault();
                e.stopImmediatePropagation();
                showMessage(studiouWcfppFront.i18n.uploadFile, 'error');
                scrollToUpload();
                return false;
            }
        });

        function scrollToUpload() {
            $('html, body').animate({
                scrollTop: $uploadWrap.offset().top - 100
            }, 400);
        }

        // Reset upload after successful WC add-to-cart
        $(document.body).on('added_to_cart', function () {
            resetUpload();
        });

        // Drag and drop
        $dropzone.on('dragover dragenter', function (e) {
            e.preventDefault();
            e.stopPropagation();
            $(this).addClass('studiou-fpp-dragover');
        });

        $dropzone.on('dragleave drop', function (e) {
            e.preventDefault();
            e.stopPropagation();
            $(this).removeClass('studiou-fpp-dragover');
        });

        $dropzone.on('drop', function (e) {
            var files = e.originalEvent.dataTransfer.files;
            if (files.length > 0) {
                handleFile(files[0]);
            }
        });

        $dropzone.on('click', function () {
            if (!isUploading) {
                $fileInput.trigger('click');
            }
        });

        $fileInput.on('change', function () {
            if (this.files.length > 0) {
                handleFile(this.files[0]);
            }
        });

        // Remove file
        $removeBtn.on('click', function () {
            removeUploadedFile();
        });

        function handleFile(file) {
            if (isUploading) {
                return;
            }

            var maxBytes = maxFileSize * 1024 * 1024;
            if (file.size > maxBytes) {
                showMessage(studiouWcfppFront.i18n.fileTooLarge.replace('%s', maxFileSize), 'error');
                return;
            }

            clearMessages();
            startChunkedUpload(file);
        }

        function startChunkedUpload(file) {
            isUploading = true;
            var totalChunks = Math.ceil(file.size / chunkSize);
            var uploadId = 'upload_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
            var currentChunk = 0;

            $dropzone.hide();
            $progress.show();

            function uploadNextChunk() {
                var start = currentChunk * chunkSize;
                var end = Math.min(start + chunkSize, file.size);
                var blob = file.slice(start, end);

                var formData = new FormData();
                formData.append('action', 'studiou_wcfpp_upload_chunk');
                formData.append('nonce', studiouWcfppFront.nonce);
                formData.append('product_id', productId);
                formData.append('upload_id', uploadId);
                formData.append('chunk_index', currentChunk);
                formData.append('total_chunks', totalChunks);
                formData.append('file_name', file.name);
                formData.append('file_size', file.size);
                formData.append('chunk', blob, 'chunk');

                // Last chunk triggers server-side assembly - needs longer timeout
                var isLastChunk = (currentChunk === totalChunks - 1);
                if (isLastChunk) {
                    $progressFill.css('width', '100%');
                    $progressText.text(studiouWcfppFront.i18n.processing || 'Processing...');
                }

                $.ajax({
                    url: studiouWcfppFront.ajaxUrl,
                    type: 'POST',
                    data: formData,
                    processData: false,
                    contentType: false,
                    timeout: isLastChunk ? 120000 : 30000,
                    success: function (response) {
                        if (response.success) {
                            if (!isLastChunk) {
                                currentChunk++;
                                var percent = Math.round((currentChunk / totalChunks) * 100);
                                $progressFill.css('width', percent + '%');
                                $progressText.text(percent + '%');
                            }

                            if (response.data.complete) {
                                uploadedAttachmentId = response.data.attachment_id;
                                uploadedFileRecordId = response.data.file_record_id;

                                // Store in WC session so any add-to-cart button picks it up
                                storeInSession(
                                    response.data.attachment_id,
                                    response.data.file_record_id,
                                    response.data.file_name
                                );

                                showPreview(response.data.thumbnail_url, response.data.file_name);
                                updateProductGallery(response.data.preview_url || response.data.thumbnail_url);
                                $progress.hide();
                                isUploading = false;
                            } else {
                                uploadNextChunk();
                            }
                        } else {
                            uploadFailed(response.data ? response.data.message : studiouWcfppFront.i18n.uploadError);
                        }
                    },
                    error: function () {
                        uploadFailed(studiouWcfppFront.i18n.uploadError);
                    }
                });
            }

            uploadNextChunk();
        }

        function storeInSession(attachmentId, fileRecordId, fileName) {
            $.ajax({
                url: studiouWcfppFront.ajaxUrl,
                type: 'POST',
                data: {
                    action: 'studiou_wcfpp_set_upload_session',
                    nonce: studiouWcfppFront.nonce,
                    attachment_id: attachmentId,
                    file_record_id: fileRecordId,
                    file_name: fileName
                }
            });
        }

        function clearSession() {
            $.ajax({
                url: studiouWcfppFront.ajaxUrl,
                type: 'POST',
                data: {
                    action: 'studiou_wcfpp_clear_upload_session',
                    nonce: studiouWcfppFront.nonce
                }
            });
        }

        function uploadFailed(message) {
            isUploading = false;
            $progress.hide();
            $dropzone.show();
            showMessage(message, 'error');
            $fileInput.val('');
        }

        function updateProductGallery(imageUrl) {
            if (!imageUrl) return;

            // Find the main product image (try common WC / theme selectors)
            var selectors = [
                '.woocommerce-product-gallery__image img',
                '.product .wp-post-image',
                '.product-image img',
                '.product-thumbnail img',
                '.entry-summary img.attachment-woocommerce_thumbnail',
                '.product-gallery img:first'
            ];

            var $img = null;
            for (var i = 0; i < selectors.length; i++) {
                $img = $(selectors[i]).first();
                if ($img.length) break;
            }

            if (!$img || !$img.length) return;

            // Save original attributes for restoration
            if (!originalGalleryImages.src) {
                originalGalleryImages.src = $img.attr('src');
                originalGalleryImages.srcset = $img.attr('srcset') || '';
                originalGalleryImages.sizes = $img.attr('sizes') || '';
                // Also save the parent link href if it's a gallery link
                var $parentLink = $img.closest('a');
                if ($parentLink.length) {
                    originalGalleryImages.href = $parentLink.attr('href');
                }
            }

            // Replace with uploaded image
            $img.attr('src', imageUrl);
            $img.removeAttr('srcset');
            $img.removeAttr('sizes');

            var $parentLink = $img.closest('a');
            if ($parentLink.length) {
                $parentLink.attr('href', imageUrl);
            }
        }

        function restoreProductGallery() {
            if (!originalGalleryImages.src) return;

            var selectors = [
                '.woocommerce-product-gallery__image img',
                '.product .wp-post-image',
                '.product-image img',
                '.product-thumbnail img',
                '.entry-summary img.attachment-woocommerce_thumbnail',
                '.product-gallery img:first'
            ];

            var $img = null;
            for (var i = 0; i < selectors.length; i++) {
                $img = $(selectors[i]).first();
                if ($img.length) break;
            }

            if (!$img || !$img.length) return;

            $img.attr('src', originalGalleryImages.src);
            if (originalGalleryImages.srcset) {
                $img.attr('srcset', originalGalleryImages.srcset);
            }
            if (originalGalleryImages.sizes) {
                $img.attr('sizes', originalGalleryImages.sizes);
            }

            if (originalGalleryImages.href) {
                var $parentLink = $img.closest('a');
                if ($parentLink.length) {
                    $parentLink.attr('href', originalGalleryImages.href);
                }
            }

            originalGalleryImages = {};
        }

        function showPreview(thumbnailUrl, fileName) {
            if (thumbnailUrl) {
                $previewImg.attr('src', thumbnailUrl).show();
            } else {
                $previewImg.hide();
            }
            $previewName.text(fileName);
            $preview.show();
        }

        function removeUploadedFile() {
            if (!uploadedFileRecordId) {
                return;
            }

            $.ajax({
                url: studiouWcfppFront.ajaxUrl,
                type: 'POST',
                data: {
                    action: 'studiou_wcfpp_remove_upload',
                    nonce: studiouWcfppFront.nonce,
                    file_record_id: uploadedFileRecordId
                },
                success: function () {
                    resetUpload();
                }
            });
        }

        function resetUpload() {
            uploadedAttachmentId = null;
            uploadedFileRecordId = null;
            clearSession();
            restoreProductGallery();
            $preview.hide();
            $previewImg.attr('src', '');
            $previewName.text('');
            $dropzone.show();
            $fileInput.val('');
            clearMessages();
        }

        function showMessage(text, type) {
            var cls = type === 'error' ? 'studiou-fpp-msg-error' : 'studiou-fpp-msg-success';
            $messages.html('<div class="studiou-fpp-msg ' + cls + '">' + escHtml(text) + '</div>');
        }

        function clearMessages() {
            $messages.empty();
        }

        function escHtml(str) {
            var div = document.createElement('div');
            div.appendChild(document.createTextNode(str));
            return div.innerHTML;
        }
    });
})(jQuery);