Element.ts

import { is_void } from '../../../utils/names';
import { get_attribute_value, get_class_attribute_value } from './shared/get_attribute_value';
import { get_slot_scope } from './shared/get_slot_scope';
import { boolean_attributes } from './shared/boolean_attributes';
import Renderer, { RenderOptions } from '../Renderer';
import Element from '../../nodes/Element';
import { x } from 'code-red';
import Expression from '../../nodes/shared/Expression';
import remove_whitespace_children from './utils/remove_whitespace_children';

export default function(node: Element, renderer: Renderer, options: RenderOptions & {
	slot_scopes: Map<any, any>;
}) {

	const children = remove_whitespace_children(node.children, node.next);

	// awkward special case
	let node_contents;

	const contenteditable = (
		node.name !== 'textarea' &&
		node.name !== 'input' &&
		node.attributes.some((attribute) => attribute.name === 'contenteditable')
	);

	const slot = node.get_static_attribute_value('slot');
	const nearest_inline_component = node.find_nearest(/InlineComponent/);

	if (slot && nearest_inline_component) {
		renderer.push();
	}

	renderer.add_string(`<${node.name}`);

	const class_expression_list = node.classes.map(class_directive => {
		const { expression, name } = class_directive;
		const snippet = expression ? expression.node : x`#ctx.${name}`; // TODO is this right?
		return x`${snippet} ? "${name}" : ""`;
	});
	if (node.needs_manual_style_scoping) {
		class_expression_list.push(x`"${node.component.stylesheet.id}"`);
	}
	const class_expression =
		class_expression_list.length > 0 &&
		class_expression_list.reduce((lhs, rhs) => x`${lhs} + ' ' + ${rhs}`);

	if (node.attributes.some(attr => attr.is_spread)) {
		// TODO dry this out
		const args = [];
		node.attributes.forEach(attribute => {
			if (attribute.is_spread) {
				args.push(attribute.expression.node);
			} else {
				const name = attribute.name.toLowerCase();
				if (name === 'value' && node.name.toLowerCase() === 'textarea') {
					node_contents = get_attribute_value(attribute);
				} else if (attribute.is_true) {
					args.push(x`{ ${attribute.name}: true }`);
				} else if (
					boolean_attributes.has(name) &&
					attribute.chunks.length === 1 &&
					attribute.chunks[0].type !== 'Text'
				) {
					// a boolean attribute with one non-Text chunk
					args.push(x`{ ${attribute.name}: ${(attribute.chunks[0] as Expression).node} || null }`);
				} else {
					args.push(x`{ ${attribute.name}: ${get_attribute_value(attribute)} }`);
				}
			}
		});

		renderer.add_expression(x`@spread([${args}], ${class_expression})`);
	} else {
		let add_class_attribute = !!class_expression;
		node.attributes.forEach(attribute => {
			const name = attribute.name.toLowerCase();
			if (name === 'value' && node.name.toLowerCase() === 'textarea') {
				node_contents = get_attribute_value(attribute);
			} else if (attribute.is_true) {
				renderer.add_string(` ${attribute.name}`);
			} else if (
				boolean_attributes.has(name) &&
				attribute.chunks.length === 1 &&
				attribute.chunks[0].type !== 'Text'
			) {
				// a boolean attribute with one non-Text chunk
				renderer.add_string(` `);
				renderer.add_expression(x`${(attribute.chunks[0] as Expression).node} ? "${attribute.name}" : ""`);
			} else if (name === 'class' && class_expression) {
				add_class_attribute = false;
				renderer.add_string(` ${attribute.name}="`);
				renderer.add_expression(x`[${get_class_attribute_value(attribute)}, ${class_expression}].join(' ').trim()`);
				renderer.add_string(`"`);
			} else if (attribute.chunks.length === 1 && attribute.chunks[0].type !== 'Text') {
				const snippet = (attribute.chunks[0] as Expression).node;
				renderer.add_expression(x`@add_attribute("${attribute.name}", ${snippet}, ${boolean_attributes.has(name) ? 1 : 0})`);
			} else {
				renderer.add_string(` ${attribute.name}="`);
				renderer.add_expression((name === 'class' ? get_class_attribute_value : get_attribute_value)(attribute));
				renderer.add_string(`"`);
			}
		});
		if (add_class_attribute) {
			renderer.add_expression(x`@add_classes([${class_expression}].join(' ').trim())`);
		}
	}

	node.bindings.forEach(binding => {
		const { name, expression } = binding;

		if (binding.is_readonly) {
			return;
		}

		if (name === 'group') {
			// TODO server-render group bindings
		} else if (contenteditable && (name === 'textContent' || name === 'innerHTML')) {
			node_contents = expression.node;

			// TODO where was this used?
			// value = name === 'textContent' ? x`@escape($$value)` : x`$$value`;
		} else if (binding.name === 'value' && node.name === 'textarea') {
			const snippet = expression.node;
			node_contents = x`${snippet} || ""`;
		} else {
			const snippet = expression.node;
			renderer.add_expression(x`@add_attribute("${name}", ${snippet}, 1)`);
		}
	});

	if (options.hydratable && options.head_id) {
		renderer.add_string(` data-svelte="${options.head_id}"`);
	}

	renderer.add_string('>');

	if (node_contents !== undefined) {
		if (contenteditable) {
			renderer.push();
			renderer.render(children, options);
			const result = renderer.pop();

			renderer.add_expression(x`($$value => $$value === void 0 ? ${result} : $$value)(${node_contents})`);
		} else {
			renderer.add_expression(node_contents);
		}

		if (!is_void(node.name)) {
			renderer.add_string(`</${node.name}>`);
		}
	} else if (slot && nearest_inline_component) {
		renderer.render(children, options);

		if (!is_void(node.name)) {
			renderer.add_string(`</${node.name}>`);
		}

		const lets = node.lets;
		const seen = new Set(lets.map(l => l.name.name));

		nearest_inline_component.lets.forEach(l => {
			if (!seen.has(l.name.name)) lets.push(l);
		});

		options.slot_scopes.set(slot, {
			input: get_slot_scope(node.lets),
			output: renderer.pop()
		});
	} else {
		renderer.render(children, options);

		if (!is_void(node.name)) {
			renderer.add_string(`</${node.name}>`);
		}
	}
}