import { string_has_contents, indented_line_iterator } from  '@efforting.tech/data/string-utilities';
import * as CF from '@efforting.tech/data/field-configuration-factories';
import { Text_Settings } from  '@efforting.tech/data/string-utilities';

export const Text_Tree_Settings = new CF.Schema({
	//BUG - there is currently no way (I think) to put defaults into a sub schema - this should be fixed
	text: Text_Settings,
	trim_head: CF.boolean(false, 'Trim the empty lines from the head of a node'),
	trim_tail: CF.boolean(false, 'Trim the empty lines from the tail of a node'),
	trim_lines: CF.boolean(false, 'Trim lines'),
}, 'Text tree settings');


export class Text_Tree_Node {
	constructor(text_tree_settings, line=undefined, indent=0, line_no=undefined, index=undefined, raw=undefined, parent=undefined) {
		Object.assign(this, { text_tree_settings, line, indent, line_no, index, raw, parent, children: [] });
	}

	get has_line() {
		return string_has_contents(this.line);
	}


	static from_string(text_tree_settings, str) {

		const root = new this(text_tree_settings);
		const { trim_head, trim_tail, trim_lines } = text_tree_settings;

		// NOTE: This first Text_Node is not added to the tree, it serves as an initial cursor only.
		let current = new this(root.text_tree_settings, undefined, 0, undefined, undefined, undefined, root);


		for (const line_info of indented_line_iterator(text_tree_settings.text, str)) {

			// TODO: Implement other variants than inherit-from-previous
			const indent = string_has_contents(line_info.line) ? line_info.indent : current.indent;

			const delta_indent = indent - current.indent;

			if (delta_indent == 0) {
				const pending = new this(current.text_tree_settings, undefined, current.indent, undefined, undefined, undefined, current.parent);	// Partial insertion - same level
				if (current.parent) {
					current.parent.children.push(pending);
				}
				current = pending;
			} else if (delta_indent > 0) {
				for (let i=0; i<delta_indent; i++) {
					const pending = new this(current.text_tree_settings, undefined, current.indent + 1, undefined, undefined, undefined, current);	// Partial insertion
					current.children.push(pending);
					current = pending;
				}
			} else {
				for (let i=0; i>delta_indent; i--) {
					current = current.parent;
				}

				const pending = new this(current.text_tree_settings, undefined, current.indent, undefined, undefined, undefined, current.parent);	// Partial insertion - same level
				if (current.parent) {
					current.parent.children.push(pending);
				}
				current = pending;
			}

			// Fill in partial insertion
			Object.assign(current, {
				line: trim_lines ? line_info.line.trim() : line_info.line,
				line_no: line_info.line_no,
				index: line_info.index,
				raw: line_info.raw,
			});


		}


		if (trim_head || trim_tail) {	//TODO: Implement
			throw new Error('Trimming is not implemented');	//TODO: Proper non implemented error
		}

		return root;

	}
}