/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";

const ContextDependencyHelpers = exports;

/**
 * Escapes regular expression metacharacters
 * @param {string} str String to quote
 * @returns {string} Escaped string
 */
const quotemeta = str => {
	return str.replace(/[-[\]\\/{}()*+?.^$|]/g, "\\$&");
};

ContextDependencyHelpers.create = (
	Dep,
	range,
	param,
	expr,
	options,
	contextOptions
) => {
	let dep;
	let prefix;
	let postfix;
	let prefixRange;
	let valueRange;
	let idx;
	let context;
	let regExp;
	if (param.isTemplateString()) {
		prefix = param.quasis[0].string;
		postfix =
			param.quasis.length > 1
				? param.quasis[param.quasis.length - 1].string
				: "";
		prefixRange = [param.quasis[0].range[0], param.quasis[0].range[1]];
		valueRange = param.range;
		idx = prefix.lastIndexOf("/");
		context = ".";
		if (idx >= 0) {
			context = prefix.substr(0, idx);
			prefix = `.${prefix.substr(idx)}`;
		}
		// If there are more than two quasis, maybe the generated RegExp can be more precise?
		regExp = new RegExp(
			`^${quotemeta(prefix)}${options.wrappedContextRegExp.source}${quotemeta(
				postfix
			)}$`
		);
		dep = new Dep(
			Object.assign(
				{
					request: context,
					recursive: options.wrappedContextRecursive,
					regExp,
					mode: "sync"
				},
				contextOptions
			),
			range,
			valueRange
		);
		dep.loc = expr.loc;
		dep.replaces = [
			{
				range: prefixRange,
				value: prefix
			}
		];
		dep.critical =
			options.wrappedContextCritical &&
			"a part of the request of a dependency is an expression";
		return dep;
	} else if (
		param.isWrapped() &&
		((param.prefix && param.prefix.isString()) ||
			(param.postfix && param.postfix.isString()))
	) {
		prefix = param.prefix && param.prefix.isString() ? param.prefix.string : "";
		postfix =
			param.postfix && param.postfix.isString() ? param.postfix.string : "";
		prefixRange =
			param.prefix && param.prefix.isString() ? param.prefix.range : null;
		valueRange = [
			prefixRange ? prefixRange[1] : param.range[0],
			param.range[1]
		];
		idx = prefix.lastIndexOf("/");
		context = ".";
		if (idx >= 0) {
			context = prefix.substr(0, idx);
			prefix = `.${prefix.substr(idx)}`;
		}
		regExp = new RegExp(
			`^${quotemeta(prefix)}${options.wrappedContextRegExp.source}${quotemeta(
				postfix
			)}$`
		);
		dep = new Dep(
			Object.assign(
				{
					request: context,
					recursive: options.wrappedContextRecursive,
					regExp,
					mode: "sync"
				},
				contextOptions
			),
			range,
			valueRange
		);
		dep.loc = expr.loc;
		dep.prepend = param.prefix && param.prefix.isString() ? prefix : null;
		dep.critical =
			options.wrappedContextCritical &&
			"a part of the request of a dependency is an expression";
		return dep;
	} else {
		dep = new Dep(
			Object.assign(
				{
					request: options.exprContextRequest,
					recursive: options.exprContextRecursive,
					regExp: options.exprContextRegExp,
					mode: "sync"
				},
				contextOptions
			),
			range,
			param.range
		);
		dep.loc = expr.loc;
		dep.critical =
			options.exprContextCritical &&
			"the request of a dependency is an expression";
		return dep;
	}
};
