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

const globToRegExp = require("./globToRegExp").globToRegExp;

function parseType(type) {
	const items = type.split("+");
	const t = items.shift();
	return {
		type: t === "*" ? null : t,
		features: items
	};
}

function isTypeMatched(baseType, testedType) {
	if (typeof baseType === "string") baseType = parseType(baseType);
	if (typeof testedType === "string") testedType = parseType(testedType);
	if (testedType.type && testedType.type !== baseType.type) return false;
	return testedType.features.every(requiredFeature => {
		return baseType.features.indexOf(requiredFeature) >= 0;
	});
}

function isResourceTypeMatched(baseType, testedType) {
	baseType = baseType.split("/");
	testedType = testedType.split("/");
	if (baseType.length !== testedType.length) return false;
	for (let i = 0; i < baseType.length; i++) {
		if (!isTypeMatched(baseType[i], testedType[i])) return false;
	}
	return true;
}

function isResourceTypeSupported(context, type) {
	return (
		context.supportedResourceTypes &&
		context.supportedResourceTypes.some(supportedType => {
			return isResourceTypeMatched(supportedType, type);
		})
	);
}

function isEnvironment(context, env) {
	return (
		context.environments &&
		context.environments.every(environment => {
			return isTypeMatched(environment, env);
		})
	);
}

const globCache = {};

function getGlobRegExp(glob) {
	const regExp = globCache[glob] || (globCache[glob] = globToRegExp(glob));
	return regExp;
}

function matchGlob(glob, relativePath) {
	const regExp = getGlobRegExp(glob);
	return regExp.exec(relativePath);
}

function isGlobMatched(glob, relativePath) {
	return !!matchGlob(glob, relativePath);
}

function isConditionMatched(context, condition) {
	const items = condition.split("|");
	return items.some(function testFn(item) {
		item = item.trim();
		const inverted = /^!/.test(item);
		if (inverted) return !testFn(item.substr(1));
		if (/^[a-z]+:/.test(item)) {
			// match named condition
			const match = /^([a-z]+):\s*/.exec(item);
			const value = item.substr(match[0].length);
			const name = match[1];
			switch (name) {
				case "referrer":
					return isGlobMatched(value, context.referrer);
				default:
					return false;
			}
		} else if (item.indexOf("/") >= 0) {
			// match supported type
			return isResourceTypeSupported(context, item);
		} else {
			// match environment
			return isEnvironment(context, item);
		}
	});
}

function isKeyMatched(context, key) {
	for (;;) {
		const match = /^\[([^\]]+)\]\s*/.exec(key);
		if (!match) return key;
		key = key.substr(match[0].length);
		const condition = match[1];
		if (!isConditionMatched(context, condition)) {
			return false;
		}
	}
}

function getField(context, configuration, field) {
	let value;
	Object.keys(configuration).forEach(key => {
		const pureKey = isKeyMatched(context, key);
		if (pureKey === field) {
			value = configuration[key];
		}
	});
	return value;
}

function getMain(context, configuration) {
	return getField(context, configuration, "main");
}

function getExtensions(context, configuration) {
	return getField(context, configuration, "extensions");
}

function matchModule(context, configuration, request) {
	const modulesField = getField(context, configuration, "modules");
	if (!modulesField) return request;
	let newRequest = request;
	const keys = Object.keys(modulesField);
	let iteration = 0;
	let match;
	let index;
	for (let i = 0; i < keys.length; i++) {
		const key = keys[i];
		const pureKey = isKeyMatched(context, key);
		match = matchGlob(pureKey, newRequest);
		if (match) {
			const value = modulesField[key];
			if (typeof value !== "string") {
				return value;
			} else if (/^\(.+\)$/.test(pureKey)) {
				newRequest = newRequest.replace(getGlobRegExp(pureKey), value);
			} else {
				index = 1;
				newRequest = value.replace(/(\/?\*)?\*/g, replaceMatcher);
			}
			i = -1;
			if (iteration++ > keys.length) {
				throw new Error("Request '" + request + "' matches recursively");
			}
		}
	}
	return newRequest;

	function replaceMatcher(find) {
		switch (find) {
			case "/**": {
				const m = match[index++];
				return m ? "/" + m : "";
			}
			case "**":
			case "*":
				return match[index++];
		}
	}
}

function matchType(context, configuration, relativePath) {
	const typesField = getField(context, configuration, "types");
	if (!typesField) return undefined;
	let type;
	Object.keys(typesField).forEach(key => {
		const pureKey = isKeyMatched(context, key);
		if (isGlobMatched(pureKey, relativePath)) {
			const value = typesField[key];
			if (!type && /\/\*$/.test(value))
				throw new Error(
					"value ('" +
						value +
						"') of key '" +
						key +
						"' contains '*', but there is no previous value defined"
				);
			type = value.replace(/\/\*$/, "/" + type);
		}
	});
	return type;
}

exports.parseType = parseType;
exports.isTypeMatched = isTypeMatched;
exports.isResourceTypeSupported = isResourceTypeSupported;
exports.isEnvironment = isEnvironment;
exports.isGlobMatched = isGlobMatched;
exports.isConditionMatched = isConditionMatched;
exports.isKeyMatched = isKeyMatched;
exports.getField = getField;
exports.getMain = getMain;
exports.getExtensions = getExtensions;
exports.matchModule = matchModule;
exports.matchType = matchType;