/**
 * URI.js
 *
 * @fileoverview An RFC 3986 compliant, scheme extendable URI parsing/validating/resolving library for JavaScript.
 * @author <a href="mailto:gary.court@gmail.com">Gary Court</a>
 * @see http://github.com/garycourt/uri-js
 */

/**
 * Copyright 2011 Gary Court. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY GARY COURT ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GARY COURT OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of Gary Court.
 */

import URI_PROTOCOL from './regexps-uri';
import IRI_PROTOCOL from './regexps-iri';
import punycode from 'punycode';
import { toUpperCase, typeOf, assign } from './util';

export interface URIComponents {
	scheme?:string;
	userinfo?:string;
	host?:string;
	port?:number|string;
	path?:string;
	query?:string;
	fragment?:string;
	reference?:string;
	error?:string;
}

export interface URIOptions {
	scheme?:string;
	reference?:string;
	tolerant?:boolean;
	absolutePath?:boolean;
	iri?:boolean;
	unicodeSupport?:boolean;
	domainHost?:boolean;
}

export interface URISchemeHandler<Components extends URIComponents = URIComponents, Options extends URIOptions = URIOptions, ParentComponents extends URIComponents = URIComponents> {
	scheme:string;
	parse(components:ParentComponents, options:Options):Components;
	serialize(components:Components, options:Options):ParentComponents;
	unicodeSupport?:boolean;
	domainHost?:boolean;
	absolutePath?:boolean;
}

export interface URIRegExps {
	NOT_SCHEME : RegExp,
	NOT_USERINFO : RegExp,
	NOT_HOST : RegExp,
	NOT_PATH : RegExp,
	NOT_PATH_NOSCHEME : RegExp,
	NOT_QUERY : RegExp,
	NOT_FRAGMENT : RegExp,
	ESCAPE : RegExp,
	UNRESERVED : RegExp,
	OTHER_CHARS : RegExp,
	PCT_ENCODED : RegExp,
	IPV4ADDRESS : RegExp,
	IPV6ADDRESS : RegExp,
}

export const SCHEMES:{[scheme:string]:URISchemeHandler} = {};

export function pctEncChar(chr:string):string {
	const c = chr.charCodeAt(0);
	let e:string;

	if (c < 16) { e = '%0' + c.toString(16).toUpperCase(); }
	else if (c < 128) { e = '%' + c.toString(16).toUpperCase(); }
	else if (c < 2048) { e = '%' + ((c >> 6) | 192).toString(16).toUpperCase() + '%' + ((c & 63) | 128).toString(16).toUpperCase(); }
	else { e = '%' + ((c >> 12) | 224).toString(16).toUpperCase() + '%' + (((c >> 6) & 63) | 128).toString(16).toUpperCase() + '%' + ((c & 63) | 128).toString(16).toUpperCase(); }

	return e;
}

export function pctDecChars(str:string):string {
	let newStr = '';
	let i = 0;
	const il = str.length;

	while (i < il) {
		const c = parseInt(str.substr(i + 1, 2), 16);

		if (c < 128) {
			newStr += String.fromCharCode(c);
			i += 3;
		}
		else if (c >= 194 && c < 224) {
			if ((il - i) >= 6) {
				const c2 = parseInt(str.substr(i + 4, 2), 16);
				newStr += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
			} else {
				newStr += str.substr(i, 6);
			}
			i += 6;
		}
		else if (c >= 224) {
			if ((il - i) >= 9) {
				const c2 = parseInt(str.substr(i + 4, 2), 16);
				const c3 = parseInt(str.substr(i + 7, 2), 16);
				newStr += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
			} else {
				newStr += str.substr(i, 9);
			}
			i += 9;
		}
		else {
			newStr += str.substr(i, 3);
			i += 3;
		}
	}

	return newStr;
}

function _normalizeComponentEncoding(components:URIComponents, protocol:URIRegExps) {
	function decodeUnreserved(str:string):string {
		const decStr = pctDecChars(str);
		return (!decStr.match(protocol.UNRESERVED) ? str : decStr);
	}

	if (components.scheme) { components.scheme = String(components.scheme).replace(protocol.PCT_ENCODED, decodeUnreserved).toLowerCase().replace(protocol.NOT_SCHEME, ''); }
	if (components.userinfo !== undefined) { components.userinfo = String(components.userinfo).replace(protocol.PCT_ENCODED, decodeUnreserved).replace(protocol.NOT_USERINFO, pctEncChar).replace(protocol.PCT_ENCODED, toUpperCase); }
	if (components.host !== undefined) { components.host = String(components.host).replace(protocol.PCT_ENCODED, decodeUnreserved).toLowerCase().replace(protocol.NOT_HOST, pctEncChar).replace(protocol.PCT_ENCODED, toUpperCase); }
	if (components.path !== undefined) { components.path = String(components.path).replace(protocol.PCT_ENCODED, decodeUnreserved).replace((components.scheme ? protocol.NOT_PATH : protocol.NOT_PATH_NOSCHEME), pctEncChar).replace(protocol.PCT_ENCODED, toUpperCase); }
	if (components.query !== undefined) { components.query = String(components.query).replace(protocol.PCT_ENCODED, decodeUnreserved).replace(protocol.NOT_QUERY, pctEncChar).replace(protocol.PCT_ENCODED, toUpperCase); }
	if (components.fragment !== undefined) { components.fragment = String(components.fragment).replace(protocol.PCT_ENCODED, decodeUnreserved).replace(protocol.NOT_FRAGMENT, pctEncChar).replace(protocol.PCT_ENCODED, toUpperCase); }

	return components;
};

function _stripLeadingZeros(str:string):string {
	return str.replace(/^0*(.*)/, '$1') || '0';
}

function _normalizeIPv4(host:string, protocol:URIRegExps):string {
	const matches = host.match(protocol.IPV4ADDRESS) || [];
	const [, address] = matches;
	
	if (address) {
		return address.split('.').map(_stripLeadingZeros).join('.');
	} else {
		return host;
	}
}

function _normalizeIPv6(host:string, protocol:URIRegExps):string {
	const matches = host.match(protocol.IPV6ADDRESS) || [];
	const [, address, zone] = matches;

	if (address) {
		const [last, first] = address.toLowerCase().split('::').reverse();
		const firstFields = first ? first.split(':').map(_stripLeadingZeros) : [];
		const lastFields = last.split(':').map(_stripLeadingZeros);
		const isLastFieldIPv4Address = protocol.IPV4ADDRESS.test(lastFields[lastFields.length - 1]);
		const fieldCount = isLastFieldIPv4Address ? 7 : 8;
		const lastFieldsStart = lastFields.length - fieldCount;
		const fields = Array<string>(fieldCount);

		for (let x = 0; x < fieldCount; ++x) {
			fields[x] = firstFields[x] || lastFields[lastFieldsStart + x] || '';
		}

		if (isLastFieldIPv4Address) {
			fields[fieldCount - 1] = _normalizeIPv4(fields[fieldCount - 1], protocol);
		}

		const allZeroFields = fields.reduce<Array<{index:number,length:number}>>((acc, field, index) => {
			if (!field || field === '0') {
				const lastLongest = acc[acc.length - 1];
				if (lastLongest && lastLongest.index + lastLongest.length === index) {
					lastLongest.length++;
				} else {
					acc.push({ index, length : 1 });
				}
			}
			return acc;
		}, []);

		const longestZeroFields = allZeroFields.sort((a, b) => b.length - a.length)[0];

		let newHost:string;
		if (longestZeroFields && longestZeroFields.length > 1) {
			const newFirst = fields.slice(0, longestZeroFields.index) ;
			const newLast = fields.slice(longestZeroFields.index + longestZeroFields.length);
			newHost = newFirst.join(':') + '::' + newLast.join(':');
		} else {
			newHost = fields.join(':');
		}

		if (zone) {
			newHost += '%' + zone;
		}

		return newHost;
	} else {
		return host;
	}
}

const URI_PARSE = /^(?:([^:\/?#]+):)?(?:\/\/((?:([^\/?#@]*)@)?(\[[^\/?#\]]+\]|[^\/?#:]*)(?:\:(\d*))?))?([^?#]*)(?:\?([^#]*))?(?:#((?:.|\n|\r)*))?/i;
const NO_MATCH_IS_UNDEFINED = (('').match(/(){0}/) as RegExpMatchArray)[1] === undefined;

export function parse(uriString:string, options:URIOptions = {}):URIComponents {
	const components:URIComponents = {};
	const protocol = (options.iri !== false ? IRI_PROTOCOL : URI_PROTOCOL);

	if (options.reference === 'suffix') { uriString = (options.scheme ? options.scheme + ':' : '') + '//' + uriString; }

	const matches = uriString.match(URI_PARSE);

	if (matches) {
		if (NO_MATCH_IS_UNDEFINED) {
			// store each component
			components.scheme = matches[1];
			components.userinfo = matches[3];
			components.host = matches[4];
			components.port = parseInt(matches[5], 10);
			components.path = matches[6] || '';
			components.query = matches[7];
			components.fragment = matches[8];

			// fix port number
			if (isNaN(components.port)) {
				components.port = matches[5];
			}
		} else {  // IE FIX for improper RegExp matching
			// store each component
			components.scheme = matches[1] || undefined;
			components.userinfo = (uriString.indexOf('@') !== -1 ? matches[3] : undefined);
			components.host = (uriString.indexOf('//') !== -1 ? matches[4] : undefined);
			components.port = parseInt(matches[5], 10);
			components.path = matches[6] || '';
			components.query = (uriString.indexOf('?') !== -1 ? matches[7] : undefined);
			components.fragment = (uriString.indexOf('#') !== -1 ? matches[8] : undefined);

			// fix port number
			if (isNaN(components.port)) {
				components.port = (uriString.match(/\/\/(?:.|\n)*\:(?:\/|\?|\#|$)/) ? matches[4] : undefined);
			}
		}

		if (components.host) {
			// normalize IP hosts
			components.host = _normalizeIPv6(_normalizeIPv4(components.host, protocol), protocol);
		}

		// determine reference type
		if (components.scheme === undefined && components.userinfo === undefined && components.host === undefined && components.port === undefined && !components.path && components.query === undefined) {
			components.reference = 'same-document';
		} else if (components.scheme === undefined) {
			components.reference = 'relative';
		} else if (components.fragment === undefined) {
			components.reference = 'absolute';
		} else {
			components.reference = 'uri';
		}

		// check for reference errors
		if (options.reference && options.reference !== 'suffix' && options.reference !== components.reference) {
			components.error = components.error || 'URI is not a ' + options.reference + ' reference.';
		}

		// find scheme handler
		const schemeHandler = SCHEMES[(options.scheme || components.scheme || '').toLowerCase()];

		// check if scheme can't handle IRIs
		if (!options.unicodeSupport && (!schemeHandler || !schemeHandler.unicodeSupport)) {
			// if host component is a domain name
			if (components.host && (options.domainHost || (schemeHandler && schemeHandler.domainHost))) {
				// convert Unicode IDN -> ASCII IDN
				try {
					components.host = punycode.toASCII(components.host.replace(protocol.PCT_ENCODED, pctDecChars).toLowerCase());
				} catch (e) {
					components.error = components.error || 'Host\'s domain name can not be converted to ASCII via punycode: ' + e;
				}
			}
			// convert IRI -> URI
			_normalizeComponentEncoding(components, URI_PROTOCOL);
		} else {
			// normalize encodings
			_normalizeComponentEncoding(components, protocol);
		}

		// perform scheme specific parsing
		if (schemeHandler && schemeHandler.parse) {
			schemeHandler.parse(components, options);
		}
	} else {
		components.error = components.error || 'URI can not be parsed.';
	}

	return components;
};

function _recomposeAuthority(components:URIComponents, options:URIOptions):string|undefined {
	const protocol = (options.iri !== false ? IRI_PROTOCOL : URI_PROTOCOL);
	const uriTokens:string[] = [];

	if (components.userinfo !== undefined) {
		uriTokens.push(components.userinfo);
		uriTokens.push('@');
	}

	if (components.host !== undefined) {
		// normalize IP hosts, add brackets and escape zone separator for IPv6
		uriTokens.push(_normalizeIPv6(_normalizeIPv4(String(components.host), protocol), protocol).replace(protocol.IPV6ADDRESS, (_, $1, $2) => '[' + $1 + ($2 ? '%25' + $2 : '') + ']'));
	}

	if (typeof components.port === 'number') {
		uriTokens.push(':');
		uriTokens.push(components.port.toString(10));
	}

	return uriTokens.length ? uriTokens.join('') : undefined;
};

const RDS1 = /^\.\.?\//;
const RDS2 = /^\/\.(\/|$)/;
const RDS3 = /^\/\.\.(\/|$)/;
const RDS4 = /^\.\.?$/;
const RDS5 = /^\/?(?:.|\n)*?(?=\/|$)/;

export function removeDotSegments(input:string):string {
	const output:string[] = [];

	while (input.length) {
		if (input.match(RDS1)) {
			input = input.replace(RDS1, '');
		} else if (input.match(RDS2)) {
			input = input.replace(RDS2, '/');
		} else if (input.match(RDS3)) {
			input = input.replace(RDS3, '/');
			output.pop();
		} else if (input === '.' || input === '..') {
			input = '';
		} else {
			const im = input.match(RDS5);
			if (im) {
				const s = im[0];
				input = input.slice(s.length);
				output.push(s);
			} else {
				throw new Error('Unexpected dot segment condition');
			}
		}
	}

	return output.join('');
};

export function serialize(components:URIComponents, options:URIOptions = {}):string {
	const protocol = (options.iri ? IRI_PROTOCOL : URI_PROTOCOL);
	const uriTokens:string[] = [];

	// find scheme handler
	const schemeHandler = SCHEMES[(options.scheme || components.scheme || '').toLowerCase()];

	// perform scheme specific serialization
	if (schemeHandler && schemeHandler.serialize) { schemeHandler.serialize(components, options); }

	if (components.host) {
		// if host component is an IPv6 address
		if (protocol.IPV6ADDRESS.test(components.host)) {
			// TODO: normalize IPv6 address as per RFC 5952
		}

		// if host component is a domain name
		else if (options.domainHost || (schemeHandler && schemeHandler.domainHost)) {
			// convert IDN via punycode
			try {
				components.host = (!options.iri ? punycode.toASCII(components.host.replace(protocol.PCT_ENCODED, pctDecChars).toLowerCase()) : punycode.toUnicode(components.host));
			} catch (e) {
				components.error = components.error || 'Host\'s domain name can not be converted to ' + (!options.iri ? 'ASCII' : 'Unicode') + ' via punycode: ' + e;
			}
		}
	}

	// normalize encoding
	_normalizeComponentEncoding(components, protocol);

	if (options.reference !== 'suffix' && components.scheme) {
		uriTokens.push(components.scheme);
		uriTokens.push(':');
	}

	const authority = _recomposeAuthority(components, options);
	if (authority !== undefined) {
		if (options.reference !== 'suffix') {
			uriTokens.push('//');
		}

		uriTokens.push(authority);

		if (components.path && components.path.charAt(0) !== '/') {
			uriTokens.push('/');
		}
	}

	if (components.path !== undefined) {
		let s = components.path;

		if (!options.absolutePath && (!schemeHandler || !schemeHandler.absolutePath)) {
			s = removeDotSegments(s);
		}

		if (authority === undefined) {
			s = s.replace(/^\/\//, '/%2F');  // don't allow the path to start with "//"
		}

		uriTokens.push(s);
	}

	if (components.query !== undefined) {
		uriTokens.push('?');
		uriTokens.push(components.query);
	}

	if (components.fragment !== undefined) {
		uriTokens.push('#');
		uriTokens.push(components.fragment);
	}

	return uriTokens.join('');  // merge tokens into a string
};

export function resolveComponents(base:URIComponents, relative:URIComponents, options:URIOptions = {}, skipNormalization?:boolean):URIComponents {
	const target:URIComponents = {};

	if (!skipNormalization) {
		base = parse(serialize(base, options), options);  // normalize base components
		relative = parse(serialize(relative, options), options);  // normalize relative components
	}
	options = options || {};

	if (!options.tolerant && relative.scheme) {
		target.scheme = relative.scheme;
		// target.authority = relative.authority;
		target.userinfo = relative.userinfo;
		target.host = relative.host;
		target.port = relative.port;
		target.path = removeDotSegments(relative.path || '');
		target.query = relative.query;
	} else {
		if (relative.userinfo !== undefined || relative.host !== undefined || relative.port !== undefined) {
			// target.authority = relative.authority;
			target.userinfo = relative.userinfo;
			target.host = relative.host;
			target.port = relative.port;
			target.path = removeDotSegments(relative.path || '');
			target.query = relative.query;
		} else {
			if (!relative.path) {
				target.path = base.path;
				if (relative.query !== undefined) {
					target.query = relative.query;
				} else {
					target.query = base.query;
				}
			} else {
				if (relative.path.charAt(0) === '/') {
					target.path = removeDotSegments(relative.path);
				} else {
					if ((base.userinfo !== undefined || base.host !== undefined || base.port !== undefined) && !base.path) {
						target.path = '/' + relative.path;
					} else if (!base.path) {
						target.path = relative.path;
					} else {
						target.path = base.path.slice(0, base.path.lastIndexOf('/') + 1) + relative.path;
					}
					target.path = removeDotSegments(target.path);
				}
				target.query = relative.query;
			}
			// target.authority = base.authority;
			target.userinfo = base.userinfo;
			target.host = base.host;
			target.port = base.port;
		}
		target.scheme = base.scheme;
	}

	target.fragment = relative.fragment;

	return target;
};

export function resolve(baseURI:string, relativeURI:string, options?:URIOptions):string {
	const schemelessOptions = assign({ scheme : 'null' }, options);
	return serialize(resolveComponents(parse(baseURI, schemelessOptions), parse(relativeURI, schemelessOptions), schemelessOptions, true), schemelessOptions);
};

export function normalize(uri:string, options?:URIOptions):string;
export function normalize(uri:URIComponents, options?:URIOptions):URIComponents;
export function normalize(uri:any, options?:URIOptions):any {
	if (typeof uri === 'string') {
		uri = serialize(parse(uri, options), options);
	} else if (typeOf(uri) === 'object') {
		uri = parse(serialize(uri as URIComponents, options), options);
	}

	return uri;
};

export function equal(uriA:string, uriB:string, options?: URIOptions):boolean;
export function equal(uriA:URIComponents, uriB:URIComponents, options?:URIOptions):boolean;
export function equal(uriA:any, uriB:any, options?:URIOptions):boolean {
	if (typeof uriA === 'string') {
		uriA = serialize(parse(uriA, options), options);
	} else if (typeOf(uriA) === 'object') {
		uriA = serialize(uriA as URIComponents, options);
	}

	if (typeof uriB === 'string') {
		uriB = serialize(parse(uriB, options), options);
	} else if (typeOf(uriB) === 'object') {
		uriB = serialize(uriB as URIComponents, options);
	}

	return uriA === uriB;
};

export function escapeComponent(str:string, options?:URIOptions):string {
	return str && str.toString().replace((!options || !options.iri ? URI_PROTOCOL.ESCAPE : IRI_PROTOCOL.ESCAPE), pctEncChar);
};

export function unescapeComponent(str:string, options?:URIOptions):string {
	return str && str.toString().replace((!options || !options.iri ? URI_PROTOCOL.PCT_ENCODED : IRI_PROTOCOL.PCT_ENCODED), pctDecChars);
};