/*
 * Copyright 2010 Haiku Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		Christophe Huriaux, c.huriaux@gmail.com
 */


#include <ctype.h>
#include <cstdio>
#include <cstdlib>
#include <new>

#include <Url.h>

static const char* kArchivedUrl = "be:url string";


BUrl::BUrl(const char* url)
	: 
	fUrlString(),
	fProtocol(),
	fUser(),
	fPassword(),
	fHost(),
	fPort(0),
	fPath(),
	fRequest(),
	fHasAuthority(false)
{
	SetUrlString(url);
}


BUrl::BUrl(BMessage* archive)
	: 
	fUrlString(),
	fProtocol(),
	fUser(),
	fPassword(),
	fHost(),
	fPort(0),
	fPath(),
	fRequest(),
	fHasAuthority(false)
{
	BString url;

	if (archive->FindString(kArchivedUrl, &url) == B_OK)
		SetUrlString(url);
}


BUrl::BUrl(const BUrl& other)
	: 
	BArchivable(),
	fUrlString(),
	fProtocol(),
	fUser(),
	fPassword(),
	fHost(),
	fPort(0),
	fPath(),
	fRequest(),
	fHasAuthority(false)
{
	*this = other;
}


BUrl::BUrl()
	: 
	fUrlString(),
	fProtocol(),
	fUser(),
	fPassword(),
	fHost(),
	fPort(0),
	fPath(),
	fRequest(),
	fHasAuthority(false)
{
}


BUrl::~BUrl()
{
}


// #pragma mark URL fields modifiers


BUrl&
BUrl::SetUrlString(const BString& url)
{
	_ExplodeUrlString(url);
	return *this;
}


BUrl&
BUrl::SetProtocol(const BString& protocol)
{
	fProtocol = protocol;
	fHasProtocol = true;
	fUrlStringValid = false;
	return *this;
}


BUrl&
BUrl::SetUserName(const BString& user)
{
	fUser = user;
	fHasUserName = true;
	fUrlStringValid = false;
	fAuthorityValid = false;
	fUserInfoValid = false;
	return *this;
}


BUrl&
BUrl::SetPassword(const BString& password)
{
	fPassword = password;
	fHasPassword = true;
	fUrlStringValid = false;
	fAuthorityValid = false;
	fUserInfoValid = false;
	return *this;
}


BUrl&
BUrl::SetHost(const BString& host)
{
	fHost = host;
	fHasHost = true;
	fUrlStringValid = false;
	fAuthorityValid = false;
	return *this;
}


BUrl&
BUrl::SetPort(int port)
{
	fPort = port;
	fHasPort = true;
	fUrlStringValid = false;
	fAuthorityValid = false;
	return *this;
}


BUrl&
BUrl::SetPath(const BString& path)
{
	fPath = path;
	fHasPath = true;
	fUrlStringValid = false;
	return *this;
}


BUrl&
BUrl::SetRequest(const BString& request)
{
	fRequest = request;
	fHasRequest = true;
	fUrlStringValid = false;
	return *this;
}


BUrl&
BUrl::SetFragment(const BString& fragment)
{
	fFragment = fragment;
	fHasFragment = true;
	fUrlStringValid = false;
	return *this;
}


// #pragma mark URL fields access


const BString&
BUrl::UrlString() const
{
	if (!fUrlStringValid) {
		fUrlString.Truncate(0);

		if (HasProtocol()) {
			fUrlString << fProtocol << ':';
			if (HasAuthority())
				fUrlString << "//";
		}

		fUrlString << Authority();
		fUrlString << Path();

		if (HasRequest())
			fUrlString << '?' << fRequest;

		if (HasFragment())
			fUrlString << '#' << fFragment;

		fUrlStringValid = true;
	}

	return fUrlString;
}


const BString&
BUrl::Protocol() const
{
	return fProtocol;
}


const BString&
BUrl::UserName() const
{
	return fUser;
}


const BString&
BUrl::Password() const
{
	return fPassword;
}


const BString&
BUrl::UserInfo() const
{
	if (!fUserInfoValid) {
		fUserInfo = fUser;

		if (HasPassword())
			fUserInfo << ':' << fPassword;

		fUserInfoValid = true;
	}

	return fUserInfo;
}


const BString&
BUrl::Host() const
{
	return fHost;
}


int
BUrl::Port() const
{
	return fPort;
}


const BString&
BUrl::Authority() const
{
	if (!fAuthorityValid) {
		fAuthority.Truncate(0);

		if (HasUserInfo())
			fAuthority << UserInfo() << '@';
		fAuthority << Host();

		if (HasPort())
			fAuthority << ':' << fPort;
			
		fAuthorityValid = true;
	}
	return fAuthority;
}


const BString&
BUrl::Path() const
{
	return fPath;
}


const BString&
BUrl::Request() const
{
	return fRequest;
}


const BString&
BUrl::Fragment() const
{
	return fFragment;
}


// #pragma mark URL fields tests


bool
BUrl::IsValid() const
{
	// TODO
	return false;
}


bool
BUrl::HasProtocol() const
{
	return fHasProtocol;
}


bool
BUrl::HasAuthority() const
{
	return fHasAuthority;
}


bool
BUrl::HasUserName() const
{
	return fHasUserName;
}


bool
BUrl::HasPassword() const
{
	return fHasPassword;
}


bool
BUrl::HasUserInfo() const
{
	return fHasUserInfo;
}


bool
BUrl::HasHost() const
{
	return fHasHost;
}


bool
BUrl::HasPort() const
{
	return fHasPort;
}


bool
BUrl::HasPath() const
{
	return fHasPath;
}


bool
BUrl::HasRequest() const
{
	return fHasRequest;
}


bool
BUrl::HasFragment() const
{
	return fHasFragment;
}


// #pragma mark URL encoding/decoding of needed fields


void
BUrl::UrlEncode(bool strict)
{
	fUser = _DoUrlEncodeChunk(fUser, strict);
	fPassword = _DoUrlEncodeChunk(fPassword, strict);
	fHost = _DoUrlEncodeChunk(fHost, strict);
	fFragment = _DoUrlEncodeChunk(fFragment, strict);
	fPath = _DoUrlEncodeChunk(fPath, strict, true);
}


void
BUrl::UrlDecode(bool strict)
{
	fUser = _DoUrlDecodeChunk(fUser, strict);
	fPassword = _DoUrlDecodeChunk(fPassword, strict);
	fHost = _DoUrlDecodeChunk(fHost, strict);
	fFragment = _DoUrlDecodeChunk(fFragment, strict);
	fPath = _DoUrlDecodeChunk(fPath, strict);
}


// #pragma mark Url encoding/decoding of string


/*static*/ BString
BUrl::UrlEncode(const BString& url, bool strict, bool directory)
{
	return _DoUrlEncodeChunk(url, strict, directory);
}


/*static*/ BString
BUrl::UrlDecode(const BString& url, bool strict)
{
	return _DoUrlDecodeChunk(url, strict);
}


// #pragma mark BArchivable members


status_t
BUrl::Archive(BMessage* into, bool deep) const
{
	status_t ret = BArchivable::Archive(into, deep);

	if (ret == B_OK)
		ret = into->AddString(kArchivedUrl, UrlString());
	
	return ret;
}


/*static*/ BArchivable*
BUrl::Instantiate(BMessage* archive)
{
	if (validate_instantiation(archive, "BUrl"))
		return new(std::nothrow) BUrl(archive);
	return NULL;
}


// #pragma mark URL comparison


bool
BUrl::operator==(BUrl& other) const
{
	UrlString();
	other.UrlString();
	
	return fUrlString == other.fUrlString;
}


bool
BUrl::operator!=(BUrl& other) const
{
	return !(*this == other);
}


// #pragma mark URL assignment


const BUrl&
BUrl::operator=(const BUrl& other)
{
	fUrlStringValid		= other.fUrlStringValid;
	if (fUrlStringValid)
		fUrlString			= other.fUrlString;
	
	fAuthorityValid		= other.fAuthorityValid;
	if (fAuthorityValid)
		fAuthority			= other.fAuthority;
	
	fUserInfoValid		= other.fUserInfoValid;
	if (fUserInfoValid)
		fUserInfo			= other.fUserInfo;
	
	fProtocol			= other.fProtocol;
	fUser				= other.fUser;
	fPassword			= other.fPassword;
	fHost				= other.fHost;
	fPort				= other.fPort;
	fPath				= other.fPath;
	fRequest			= other.fRequest;
	fFragment			= other.fFragment;
	
	fHasProtocol		= other.fHasProtocol;
	fHasUserName		= other.fHasUserName;
	fHasPassword		= other.fHasPassword;
	fHasUserInfo		= other.fHasUserInfo;
	fHasHost			= other.fHasHost;
	fHasPort			= other.fHasPort;
	fHasAuthority		= other.fHasAuthority;
	fHasPath			= other.fHasPath;
	fHasRequest			= other.fHasRequest;
	fHasFragment		= other.fHasFragment;
	
	return *this;
}


const BUrl&
BUrl::operator=(const BString& string)
{
	SetUrlString(string);
	return *this;
}


const BUrl&
BUrl::operator=(const char* string)
{
	SetUrlString(string);
	return *this;
}


// #pragma mark URL to string conversion


BUrl::operator const char*() const
{
	return UrlString();
}


void
BUrl::_ResetFields()
{
	fHasProtocol = false;
	fHasUserName = false;
	fHasPassword = false;
	fHasUserInfo = false;
	fHasHost = false;
	fHasPort = false;
	fHasAuthority = false;
	fHasPath = false;
	fHasRequest = false;
	fHasFragment = false;

	fProtocol.Truncate(0);
	fUser.Truncate(0);
	fPassword.Truncate(0);
	fHost.Truncate(0);
	fPort = 0;
	fPath.Truncate(0);
	fRequest.Truncate(0);
	fFragment.Truncate(0);

	// Force re-generation of these fields
	fUrlStringValid = false;
	fUserInfoValid = false;
	fAuthorityValid = false;
}


void
BUrl::_ExplodeUrlString(const BString& url)
{
	int16 urlIndex = 0;

	_ResetFields();

	_ExtractProtocol(url, &urlIndex);
	_ExtractAuthority(url, &urlIndex);
	_ExtractPath(url, &urlIndex);
	_ExtractRequestAndFragment(url, &urlIndex);
}


void
BUrl::_ExtractProtocol(const BString& urlString, int16* origin)
{
	int16 firstColon = urlString.FindFirst(':', *origin);

	// If no colon is found, assume the protocol
	// is not present
	if (firstColon == -1) 
		return;
	else {
		urlString.CopyInto(fProtocol, *origin, firstColon - *origin);
		*origin = firstColon + 1;
	}

	if (!_IsProtocolValid()) {
		fHasProtocol = false;
		fProtocol.Truncate(0);
	} else
		fHasProtocol = true;
}


void
BUrl::_ExtractAuthority(const BString& urlString, int16* origin)
{
	// URI doesn't contain an authority field
	if (urlString.FindFirst("//", *origin) != *origin)
		return;

	fHasAuthority = true;

//	while (urlString.ByteAt(*origin) == '/')
//		(*origin)++;

	(*origin) += 2;


	int16 userInfoEnd = urlString.FindFirst('@', *origin);

	// URL contains userinfo field
	if (userInfoEnd != -1) {
		BString userInfo;
		urlString.CopyInto(userInfo, *origin, userInfoEnd - *origin);

		int16 colonDelimiter = userInfo.FindFirst(':', 0);

		if (colonDelimiter == *origin) {
			fHasPassword = true;
			fPassword = userInfo;
		} else if (colonDelimiter != -1) {
			fHasUserName = true;
			fHasPassword = true;

			userInfo.CopyInto(fUser, 0, colonDelimiter);
			userInfo.CopyInto(fPassword, colonDelimiter + 1,
				userInfo.Length() - colonDelimiter);
		} else {
			fHasUserName = true;
			fUser = userInfo;
		}

		fHasUserInfo = true;
		*origin = userInfoEnd + 1;
	}


	// Extract the host part
	int16 hostEnd = *origin;

	while (hostEnd < urlString.Length()
		&& !_IsAuthorityTerminator(urlString.ByteAt(hostEnd))
		&& urlString.ByteAt(hostEnd) != ':') {
		hostEnd++;
	}

	// The host is likely to be present if an authority is
	// defined, but in some weird cases, it's not.
	if (hostEnd != *origin) {
		urlString.CopyInto(fHost, *origin, hostEnd - *origin);

		*origin = hostEnd;
		fHasHost = true;
	}

	// Extract the port part
	fPort = 0;
	if (urlString.ByteAt(*origin) == ':') {
		int16 portEnd = ++(*origin);

		while (portEnd < urlString.Length()
			&& !_IsAuthorityTerminator(urlString.ByteAt(portEnd)))
			portEnd++;

		BString portString;
		urlString.CopyInto(portString, *origin, portEnd - *origin);
		fPort = atoi(portString.String());

		//  Even if the port is invalid, the URL is considered to
		// have a port.
		fHasPort = portString.Length() > 0;
		*origin = portEnd;
	}
}


void
BUrl::_ExtractPath(const BString& urlString, int16* origin)
{
	// Extract path from URL
	if (urlString.ByteAt(*origin) == '/' || !HasAuthority()) {
		int16 pathEnd = *origin;

		while (pathEnd < urlString.Length()
				&& !_IsPathTerminator(urlString.ByteAt(pathEnd))) {
				pathEnd++;
		}

		urlString.CopyInto(fPath, *origin, pathEnd - *origin);

		*origin = pathEnd;
		fHasPath = true;
	}
}


void
BUrl::_ExtractRequestAndFragment(const BString& urlString, int16* origin)
{
	// Extract request field from URL
	if (urlString.ByteAt(*origin) == '?') {
		(*origin)++;
		int16 requestEnd = urlString.FindFirst('#', *origin);

		fHasRequest = true;

		if (requestEnd == -1) {
			urlString.CopyInto(fRequest, *origin, urlString.Length() - *origin);
			return;
		} else {
			urlString.CopyInto(fRequest, *origin, requestEnd - *origin);
			*origin = requestEnd;
		}
	}

	// Extract fragment field if needed
	if (urlString.ByteAt(*origin) == '#') {
		(*origin)++;
		urlString.CopyInto(fFragment, *origin, urlString.Length() - *origin);

		fHasFragment = true;
	}
}


/*static*/ BString
BUrl::_DoUrlEncodeChunk(const BString& chunk, bool strict, bool directory)
{
	BString result;
	
	for (int32 i = 0; i < chunk.Length(); i++) {
		if (_IsUnreserved(chunk[i])
			|| (directory && (chunk[i] == '/' || chunk[i] == '\\')))
			result << chunk[i];
		else {
			if (chunk[i] == ' ' && !strict) {
				result << '+';
					// In non-strict mode, spaces are encoded by a plus sign
			} else {
				char hexString[5];
				snprintf(hexString, 5, "%X", chunk[i]);
				
				result << '%' << hexString;
			}
		}
	}
	
	return result;
}


/*static*/ BString
BUrl::_DoUrlDecodeChunk(const BString& chunk, bool strict)
{
	BString result;
	
	for (int32 i = 0; i < chunk.Length(); i++) {
		if (chunk[i] == '+' && !strict)
			result << ' ';
		else if (chunk[i] != '%')
			result << chunk[i];
		else {
			char hexString[] = { chunk[i+1], chunk[i+2], 0 };
			result << (char)strtol(hexString, NULL, 16);
			
			i += 2;
		}
	}
	return result;
}


bool
BUrl::_IsProtocolValid()
{
	for (int8 index = 0; index < fProtocol.Length(); index++) {
		char c = fProtocol[index];

		if (index == 0 && !isalpha(c))
			return false;
		else if (!isalnum(c) && c != '+' && c != '-' && c != '.')
			return false;
	}

	return true;
}


bool
BUrl::_IsAuthorityTerminator(char c)
{
	if (c == '/' || _IsPathTerminator(c))
		return true;
	else
		return false;
}


bool
BUrl::_IsPathTerminator(char c)
{
	if (c == '?' || _IsRequestTerminator(c))
		return true;
	else
		return false;
}


bool
BUrl::_IsRequestTerminator(char c)
{
	if (c == '#')
		return true;
	else
		return false;
}


bool
BUrl::_IsUnreserved(char c)
{
	if (isalnum(c) || c == '-' || c == '.' || c == '_' || c == '~')
		return true;
	else
		return false;
}


bool
BUrl::_IsGenDelim(char c)
{
	if (c == ':' || c == '/' || c == '?' || c == '#' || c == '[' 
		|| c == ']' || c == '@')
		return true;
	else
		return false;
}


bool
BUrl::_IsSubDelim(char c)
{
	if (c == '!' || c == '$' || c == '&' || c == '\'' || c == '(' 
		|| c == ')' || c == '*' || c == '+' || c == ',' || c == ';'
		|| c == '=')
		return true;
	else
		return false;
}