/*
 * This source file is part of RmlUi, the HTML/CSS Interface Middleware
 *
 * For the latest information, see http://github.com/mikke89/RmlUi
 *
 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
 * Copyright (c) 2019 The RmlUi Team, and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

#include "../../Include/RmlUi/Core/Log.h"
#include "../../Include/RmlUi/Core/StringUtilities.h"
#include "../../Include/RmlUi/Core/URL.h"
#include <string.h>

namespace Rml {

const char* DEFAULT_PROTOCOL = "file";

// Constructs an Empty URL.
URL::URL()
{
	port = 0;
	url_dirty = false;
}

// Constructs a new URL from the given string.
URL::URL(const String& _url)
{
	port = 0;
	RMLUI_VERIFY(SetURL(_url));
}

// Constructs a new URL from the given string.
URL::URL(const char* _url)
{
	port = 0;
	RMLUI_VERIFY(SetURL(_url));
}

// Destroys the URL.
URL::~URL()
{
}

// Assigns a new URL to the object.
bool URL::SetURL(const String& _url)
{
	url_dirty = false;
	url = _url;

	// Make sure an Empty URL is completely Empty.
	if (url.empty())
	{
		protocol.clear();
		login.clear();
		password.clear();
		host.clear();
		port = 0;
		path.clear();
		file_name.clear();
		extension.clear();

		return true;
	}

	// Find the protocol. This consists of the string appearing before the
	// '://' token (ie, file://, http://).
	const char* host_begin = strchr(_url.c_str(), ':');
	if (nullptr != host_begin)
	{
		protocol = String(_url.c_str(), host_begin);
		if (0 != strncmp(host_begin, "://", 3))
		{
			char malformed_terminator[4] = {0, 0, 0, 0};
			strncpy(malformed_terminator, host_begin, 3);
			Log::Message(Log::LT_ERROR, "Malformed protocol identifier found in URL %s; expected %s://, found %s%s.\n", _url.c_str(), protocol.c_str(), protocol.c_str(), malformed_terminator);

			return false;
		}
		host_begin += 3;
	}
	else
	{
		protocol = DEFAULT_PROTOCOL;
		host_begin = _url.c_str();
	}


	// We only want to look for a host if a protocol was specified.
	const char* path_begin;
	if (host_begin != _url.c_str())
	{
		// Find the host. This is the string appearing after the protocol or after
		// the username:password combination, and terminated either with a colon, 
		// if a port is specified, or a forward slash if there is no port.

		// Check for a login pair
		const char* at_symbol = strchr( host_begin, '@' );
		if ( at_symbol )
		{
			String login_password;
			login_password = String( host_begin, at_symbol );			
			host_begin = at_symbol + 1;

			const char* password_ptr = strchr( login_password.c_str(), ':' );
			if ( password_ptr )
			{
				login = String( login_password.c_str(), password_ptr );
				password = String( password_ptr + 1 );
			}
			else
			{
				login = login_password;
			}
		}

		// Get the host portion
		path_begin = strchr(host_begin, '/');
		// Search for the colon in the host name, which will indicate a port.
		const char* port_begin = strchr(host_begin, ':');
		if (nullptr != port_begin && (nullptr == path_begin || port_begin < path_begin))
		{
			if (1 != sscanf(port_begin, ":%d", &port))
			{
				Log::Message(Log::LT_ERROR, "Malformed port number found in URL %s.\n", _url.c_str());
				return false;
			}

			host = String(host_begin, port_begin);

			// Don't continue if there is no path.
			if (nullptr == path_begin)
			{
				return true;
			}

			// Increment the path string past the trailing slash.
			++path_begin;
		}
		else
		{
			port = -1;

			if (nullptr == path_begin)
			{
				host = host_begin;
				return true;
			}
			else
			{
				// Assign the host name, then increment the path string past the
				// trailing slash.
				host = String(host_begin, path_begin);
				++path_begin;
			}
		}
	}
	else
	{
		path_begin = _url.c_str();
	}
	
	// Check for parameters
	String path_segment;
	const char* parameters = strchr(path_begin, '?');
	if ( parameters )
	{
		// Pull the path segment out, so further processing doesn't read the parameters
		path_segment = String(path_begin, parameters);
		path_begin = path_segment.c_str();
		
		// Loop through all parameters, loading them
		StringList parameter_list;
		StringUtilities::ExpandString( parameter_list, parameters + 1, '&' );
		for ( size_t i = 0; i < parameter_list.size(); i++ )
		{
			// Split into key and value
			StringList key_value;
			StringUtilities::ExpandString( key_value, parameter_list[i], '=' );

			key_value[0] = UrlDecode(key_value[0]);
			if ( key_value.size() == 2 )
				this->parameters[key_value[0]] = UrlDecode(key_value[1]);
			else
				this->parameters[key_value[0]] = "";
		}
	}


	// Find the path. This is the string appearing after the host, terminated
	// by the last forward slash.
	const char* file_name_begin = strrchr(path_begin, '/');
	if (nullptr == file_name_begin)
	{
		// No path!
		file_name_begin = path_begin;
		path = "";
	}
	else
	{
		// Copy the path including the trailing slash.
		path = String(path_begin, ++file_name_begin);

		// Normalise the path, stripping any ../'s from it
		size_t parent_dir_pos = String::npos;
		while ((parent_dir_pos = path.find("/../")) != String::npos && parent_dir_pos != 0)
		{
			// Find the start of the parent directory.
			size_t parent_dir_start_pos = path.rfind('/', parent_dir_pos - 1);
			if (parent_dir_start_pos == String::npos)
				parent_dir_start_pos = 0;
			else
				parent_dir_start_pos += 1;

			// Strip out the parent dir and the /..
			path.erase(parent_dir_start_pos, parent_dir_pos - parent_dir_start_pos + 4);

			// We've altered the URL, mark it dirty
			url_dirty = true;
		}
	}


	// Find the file name. This is the string after the trailing slash of the
	// path, and just before the extension.
	const char* extension_begin = strrchr(file_name_begin, '.');
	if (nullptr == extension_begin)
	{
		file_name = file_name_begin;
		extension = "";
	}
	else
	{
		file_name = String(file_name_begin, extension_begin);
		extension = extension_begin + 1;
	}
	
	return true;
}

// Returns the entire URL.
const String& URL::GetURL() const
{
	if (url_dirty)
		ConstructURL();
	
	return url;
}

// Sets the URL's protocol.
bool URL::SetProtocol(const String& _protocol)
{
	protocol = _protocol;
	url_dirty = true;

	return true;
}

// Returns the protocol this URL is utilising.
const String& URL::GetProtocol() const
{
	return protocol;
}

/// Sets the URL's login
bool URL::SetLogin( const String& _login )
{
	login = _login;
	url_dirty = true;
	return true;
}

/// Returns the URL's login
const String& URL::GetLogin() const
{
	return login;
}

/// Sets the URL's password
bool URL::SetPassword(const String& _password)
{
	password = _password;
	url_dirty = true;
	return true;
}

/// Returns the URL's password
const String& URL::GetPassword() const
{
	return password;
}

// Sets the URL's host.
bool URL::SetHost(const String& _host)
{
	host = _host;
	url_dirty = true;

	return true;
}

// Returns the URL's host.
const String& URL::GetHost() const
{
	return host;
}

// Sets the URL's port number.
bool URL::SetPort(int _port)
{
	port = _port;
	url_dirty = true;

	return true;
}

// Returns the URL's port number.
int URL::GetPort() const
{
	return port;
}

// Sets the URL's path.
bool URL::SetPath(const String& _path)
{
	path = _path;
	url_dirty = true;

	return true;
}

// Prefixes the URL's existing path with the given prefix.
bool URL::PrefixPath(const String& prefix)
{
	// If there's no trailing slash on the end of the prefix, add one.
	if (!prefix.empty() &&
		prefix[prefix.size() - 1] != '/')
		path = prefix + "/" + path;
	else
		path = prefix + path;

	url_dirty = true;

	return true;
}

// Returns the URL's path.
const String& URL::GetPath() const
{
	return path;
}

// Sets the URL's file name.
bool URL::SetFileName(const String& _file_name)
{
	file_name = _file_name;
	url_dirty = true;

	return true;
}

// Returns the URL's file name.
const String& URL::GetFileName() const
{
	return file_name;
}

// Sets the URL's file extension.
bool URL::SetExtension(const String& _extension)
{
	extension = _extension;
	url_dirty = true;

	return true;
}

// Returns the URL's file extension.
const String& URL::GetExtension() const
{
	return extension;
}

// Gets the current parameters
const URL::Parameters& URL::GetParameters() const
{
	return parameters;
}

// Set an individual parameter
void URL::SetParameter(const String& key, const String& value)
{
	parameters[key] = value;
	url_dirty = true;
}

// Set all parameters
void URL::SetParameters(const Parameters& _parameters)
{
	parameters = _parameters;
	url_dirty = true;
}

// Clear the parameters
void URL::ClearParameters()
{
	parameters.clear();
}

// Returns the URL's path, file name and extension.
String URL::GetPathedFileName() const
{
	String pathed_file_name = path;
	
	// Append the file name.
	pathed_file_name += file_name;
	
	// Append the extension.
	if (!extension.empty())
	{
		pathed_file_name += ".";
		pathed_file_name += extension;
	}
	
	return pathed_file_name;
}

String URL::GetQueryString() const
{
	String query_string;
	
	int count = 0;
	for ( Parameters::const_iterator itr = parameters.begin(); itr != parameters.end(); ++itr )
	{
		query_string += ( count == 0 ) ? "" : "&";
		
		query_string += UrlEncode((*itr).first);
		query_string += "=";
		query_string += UrlEncode((*itr).second);
		
		count++;
	}
	
	return query_string;
}

// Less-than operator for use as a key in STL containers.
bool URL::operator<(const URL& rhs) const
{
	if (url_dirty)
		ConstructURL();
	if (rhs.url_dirty)
		rhs.ConstructURL();
	
	return url < rhs.url;
}

void URL::ConstructURL() const
{
	url = "";

	// Append the protocol.
	if (!protocol.empty() && !host.empty())	
	{
		url = protocol;
		url += "://";
	}

	// Append login and password
	if (!login.empty())
	{
		url +=  login ;
		if (!password.empty())
		{		
			url +=  ":" ;
			url +=  password ;
		}
		url +=  "@" ;
	}
	RMLUI_ASSERTMSG( password.empty() || ( !password.empty() && !login.empty() ), "Can't have a password without a login!" );

	// Append the host.
	url += host;
	
	// Only check ports if there is some host/protocol part
	if ( !url.empty() )
	{		
		if (port > 0)
		{
			RMLUI_ASSERTMSG( !host.empty(), "Can't have a port without a host!" );
			char port_string[16];
			sprintf(port_string, ":%d/", port);
			url += port_string;
		}
		else
		{
			url += "/";
		}
	}

	// Append the path.
	if (!path.empty())
	{
		url += path;
	}

	// Append the file name.
	url += file_name;

	// Append the extension.
	if (!extension.empty())
	{
		url += ".";
		url += extension;
	}
	
	// Append parameters
	if (!parameters.empty())
	{
		url += "?";
		url += GetQueryString();		
	}
	
	url_dirty = false;
}

String URL::UrlEncode(const String &value)
{
	String encoded;
	char hex[4] = {0,0,0,0};

	encoded.clear();

	const char *value_c = value.c_str();
	for (String::size_type i = 0; value_c[i]; i++) 
	{
		char c = value_c[i];
		if (IsUnreservedChar(c))
			encoded += c;
		else
		{
			sprintf(hex, "%%%02X", c);
			encoded += hex;
		}
	}

	return encoded;
}

String URL::UrlDecode(const String &value)
{
	String decoded;

	decoded.clear();

	const char *value_c = value.c_str();
	String::size_type value_len = value.size();
	for (String::size_type i = 0; i < value_len; i++) 
	{
		char c = value_c[i];
		if (c == '+')
		{
			decoded += ' ';
		}
		else if (c == '%')
		{
			char *endp;
			String t = value.substr(i+1, 2);
			int ch = strtol(t.c_str(), &endp, 16);
			if (*endp == '\0')
				decoded += char(ch);
			else
				decoded += t;
			i += 2;
		}
		else
		{
			decoded += c;
		}
	}

	return decoded;
}

bool URL::IsUnreservedChar(const char in)
{
	switch (in)
	{
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
		case 'a': case 'b': case 'c': case 'd': case 'e':
		case 'f': case 'g': case 'h': case 'i': case 'j':
		case 'k': case 'l': case 'm': case 'n': case 'o':
		case 'p': case 'q': case 'r': case 's': case 't':
		case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
		case 'A': case 'B': case 'C': case 'D': case 'E':
		case 'F': case 'G': case 'H': case 'I': case 'J':
		case 'K': case 'L': case 'M': case 'N': case 'O':
		case 'P': case 'Q': case 'R': case 'S': case 'T':
		case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
		case '-': case '.': case '_': case '~':
			return true;
		default:
			break;
	}
	return false;
}

} // namespace Rml