/**
 * @file llhttpnode.cpp
 * @brief Implementation of classes for generic HTTP/LSL/REST handling.
 *
 * $LicenseInfo:firstyear=2006&license=viewergpl$
 *
 * Copyright (c) 2006-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "boost/tokenizer.hpp"

#include "llhttpnode.h"

#include "llhttpconstants.h"
#include "llstl.h"

/**
 * LLHTTPNode
 */

class LLHTTPNode::Impl
{
public:
	typedef std::map<std::string, LLHTTPNode*> ChildMap;

	ChildMap mNamedChildren;
	LLHTTPNode* mWildcardChild;
	std::string mWildcardName;
	std::string mWildcardKey;
	LLHTTPNode* mParentNode;

	Impl() : mWildcardChild(NULL), mParentNode(NULL) {}

	LLHTTPNode* findNamedChild(const std::string& name) const;
};

LLHTTPNode* LLHTTPNode::Impl::findNamedChild(const std::string& name) const
{
	LLHTTPNode* child = get_ptr_in_map(mNamedChildren, name);

	if (!child && (name[0] == '*' || name == mWildcardName))
	{
		child = mWildcardChild;
	}

	return child;
}

LLHTTPNode::LLHTTPNode()
:	impl(*new Impl)
{
}

// virtual
LLHTTPNode::~LLHTTPNode()
{
	std::for_each(impl.mNamedChildren.begin(), impl.mNamedChildren.end(),
				  DeletePairedPointer());
	impl.mNamedChildren.clear();
	delete impl.mWildcardChild;
	delete &impl;
}

namespace
{
	class NotImplemented
	{
	};
}

// virtual
LLSD LLHTTPNode::simpleGet() const
{
	throw NotImplemented();
}

// virtual
LLSD LLHTTPNode::simplePut(const LLSD& input) const
{
	throw NotImplemented();
}

// virtual
LLSD LLHTTPNode::simplePost(const LLSD& input) const
{
	throw NotImplemented();
}

// virtual
void LLHTTPNode::get(LLHTTPNode::ResponsePtr response,
					 const LLSD& context) const
{
	try
	{
		response->result(simpleGet());
	}
	catch (NotImplemented)
	{
		response->methodNotAllowed();
	}
}

// virtual
void LLHTTPNode::put(LLHTTPNode::ResponsePtr response, const LLSD& context,
					 const LLSD& input) const
{
	try
	{
		response->result(simplePut(input));
	}
	catch (NotImplemented)
	{
		response->methodNotAllowed();
	}
}

// virtual
void LLHTTPNode::post(LLHTTPNode::ResponsePtr response, const LLSD& context,
					  const LLSD& input) const
{
	try
	{
		response->result(simplePost(input));
	}
	catch (NotImplemented)
	{
		response->methodNotAllowed();
	}
}

// virtual
void LLHTTPNode::del(LLHTTPNode::ResponsePtr response,
					 const LLSD& context) const
{
    try
    {
	response->result(simpleDel(context));
    }
    catch (NotImplemented)
    {
	response->methodNotAllowed();
    }
}

// virtual
LLSD LLHTTPNode::simpleDel(const LLSD&) const
{
	throw NotImplemented();
}

// virtual
void LLHTTPNode::options(ResponsePtr response, const LLSD& context) const
{
	LL_DEBUGS("LLHTTPNode") << "context: " << context << LL_ENDL;
	// default implementation constructs an url to the documentation.
	// *TODO: Check for 'Host' header instead of 'host' header?
	std::string host;
	host = context[CONTEXT_REQUEST][CONTEXT_HEADERS][HTTP_IN_HEADER_HOST].asString();
	if (host.empty())
	{
		response->status(HTTP_BAD_REQUEST, "Bad Request -- need Host header");
		return;
	}
	std::ostringstream ostr;
	ostr << "http://" << host << "/web/server/api";
	ostr << context[CONTEXT_REQUEST][CONTEXT_PATH].asString();
	static const std::string DOC_HEADER("X-Documentation-URL");
	response->addHeader(DOC_HEADER, ostr.str());
	response->status(HTTP_OK, "OK");
}

// virtual
LLHTTPNode* LLHTTPNode::getChild(const std::string& name, LLSD& context) const
{
	LLHTTPNode* namedChild = get_ptr_in_map(impl.mNamedChildren, name);
	if (namedChild)
	{
		return namedChild;
	}

	if (impl.mWildcardChild && impl.mWildcardChild->validate(name, context))
	{
		context[CONTEXT_REQUEST][CONTEXT_WILDCARD][impl.mWildcardKey] = name;
		return impl.mWildcardChild;
	}

	return NULL;
}

// virtual
bool LLHTTPNode::handles(const LLSD& remainder, LLSD& context) const
{
	return remainder.size() == 0;
}

// virtual
bool LLHTTPNode::validate(const std::string& name, LLSD& context) const
{
	return false;
}

const LLHTTPNode* LLHTTPNode::traverse(const std::string& path,
									   LLSD& context) const
{
	typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
	boost::char_separator<char> sep("/", "", boost::drop_empty_tokens);
	tokenizer tokens(path, sep);
	tokenizer::iterator iter = tokens.begin();
	tokenizer::iterator end = tokens.end();

	const LLHTTPNode* node = this;
	for ( ; iter != end; ++iter)
	{
		LLHTTPNode* child = node->getChild(*iter, context);
		if (!child)
		{
			LL_DEBUGS("HTTPNode") << "LLHTTPNode::traverse: Couldn't find '"
								  << *iter << "'" << LL_ENDL;
			break;
		}
		LL_DEBUGS("HTTPNode") << "LLHTTPNode::traverse: Found '" << *iter
							  << "'" << LL_ENDL;

		node = child;
	}

	LLSD& remainder = context[CONTEXT_REQUEST]["remainder"];
	for ( ; iter != end; ++iter)
	{
		remainder.append(*iter);
	}

	return node->handles(remainder, context) ? node : NULL;
}

void LLHTTPNode::addNode(const std::string& path, LLHTTPNode* nodeToAdd)
{
	typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
	boost::char_separator<char> sep("/", "", boost::drop_empty_tokens);
	tokenizer tokens(path, sep);
	tokenizer::iterator iter = tokens.begin();
	tokenizer::iterator end = tokens.end();

	LLHTTPNode* node = this;
	for ( ; iter != end; ++iter)
	{
		LLHTTPNode* child = node->impl.findNamedChild(*iter);
		if (!child) break;
		node = child;
	}

	if (iter == end)
	{
		llwarns << "There is already a node handling " << path << llendl;
		return;
	}

	while (true)
	{
		std::string pathPart = *iter++;
		bool lastOne = iter == end;

		LLHTTPNode* nextNode = lastOne ? nodeToAdd : new LLHTTPNode();

		switch (pathPart[0])
		{
			case '<':
			{
				// *NOTE: This should really validate that it is of
				// the proper form: <wildcardkey> so that the substr()
				// generates the correct key name.
				node->impl.mWildcardChild = nextNode;
				node->impl.mWildcardName = pathPart;
				if (node->impl.mWildcardKey.empty())
				{
					node->impl.mWildcardKey = pathPart.substr(1,
															  pathPart.size() - 2);
				}
				break;
			}

			case '*':
			{
				node->impl.mWildcardChild = nextNode;
				if (node->impl.mWildcardName.empty())
				{
					node->impl.mWildcardName = pathPart;
				}
				break;
			}

			default:
			{
				node->impl.mNamedChildren[pathPart] = nextNode;
			}
		}
		nextNode->impl.mParentNode = node;

		if (lastOne) break;
		node = nextNode;
	}
}

static void append_node_paths(LLSD& result, const std::string& name,
							  const LLHTTPNode* node)
{
	result.append(name);

	LLSD paths = node->allNodePaths();
	for (LLSD::array_const_iterator i = paths.beginArray(),
									end = paths.endArray();
		 i != end; ++i)
	{
		result.append(name + "/" + i->asString());
	}
}

LLSD LLHTTPNode::allNodePaths() const
{
	LLSD result;

	Impl::ChildMap::const_iterator i = impl.mNamedChildren.begin();
	Impl::ChildMap::const_iterator end = impl.mNamedChildren.end();
	for ( ; i != end; ++i)
	{
		append_node_paths(result, i->first, i->second);
	}

	if (impl.mWildcardChild)
	{
		append_node_paths(result, impl.mWildcardName, impl.mWildcardChild);
	}

	return result;
}

const LLHTTPNode* LLHTTPNode::rootNode() const
{
	const LLHTTPNode* node = this;

	while (true)
	{
		const LLHTTPNode* next = node->impl.mParentNode;
		if (!next)
		{
			return node;
		}
		node = next;
	}
}

const LLHTTPNode* LLHTTPNode::findNode(const std::string& name) const
{
	return impl.findNamedChild(name);
}

void LLHTTPNode::Response::statusUnknownError(S32 code)
{
	status(code, "Unknown Error");
}

void LLHTTPNode::Response::notFound(const std::string& message)
{
	status(HTTP_NOT_FOUND, message);
}

void LLHTTPNode::Response::notFound()
{
	status(HTTP_NOT_FOUND, "Not Found");
}

void LLHTTPNode::Response::methodNotAllowed()
{
	status(HTTP_METHOD_NOT_ALLOWED, "Method Not Allowed");
}

void LLHTTPNode::Response::addHeader(const std::string& name,
									 const std::string& value)
{
	mHeaders[name] = value;
}

void LLHTTPNode::describe(Description& desc) const
{
	desc.shortInfo("unknown service (missing describe() method)");
}

const LLChainIOFactory* LLHTTPNode::getProtocolHandler() const
{
	return NULL;
}

namespace
{
    typedef std::map<std::string, LLHTTPRegistrar::NodeFactory*>  FactoryMap;

    FactoryMap& factoryMap()
    {
        static FactoryMap theMap;
        return theMap;
    }
}

void LLHTTPRegistrar::registerFactory(const std::string& path,
									  NodeFactory& factory)
{
	factoryMap()[path] = &factory;
}

void LLHTTPRegistrar::buildAllServices(LLHTTPNode& root)
{
    const FactoryMap& map = factoryMap();
    for (FactoryMap::const_iterator i = map.begin(), end = map.end();
		 i != end; ++i)
    {
		LL_DEBUGS("AppInit") << "Adding node for path " << i->first << LL_ENDL;
        root.addNode(i->first, i->second->build());
    }
}

LLPointer<LLSimpleResponse> LLSimpleResponse::create()
{
	return new LLSimpleResponse();
}

void LLSimpleResponse::result(const LLSD& result)
{
	status(HTTP_OK, "OK");
}

void LLSimpleResponse::extendedResult(S32 code, const std::string& body,
									  const LLSD& headers)
{
	status(code, body);
}

void LLSimpleResponse::extendedResult(S32 code, const LLSD& r,
									  const LLSD& headers)
{
	status(code, "(LLSD)");
}

void LLSimpleResponse::status(S32 code, const std::string& message)
{
	mCode = code;
	mMessage = message;
}

void LLSimpleResponse::print(std::ostream& out) const
{
	out << mCode << " " << mMessage;
}

std::ostream& operator<<(std::ostream& out, const LLSimpleResponse& resp)
{
	resp.print(out);
	return out;
}