urlbuffer.cpp

/* Copyright (C) 2011 uberspot
*
* Compiling: znc-buildmod urlbuffer.cpp 
* Dependencies: curl, wget, sed and a unix environment.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 as published
* by the Free Software Foundation (https://www.gnu.org/licenses/gpl-3.0.txt).
*/ 

#include <znc/Client.h>
#include <znc/Chan.h>
#include <znc/User.h>
#include <znc/Modules.h>
#include <znc/FileUtils.h>
#include <znc/IRCNetwork.h>
#include <climits>
#include <fstream>

#define MAX_EXTS 8
#define MAX_CHARS 16

class CUrlBufferModule : public CModule 
{
private:
    /* Vectors containing the last urls posted + the nicknames of the users posting them. */
	VCString lastUrls, nicks;
	
    /* Supported file extensions in links that should be downloaded. */
	static const CString supportedExts[MAX_EXTS];
	
    /* Unsupported characters that should be ignored when found in strings describing file directories. */
    static const char unSupportedChars[MAX_CHARS];

    /* Executes the given command in a unix pipeline and returns the result. */
	static inline CString getStdoutFromCommand(const CString& cmd);
	
    /* Load the default options if no other were found. */
    inline void LoadDefaults();
	
	inline bool isValidExtension(CString ext)
	{
		ext.MakeLower();
		for(int i=0; i< MAX_EXTS; i++)
		{
			if( ext == supportedExts[i])
				return true;
		}
		return false;
	}

	inline bool isValidDir(const CString& dir)
	{
		for(int i=0; i< MAX_CHARS; i++)
		{
			if (dir.find(unSupportedChars[i]) !=CString::npos)
				return false;
		}
		return true;
	}
	
	inline void CheckLineForLink(const CString& sMessage, const CString& sOrigin);
	inline void CheckLineForTrigger(const CString& sMessage, const CString& sTarget); 
public:
	MODCONSTRUCTOR(CUrlBufferModule) {}

	bool OnLoad(const CString& sArgs, CString& sErrorMsg);
	virtual ~CUrlBufferModule(); 
	EModRet OnUserMsg(CString& sTarget, CString& sMessage);
	EModRet OnPrivMsg(CNick& Nick, CString& sMessage);
	EModRet OnChanMsg(CNick& Nick, CChan& Channel, CString& sMessage);
	void OnModCommand(const CString& sCommand);
	
};

const CString CUrlBufferModule::supportedExts[MAX_EXTS] = 
				{"jpg", "png", "gif", "jpeg", "bmp", "tiff", "webm", "gifv"} ;

const char CUrlBufferModule::unSupportedChars[MAX_CHARS] = 
				{'|', ';', '!', '@', '#', '(', ')', '<', '>', '"',  '\'', '`', '~', '=', '&', '^'};

bool CUrlBufferModule::OnLoad(const CString& sArgs, CString& sErrorMsg) 
{
	LoadDefaults();
	return true;
}

CUrlBufferModule::~CUrlBufferModule() {}

CUrlBufferModule::EModRet CUrlBufferModule::OnUserMsg(CString& sTarget, CString& sMessage) 
{
	CheckLineForLink(sMessage, "");
	CheckLineForTrigger(sMessage, m_pUser->GetUserName() );
	return CONTINUE;
}

CUrlBufferModule::EModRet CUrlBufferModule::OnPrivMsg(CNick& Nick, CString& sMessage) 
{ 
	CheckLineForLink(sMessage, Nick.GetNick());
	CheckLineForTrigger(sMessage, Nick.GetNick());
	return CONTINUE;
}

CUrlBufferModule::EModRet CUrlBufferModule::OnChanMsg(CNick& Nick, CChan& Channel, CString& sMessage) 
{
	CheckLineForLink(sMessage, Nick.GetNick());
	CheckLineForTrigger(sMessage, Nick.GetNick());
	return CONTINUE;
}

void CUrlBufferModule::OnModCommand(const CString& sCommand) 
{
	CString command = sCommand.Token(0).AsLower().Trim_n();
	
	if (command == "help") 
	{
		CTable CmdTable;

		CmdTable.AddColumn("Command");
		CmdTable.AddColumn("Description");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "ENABLE");
		CmdTable.SetCell("Description", "Activates link buffering.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "DISABLE");
		CmdTable.SetCell("Description", "Deactivates link buffering.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "ENABLELOCAL");
		CmdTable.SetCell("Description", "Enables downloading of each link to local directory.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "DISABLELOCAL");
		CmdTable.SetCell("Description", "Disables downloading of each link to local directory.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command","ENABLEPUBLIC");
		CmdTable.SetCell("Description", "Enables the usage of !showlinks publicly, by other users.");

		CmdTable.AddRow();
        CmdTable.SetCell("Command","DISABLEPUBLIC");
        CmdTable.SetCell("Description", "Disables the usage of !showlinks publicly, by other users.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "DIRECTORY <#directory>");
		CmdTable.SetCell("Description", "Sets the local directory where the links will be saved.");
		
		CmdTable.AddRow();
		CmdTable.SetCell("Command", "CLEARBUFFER");
		CmdTable.SetCell("Description", "Empties the link buffer.");
		
		CmdTable.AddRow();
		CmdTable.SetCell("Command", "BUFFERSIZE <#size>");
		CmdTable.SetCell("Description", "Sets the size of the link buffer. Only integers >=0.");
		
		CmdTable.AddRow();
		CmdTable.SetCell("Command", "SHOWSETTINGS");
		CmdTable.SetCell("Description", "Prints all the settings.");

		CmdTable.AddRow();
        CmdTable.SetCell("Command", "BUFFERALLLINKS");
        CmdTable.SetCell("Description", "Toggles the buffering of all links or only image links.");

        CmdTable.AddRow();
        CmdTable.SetCell("Command", "REUPLOAD");
        CmdTable.SetCell("Description", "Toggles the reuploading of image links to imgur.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "SHOWLINKS <#number>");
		CmdTable.SetCell("Description", "Prints <#number> or <#buffersize> number of cached links.");

		CmdTable.AddRow();
		CmdTable.SetCell("Command", "HELP");
		CmdTable.SetCell("Description", "This help.");

		PutModule(CmdTable);
		return;
	} else if (command == "enable") 
	{
		SetNV("enable","true",true);
		PutModule("Enabled buffering");
	} else if (command == "disable") 
	{
		SetNV("enable","false",true);
		PutModule("Disabled buffering");
	} else if (command == "enablelocal")
	{
		if(GetNV("directory") == "")
		{
			PutModule("Directory is not set. First set a directory and then enable local caching");
			return;
		}
		SetNV("enablelocal","true",true);
		PutModule("Enabled local caching");
	} else if (command == "disablelocal")
	{
		SetNV("enablelocal", "false", true);
		PutModule("Disabled local caching");
	} else if (command == "enablepublic")
	{
		SetNV("enablepublic", "true", true);
		PutModule("Enabled public usage of showlinks.");
	} else if (command == "disablepublic")
        {
                SetNV("enablepublic", "false", true);
                PutModule("Disabled public usage of showlinks.");
        } else if (command == "directory") 
	{
		CString dir=sCommand.Token(1).Replace_n("//", "/").TrimRight_n("/") + "/";
		if (!isValidDir(dir))
		{
			PutModule("Error in directory name. Avoid using: | ; ! @ # ( ) < > \" ' ` ~ = & ^ <space> <tab>");
			return;
		}
		// Check if file exists and is directory
		if (dir.empty() || !CFile::Exists(dir) || !CFile::IsDir(dir, false))
		{
			PutModule("Invalid path or no write access to ["+ sCommand.Token(1) +"].");
			return;
		} 
		SetNV("directory", dir, true);
		PutModule("Directory for local caching set to " + GetNV("directory"));
	} else if (command == "clearbuffer")
	{
		lastUrls.clear();
		nicks.clear();
	} else if (command == "buffersize")
	{
		unsigned int bufSize = sCommand.Token(1).ToUInt();
		if(bufSize==0 || bufSize==UINT_MAX)
		{
			PutModule("Error in buffer size. Use only integers >= 0.");
			return;
		}
		SetNV("buffersize", CString(bufSize), true);
		PutModule("Buffer size set to " + GetNV("buffersize")); 
	} else if (command == "showsettings")
	{
		for(MCString::iterator it = BeginNV(); it != EndNV(); it++)
		{
			PutModule(it->first.AsUpper() + " : " + it->second);
		}
	} else if(command == "bufferalllinks"){
		SetNV("bufferalllinks", CString(!GetNV("bufferalllinks").ToBool()), true); 
		PutModule( CString(GetNV("bufferalllinks").ToBool()?"Enabled":"Disabled") + " buffering of all links.");
	} else if(command == "reupload"){
                SetNV("reupload", CString(!GetNV("reupload").ToBool()), true);
                PutModule( CString(GetNV("reupload").ToBool()?"Enabled":"Disabled") + " reuploading of images.");
    } else if (command == "showlinks")
	{
		 if(lastUrls.empty())
                        PutModule("No links were found...");
                 else
                 {
                        unsigned int maxLinks = GetNV("buffersize").ToUInt();
                        unsigned int size = sCommand.Token(1).ToUInt();
                        if(size!=0 && size<UINT_MAX) //if it was a valid number
                              maxLinks = size;
			unsigned int maxSize = lastUrls.size()-1;
			for(unsigned int i=0; i<=maxSize && i< maxLinks; i++)
		    {
                		PutModule(nicks[maxSize-i] + ": " + lastUrls[maxSize-i]);
            }
  		 }
	} else
	{
		PutModule("Unknown command! Try HELP.");
	}
}

void CUrlBufferModule::LoadDefaults() 
{
	if(GetNV("enable")=="")
		SetNV("enable", "true", true);
	if(GetNV("enablelocal")=="")
		SetNV("enablelocal", "false", true);
	if(GetNV("buffersize")== "")
		SetNV("buffersize", "5", true);
	if(GetNV("enablepublic")=="")
		SetNV("enablepublic", "true", true);
	if(GetNV("bufferalllinks")=="")
		SetNV("bufferalllinks", "false", true);
    if(GetNV("reupload")=="")
        SetNV("reupload", "true", true);    
}

void CUrlBufferModule::CheckLineForLink(const CString& sMessage, const CString& sOrigin)
{
	if(sOrigin != m_pUser->GetUserName() && GetNV("enable").ToBool() )
	{	
		VCString words;
		CString output;
		sMessage.Split(" ", words, false, "", "", true, true);
		for (size_t a = 0; a < words.size(); a++) 
		{
			CString& word = words[a];
			if(word.Left(4) == "http" || word.Left(4) == "www.")
			{            
				//if you find an image download it, save it in the www directory and keep the new link in buffer
				VCString tokens;
				word.Split("/", tokens, false, "", "", true, true);
				CString name = tokens[tokens.size()-1];
				word.Split(".", tokens, false, "", "", true, true);

				//if it's an image link download/upload it else just keep the link
                time_t curtime;
                time(&curtime);
                CString dir = GetNV("directory") + CUtils::FormatTime(curtime,"%Y-%m-%d", m_pUser->GetTimezone()) + "/";
                CString nickname = (sOrigin.empty())? m_pUser->GetUserName() : sOrigin;
                if(!CFile::Exists(dir) && !CFile::IsDir(dir, false))
                {
                        CDir::MakeDir(dir, 0775);
                }

				if(isValidExtension( tokens[tokens.size()-1] ))
				{

                    std::stringstream ss;
					if( GetNV("enablelocal").ToBool())
					{
						ss << "wget -b -O " << dir.c_str() << name <<" -q " << word.c_str() << " 2>&1";
                        getStdoutFromCommand(ss.str());
					}
					ss.str("");
					if (!word.WildCmp("*imgur*") && GetNV("reupload").ToBool()) {
						ss << "curl -d \"image=" << word.c_str() << "\" -d \"key=5ce86e7f95d8e58b18931bf290f387be\" http://api.imgur.com/2/upload.xml | sed -n 's/.*<original>\\(.*\\)<\\/original>.*/\\1/p' 2>&1";
						output = getStdoutFromCommand(ss.str());
						lastUrls.push_back(output);
					} else {
						lastUrls.push_back(word);
					}
				} else if(GetNV("bufferalllinks").ToBool()){
					lastUrls.push_back(word);
                    //append nick:link to file
                    CString filename = dir + "links.txt";
                    std::ofstream log(filename.c_str() , std::ios_base::app | std::ios_base::out);
                    log << nickname << ": " << word << "\n"; 
				}
                                nicks.push_back( nickname );
			}
		}
	}
}

CString CUrlBufferModule::getStdoutFromCommand(const CString& cmd) 
{
	CString data="";
	char buffer[128];
	FILE* stream = popen(cmd.c_str(), "r");
	if (stream == NULL || !stream || ferror(stream))
	{ 
		return "Error!";
	}
	while (!feof(stream))
	{
		if (fgets(buffer, 128, stream) != NULL)
			data.append(buffer);
	}
	pclose(stream);
	return data;
}

void CUrlBufferModule::CheckLineForTrigger(const CString& sMessage, const CString& sTarget)
{
	if(GetNV("enablepublic").ToBool())
	{
		VCString words;
		sMessage.Split(" ", words, false, "", "", true, true);
		for (size_t a = 0; a < words.size(); a++) 
		{
			CString& word = words[a];
			if(word.AsLower() == "!showlinks")
			{
				if(lastUrls.empty())
					PutIRC("PRIVMSG " + sTarget + " :No links were found...");
				else 
				{
					unsigned int maxLinks = GetNV("buffersize").ToUInt();
								
					if (a+1 < words.size())
					{
						unsigned int size = words[a+1].ToUInt();
						if(size!=0 && size<UINT_MAX) //if it was a valid number
							maxLinks = size;
					}
                                        
                    unsigned int maxSize = lastUrls.size()-1;
                    for(unsigned int i=0; i<=maxSize && i<maxLinks; i++)
                    {
                          sleep(1);
                          PutIRC("PRIVMSG " + sTarget + " :" + nicks[maxSize-i] + ": "+ lastUrls[maxSize-i]);
                    }

				}
			}
		}
	}
}

template<> void TModInfo<CUrlBufferModule>(CModInfo& Info) {
    Info.SetWikiPage("urlbuffer");
    Info.SetHasArgs(false);
}


USERMODULEDEFS(CUrlBufferModule, "Module that caches locally images/links posted on irc channels.")