// /file PostfixIntegrate.cpp
//
// Copyright (C) 2011, ARM Research Labs, LLC.
// See www.armresearch.com for the copyright terms.
//
// This file contains the functions for PostfixIntegrate.
//
// $Id$
//
///////////////////////////////////////////////////////////////////////////////////////////////////

#include <cstdlib>
#include <cerrno>
#include <cstring>

#include <iostream>
#include <exception>
#include <stdexcept>
#include <sstream>
#include <fstream>

#include "PostfixIntegrate.hpp"

//////////////////////////////////////////////////////////////////////////////////////////////////////////
// Configuration. ////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////////

const std::string SnfMilterMainCfSearchString("Added by PostfixIntegrate");

const std::string SnfMilterMainCfIntegrationString("smtpd_milters = unix:/var/snf-milter/socket $smtpd_milters # Added by PostfixIntegrate");

//////////////////////////////////////////////////////////////////////////////////////////////////////////
// End of configuration. /////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////////

void
PostfixIntegrate::SetOperatingSystem(std::string OperatingSystemType) {

    MtaIsRunningCommand = "ps axl | grep -v grep | grep -q 'postfix/master'";

    if ("OpenBSD" == OperatingSystemType) {

	PostfixMainCfPath = "/usr/local/etc/postfix/main.cf";
	PostfixMasterCfPath = "/usr/local/etc/postfix/master.cf";
	ReloadMtaCommand = "/usr/local/sbin/postfix reload";

    } else if ("FreeBSD" == OperatingSystemType) {

	PostfixMainCfPath = "/etc/postfix/main.cf";
	PostfixMasterCfPath = "/etc/postfix/master.cf";
	ReloadMtaCommand = "/usr/local/sbin/postfix reload";

    } else if ("Ubuntu" == OperatingSystemType) {

	PostfixMainCfPath = "/etc/postfix/main.cf";
	PostfixMasterCfPath = "/etc/postfix/master.cf";
	ReloadMtaCommand = "/usr/sbin/postfix reload";

    } else if ("RedHat" == OperatingSystemType) {

	PostfixMainCfPath = "/etc/postfix/main.cf";
	PostfixMasterCfPath = "/etc/postfix/master.cf";
	ReloadMtaCommand = "/usr/sbin/postfix reload";

    } else if ("Suse" == OperatingSystemType) {

	PostfixMainCfPath = "/etc/postfix/main.cf";
	PostfixMasterCfPath = "/etc/postfix/master.cf";
	ReloadMtaCommand = "/usr/sbin/postfix reload";

    } else {

	std::ostringstream Temp;

	Temp << "***Error from PostfixIntegrate::SetOperatingSystem:  Invalid value of OperatingSystemType:  "
	     << OperatingSystemType;

	throw std::runtime_error(Temp.str());

    }

}

void
PostfixIntegrate::Integrate(FileBackup *SaveFile) {

    if (IsIntegrated()) {

	return;

    }

    if (Verbose()) {

	std::cout << "Add to postfix file " << PostfixMainCfPath << ":  '"
	     << SnfMilterMainCfIntegrationString << "'...";

    }

    if (!Explain()) {

	SaveFile->CreateBackupFile(PostfixMainCfPath);                          // Save any existing file.

        std::ofstream Output;                                                   // Append the configuration.

	Output.open(PostfixMainCfPath.c_str(), std::ios::app);
	if (!Output) {
	    std::string Temp;

	    Temp = "Error opening the postfix configuration file " + PostfixMainCfPath;
	    Temp += " for writing:  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

	Output << SnfMilterMainCfIntegrationString << "\n";
	if (!Output) {
	    std::string Temp;

	    Temp = "Error appending to the postfix configuration file " + PostfixMainCfPath;
	    Temp += ":  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

	Output.close();
	if (!Output) {
	    std::string Temp;

	    Temp = "Error closing the postfix configuration file " + PostfixMainCfPath;
	    Temp += " after appending:  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

    }

    OutputVerboseEnd();

    if (!ReloadMta()) {

        std::cerr << "Unable to reload the postfix configuration.  Please run "
		  << "'postfix reload' for the integration with SNFMilter to take effect.";

    }

}

void
PostfixIntegrate::Unintegrate(FileBackup *SaveFile) {

    if (!IsIntegrated()) {

	return;

    }

    std::ifstream Input;

    if (Verbose()) {

	std::cout << "Remove integration in postfix file " << PostfixMainCfPath << "--\n";

    }

    if (!Explain()) {

	SaveFile->CreateBackupFile(PostfixMainCfPath);                          // Save any existing file.

	Input.open(PostfixMainCfPath.c_str());                                  // Read the contents.
	if (!Input) {
	    std::string Temp;

	    Temp = "Error opening the postfix configuration file " + PostfixMainCfPath;
	    Temp += " for reading:  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

	std::string Content;
	std::string Line;

	while (getline(Input, Line)) {

	    if (std::string::npos != Line.find(SnfMilterMainCfSearchString)) {      // Check for integration line.

		if (Verbose()) {

		    std::cout << "  Remove '" << Line << "'...\n";

		}
		continue;                                                           // Do not copy this line.

	    }

	    Content += Line + "\n";                                                 // Copy this line.

	}

	if (!Input.eof()) {                                                         // Should be at end-of-file.
	    std::string Temp;

	    Temp = "Error reading the postfix configuration file " + PostfixMainCfPath;
	    Temp += ":  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

	Input.close();
	if (Input.bad()) {
	    std::string Temp;

	    Temp = "Error closing the postfix configuration file " + PostfixMainCfPath;
	    Temp += " after reading:  ";
	    Temp += strerror(errno);
	    throw std::runtime_error(Temp);
	}

	if (!Explain()) {

	    std::ofstream Output;                                                          // Write the updated contents.

	    Output.open(PostfixMainCfPath.c_str(), std::ios::trunc);
	    if (!Output) {
		std::string Temp;

		Temp = "Error opening the postfix configuration file " + PostfixMainCfPath;
		Temp += " for writing:  ";
		Temp += strerror(errno);
		throw std::runtime_error(Temp);
	    }

	    Output << Content;
	    if (!Output) {
		std::string Temp;

		Temp = "Error writing the postfix configuration file " + PostfixMainCfPath;
		Temp += ":  ";
		Temp += strerror(errno);
		throw std::runtime_error(Temp);
	    }

	    Output.close();
	    if (!Output) {
		std::string Temp;

		Temp = "Error closing the postfix configuration file " + PostfixMainCfPath;
		Temp += " after writing:  ";
		Temp += strerror(errno);
		throw std::runtime_error(Temp);
	    }

	}

    }

    OutputVerboseEnd();

    if (!ReloadMta()) {

        std::cerr << "Unable to reload the postfix configuration.  Please run "
		  << "'postfix reload' for the integration with SNFMilter to take effect.";

    }

}

bool
PostfixIntegrate::MtaIsRunningDetected() {

    if (Verbose()) {

	std::cout << "Checking whether postfix is detected to be running...";

    }

    bool IsRunningDetected;

    IsRunningDetected = (std::system(MtaIsRunningCommand.c_str()) == 0);

    if (Verbose()) {

	std::cout << (IsRunningDetected ? "yes..." : "no...");

    }

    OutputVerboseEnd();

    return IsRunningDetected;

}

bool
PostfixIntegrate::ReloadMta() {

    if (!MtaIsRunningDetected()) {

        return true;

    }

    if (Verbose()) {

	std::cout << "Reloading postfix...\n";
	std::cout.flush();

    }

    bool Succeeded;

    if (!Explain()) {

	Succeeded = (std::system(ReloadMtaCommand.c_str()) == 0);

	if (Verbose()) {

	    std::cout << (Succeeded ? "succeeded..." : "failed...");

	}

    }

    OutputVerboseEnd();

    return Succeeded;

}

bool
PostfixIntegrate::IsIntegrated() {

    if (Verbose()) {

	std::cout << "Checking for any SNFMilter integration in the postfix file " << PostfixMainCfPath << "...";

    }

    if (!FileExists(PostfixMainCfPath)) {

	if (Verbose()) {

	    std::cout << "file doesn't exist; postfix is not integrated...";

	}

	OutputVerboseEnd();

	return false;

    }

    bool Integrated = false;

    std::ifstream Input;

    Input.open(PostfixMainCfPath.c_str());                                      // Read the contents.
    if (!Input) {
	std::string Temp;

	Temp = "Error opening the postfix configuration file " + PostfixMainCfPath;
	Temp += " for reading:  ";
	Temp += strerror(errno);
	throw std::runtime_error(Temp);
    }

    std::string Line;

    while (getline(Input, Line)) {

	if (std::string::npos != Line.find(SnfMilterMainCfSearchString)) {     // Check for integration line.

	    Integrated = true;                                                 // Found it.

	    break;

	}

    }

    Input.close();
    if (Input.bad()) {
	std::string Temp;

	Temp = "Error closing the postfix configuration file " + PostfixMainCfPath;
	Temp += " after reading:  ";
	Temp += strerror(errno);
	throw std::runtime_error(Temp);
    }

    if (Verbose()) {

	if (Integrated) {

	    std::cout << "found '" << Line << "'...";

	} else {

	    std::cout << "none found...";

	}

    }

    OutputVerboseEnd();

    return Integrated;

}