/*
* Search4j utility
* Command Line utility to search a system for java, launch a jar, or compare java versions
* base on launch4j
*/

#include <iostream>
#include <string>
#include <windows.h>
using namespace std;

bool verbose = false;

enum JvmProperty {
	JavaHome,
	Version,
	Executable
};

enum Action {
	Find,
	Launch,
	Compare
};

int process( char* command, string &output ) {
	PROCESS_INFORMATION pi;
	STARTUPINFO si;
    memset(&pi, 0, sizeof(pi));
    memset(&si, 0, sizeof(si));
    si.cb = sizeof(si);

	DWORD dwExitCode = -1;
	char cmdline[1024];
    strcpy(cmdline, "dir");

	if ( CreateProcess(NULL, command, NULL, NULL, TRUE, 0, NULL, NULL, &si, &pi) ) {
		WaitForSingleObject(pi.hProcess, INFINITE);
		GetExitCodeProcess(pi.hProcess, &dwExitCode);
		CloseHandle(pi.hThread);
		CloseHandle(pi.hProcess);
	}
	return 1;

}

class Jvm {

	string javaHome;
	bool isJdk;

	// version string. era.major.minor_update. eg: 1.4.2_02
	string version;
	int era;
	int major;
	int minor;
	int update;

	public:	

	void setJavaHome( string jh ) {
		javaHome = jh;
		setVersion();
	}

	string getJavaHome() {
		return javaHome;
	}

	string getExecutable() {
		string exec = "";
		exec.append( javaHome );
		exec.append( "\\bin\\java.exe" );
		return exec;
	}

	string getVersion() {
		return version;
	}
	
	bool check() {
		return true;
	}
	
	private:
	
	void setVersion() {

		string command = "", output="";
		command.append( getExecutable() );
		command.append(" -version");
		//bool result = process( command, output );
	}
	
	
};


string actionToString( Action a ) {
	if ( a == Find ) 
		return "Find";
	else if ( a == Launch )
		return "Launch";
	else if ( a == Compare )
		return "Compare";
	return "Unknown";
}

string jvmPropertyToString( JvmProperty jp ) {
	if ( jp == JavaHome ) 
		return "JavaHome";
	else if ( jp == Version )
		return "Version";
	else if ( jp == Executable )
		return "Executable";
	return "Unknown";
}

void usage() {
	
	cout
		<< "-----------------" << endl
		<< " search4j: usage" << endl
		<< "-----------------" << endl
		<< "Three usage methods: find, compare and launch" << endl
		<< endl
		<< "find:     find java and print out information about it" << endl
		<< endl
		<< "          search4j [-v|-e] [-m VERSION_STRING]" << endl
		<< "          eg: search4j -m 1.4.1_01 -e" << endl
		<< endl
		<< "          by default, print JAVA_HOME. E.g., C:\\Program Files\\jre1.5.0_15, or" << endl
		<< "          if -v is specified, print the java version string. E.g. 1.5.0_15, or" << endl
		<< "          if -e is specified, print the path the to the java executable. E.g. C:\\Program Files\\jre1.5.0_15\\bin\\java.exe" << endl
		<< "          if -m option is used, find a java of the given version or newer, or fail" << endl
		<< endl
		<< "compare:  compare the found java with the given java version string" << endl
		<< endl
		<< "          search4j -c VERSION_STRING" << endl
		<< "          eg: search4j -c VERSION_STRING" << endl
		<< endl
		<< "          print -1 if found java is older" << endl
		<< "          print 0 if found java is same" << endl
		<< "          print 1 if found java is newer" << endl
		<< endl
		<< "launch:   launch the given executable jar with the found java" << endl
		<< endl
		<< "          search4j -l EXECUTABLE_JAR [-m VERSION_STRING]" << endl
		<< "          eg: search4j -l greenstone3.jar" << endl
		<< endl
		<< "          specify the location of the jar relative to the current directory" << endl
		<< "          if -m option is used, find a java of the given version or newer" << endl
		<< endl
		<< "Global Options:" << endl
		<< "          --verbose : have search4j print out information about what its doing" << endl
		<< "          --help : display this usage screen" << endl
		<< endl
		;
}


/*
* function to find java
* implements the logic drawn on the dl lab whiteboard in feb 08
* return a Jvm object which represents the jvm on disk
*/
bool find( Jvm &jvm ) {
	
	if ( verbose ) cout << "Searching for a JVM" << endl;
	char *javaHome = "";
	bool jvmFound = false;
	
	if ( !jvmFound ) {
		//try JAVA_HOME
		if ( verbose ) cout << " - trying JAVA_HOME" << endl;	
		javaHome = getenv( "JAVA_HOME" );
		if ( javaHome != NULL ) {
			jvm.setJavaHome( javaHome );
			if ( jvm.check() ) {
				jvmFound = true;
			}
		}
	}
	
	if ( !jvmFound ) {
		//try JRE_HOME
		if ( verbose ) cout << " - trying JRE_HOME" << endl;
		javaHome = getenv( "JRE_HOME" );
		if ( javaHome != NULL ) {
			jvm.setJavaHome( javaHome );
			if ( jvm.check() ) {
				jvmFound = true;
			}
		}
	}

	return jvmFound;
}


int main ( int argc, char** argv ) {

	string output = "";
	int result = process("dir", output);
	cout << "dir:" << endl << output << endl << result << endl;
	
	JvmProperty jvmProperty = JavaHome;
	Action action = Find;
	string arg1 = "";
	
	//parse commandline arguments
	for (int i=1; i<argc; i++) {
		if ( _stricmp(argv[i], "--verbose") == 0 ) {
			verbose = true;
		} else if ( _stricmp(argv[i], "--help") == 0 || _stricmp(argv[i], "--usage") == 0 ) {
			usage();
			return 0;
		} else if ( _stricmp(argv[i], "-v") == 0 ) {
			jvmProperty = Version;
		} else if ( _stricmp(argv[i], "-e") == 0 ) {
			jvmProperty = Executable;
		} else if ( _stricmp(argv[i], "-c") == 0 ) {
			action = Compare;
			if ( i == argc-1 ) {
				usage();
				return 0;
			} else {
				arg1 = argv[++i];
			}
		} else if ( _stricmp(argv[i], "-l") == 0 ) {
			action = Launch;
			arg1 = argv[++i];
		} else {
			cout << "unknown option: " << argv[i] << endl;
			return -1;
		}
	}
	
	//summarise commandline arguments
	if ( verbose ) {
		cout << "Action: " << actionToString( action ) << endl;
		if ( action == Find ) cout << "Property to print: " << jvmPropertyToString( jvmProperty ) << endl;
		if ( action == Compare ) cout << "Compare to java at: " << arg1 << endl;
		if ( action == Launch ) cout << "Jar to launch: " << arg1 << endl;
	}


	//Find Action
	//---------------
	if ( action == Find ) {
		
		//find java
		Jvm jvm;
		bool found = find( jvm );
		
		//check if it was found
		if ( found ) {

			//found - print out info about it
			if ( verbose ) cout << "JVM found!" << endl;
			if ( jvmProperty == JavaHome ) {
				cout << jvm.getJavaHome() << endl;
			} else if ( jvmProperty == Version ) {
				cout << jvm.getVersion() << endl;
			} else if ( jvmProperty == Version ) {
				cout << jvm.getExecutable() << endl;
			} else {
				return -1; //should never happen
			}
			
		} else {
		
			//not found - exit with -1
			if ( verbose ) cout << "JVM not found" << endl;
			return -1;
			
		}
	
	

	//Compare Action
	//---------------
	} else if ( action == Compare ) {
		//compare();



	//Launch Action
	//---------------
	} else if ( action == Launch ) {
		//launch();
	}
	
	
	return 0;
}