// MAR 02/21/00
// Written to demonstrate major capabilities of string library
// plus use of some generic functions from algorithm library on strings
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

// prototypes
// tells whether a passed char is an a or not
bool isA (char c);


int main() {
	string plate1;
	string plate2("HGB 634");
	string plate3 = "TRT 321";
	string plate4(plate2);   // copy constructor

	cout << plate1 << endl;


	cout << plate2 << endl;

	cout << plate3 << endl;

	cout << plate4 << endl;

	// look at subscripts
	cout << plate2[2] << endl;
	plate2[2] = 'X';
	cout << plate2 << endl;

	// substring
	// ends with 
	string end = plate2.substr(4,3);
	cout << "ends: " << end << endl;

	/*
	cout << "please enter the plate # for plate 7 followed by # then return key  " << flush;
	string plate7;
	getline(cin,plate7,'#');
	cout << endl << "plate7: " << plate7 << endl;
	*/

	// check empty string
	bool mt = plate1.empty();
	if (mt) {
		cout << "plate1 is unknown" << endl;
	}
	else {
		cout << "not empty" << endl;
	}

	cout << "lengths: " << plate1.length() << " " << plate2.length() << " "
		<< plate3.length() << " " << plate4.length() << endl;

	// watch - it catches the following error
	// plate1[5] = 'Z';

	// resizing strings
	plate1.resize(7,'-'); // expand string and fill with dashes
	cout << "string " << plate1 << " has size: " << plate1.length() << endl;

	plate1.resize(15,'%'); // expand string and fill with percent signs
	cout << "string " << plate1 << " has size: " << plate1.length() << endl;

	plate1.resize(8); // shorten string
	cout << "string " << plate1 << " has size: " << plate1.length() << endl;

	// assignment, append, concatenate
	string plate5;
	plate5 = plate1;
	cout << "plates 1 and 5: " << plate1 << " " << plate5 << endl;
	plate1 = 'I';
	cout << "plates 1 and 5: " << plate1 << " " << plate5 << endl;
	plate1 += " M GR8";
	cout << "plates 1 and 5: " << plate1 << " " << plate5 << endl;

	cout << "plates 1 and 5: " << plate1 + " " + plate5 << endl;

	// comparison
	string plate6(plate1);
	if (plate1 > plate2) {
		cout << plate1 << " greater than " << plate2 << endl;
	}
	else {
		cout << plate1 << " NOT greater than " << plate2 << endl;
	}
	if (plate4 >= plate2) {
		cout << plate4 << " greater than or equal to " << plate2 << endl;
	}
	else {
		cout << plate4 << " NOT greater than or equal to " << plate2 << endl;
	}
	if (plate1 == plate6) {
		cout << plate1 << " equal to " << plate6 << endl;
	}
	else {
		cout << plate1 << " NOT equal to " << plate6 << endl;
	}

	// just wait so results can be seen
	// char wait;
	string wait;
	cout << "enter any char to continue> " << flush;
	cin >> wait;

	string plates[20];
	// prepare to illustrate searching for particular substring in a string
	// haphazardly assign letters and numbers to plates 
	// STUDENTS: mostly ignore assignment of plates (next 35 lines or so)
	char now = 'A';
	// loop through first three chars
	for (int pos = 0; pos < 3; pos++) {
		// loop through all plates
		for (int cnt = 0;cnt < 20;cnt++){
			plates[cnt] += now;
			// go to next letter
			now++;
			// make sure don't go past Z
			if (now > 'Z') {
				now = 'A';
			}
		}
	}
	// add spaces
	for (int count = 0; count < 20; count++){
		plates[count] += ' ';
	}
	int curr = '0';
	// add numbers in last three positions
	for (int pos2 = 0; pos2 < 3; pos2++) {
		// loop through all plates
		for (int cnt = 0;cnt < 20;cnt++){
			plates[cnt] += curr;
			// go to next letter
			curr++;
			// make sure don't go past Z
			if (curr > '9') {
				curr = '0';
			}
		}
	}

	// show these
	for (int i = 0; i < 20; i++) {
		cout << "   " << plates[i] << endl;
	}


	// just wait so results can be seen
	cout << "enter any char to continue> " << flush;
	cin >> wait;
	// seems to leave a \n here ?? or next one above?
	


	// I think the truck that hit me had a "XR" in the plate
	for (int j = 0; j < 20;  j++) {
		int found = plates[j].find("XR");
		int len = plates[j].length();
		// debugging
		// cout << plates[j] << " found: " << found << " length: " << len << endl;

		if ((found > 0) && (found < len)) {
			cout << "Plate: " << plates[j] << " is a possibility " << endl;
		}
	}

	
	
	// input of string from keyboard
	cout << "please enter the plate # for plate 7 followed by # (then return key) " << flush;
	string plate7;
	getline(cin,plate7,'#');
	cout << endl << "plate7: " << plate7 << endl;
	

	// some more things - no real tie to license plates in examples below
	//     (just using them as strings)

	// insertion, removal and replacement
	cout << "about to play with plate 1: " << plate1 << endl;
	// insert starting at position 3
	plate1.insert(3,"XYZ");
	cout << "new plate1: " << plate1 << endl;
	// replace two characters starting at position 6
	plate1.replace(6,2,"ABC");
	cout << "new plate1: " << plate1 << endl;
	// our system doesn't seem to have remove
	// but it can be done using replace
	// replace 2 chars starting at position 2 with nothing
	plate1.replace(2,2,"");
	cout << "new plate1: " << plate1 << endl;

	// iterator - for plate 1 - set to first element in the string (container of chars)
	string::iterator itr = plate1.begin();
	// until the iterator reaches the end of the container - display value 
	for ( ; itr != plate1.end() ; itr++) {
		// * operation defined for iterators of a collection class
		// not frequently needed by user (client) code, because of all of 
		// the many other capabilities provided
		cout << *itr << endl;
	}
	// iterators more commonly used for using generic functions
	// (these are in the algorithm library and are not exactly object-oriented)
	// e.g. reverse
	reverse(plate7.begin(),plate7.end());
	cout << "new plate7: " << plate7 << endl;
	// e.g. sort
	sort(plate7.begin(),plate7.end());
	cout << "new plate7: " << plate7 << endl;
	
	
	// just wait so results can be seen
	cout << "enter any char to continue> " << flush;
	cin >> wait;

	// a non-license plate example
	string statement = "There was a time, not so long ago, when programmers used Pascal, not C++";
	// count number of occurrences of the char 'a'
	int countA;
	// book says that this function returns result via reference 
	// rather than via return - but our compiler uses 3 params and returns result
	// ALSO - our compiler wants a function parameter - not just a value 
	// to count - for count as well as count_if
	// count(statement.begin(),statement.end(),'a',countA);
	// countA = count(statement.begin(),statement.end(),'a');
	countA = count_if(statement.begin(),statement.end(),isA);
	cout << "There are " << countA << " 'a's in the statement: " <<
		endl << "      " << statement << endl;

	// replace occurences of 'e' with 'E'
	replace(statement.begin(),statement.end(),'e','E');
	cout << "New statement: " << endl << "      " << statement << endl;

	// find first occurence of 't'
	// I don't find this find that necessary for strings because of the string 
	// class find functions (plus generic count function)
	string::iterator firstTitr = find(statement.begin(),statement.end(),'t');
	// show rest of string
	// until the iterator reaches the end of the container - display value 
	for ( ; firstTitr != statement.end() ; firstTitr++) {
		cout << *firstTitr << "|";
	}
	cout << endl;

	// transform to all lower case
	string result(statement); // initialize with source so string contains
								// enough elements
	// iterators bound the source and start the target
	// tolower function is used to transform each given char
	transform(statement.begin(),statement.end(),result.begin(), tolower);
	cout << "statement transformed to all lower case: " << endl << "      "
		<< result << endl;

	return 0;
}


bool isA (char c) {
	if (c == 'a') {
		return true;
	}
	else {
		return false;
	}
	return true; // should never execute
}