/* string.cpp
 *
 * Note: http://msdn.microsoft.com/en-us/magazine/cc163742.aspx
 *
 */

#include "string.h"
#include <sstream>

MyString::MyString(int len) : str_(new char[len + 1]), length_(len)
{
}

MyString::MyString(const char *str) : length_(strlen(str))
{
    str_ = new char[length_ + 1];
    strcpy(str_, str);
}

MyString::MyString(const MyString& str) : str_(new char[str.length_ + 1]),
                                          length_(str.length_)
{
    strcpy(str_, str.str_);
}

MyString::~MyString()
{
    delete[] str_;
}

int MyString::indexOf(char ch, int pos) const
{
    while (pos < length_)
    {
        if (str_[pos] == ch)
            return pos;

        pos++;
    }

    return -1;
}

bool MyString::isSubstring(const MyString& str) const
{
    if (length_ < str.length_)
        return false;

    int i, j, temp;

    for (i = 0; i < length_; i++)
    {
        j = 0;
        temp = i;
        while ((j < str.length_) && (str_[temp] == str.str_[j]))
        {
            temp++;
            j++;
        }

        if (j == str.length_)
        return true;
    }

    return false;
}

bool MyString::isSubstring(const char *str) const
{
    int i, j, k;
    for (i = 0; i < length_; i++)
    {
        j = i;
        k = 0;
        while (str_[j++] == str[k++])
            ;

        if (str[k-1] == '\0')
            return true;
    }

    return false;
}

/* there are few ways to implement this */
MyString& MyString::concat(const MyString& str)
{
    /* right way to do this would be to use realloc and double the buffer each
     * we append something (if it's full)
     */
    MyString ret(length_ + str.length_);
    strcpy(ret.str_, str_);
    strcat(ret.str_, str.str_);

    return (*this = ret);
}

MyString& MyString::concat(const char *str)
{
    char *newstr = new char[length_ + strlen(str) + 1];

    strcpy(newstr, str_);
    strcpy(newstr + length_, str);
    delete[] str_;

    length_ += strlen(str);
    str_ = newstr;

    return *this;
}

MyString& MyString::operator=(const MyString& rhs)
{
    /* don't do anything if object assigns itself */
    if (this == &rhs)
        return *this;

    length_ = rhs.length_;
    delete[] str_;
    str_ = new char[ length_ + 1];
    strcpy(str_, rhs.str_);

    /* assignment operator requires this */
    return *this;
}

bool operator==(const MyString& lhs, const MyString& rhs)
{
    if (lhs.length_ != rhs.length_)
        return false;

    if (strcmp(lhs.str_, rhs.str_) == 0)
        return true;
    else
        return false;
}

/* seems like the ostream& in front has nothing to do with dereferencing a pointer,
 * but it seems like the & is placed there so we can make consecutive overloaded
 * calls to cout, effectively chaining all of the calls
 */
ostream& operator<<(ostream& ostr, const MyString& rhs)
{
    return (ostr << rhs.str_);
}