#include "food_chain.h"

#include <string>

namespace food_chain {

using namespace std;


static const char *animals[] = 
    {"fly", "spider", "bird", "cat", "dog", "goat", "cow", "horse"};

static const char *verse_phrase[] = {
    "",
    "It wriggled and jiggled and tickled inside her.\n",
    "How absurd to swallow a bird!\n",
    "Imagine that, to swallow a cat!\n",
    "What a hog, to swallow a dog!\n",
    "Just opened her throat and swallowed a goat!\n",
    "I don't know how she swallowed a cow!\n",
    "She's dead, of course!\n"
};

static const int size_of_animals = sizeof(animals) / sizeof(*animals);


string verse(int index)
{
    string result;

    --index;

    result += string("I know an old lady who swallowed a ")
       + animals[index]
       + ".\n"
       + verse_phrase[index];

    if (index != size_of_animals - 1) {

        for (int i = index; i > 0; --i) {

            if (i == 2) {

                result += "She swallowed the bird to catch the spider "
                          "that wriggled and jiggled and tickled inside her.\n";
            }
            else {

                result += string("She swallowed the ")
                   + animals[i]
                   + " to catch the "
                   + animals[i-1]
                   + ".\n";
            }
        }

        result += "I don't know why she swallowed the fly. "
                  "Perhaps she'll die.\n";
    }

    return result;
}

string verses(int from_index, int to_index)
{
    string result;

    for (int i = from_index; i <= to_index; ++i)
        result += verse(i) + '\n';

    return result;
}

string sing()
{
    return verses(1, 8);
}

}