/*-----------------------------
    enum.c -- 使用枚举类型的值
-----------------------------*/

#include <stdio.h>
#include <string.h>
//#include <stdbool.h>    //C99特性

#define LEN 30

char* s_gets(char *st, int n);

enum spectrum {red, orange, yellow, green, blue, violet};
const char *colors[] = {"red", "orange", "yellow", "green", "blue", "violet"};

int main()
{
    char choice[LEN];
    int color;
    bool color_is_found = false;

    puts("Enter a color (empty line to quit):");

    while (s_gets(choice, LEN) != NULL && choice[0] != '\0')
    {
        for (color = red; color != violet; ++color)
        {
            if (strcmp(choice, colors[color]) == 0)
            {
                color_is_found = true;
                break;
            }
        }

        if (color_is_found)
            switch (color)
            {
            case red:
                puts("Roses are red.");
                break;
            case orange:
                puts("Poppies are orange.");
                break;
            case yellow:
                puts("Sunflowers are yellow.");
                break;
            case green:
                puts("Grass is green");
                break;
            case blue:
                puts("Bluebells are blue");
                break;
            case violet:
                puts("Violets are violet");
                break;
            }
        else
            printf("I don't know about the color %s.\n", choice);

        color_is_found = false;
        
        puts("Next color, please (empty line to quit):");
    }

    puts("Goodbye");

    return 0;
}

char* s_gets(char *st, int n)
{
    char *ret_val, *find;

    if (ret_val = fgets(st, n, stdin))
    {
        if (find = strchr(st, '\n'))
            *find = '\0';
        else
            while (fgetc(stdin) != '\n') continue;
    }

    return ret_val;
}