/*
   testlist.c - a solution to CS 12 assignment 3, part 2, Fall 2008
   cmc, updated 10/28/08
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "basiclist.h"

#define MAXLINE      80
#define MAXITEM      50   /* max string to insert is 49 characters */
#define MAXOTHER     10

enum command { insert, delete, clear, advance, reset, show, quit, reject };
enum position { first, last, current, before, after, all, bad };

/* utility methods defined below main */
enum command identifyCommand(char *);
enum position identifyPosition(enum command, char *);
void *copyToken(char *);
void printAll(ListPointer);
void print(char *, void *);

int main(void) {
    ListPointer list;
    char line[MAXLINE], token1[MAXOTHER], token2[MAXOTHER], token3[MAXITEM];
    char *item;
    int tokenCount;
    enum command cmnd;
    enum position pos;
    
    list = createList();
    while ((fgets(line, MAXLINE, stdin)) != NULL) {

        /* split line into tokens - just the first 3 matter */
        tokenCount = sscanf(line, "%s %s %s", token1, token2, token3);

        /* ignore blank lines and comments */
        if (tokenCount < 1 || token1[0] == '#')
           continue;

        /* first token is the primary command */
        cmnd = identifyCommand(token1);
        switch (cmnd) {

            case quit:
                return 0;
            case reject:
                printf("bad command: %s\n", token1);
                break;
            case clear:
                clearList(list);
                printf("cleared\n");
                break;
            case advance:
                advanceCurrent(list);
                print("advanced to:", currentInfo(list));
                break;
            case reset:
                resetCurrent(list);
                print("reset to:", currentInfo(list));
                break;

            default:   /* insert, delete, and show are more complicated */
                if (tokenCount < 2) {
                    printf("missing position to %s\n", token1);
                    break;
                }
                /* second token identifies position to carry out command */
                pos = identifyPosition(cmnd, token2);
                if (pos == bad)
                    printf("bad position: %s\n", token2);
                else if (cmnd == insert) {
                    if (tokenCount < 3)
                       printf("missing item to insert\n");
                    else {
                       /* third token is the item to insert */
                       item = copyToken(token3);
                       if (pos == first) {
                          insertFirst(item, list);
                          printf("inserted first: %s\n",item);
                       }else if (pos == last) {
                          insertLast(item, list);
                          printf("inserted last: %s\n",item);
                       }else if (pos == before) {
                          insertBeforeCurrent(item, list);
                          printf("inserted before current: %s\n",item);
                       }else {
                          insertAfterCurrent(item, list);
                          printf("inserted after current: %s\n",item);
                       }
                    }
                    
                }else if (cmnd == delete) {
                    if (pos == first)
                        item = deleteFirst(list);
                    else if (pos == last)
                        item = deleteLast(list);
                    else
                        item = deleteCurrent(list);
                    print("deleted:", item);
                    free(item);
                }else {  /* cmnd == show */
                    if (pos == first)
                        print("first item:", firstInfo(list));
                    else if (pos == last)
                        print("last item:", lastInfo(list));
                    else if (pos == current)
                        print("current item:", currentInfo(list));
                    else
                        printAll(list);
                }
                break;
        }
    }
    return 0;
}

/* identify the command given by the token */
enum command identifyCommand(char *token) {
    if (!strcmp("insert", token)) return insert;
    if (!strcmp("delete", token)) return delete;
    if (!strcmp("clear", token)) return clear;
    if (!strcmp("advance", token)) return advance;
    if (!strcmp("reset", token)) return reset;
    if (!strcmp("show", token)) return show;
    if (!strcmp("quit", token)) return quit;
    return reject;
}

/* identify the position given by the token
   validity depends on the command */
enum position identifyPosition(enum command cmnd, char *token) {
    if (!strcmp("first", token)) return first;
    if (!strcmp("last", token)) return last;
    if (cmnd == delete || cmnd == show)
        if (!strcmp("current", token)) return current;
    if (cmnd == insert) {
        if (!strcmp("before", token)) return before;
        if (!strcmp("after", token)) return after;
    }
    if (cmnd == show)
       if (!strcmp("all", token)) return all;
    return bad;
}

/* allocate space for new string and copy token to it */
void *copyToken(char *token) {
    char *p;
    size_t length = strlen(token);
    p = malloc((length+1) * sizeof(char));
    strcpy(p, token);
    return p;
}

/* prints "[tag] ", followed by item value or "null", and newline */
void print(char *tag, void *item) {
    printf("%s ", tag);
    if (item != NULL)
        printf("%s\n", (char *)item);
    else
        printf("NULL\n");
}

/* custom display function for a list that holds strings
   Note: unavoidably moves the current pointer, so resets when done. */
void printAll(ListPointer list) {
    printf("list: (");
    resetCurrent(list);
    if (!emptyList(list))
        printf("%s", (char *)(firstInfo(list)));
    while (hasMoreInfo(list)) {
        advanceCurrent(list);
        printf(",%s", (char *)(currentInfo(list)));
    }
    resetCurrent(list);
    printf(")\n");
}