#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#include <ctype.h>

#include "buffer.h"

#define RADIX (10)   // base for cursor numbers

// Minimalist text editor with optional multiple buffers.
//
// Each command is preceded by a number in decimal specifying a cursor.
// If number is omitted, defaults to 0.
//
// commands are
//
// <n>/<char> insert char before cursor n; if <char> is EOF, exit
// <n>+       move cursor n forward
// <n>-       move cursor n back
// .          print buffer contents
// #          comment: consume all characters to EOF or '\n'
//
// Any character that is not a digit or part of a command is ignored.
//
// Commands to cursor i go to buffer i % m, where m is a command-line argument.
int
main(int argc, char **argv)
{
    int m;  // number of buffers

    switch(argc) {

        case 2:

            m = 1;
            break;

        case 3:

            m = atoi(argv[2]);
            break;

        default:

            fprintf(stderr, "Usage: %s number-of-cursors [number-of-buffers]\n", argv[0]);
            return 1;

    }

    Buffer b[m];

    for(int i = 0; i < m; i++) {
        b[i] = bufferCreate(atoi(argv[1]));
    }

    int c;
    size_t cursor = 0;
    char *contents;    // for printing buffer contents

    while((c = getchar()) != EOF) {
        if(isdigit(c)) {
            cursor = cursor * RADIX + (c - '0');
        } else {
            switch(c) {

                case '/':
                    if((c = getchar()) == EOF) {
                        goto done;
                    }
                    // else insert c
                    bufferInsert(b[cursor % m], cursor, c);
                    cursor = 0;
                    break;

                case '+':
                    bufferCursorForward(b[cursor % m], cursor);
                    cursor = 0;
                    break;

                case '-':
                    bufferCursorBack(b[cursor % m], cursor);
                    cursor = 0;
                    break;

                case '.':
                    contents = bufferContents(b[cursor % m]);
                    fputs(contents, stdout);
                    free(contents);
                    break;

                default:
                    // do nothing
                    break;
            }
        }
    }

done:

    for(int i = 0; i < m; i++) {
        printf("\n[%zu cursors and %zu characters]\n", bufferCursors(b[i]), bufferSize(b[i]));
        bufferDestroy(b[i]);
    }

    return 0;
}