42sh/src/utils/args/args.c

#define _POSIX_C_SOURCE 200809L
#include "./args.h"

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../lists/lists.h"
#include "../string_utils/string_utils.h"
#include "../vars/vars.h"

static void strlen_acc(void *acc, void *data)
{
    size_t *len = (size_t *)acc;
    char *str = (char *)data;
    *len += strlen(str);
}

static char *concat_list_str(struct list *list)
{
    char *res = NULL;
    size_t total_len = list_length(list) + 1; // + spaces + null terminator

    list_fold(list, &total_len, strlen_acc);

    res = malloc(total_len);
    if (res != NULL)
    {
        res[0] = 0;
        for (struct list *it = list; it != NULL; it = it->next)
        {
            strcat(res, (char *)it->data);
            if (it->next != NULL)
                strcat(res, " ");
        }
        res[total_len - 1] = 0;
    }

    return res;
}

static void args_in_var(struct hash_map *vars, struct list *args_list)
{
    int arg_index = 1;
    char index_str[11];

    for (struct list *it = args_list; it != NULL; it = it->next)
    {
        int_to_str(arg_index++, index_str);
        set_var_copy(vars, index_str, (char *)it->data);
    }

    char *concated_args = concat_list_str(args_list);
    set_var_copy(vars, "*", concated_args);

    char *key = strdup("@");
    set_var(vars, key, concated_args, NULL);
    // key and concated_args consumed by hash_map

    int_to_str(arg_index - 1, index_str);
    set_var_copy(vars, "#", index_str);
}

int args_handler(int argc, char **argv, struct args_options *options,
                 struct hash_map *vars)
{
    options->type = INPUT_UNDEFINED;
    options->input_source = NULL;
    // options->pretty_print = false;
    options->verbose = false;

    struct list *args_list = NULL;

    set_var_copy(vars, "0", argv[0]);

    for (int i = 1; i < argc; i++)
    {
        /* if (strcmp(argv[i], "--pretty-print") == 0)
        {
            options->pretty_print = true;
        } */
        if (strcmp(argv[i], "--verbose") == 0)
        {
            options->verbose = true;
        }
        else if (strcmp(argv[i], "-c") == 0)
        {
            if (options->type != INPUT_UNDEFINED)
            {
                fprintf(stderr, "Multiple input sources specified: %s\n",
                        argv[i + 1]);
                return 1;
            }
            else if (i + 1 >= argc)
            {
                fprintf(stderr, "No command provided after -c\n");
                return 1;
            }

            options->type = INPUT_CMD;
            options->input_source = argv[i + 1];
            i++;
        }
        else if (argv[i][0] == '-')
        {
            fprintf(stderr, "Unknown option: %s\n", argv[i]);
            return 1;
        }
        else if (options->type == INPUT_UNDEFINED)
        {
            options->type = INPUT_FILE;
            options->input_source = argv[i];
        }
        else
        {
            // All remaining arguments are treated as additional arguments
            args_list = list_append(args_list, argv[i]);
            continue;
        }
    }

    args_in_var(vars, args_list);
    list_destroy(&args_list);

    if (options->type == INPUT_UNDEFINED)
        options->type = INPUT_STDIN;

    return 0;
}

void args_print(struct args_options *options)
{
    printf("Input type: %s\n",
           options->type == INPUT_CMD         ? "COMMAND"
               : options->type == INPUT_FILE  ? "FILE"
               : options->type == INPUT_STDIN ? "STDIN"
                                              : "UNDEFINED");
    printf("Input source: %s\n",
           options->input_source ? options->input_source : "NULL");
    // printf("Pretty print: %s\n", options->pretty_print ? "true" : "false");
    printf("Verbose: %s\n", options->verbose ? "true" : "false");
}

void print_usage(FILE *std, const char *program_name)
{
    fprintf(std, "Usage: %s [OPTIONS] [SCRIPT] [ARGUMENTS...]\n", program_name);
    fprintf(std, "Options:\n");
    fprintf(std, "  -c [SCRIPT]        Execute the given command string.\n");
    // fprintf(std, "  --pretty-print     Enable pretty printing of
    // outputs.\n");
    fprintf(std, "  --verbose          Enable verbose mode.\n");
    fprintf(std,
            "If no SCRIPT is provided, input is read from standard input.\n");
}