/*
 * Copyright (c) 2009, 2010 Nicira, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <config.h>

#include "json.h"

#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>

#include "util.h"

/* --pretty: If set, the JSON output is pretty-printed, instead of printed as
 * compactly as possible.  */
static int pretty = 0;

/* --multiple: If set, the input is a sequence of JSON objects or arrays,
 * instead of exactly one object or array. */
static int multiple = 0;

static bool
print_and_free_json(struct json *json)
{
    bool ok;
    if (json->type == JSON_STRING) {
        printf("error: %s\n", json->u.string);
        ok = false;
    } else {
        char *s = json_to_string(json, JSSF_SORT | (pretty ? JSSF_PRETTY : 0));
        puts(s);
        free(s);
        ok = true;
    }
    json_destroy(json);
    return ok;
}

static bool
refill(FILE *file, void *buffer, size_t buffer_size, size_t *n, size_t *used)
{
    *used = 0;
    if (feof(file)) {
        *n = 0;
        return false;
    } else {
        *n = fread(buffer, 1, buffer_size, file);
        if (ferror(file)) {
            ovs_fatal(errno, "Error reading input file");
        }
        return *n > 0;
    }
}

static bool
parse_multiple(FILE *stream)
{
    struct json_parser *parser;
    char buffer[BUFSIZ];
    size_t n, used;
    bool ok;

    parser = NULL;
    n = used = 0;
    ok = true;
    while (used < n || refill(stream, buffer, sizeof buffer, &n, &used)) {
        if (!parser && isspace((unsigned char) buffer[used])) {
            /* Skip white space. */
            used++;
        } else {
            if (!parser) {
                parser = json_parser_create(0);
            }

            used += json_parser_feed(parser, &buffer[used], n - used);
            if (used < n) {
                if (!print_and_free_json(json_parser_finish(parser))) {
                    ok = false;
                }
                parser = NULL;
            }
        }
    }
    if (parser) {
        if (!print_and_free_json(json_parser_finish(parser))) {
            ok = false;
        }
    }
    return ok;
}

int
main(int argc, char *argv[])
{
    const char *input_file;
    FILE *stream;
    bool ok;

    set_program_name(argv[0]);

    for (;;) {
        static const struct option options[] = {
            {"pretty", no_argument, &pretty, 1},
            {"multiple", no_argument, &multiple, 1},
        };
        int option_index = 0;
        int c = getopt_long (argc, argv, "", options, &option_index);

        if (c == -1) {
            break;
        }
        switch (c) {
        case 0:
            break;

        case '?':
            exit(1);

        default:
            abort();
        }
    }

    if (argc - optind != 1) {
        ovs_fatal(0, "usage: %s [--pretty] [--multiple] INPUT.json",
                  program_name);
    }

    input_file = argv[optind];
    stream = !strcmp(input_file, "-") ? stdin : fopen(input_file, "r");
    if (!stream) {
        ovs_fatal(errno, "Cannot open \"%s\"", input_file);
    }

    if (multiple) {
        ok = parse_multiple(stream);
    } else {
        ok = print_and_free_json(json_from_stream(stream));
    }

    fclose(stream);

    return !ok;
}
