/*
 * Copyright (c) 2010 Serge A. Zaitsev
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * Slightly modified by AK to not assume 0 terminated input.
 */

#include <stdlib.h>
#include "jsmn.h"

/*
 * Allocates a fresh unused token from the token pool.
 */
static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser,
                                   jsmntok_t *tokens, size_t num_tokens)
{
        jsmntok_t *tok;

        if ((unsigned)parser->toknext >= num_tokens)
                return NULL;
        tok = &tokens[parser->toknext++];
        tok->start = tok->end = -1;
        tok->size = 0;
        return tok;
}

/*
 * Fills token type and boundaries.
 */
static void jsmn_fill_token(jsmntok_t *token, jsmntype_t type,
                            int start, int end)
{
        token->type = type;
        token->start = start;
        token->end = end;
        token->size = 0;
}

/*
 * Fills next available token with JSON primitive.
 */
static jsmnerr_t jsmn_parse_primitive(jsmn_parser *parser, const char *js,
                                      size_t len,
                                      jsmntok_t *tokens, size_t num_tokens)
{
        jsmntok_t *token;
        int start;

        start = parser->pos;

        for (; parser->pos < len; parser->pos++) {
                switch (js[parser->pos]) {
#ifndef JSMN_STRICT
                /*
                 * In strict mode primitive must be followed by ","
                 * or "}" or "]"
                 */
                case ':':
#endif
                case '\t':
                case '\r':
                case '\n':
                case ' ':
                case ',':
                case ']':
                case '}':
                        goto found;
                default:
                        break;
                }
                if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
                        parser->pos = start;
                        return JSMN_ERROR_INVAL;
                }
        }
#ifdef JSMN_STRICT
        /*
         * In strict mode primitive must be followed by a
         * comma/object/array.
         */
        parser->pos = start;
        return JSMN_ERROR_PART;
#endif

found:
        token = jsmn_alloc_token(parser, tokens, num_tokens);
        if (token == NULL) {
                parser->pos = start;
                return JSMN_ERROR_NOMEM;
        }
        jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
        parser->pos--; /* parent sees closing brackets */
        return JSMN_SUCCESS;
}

/*
 * Fills next token with JSON string.
 */
static jsmnerr_t jsmn_parse_string(jsmn_parser *parser, const char *js,
                                   size_t len,
                                   jsmntok_t *tokens, size_t num_tokens)
{
        jsmntok_t *token;
        int start = parser->pos;

        /* Skip starting quote */
        parser->pos++;

        for (; parser->pos < len; parser->pos++) {
                char c = js[parser->pos];

                /* Quote: end of string */
                if (c == '\"') {
                        token = jsmn_alloc_token(parser, tokens, num_tokens);
                        if (token == NULL) {
                                parser->pos = start;
                                return JSMN_ERROR_NOMEM;
                        }
                        jsmn_fill_token(token, JSMN_STRING, start+1,
                                        parser->pos);
                        return JSMN_SUCCESS;
                }

                /* Backslash: Quoted symbol expected */
                if (c == '\\') {
                        parser->pos++;
                        switch (js[parser->pos]) {
                                /* Allowed escaped symbols */
                        case '\"':
                        case '/':
                        case '\\':
                        case 'b':
                        case 'f':
                        case 'r':
                        case 'n':
                        case 't':
                                break;
                                /* Allows escaped symbol \uXXXX */
                        case 'u':
                                /* TODO */
                                break;
                                /* Unexpected symbol */
                        default:
                                parser->pos = start;
                                return JSMN_ERROR_INVAL;
                        }
                }
        }
        parser->pos = start;
        return JSMN_ERROR_PART;
}

/*
 * Parse JSON string and fill tokens.
 */
jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, size_t len,
                     jsmntok_t *tokens, unsigned int num_tokens)
{
        jsmnerr_t r;
        int i;
        jsmntok_t *token;

        for (; parser->pos < len; parser->pos++) {
                char c;
                jsmntype_t type;

                c = js[parser->pos];
                switch (c) {
                case '{':
                case '[':
                        token = jsmn_alloc_token(parser, tokens, num_tokens);
                        if (token == NULL)
                                return JSMN_ERROR_NOMEM;
                        if (parser->toksuper != -1)
                                tokens[parser->toksuper].size++;
                        token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
                        token->start = parser->pos;
                        parser->toksuper = parser->toknext - 1;
                        break;
                case '}':
                case ']':
                        type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
                        for (i = parser->toknext - 1; i >= 0; i--) {
                                token = &tokens[i];
                                if (token->start != -1 && token->end == -1) {
                                        if (token->type != type)
                                                return JSMN_ERROR_INVAL;
                                        parser->toksuper = -1;
                                        token->end = parser->pos + 1;
                                        break;
                                }
                        }
                        /* Error if unmatched closing bracket */
                        if (i == -1)
                                return JSMN_ERROR_INVAL;
                        for (; i >= 0; i--) {
                                token = &tokens[i];
                                if (token->start != -1 && token->end == -1) {
                                        parser->toksuper = i;
                                        break;
                                }
                        }
                        break;
                case '\"':
                        r = jsmn_parse_string(parser, js, len, tokens,
                                              num_tokens);
                        if (r < 0)
                                return r;
                        if (parser->toksuper != -1)
                                tokens[parser->toksuper].size++;
                        break;
                case '\t':
                case '\r':
                case '\n':
                case ':':
                case ',':
                case ' ':
                        break;
#ifdef JSMN_STRICT
                        /*
                         * In strict mode primitives are:
                         * numbers and booleans.
                         */
                case '-':
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                case '8':
                case '9':
                case 't':
                case 'f':
                case 'n':
#else
                        /*
                         * In non-strict mode every unquoted value
                         * is a primitive.
                         */
                        /*FALL THROUGH */
                default:
#endif
                        r = jsmn_parse_primitive(parser, js, len, tokens,
                                                 num_tokens);
                        if (r < 0)
                                return r;
                        if (parser->toksuper != -1)
                                tokens[parser->toksuper].size++;
                        break;

#ifdef JSMN_STRICT
                        /* Unexpected char in strict mode */
                default:
                        return JSMN_ERROR_INVAL;
#endif
                }
        }

        for (i = parser->toknext - 1; i >= 0; i--) {
                /* Unmatched opened object or array */
                if (tokens[i].start != -1 && tokens[i].end == -1)
                        return JSMN_ERROR_PART;
        }

        return JSMN_SUCCESS;
}

/*
 * Creates a new parser based over a given  buffer with an array of tokens
 * available.
 */
void jsmn_init(jsmn_parser *parser)
{
        parser->pos = 0;
        parser->toknext = 0;
        parser->toksuper = -1;
}

const char *jsmn_strerror(jsmnerr_t err)
{
        switch (err) {
        case JSMN_ERROR_NOMEM:
                return "No enough tokens";
        case JSMN_ERROR_INVAL:
                return "Invalid character inside JSON string";
        case JSMN_ERROR_PART:
                return "The string is not a full JSON packet, more bytes expected";
        case JSMN_SUCCESS:
                return "Success";
        default:
                return "Unknown json error";
        }
}