/* inih -- simple .INI file parser

The "inih" library is distributed under the New BSD license:

Copyright (c) 2009, Ben Hoyt
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of Ben Hoyt nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY BEN HOYT ''AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL BEN HOYT BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

https://github.com/benhoyt/inih

*/

#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif

#include <stdio.h>
#include <ctype.h>
#include <string.h>

#include "ini.h"

#if !INI_USE_STACK
#include <stdlib.h>
#endif

#define MAX_SECTION 50
#define MAX_NAME 50

/* Used by ini_parse_string() to keep track of string parsing state. */
typedef struct {
    const char* ptr;
    size_t num_left;
} ini_parse_string_ctx;

/* Strip whitespace chars off end of given string, in place. Return s. */
static char* rstrip(char* s)
{
    char* p = s + strlen(s);
    while (p > s && isspace((unsigned char)(*--p)))
        *p = '\0';
    return s;
}

/* Return pointer to first non-whitespace char in given string. */
static char* lskip(const char* s)
{
    while (*s && isspace((unsigned char)(*s)))
        s++;
    return (char*)s;
}

/* Return pointer to first char (of chars) or inline comment in given string,
   or pointer to null at end of string if neither found. Inline comment must
   be prefixed by a whitespace character to register as a comment. */
static char* find_chars_or_comment(const char* s, const char* chars)
{
#if INI_ALLOW_INLINE_COMMENTS
    int was_space = 0;
    while (*s && (!chars || !strchr(chars, *s)) &&
           !(was_space && strchr(INI_INLINE_COMMENT_PREFIXES, *s))) {
        was_space = isspace((unsigned char)(*s));
        s++;
    }
#else
    while (*s && (!chars || !strchr(chars, *s))) {
        s++;
    }
#endif
    return (char*)s;
}

/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
static char* strncpy0(char* dest, const char* src, size_t size)
{
    strncpy(dest, src, size - 1);
    dest[size - 1] = '\0';
    return dest;
}

/* See documentation in header file. */
int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
                     void* user)
{
    /* Uses a fair bit of stack (use heap instead if you need to) */
#if INI_USE_STACK
    char line[INI_MAX_LINE];
    int max_line = INI_MAX_LINE;
#else
    char* line;
    int max_line = INI_INITIAL_ALLOC;
#endif
#if INI_ALLOW_REALLOC && !INI_USE_STACK
    char* new_line;
    int offset;
#endif
    char section[MAX_SECTION] = "";
    char prev_name[MAX_NAME] = "";

    char* start;
    char* end;
    char* name;
    char* value;
    int lineno = 0;
    int error = 0;

#if !INI_USE_STACK
    line = (char*)malloc(INI_INITIAL_ALLOC);
    if (!line) {
        return -2;
    }
#endif

#if INI_HANDLER_LINENO
#define HANDLER(u, s, n, v) handler(u, s, n, v, lineno)
#else
#define HANDLER(u, s, n, v) handler(u, s, n, v)
#endif

    /* Scan through stream line by line */
    while (reader(line, max_line, stream) != NULL) {
#if INI_ALLOW_REALLOC && !INI_USE_STACK
        offset = strlen(line);
        while (offset == max_line - 1 && line[offset - 1] != '\n') {
            max_line *= 2;
            if (max_line > INI_MAX_LINE)
                max_line = INI_MAX_LINE;
            new_line = realloc(line, max_line);
            if (!new_line) {
                free(line);
                return -2;
            }
            line = new_line;
            if (reader(line + offset, max_line - offset, stream) == NULL)
                break;
            if (max_line >= INI_MAX_LINE)
                break;
            offset += strlen(line + offset);
        }
#endif

        lineno++;

        start = line;
#if INI_ALLOW_BOM
        if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
                           (unsigned char)start[1] == 0xBB &&
                           (unsigned char)start[2] == 0xBF) {
            start += 3;
        }
#endif
        start = lskip(rstrip(start));

        if (strchr(INI_START_COMMENT_PREFIXES, *start)) {
            /* Start-of-line comment */
        }
#if INI_ALLOW_MULTILINE
        else if (*prev_name && *start && start > line) {
            /* Non-blank line with leading whitespace, treat as continuation
               of previous name's value (as per Python configparser). */
            if (!HANDLER(user, section, prev_name, start) && !error)
                error = lineno;
        }
#endif
        else if (*start == '[') {
            /* A "[section]" line */
            end = find_chars_or_comment(start + 1, "]");
            if (*end == ']') {
                *end = '\0';
                strncpy0(section, start + 1, sizeof(section));
                *prev_name = '\0';
            }
            else if (!error) {
                /* No ']' found on section line */
                error = lineno;
            }
        }
        else if (*start) {
            /* Not a comment, must be a name[=:]value pair */
            end = find_chars_or_comment(start, "=:");
            if (*end == '=' || *end == ':') {
                *end = '\0';
                name = rstrip(start);
                value = end + 1;
#if INI_ALLOW_INLINE_COMMENTS
                end = find_chars_or_comment(value, NULL);
                if (*end)
                    *end = '\0';
#endif
                value = lskip(value);
                rstrip(value);

                /* Valid name[=:]value pair found, call handler */
                strncpy0(prev_name, name, sizeof(prev_name));
                if (!HANDLER(user, section, name, value) && !error)
                    error = lineno;
            }
            else if (!error) {
                /* No '=' or ':' found on name[=:]value line */
                error = lineno;
            }
        }

#if INI_STOP_ON_FIRST_ERROR
        if (error)
            break;
#endif
    }

#if !INI_USE_STACK
    free(line);
#endif

    return error;
}

/* See documentation in header file. */
int ini_parse_file(FILE* file, ini_handler handler, void* user)
{
    return ini_parse_stream((ini_reader)fgets, file, handler, user);
}

/* See documentation in header file. */
int ini_parse(const char* filename, ini_handler handler, void* user)
{
    FILE* file;
    int error;

    file = fopen(filename, "r");
    if (!file)
        return -1;
    error = ini_parse_file(file, handler, user);
    fclose(file);
    return error;
}

/* An ini_reader function to read the next line from a string buffer. This
   is the fgets() equivalent used by ini_parse_string(). */
static char* ini_reader_string(char* str, int num, void* stream) {
    ini_parse_string_ctx* ctx = (ini_parse_string_ctx*)stream;
    const char* ctx_ptr = ctx->ptr;
    size_t ctx_num_left = ctx->num_left;
    char* strp = str;
    char c;

    if (ctx_num_left == 0 || num < 2)
        return NULL;

    while (num > 1 && ctx_num_left != 0) {
        c = *ctx_ptr++;
        ctx_num_left--;
        *strp++ = c;
        if (c == '\n')
            break;
        num--;
    }

    *strp = '\0';
    ctx->ptr = ctx_ptr;
    ctx->num_left = ctx_num_left;
    return str;
}

/* See documentation in header file. */
int ini_parse_string(const char* string, ini_handler handler, void* user) {
    ini_parse_string_ctx ctx;

    ctx.ptr = string;
    ctx.num_left = strlen(string);
    return ini_parse_stream((ini_reader)ini_reader_string, &ctx, handler,
                            user);
}