/* inih -- simple .INI file parser

SPDX-License-Identifier: BSD-3-Clause

Copyright (C) 2009-2020, Ben Hoyt

inih is released under the New BSD license (see LICENSE.txt). Go to the project
home page for more info:

https://github.com/benhoyt/inih

*/

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

#include "ini.h"

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

#if !INI_USE_STACK
#if INI_CUSTOM_ALLOCATOR
#include <stddef.h>
void *ini_malloc(size_t size);
void ini_free(void *ptr);
void *ini_realloc(void *ptr, size_t size);
#else
#include <stdlib.h>
#define ini_malloc malloc
#define ini_free free
#define ini_realloc realloc
#endif
#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 *ini_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 *ini_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 NUL at end of string if neither found. Inline comment must
   be prefixed by a whitespace character to register as a comment. */
static char *ini_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;
}

/* Similar to strncpy, but ensures dest (size bytes) is
   NUL-terminated, and doesn't pad with NULs. */
static char *ini_strncpy0(char *dest, const char *src, size_t size)
{
        /* Could use strncpy internally, but it causes gcc warnings (see issue #91)
     */
        size_t i;
        for (i = 0; i < size - 1 && src[i]; i++)
                dest[i] = src[i];
        dest[i] = '\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];
        size_t max_line = INI_MAX_LINE;
#else
        char *line;
        size_t max_line = INI_INITIAL_ALLOC;
#endif
#if INI_ALLOW_REALLOC && !INI_USE_STACK
        char *new_line;
        size_t offset;
#endif
        char section[MAX_SECTION] = "";
#if INI_ALLOW_MULTILINE
        char prev_name[MAX_NAME] = "";
#endif

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

#if !INI_USE_STACK
        line = (char *)ini_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, (int)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 = ini_realloc(line, max_line);
                        if (!new_line) {
                                ini_free(line);
                                return -2;
                        }
                        line = new_line;
                        if (reader(line + offset, (int)(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 = ini_rstrip(ini_lskip(start));

                if (strchr(INI_START_COMMENT_PREFIXES, *start)) {
                        /* Start-of-line comment */
                }
#if INI_ALLOW_MULTILINE
                else if (*prev_name && *start && start > line) {
#if INI_ALLOW_INLINE_COMMENTS
                        end = ini_find_chars_or_comment(start, NULL);
                        if (*end)
                                *end = '\0';
                        ini_rstrip(start);
#endif
                        /* 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 = ini_find_chars_or_comment(start + 1, "]");
                        if (*end == ']') {
                                *end = '\0';
                                ini_strncpy0(section, start + 1,
                                             sizeof(section));
#if INI_ALLOW_MULTILINE
                                *prev_name = '\0';
#endif
#if INI_CALL_HANDLER_ON_NEW_SECTION
                                if (!HANDLER(user, section, NULL, NULL) &&
                                    !error)
                                        error = lineno;
#endif
                        } else if (!error) {
                                /* No ']' found on section line */
                                error = lineno;
                        }
                } else if (*start) {
                        /* Not a comment, must be a name[=:]value pair */
                        end = ini_find_chars_or_comment(start, "=:");
                        if (*end == '=' || *end == ':') {
                                *end = '\0';
                                name = ini_rstrip(start);
                                value = end + 1;
#if INI_ALLOW_INLINE_COMMENTS
                                end = ini_find_chars_or_comment(value, NULL);
                                if (*end)
                                        *end = '\0';
#endif
                                value = ini_lskip(value);
                                ini_rstrip(value);

#if INI_ALLOW_MULTILINE
                                ini_strncpy0(prev_name, name,
                                             sizeof(prev_name));
#endif
                                /* Valid name[=:]value pair found, call handler */
                                if (!HANDLER(user, section, name, value) &&
                                    !error)
                                        error = lineno;
                        } else if (!error) {
                                /* No '=' or ':' found on name[=:]value line */
#if INI_ALLOW_NO_VALUE
                                *end = '\0';
                                name = ini_rstrip(start);
                                if (!HANDLER(user, section, name, NULL) &&
                                    !error)
                                        error = lineno;
#else
                                error = lineno;
#endif
                        }
                }

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

#if !INI_USE_STACK
        ini_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);
}
