/*
 * fileio.c
 * File reading utilities
 *
 * Copyright (c) 2012, 2025 pkgconf authors (see AUTHORS).
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * This software is provided 'as is' and without any warranty, express or
 * implied.  In no event shall the authors be liable for any damages arising
 * from the use of this software.
 */

#include <libpkgconf/stdinc.h>
#include <libpkgconf/libpkgconf.h>

bool
pkgconf_fgetline(pkgconf_buffer_t *buffer, FILE *stream)
{
        bool quoted = false;
        int c = '\0', c2;

        while ((c = getc(stream)) != EOF)
        {
                if (c == '\\' && !quoted)
                {
                        quoted = true;
                        continue;
                }
                else if (c == '#')
                {
                        if (!quoted) {
                                /* Skip the rest of the line */
                                do {
                                        c = getc(stream);
                                } while (c != '\n' && c != EOF);
                                pkgconf_buffer_push_byte(buffer, c);
                                break;
                        }
                        else
                                pkgconf_buffer_push_byte(buffer, c);

                        quoted = false;
                        continue;
                }
                else if (c == '\n')
                {
                        if (quoted)
                        {
                                /* Trim spaces */
                                do {
                                        c2 = getc(stream);
                                } while (c2 == '\t' || c2 == ' ');

                                ungetc(c2, stream);

                                quoted = false;
                                continue;
                        }
                        else
                        {
                                pkgconf_buffer_push_byte(buffer, c);
                        }

                        break;
                }
                else if (c == '\r')
                {
                        pkgconf_buffer_push_byte(buffer, '\n');

                        if ((c2 = getc(stream)) == '\n')
                        {
                                if (quoted)
                                {
                                        quoted = false;
                                        continue;
                                }

                                break;
                        }

                        ungetc(c2, stream);

                        if (quoted)
                        {
                                quoted = false;
                                continue;
                        }

                        break;
                }
                else
                {
                        if (quoted) {
                                pkgconf_buffer_push_byte(buffer, '\\');
                                quoted = false;
                        }
                        pkgconf_buffer_push_byte(buffer, c);
                }

        }

        /* Remove newline character. */
        if (pkgconf_buffer_lastc(buffer) == '\n')
                pkgconf_buffer_trim_byte(buffer);

        if (pkgconf_buffer_lastc(buffer) == '\r')
                pkgconf_buffer_trim_byte(buffer);

        return !(c == EOF || ferror(stream));
}