chatmail-core/src/dc_tools.rs

//! Some tools and enhancements to the used libraries, there should be
//! no references to Context and other "larger" entities here.

use std::borrow::Cow;
use std::ffi::{CStr, CString, OsString};
use std::path::{Path, PathBuf};
use std::str::FromStr;
use std::time::SystemTime;
use std::{fmt, fs, ptr};

use chrono::{Local, TimeZone};
use libc::uintptr_t;
use mmime::clist::*;
use mmime::mailimf_types::*;
use rand::{thread_rng, Rng};

use crate::context::Context;
use crate::error::Error;
use crate::x::*;

pub fn dc_exactly_one_bit_set(v: libc::c_int) -> bool {
    0 != v && 0 == v & (v - 1)
}

/// Duplicates a string
///
/// returns an empty string if NULL is given, never returns NULL (exits on errors)
///
/// # Examples
///
/// ```
/// use deltachat::dc_tools::{dc_strdup, to_string};
/// unsafe {
///     let str_a = b"foobar\x00" as *const u8 as *const libc::c_char;
///     let str_a_copy = dc_strdup(str_a);
///     assert_eq!(to_string(str_a_copy), "foobar");
///     assert_ne!(str_a, str_a_copy);
/// }
/// ```
pub unsafe fn dc_strdup(s: *const libc::c_char) -> *mut libc::c_char {
    let ret: *mut libc::c_char;
    if !s.is_null() {
        ret = strdup(s);
        assert!(!ret.is_null());
    } else {
        ret = calloc(1, 1) as *mut libc::c_char;
        assert!(!ret.is_null());
    }

    ret
}

/// Duplicates a string, returns null if given string is null
///
/// # Examples
///
/// ```
/// use deltachat::dc_tools::{dc_strdup_keep_null, to_string};
/// use std::ffi::{CStr};
///
/// unsafe {
///     let str_a = b"foobar\x00" as *const u8 as *const libc::c_char;
///     let str_a_copy = dc_strdup_keep_null(str_a);
///     assert_eq!(to_string(str_a_copy), "foobar");
///     assert_ne!(str_a, str_a_copy);
/// }
/// ```
pub unsafe fn dc_strdup_keep_null(s: *const libc::c_char) -> *mut libc::c_char {
    if !s.is_null() {
        dc_strdup(s)
    } else {
        ptr::null_mut()
    }
}

pub unsafe fn dc_atoi_null_is_0(s: *const libc::c_char) -> libc::c_int {
    if !s.is_null() {
        as_str(s).parse().unwrap_or_default()
    } else {
        0
    }
}

pub unsafe fn dc_str_replace(
    haystack: *mut *mut libc::c_char,
    needle: *const libc::c_char,
    replacement: *const libc::c_char,
) {
    let haystack_s = to_string(*haystack);
    let needle_s = to_string(needle);
    let replacement_s = to_string(replacement);

    free(*haystack as *mut libc::c_void);

    *haystack = haystack_s.replace(&needle_s, &replacement_s).strdup();
}

unsafe fn dc_ltrim(buf: *mut libc::c_char) {
    let mut len: libc::size_t;
    let mut cur: *const libc::c_uchar;
    if !buf.is_null() && 0 != *buf as libc::c_int {
        len = strlen(buf);
        cur = buf as *const libc::c_uchar;
        while 0 != *cur as libc::c_int && 0 != libc::isspace(*cur as libc::c_int) {
            cur = cur.offset(1isize);
            len = len.wrapping_sub(1)
        }
        if buf as *const libc::c_uchar != cur {
            memmove(
                buf as *mut libc::c_void,
                cur as *const libc::c_void,
                len.wrapping_add(1),
            );
        }
    };
}

unsafe fn dc_rtrim(buf: *mut libc::c_char) {
    let mut len: libc::size_t;
    let mut cur: *mut libc::c_uchar;
    if !buf.is_null() && 0 != *buf as libc::c_int {
        len = strlen(buf);
        cur = (buf as *mut libc::c_uchar)
            .offset(len as isize)
            .offset(-1isize);
        while cur != buf as *mut libc::c_uchar && 0 != libc::isspace(*cur as libc::c_int) {
            cur = cur.offset(-1isize);
            len = len.wrapping_sub(1)
        }
        *cur.offset(
            (if 0 != libc::isspace(*cur as libc::c_int) {
                0
            } else {
                1
            }) as isize,
        ) = '\u{0}' as i32 as libc::c_uchar
    };
}

pub unsafe fn dc_trim(buf: *mut libc::c_char) {
    dc_ltrim(buf);
    dc_rtrim(buf);
}

/* the result must be free()'d */
pub unsafe fn dc_null_terminate(
    in_0: *const libc::c_char,
    bytes: libc::c_int,
) -> *mut libc::c_char {
    let out: *mut libc::c_char = malloc(bytes as usize + 1) as *mut libc::c_char;
    assert!(!out.is_null());
    if !in_0.is_null() && bytes > 0 {
        strncpy(out, in_0, bytes as usize);
    }
    *out.offset(bytes as isize) = 0 as libc::c_char;

    out
}

/* remove all \r characters from string */
pub unsafe fn dc_remove_cr_chars(buf: *mut libc::c_char) {
    /* search for first `\r` */
    let mut p1: *const libc::c_char = buf;
    while 0 != *p1 {
        if *p1 as libc::c_int == '\r' as i32 {
            break;
        }
        p1 = p1.offset(1isize)
    }
    /* p1 is `\r` or null-byte; start removing `\r` */
    let mut p2: *mut libc::c_char = p1 as *mut libc::c_char;
    while 0 != *p1 {
        if *p1 as libc::c_int != '\r' as i32 {
            *p2 = *p1;
            p2 = p2.offset(1isize)
        }
        p1 = p1.offset(1isize)
    }
    *p2 = 0 as libc::c_char;
}

/* replace bad UTF-8 characters by sequences of `_` (to avoid problems in filenames, we do not use eg. `?`) the function is useful if strings are unexpectingly encoded eg. as ISO-8859-1 */
#[allow(non_snake_case)]
pub unsafe fn dc_replace_bad_utf8_chars(buf: *mut libc::c_char) {
    let mut OK_TO_CONTINUE = true;
    if buf.is_null() {
        return;
    }
    /* force unsigned - otherwise the `> ' '` comparison will fail */
    let mut p1: *mut libc::c_uchar = buf as *mut libc::c_uchar;
    let p1len: libc::c_int = strlen(buf) as libc::c_int;
    let mut c: libc::c_int;
    let mut i: libc::c_int;
    let ix: libc::c_int;
    let mut n: libc::c_int;
    let mut j: libc::c_int;
    i = 0;
    ix = p1len;
    's_36: loop {
        if !(i < ix) {
            break;
        }
        c = *p1.offset(i as isize) as libc::c_int;
        if c > 0 && c <= 0x7f {
            n = 0
        } else if c & 0xe0 == 0xc0 {
            n = 1
        } else if c == 0xed
            && i < ix - 1
            && *p1.offset((i + 1) as isize) as libc::c_int & 0xa0 == 0xa0
        {
            /* U+d800 to U+dfff */
            OK_TO_CONTINUE = false;
            break;
        } else if c & 0xf0 == 0xe0 {
            n = 2
        } else if c & 0xf8 == 0xf0 {
            n = 3
        } else {
            //else if ((c & 0xFC) == 0xF8)                          { n=4; }        /* 111110bb - not valid in https://tools.ietf.org/html/rfc3629 */
            //else if ((c & 0xFE) == 0xFC)                          { n=5; }        /* 1111110b - not valid in https://tools.ietf.org/html/rfc3629 */
            OK_TO_CONTINUE = false;
            break;
        }
        j = 0;
        while j < n && i < ix {
            /* n bytes matching 10bbbbbb follow ? */
            i += 1;
            if i == ix || *p1.offset(i as isize) as libc::c_int & 0xc0 != 0x80 {
                OK_TO_CONTINUE = false;
                break 's_36;
            }
            j += 1
        }
        i += 1
    }
    if OK_TO_CONTINUE == false {
        while 0 != *p1 {
            if *p1 as libc::c_int > 0x7f {
                *p1 = '_' as i32 as libc::c_uchar
            }
            p1 = p1.offset(1isize)
        }
        return;
    }
}

/// Shortens a string to a specified length and adds "..." or "[...]" to the end of
/// the shortened string.
///
/// # Examples
/// ```
/// use deltachat::dc_tools::dc_truncate;
///
/// let s = "this is a little test string";
/// assert_eq!(dc_truncate(s, 16, false), "this is a [...]");
/// assert_eq!(dc_truncate(s, 16, true), "this is a ...");
/// ```
pub fn dc_truncate(buf: &str, approx_chars: usize, do_unwrap: bool) -> Cow<str> {
    let ellipse = if do_unwrap { "..." } else { "[...]" };

    let count = buf.chars().count();
    if approx_chars > 0 && count > approx_chars + ellipse.len() {
        let end_pos = buf
            .char_indices()
            .nth(approx_chars)
            .map(|(n, _)| n)
            .unwrap_or_default();

        if let Some(index) = buf[..end_pos].rfind(|c| c == ' ' || c == '\n') {
            Cow::Owned(format!("{}{}", &buf[..index + 1], ellipse))
        } else {
            Cow::Owned(format!("{}{}", &buf[..end_pos], ellipse))
        }
    } else {
        Cow::Borrowed(buf)
    }
}

#[allow(non_snake_case)]
pub unsafe fn dc_truncate_n_unwrap_str(
    buf: *mut libc::c_char,
    approx_characters: libc::c_int,
    do_unwrap: libc::c_int,
) {
    /* Function unwraps the given string and removes unnecessary whitespace.
    Function stops processing after approx_characters are processed.
    (as we're using UTF-8, for simplicity, we cut the string only at whitespaces). */
    /* a single line is truncated `...` instead of `[...]` (the former is typically also used by the UI to fit strings in a rectangle) */
    let ellipse_utf8: *const libc::c_char = if 0 != do_unwrap {
        b" ...\x00" as *const u8 as *const libc::c_char
    } else {
        b" [...]\x00" as *const u8 as *const libc::c_char
    };
    let mut lastIsCharacter: libc::c_int = 0;
    /* force unsigned - otherwise the `> ' '` comparison will fail */
    let mut p1: *mut libc::c_uchar = buf as *mut libc::c_uchar;
    while 0 != *p1 {
        if *p1 as libc::c_int > ' ' as i32 {
            lastIsCharacter = 1
        } else if 0 != lastIsCharacter {
            let used_bytes = (p1 as uintptr_t).wrapping_sub(buf as uintptr_t) as libc::size_t;
            if dc_utf8_strnlen(buf, used_bytes) >= approx_characters as usize {
                let buf_bytes = strlen(buf);
                if buf_bytes.wrapping_sub(used_bytes) >= strlen(ellipse_utf8) {
                    strcpy(p1 as *mut libc::c_char, ellipse_utf8);
                }
                break;
            } else {
                lastIsCharacter = 0;
                if 0 != do_unwrap {
                    *p1 = ' ' as i32 as libc::c_uchar
                }
            }
        } else if 0 != do_unwrap {
            *p1 = '\r' as i32 as libc::c_uchar
        }
        p1 = p1.offset(1isize)
    }
    if 0 != do_unwrap {
        dc_remove_cr_chars(buf);
    };
}

unsafe fn dc_utf8_strnlen(s: *const libc::c_char, n: libc::size_t) -> libc::size_t {
    if s.is_null() {
        return 0;
    }

    let mut j: libc::size_t = 0;
    for i in 0..n {
        if *s.add(i) as libc::c_int & 0xc0 != 0x80 {
            j = j.wrapping_add(1)
        }
    }

    j
}

pub unsafe fn dc_str_from_clist(
    list: *const clist,
    delimiter: *const libc::c_char,
) -> *mut libc::c_char {
    let mut res = String::new();

    if !list.is_null() {
        let mut cur: *mut clistiter = (*list).first;
        while !cur.is_null() {
            let rfc724_mid = (if !cur.is_null() {
                (*cur).data
            } else {
                ptr::null_mut()
            }) as *const libc::c_char;

            if !rfc724_mid.is_null() {
                if !res.is_empty() && !delimiter.is_null() {
                    res += as_str(delimiter);
                }
                res += as_str(rfc724_mid);
            }
            cur = if !cur.is_null() {
                (*cur).next
            } else {
                ptr::null_mut()
            }
        }
    }

    res.strdup()
}

pub unsafe fn dc_str_to_clist(
    str: *const libc::c_char,
    delimiter: *const libc::c_char,
) -> *mut clist {
    let list: *mut clist = clist_new();
    assert!(!list.is_null());

    if !str.is_null() && !delimiter.is_null() && strlen(delimiter) >= 1 {
        let mut p1: *const libc::c_char = str;
        loop {
            let p2: *const libc::c_char = strstr(p1, delimiter);
            if p2.is_null() {
                clist_insert_after(list, (*list).last, strdup(p1) as *mut libc::c_void);
                break;
            } else {
                clist_insert_after(
                    list,
                    (*list).last,
                    strndup(p1, p2.wrapping_offset_from(p1) as libc::c_ulong) as *mut libc::c_void,
                );
                p1 = p2.add(strlen(delimiter))
            }
        }
    }

    list
}

/* the colors must fulfill some criterions as:
- contrast to black and to white
- work as a text-color
- being noticeable on a typical map
- harmonize together while being different enough
(therefore, we cannot just use random rgb colors :) */
const COLORS: [u32; 16] = [
    0xe56555, 0xf28c48, 0x8e85ee, 0x76c84d, 0x5bb6cc, 0x549cdd, 0xd25c99, 0xb37800, 0xf23030,
    0x39b249, 0xbb243b, 0x964078, 0x66874f, 0x308ab9, 0x127ed0, 0xbe450c,
];

pub fn dc_str_to_color(s: impl AsRef<str>) -> u32 {
    let str_lower = s.as_ref().to_lowercase();
    let mut checksum = 0;
    let bytes = str_lower.as_bytes();
    for (i, byte) in bytes.iter().enumerate() {
        checksum += (i + 1) * *byte as usize;
        checksum %= 0xffffff;
    }
    let color_index = checksum % COLORS.len();

    COLORS[color_index]
}

/* clist tools */
/* calls free() for each item content */
pub unsafe fn clist_free_content(haystack: *const clist) {
    let mut iter = (*haystack).first;

    while !iter.is_null() {
        free((*iter).data);
        (*iter).data = ptr::null_mut();
        iter = if !iter.is_null() {
            (*iter).next
        } else {
            ptr::null_mut()
        }
    }
}

pub unsafe fn clist_search_string_nocase(
    haystack: *const clist,
    needle: *const libc::c_char,
) -> bool {
    (&*haystack)
        .into_iter()
        .any(|data| strcasecmp(data.cast(), needle) == 0)
}

/* date/time tools */
/* the result is UTC or DC_INVALID_TIMESTAMP */
pub unsafe fn dc_timestamp_from_date(date_time: *mut mailimf_date_time) -> i64 {
    let sec = (*date_time).dt_sec;
    let min = (*date_time).dt_min;
    let hour = (*date_time).dt_hour;
    let day = (*date_time).dt_day;
    let month = (*date_time).dt_month;
    let year = (*date_time).dt_year;

    let ts = chrono::NaiveDateTime::new(
        chrono::NaiveDate::from_ymd(year, month as u32, day as u32),
        chrono::NaiveTime::from_hms(hour as u32, min as u32, sec as u32),
    );

    let (zone_hour, zone_min) = if (*date_time).dt_zone >= 0 {
        ((*date_time).dt_zone / 100, (*date_time).dt_zone % 100)
    } else {
        (
            -(-(*date_time).dt_zone / 100),
            -(-(*date_time).dt_zone % 100),
        )
    };

    ts.timestamp() - (zone_hour * 3600 + zone_min * 60) as i64
}

/* ******************************************************************************
 * date/time tools
 ******************************************************************************/

pub fn dc_timestamp_to_str(wanted: i64) -> String {
    let ts = chrono::Utc.timestamp(wanted, 0);
    ts.format("%Y.%m.%d %H:%M:%S").to_string()
}

pub fn dc_gm2local_offset() -> i64 {
    let lt = Local::now();
    ((lt.offset().local_minus_utc() / (60 * 60)) * 100) as i64
}

/* timesmearing */
pub fn dc_smeared_time(context: &Context) -> i64 {
    /* function returns a corrected time(NULL) */
    let mut now = time();
    let ts = *context.last_smeared_timestamp.clone().read().unwrap();
    if ts >= now {
        now = ts + 1;
    }

    now
}

pub fn dc_create_smeared_timestamp(context: &Context) -> i64 {
    let now = time();
    let mut ret = now;

    let ts = *context.last_smeared_timestamp.clone().write().unwrap();
    if ret <= ts {
        ret = ts + 1;
        if ret - now > 5 {
            ret = now + 5
        }
    }

    ret
}

pub fn dc_create_smeared_timestamps(context: &Context, count: libc::c_int) -> i64 {
    /* get a range to timestamps that can be used uniquely */
    let now = time();
    let start = now + (if count < 5 { count } else { 5 }) as i64 - count as i64;

    let ts = *context.last_smeared_timestamp.clone().write().unwrap();
    if ts + 1 > start {
        ts + 1
    } else {
        start
    }
}

/* Message-ID tools */
pub fn dc_create_id() -> String {
    /* generate an id. the generated ID should be as short and as unique as possible:
    - short, because it may also used as part of Message-ID headers or in QR codes
    - unique as two IDs generated on two devices should not be the same. However, collisions are not world-wide but only by the few contacts.
    IDs generated by this function are 66 bit wide and are returned as 11 base64 characters.
    If possible, RNG of OpenSSL is used.

    Additional information when used as a message-id or group-id:
    - for OUTGOING messages this ID is written to the header as `Chat-Group-ID:` and is added to the message ID as Gr.<grpid>.<random>@<random>
    - for INCOMING messages, the ID is taken from the Chat-Group-ID-header or from the Message-ID in the In-Reply-To: or References:-Header
    - the group-id should be a string with the characters [a-zA-Z0-9\-_] */

    let mut rng = thread_rng();
    let buf: [u32; 3] = [rng.gen(), rng.gen(), rng.gen()];

    encode_66bits_as_base64(buf[0usize], buf[1usize], buf[2usize])
}

/// Encode 66 bits as a base64 string.
/// This is useful for ID generating with short strings as we save 5 character
/// in each id compared to 64 bit hex encoding. For a typical group ID, these
/// are 10 characters (grpid+msgid):
///    hex:    64 bit, 4 bits/character, length = 64/4 = 16 characters
///    base64: 64 bit, 6 bits/character, length = 64/6 = 11 characters (plus 2 additional bits)
/// Only the lower 2 bits of `fill` are used.
fn encode_66bits_as_base64(v1: u32, v2: u32, fill: u32) -> String {
    use byteorder::{BigEndian, WriteBytesExt};

    let mut wrapped_writer = Vec::new();
    {
        let mut enc = base64::write::EncoderWriter::new(&mut wrapped_writer, base64::URL_SAFE);
        enc.write_u32::<BigEndian>(v1).unwrap();
        enc.write_u32::<BigEndian>(v2).unwrap();
        enc.write_u8(((fill & 0x3) as u8) << 6).unwrap();
        enc.finish().unwrap();
    }
    assert_eq!(wrapped_writer.pop(), Some('A' as u8)); // Remove last "A"
    String::from_utf8(wrapped_writer).unwrap()
}

pub fn dc_create_incoming_rfc724_mid(
    message_timestamp: i64,
    contact_id_from: u32,
    contact_ids_to: &Vec<u32>,
) -> *mut libc::c_char {
    if contact_ids_to.is_empty() {
        return ptr::null_mut();
    }
    /* find out the largest receiver ID (we could also take the smallest, but it should be unique) */
    let largest_id_to = contact_ids_to.iter().max().copied().unwrap_or_default();

    let result = format!(
        "{}-{}-{}@stub",
        message_timestamp, contact_id_from, largest_id_to
    );

    unsafe { result.strdup() }
}

/// Function generates a Message-ID that can be used for a new outgoing message.
/// - this function is called for all outgoing messages.
/// - the message ID should be globally unique
/// - do not add a counter or any private data as as this may give unneeded information to the receiver
pub unsafe fn dc_create_outgoing_rfc724_mid(
    grpid: *const libc::c_char,
    from_addr: *const libc::c_char,
) -> *mut libc::c_char {
    let rand2 = dc_create_id();

    let at_hostname = as_opt_str(strchr(from_addr, '@' as i32)).unwrap_or_else(|| "@nohost");

    let ret = if !grpid.is_null() {
        format!("Gr.{}.{}{}", as_str(grpid), rand2, at_hostname,)
    } else {
        let rand1 = dc_create_id();
        format!("Mr.{}.{}{}", rand1, rand2, at_hostname)
    };

    ret.strdup()
}

/// Generate globally-unique message-id for a new outgoing message.
///
/// Note: Do not add a counter or any private data as as this may give
/// unneeded information to the receiver
pub fn dc_create_outgoing_rfc724_mid_safe(grpid: Option<&str>, from_addr: &str) -> String {
    let hostname = from_addr
        .find('@')
        .map(|k| &from_addr[k..])
        .unwrap_or("@nohost");
    match grpid {
        Some(grpid) => format!("Gr.{}.{}{}", grpid, dc_create_id(), hostname),
        None => format!("Mr.{}.{}{}", dc_create_id(), dc_create_id(), hostname),
    }
}

/// Extract the group id (grpid) from a message id (mid)
///
/// # Arguments
///
/// * `mid` - A string that holds the message id
///
/// # Examples
///
/// ```
/// use deltachat::dc_tools::dc_extract_grpid_from_rfc724_mid;
/// let mid = "Gr.12345678901.morerandom@domain.de";
/// let grpid = dc_extract_grpid_from_rfc724_mid(mid);
/// assert_eq!(grpid, Some("12345678901"));
/// ```
pub fn dc_extract_grpid_from_rfc724_mid(mid: &str) -> Option<&str> {
    if mid.len() < 9 || !mid.starts_with("Gr.") {
        return None;
    }

    if let Some(mid_without_offset) = mid.get(3..) {
        if let Some(grpid_len) = mid_without_offset.find('.') {
            /* strict length comparison, the 'Gr.' magic is weak enough */
            if grpid_len == 11 || grpid_len == 16 {
                return Some(mid_without_offset.get(0..grpid_len).unwrap());
            }
        }
    }

    None
}

pub unsafe fn dc_extract_grpid_from_rfc724_mid_list(list: *const clist) -> *mut libc::c_char {
    if !list.is_null() {
        let mut cur: *mut clistiter = (*list).first;
        while !cur.is_null() {
            let mid = if !cur.is_null() {
                as_str((*cur).data as *const libc::c_char)
            } else {
                ""
            };

            if let Some(grpid) = dc_extract_grpid_from_rfc724_mid(mid) {
                return grpid.strdup();
            }
            cur = if !cur.is_null() {
                (*cur).next
            } else {
                ptr::null_mut()
            }
        }
    }

    ptr::null_mut()
}

pub fn dc_ensure_no_slash_safe(path: &str) -> &str {
    if path.ends_with('/') || path.ends_with('\\') {
        return &path[..path.len() - 1];
    }
    path
}

/// Function modifies the given buffer and replaces all characters not valid in filenames by a "-".
fn validate_filename(filename: &str) -> String {
    filename
        .replace('/', "-")
        .replace('\\', "-")
        .replace(':', "-")
}

pub unsafe fn dc_get_filename(path_filename: impl AsRef<str>) -> *mut libc::c_char {
    if let Some(p) = Path::new(path_filename.as_ref()).file_name() {
        p.to_string_lossy().strdup()
    } else {
        ptr::null_mut()
    }
}

// the returned suffix is lower-case
#[allow(non_snake_case)]
pub unsafe fn dc_get_filesuffix_lc(path_filename: impl AsRef<str>) -> *mut libc::c_char {
    if let Some(p) = Path::new(path_filename.as_ref()).extension() {
        p.to_string_lossy().to_lowercase().strdup()
    } else {
        ptr::null_mut()
    }
}

/// Returns the `(width, height)` of the given image buffer.
pub fn dc_get_filemeta(buf: &[u8]) -> Result<(u32, u32), Error> {
    let meta = image_meta::load_from_buf(buf)?;

    Ok((meta.dimensions.width, meta.dimensions.height))
}

/// Expand paths relative to $BLOBDIR into absolute paths.
///
/// If `path` starts with "$BLOBDIR", replaces it with the blobdir path.
/// Otherwise, returns path as is.
pub fn dc_get_abs_path<P: AsRef<std::path::Path>>(
    context: &Context,
    path: P,
) -> std::path::PathBuf {
    let p: &std::path::Path = path.as_ref();
    if let Ok(p) = p.strip_prefix("$BLOBDIR") {
        context.get_blobdir().join(p)
    } else {
        p.into()
    }
}

pub fn dc_file_exist(context: &Context, path: impl AsRef<std::path::Path>) -> bool {
    dc_get_abs_path(context, &path).exists()
}

pub fn dc_get_filebytes(context: &Context, path: impl AsRef<std::path::Path>) -> u64 {
    let path_abs = dc_get_abs_path(context, &path);
    match fs::metadata(&path_abs) {
        Ok(meta) => meta.len() as u64,
        Err(_err) => 0,
    }
}

pub fn dc_delete_file(context: &Context, path: impl AsRef<std::path::Path>) -> bool {
    let path_abs = dc_get_abs_path(context, &path);
    if !path_abs.is_file() {
        warn!(
            context,
            "Will not delete directory \"{}\".",
            path.as_ref().display()
        );
        return false;
    }

    match fs::remove_file(path_abs) {
        Ok(_) => true,
        Err(_err) => {
            warn!(context, "Cannot delete \"{}\".", path.as_ref().display());
            false
        }
    }
}

pub fn dc_copy_file(
    context: &Context,
    src: impl AsRef<std::path::Path>,
    dest: impl AsRef<std::path::Path>,
) -> bool {
    let src_abs = dc_get_abs_path(context, &src);
    let dest_abs = dc_get_abs_path(context, &dest);
    match fs::copy(&src_abs, &dest_abs) {
        Ok(_) => true,
        Err(_) => {
            error!(
                context,
                "Cannot copy \"{}\" to \"{}\".",
                src.as_ref().display(),
                dest.as_ref().display(),
            );
            false
        }
    }
}

pub fn dc_create_folder(context: &Context, path: impl AsRef<std::path::Path>) -> bool {
    let path_abs = dc_get_abs_path(context, &path);
    if !path_abs.exists() {
        match fs::create_dir_all(path_abs) {
            Ok(_) => true,
            Err(_err) => {
                warn!(
                    context,
                    "Cannot create directory \"{}\".",
                    path.as_ref().display(),
                );
                false
            }
        }
    } else {
        true
    }
}

/// Write a the given content to provied file path.
pub fn dc_write_file(context: &Context, path: impl AsRef<Path>, buf: &[u8]) -> bool {
    let path_abs = dc_get_abs_path(context, &path);
    if let Err(_err) = fs::write(&path_abs, buf) {
        warn!(
            context,
            "Cannot write {} bytes to \"{}\".",
            buf.len(),
            path.as_ref().display(),
        );
        false
    } else {
        true
    }
}

#[allow(non_snake_case)]
pub unsafe fn dc_read_file(
    context: &Context,
    pathNfilename: *const libc::c_char,
    buf: *mut *mut libc::c_void,
    buf_bytes: *mut libc::size_t,
) -> libc::c_int {
    if pathNfilename.is_null() {
        return 0;
    }
    if let Some(mut bytes) = dc_read_file_safe(context, as_str(pathNfilename)) {
        *buf = &mut bytes[..] as *mut _ as *mut libc::c_void;
        *buf_bytes = bytes.len();
        std::mem::forget(bytes);
        1
    } else {
        0
    }
}

pub fn dc_read_file_safe<P: AsRef<std::path::Path>>(context: &Context, path: P) -> Option<Vec<u8>> {
    let path_abs = dc_get_abs_path(context, &path);
    match fs::read(&path_abs) {
        Ok(bytes) => Some(bytes),
        Err(_err) => {
            warn!(
                context,
                "Cannot read \"{}\" or file is empty.",
                path.as_ref().display()
            );
            None
        }
    }
}

pub fn dc_get_fine_path_filename(
    context: &Context,
    folder: impl AsRef<Path>,
    desired_filename_suffix: impl AsRef<str>,
) -> PathBuf {
    let now = time();

    let folder = PathBuf::from(folder.as_ref());
    let suffix = validate_filename(desired_filename_suffix.as_ref());

    let file_name = PathBuf::from(suffix);
    let extension = file_name.extension().map(|c| c.clone());

    for i in 0..100_000 {
        let ret = if i == 0 {
            let mut folder = folder.clone();
            folder.push(&file_name);
            folder
        } else {
            let idx = if i < 100 { i } else { now + i };
            let file_name = if let Some(stem) = file_name.file_stem() {
                let mut stem = stem.to_os_string();
                stem.push(format!("-{}", idx));
                stem
            } else {
                OsString::from(idx.to_string())
            };
            let mut folder = folder.clone();
            folder.push(file_name);
            if let Some(ext) = extension {
                folder.set_extension(&ext);
            }
            folder
        };

        if !dc_file_exist(context, &ret) {
            // fine filename found
            return ret;
        }
    }

    panic!("Something is really wrong, you need to clean up your disk");
}

pub fn dc_is_blobdir_path(context: &Context, path: impl AsRef<str>) -> bool {
    context
        .get_blobdir()
        .to_str()
        .map(|s| path.as_ref().starts_with(s))
        .unwrap_or_default()
        || path.as_ref().starts_with("$BLOBDIR")
}

fn dc_make_rel_path(context: &Context, path: &mut String) {
    if context
        .get_blobdir()
        .to_str()
        .map(|s| path.starts_with(s))
        .unwrap_or_default()
    {
        *path = path.replace("$BLOBDIR", context.get_blobdir().to_str().unwrap());
    }
}

pub fn dc_make_rel_and_copy(context: &Context, path: &mut String) -> bool {
    if dc_is_blobdir_path(context, &path) {
        dc_make_rel_path(context, path);
        return true;
    }
    let blobdir_path = dc_get_fine_path_filename(context, "$BLOBDIR", &path);
    if dc_copy_file(context, &path, &blobdir_path) {
        *path = blobdir_path.to_string_lossy().to_string();
        dc_make_rel_path(context, path);
        return true;
    }

    false
}

/// Error type for the [OsStrExt] trait
#[derive(Debug, Fail, PartialEq)]
pub enum CStringError {
    /// The string contains an interior null byte
    #[fail(display = "String contains an interior null byte")]
    InteriorNullByte,
    /// The string is not valid Unicode
    #[fail(display = "String is not valid unicode")]
    NotUnicode,
}

/// Extra convenience methods on [std::ffi::OsStr] to work with `*libc::c_char`.
///
/// The primary function of this trait is to more easily convert
/// [OsStr], [OsString] or [Path] into pointers to C strings.  This always
/// allocates a new string since it is very common for the source
/// string not to have the required terminal null byte.
///
/// It is implemented for `AsRef<std::ffi::OsStr>>` trait, which
/// allows any type which implements this trait to transparently use
/// this.  This is how the conversion for [Path] works.
///
/// [OsStr]: std::ffi::OsStr
/// [OsString]: std::ffi::OsString
/// [Path]: std::path::Path
///
/// # Example
///
/// ```
/// use deltachat::dc_tools::{dc_strdup, OsStrExt};
/// let path = std::path::Path::new("/some/path");
/// let path_c = path.to_c_string().unwrap();
/// unsafe {
///     let mut c_ptr: *mut libc::c_char = dc_strdup(path_c.as_ptr());
/// }
/// ```
pub trait OsStrExt {
    /// Convert a  [std::ffi::OsStr] to an [std::ffi::CString]
    ///
    /// This is useful to convert e.g. a [std::path::Path] to
    /// [*libc::c_char] by using
    /// [Path::as_os_str()](std::path::Path::as_os_str) and
    /// [CStr::as_ptr()](std::ffi::CStr::as_ptr).
    ///
    /// This returns [CString] and not [&CStr] because not all [OsStr]
    /// slices end with a null byte, particularly those coming from
    /// [Path] do not have a null byte and having to handle this as
    /// the caller would defeat the point of this function.
    ///
    /// On Windows this requires that the [OsStr] contains valid
    /// unicode, which should normally be the case for a [Path].
    ///
    /// [CString]: std::ffi::CString
    /// [CStr]: std::ffi::CStr
    /// [OsStr]: std::ffi::OsStr
    /// [Path]: std::path::Path
    ///
    /// # Errors
    ///
    /// Since a C `*char` is terminated by a NULL byte this conversion
    /// will fail, when the [OsStr] has an interior null byte.  The
    /// function will return
    /// `[Err]([CStringError::InteriorNullByte])`.  When converting
    /// from a [Path] it should be safe to
    /// [`.unwrap()`](std::result::Result::unwrap) this anyway since a
    /// [Path] should not contain interior null bytes.
    ///
    /// On windows when the string contains invalid Unicode
    /// `[Err]([CStringError::NotUnicode])` is returned.
    fn to_c_string(&self) -> Result<CString, CStringError>;
}

impl<T: AsRef<std::ffi::OsStr>> OsStrExt for T {
    #[cfg(not(target_os = "windows"))]
    fn to_c_string(&self) -> Result<CString, CStringError> {
        use std::os::unix::ffi::OsStrExt;
        CString::new(self.as_ref().as_bytes()).map_err(|err| match err {
            std::ffi::NulError { .. } => CStringError::InteriorNullByte,
        })
    }

    #[cfg(target_os = "windows")]
    fn to_c_string(&self) -> Result<CString, CStringError> {
        os_str_to_c_string_unicode(&self)
    }
}

// Implementation for os_str_to_c_string on windows.
#[allow(dead_code)]
fn os_str_to_c_string_unicode(
    os_str: &dyn AsRef<std::ffi::OsStr>,
) -> Result<CString, CStringError> {
    match os_str.as_ref().to_str() {
        Some(val) => CString::new(val.as_bytes()).map_err(|err| match err {
            std::ffi::NulError { .. } => CStringError::InteriorNullByte,
        }),
        None => Err(CStringError::NotUnicode),
    }
}

/// Convenience methods/associated functions for working with [CString]
///
/// This is helps transitioning from unsafe code.
pub trait CStringExt {
    /// Create a new [CString], yolo style
    ///
    /// This unwrap the result, panicking when there are embedded NULL
    /// bytes.
    fn yolo<T: Into<Vec<u8>>>(t: T) -> CString {
        CString::new(t).expect("String contains null byte, can not be CString")
    }
}

impl CStringExt for CString {}

/// Convenience methods to make transitioning from raw C strings easier.
///
/// To interact with (legacy) C APIs we often need to convert from
/// Rust strings to raw C strings.  This can be clumsy to do correctly
/// and the compiler sometimes allows it in an unsafe way.  These
/// methods make it more succinct and help you get it right.
pub trait StrExt {
    /// Allocate a new raw C `*char` version of this string.
    ///
    /// This allocates a new raw C string which must be freed using
    /// `free`.  It takes care of some common pitfalls with using
    /// [CString.as_ptr].
    ///
    /// [CString.as_ptr]: std::ffi::CString.as_ptr
    ///
    /// # Panics
    ///
    /// This function will panic when the original string contains an
    /// interior null byte as this can not be represented in raw C
    /// strings.
    unsafe fn strdup(&self) -> *mut libc::c_char;
}

impl<T: AsRef<str>> StrExt for T {
    unsafe fn strdup(&self) -> *mut libc::c_char {
        let tmp = CString::yolo(self.as_ref());
        dc_strdup(tmp.as_ptr())
    }
}

pub fn to_string(s: *const libc::c_char) -> String {
    if s.is_null() {
        return "".into();
    }

    let cstr = unsafe { CStr::from_ptr(s) };

    cstr.to_str().map(|s| s.to_string()).unwrap_or_else(|err| {
        panic!(
            "Non utf8 string: '{:?}' ({:?})",
            cstr.to_string_lossy(),
            err
        );
    })
}

pub fn to_string_lossy(s: *const libc::c_char) -> String {
    if s.is_null() {
        return "".into();
    }

    let cstr = unsafe { CStr::from_ptr(s) };

    cstr.to_str()
        .map(|s| s.to_string())
        .unwrap_or_else(|_| cstr.to_string_lossy().to_string())
}

pub fn as_str<'a>(s: *const libc::c_char) -> &'a str {
    as_str_safe(s).unwrap_or_else(|err| panic!("{}", err))
}

/// Converts a C string to either a Rust `&str` or `None` if  it is a null pointer.
pub fn as_opt_str<'a>(s: *const libc::c_char) -> Option<&'a str> {
    if s.is_null() {
        return None;
    }
    Some(as_str(s))
}

fn as_str_safe<'a>(s: *const libc::c_char) -> Result<&'a str, Error> {
    assert!(!s.is_null(), "cannot be used on null pointers");

    let cstr = unsafe { CStr::from_ptr(s) };

    cstr.to_str()
        .map_err(|err| format_err!("Non utf8 string: '{:?}' ({:?})", cstr.to_bytes(), err))
}

/// Convert a C `*char` pointer to a [std::path::Path] slice.
///
/// This converts a `*libc::c_char` pointer to a [Path] slice.  This
/// essentially has to convert the pointer to [std::ffi::OsStr] to do
/// so and thus is the inverse of [OsStrExt::to_c_string].  Just like
/// [OsStrExt::to_c_string] requires valid Unicode on Windows, this
/// requires that the pointer contains valid UTF-8 on Windows.
///
/// Because this returns a reference the [Path] silce can not outlive
/// the original pointer.
///
/// [Path]: std::path::Path
#[cfg(not(target_os = "windows"))]
pub fn as_path<'a>(s: *const libc::c_char) -> &'a std::path::Path {
    assert!(!s.is_null(), "cannot be used on null pointers");
    use std::os::unix::ffi::OsStrExt;
    unsafe {
        let c_str = std::ffi::CStr::from_ptr(s).to_bytes();
        let os_str = std::ffi::OsStr::from_bytes(c_str);
        std::path::Path::new(os_str)
    }
}

// as_path() implementation for windows, documented above.
#[cfg(target_os = "windows")]
pub fn as_path<'a>(s: *const libc::c_char) -> &'a std::path::Path {
    as_path_unicode(s)
}

// Implementation for as_path() on Windows.
//
// Having this as a separate function means it can be tested on unix
// too.
#[allow(dead_code)]
fn as_path_unicode<'a>(s: *const libc::c_char) -> &'a std::path::Path {
    assert!(!s.is_null(), "cannot be used on null pointers");
    std::path::Path::new(as_str(s))
}

pub fn time() -> i64 {
    SystemTime::now()
        .duration_since(SystemTime::UNIX_EPOCH)
        .unwrap()
        .as_secs() as i64
}

/// Very simple email address wrapper.
///
/// Represents an email address, right now just the `name@domain` portion.
///
/// # Example
///
/// ```
/// use deltachat::dc_tools::EmailAddress;
/// let email = match EmailAddress::new("someone@example.com") {
///     Ok(addr) => addr,
///     Err(e) => panic!("Error parsing address, error was {}", e),
/// };
/// assert_eq!(&email.local, "someone");
/// assert_eq!(&email.domain, "example.com");
/// assert_eq!(email.to_string(), "someone@example.com");
/// ```
#[derive(Debug, PartialEq, Clone)]
pub struct EmailAddress {
    pub local: String,
    pub domain: String,
}

impl EmailAddress {
    pub fn new(input: &str) -> Result<Self, Error> {
        input.parse::<EmailAddress>()
    }
}

impl fmt::Display for EmailAddress {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}@{}", self.local, self.domain)
    }
}

impl FromStr for EmailAddress {
    type Err = Error;

    /// Performs a dead-simple parse of an email address.
    fn from_str(input: &str) -> Result<EmailAddress, Error> {
        ensure!(!input.is_empty(), "empty string is not valid");
        let parts: Vec<&str> = input.rsplitn(2, '@').collect();

        ensure!(parts.len() > 1, "missing '@' character");
        let local = parts[1];
        let domain = parts[0];

        ensure!(
            !local.is_empty(),
            "empty string is not valid for local part"
        );
        ensure!(domain.len() > 3, "domain is too short");

        let dot = domain.find('.');
        ensure!(dot.is_some(), "invalid domain");
        ensure!(dot.unwrap() < domain.len() - 2, "invalid domain");

        Ok(EmailAddress {
            local: local.to_string(),
            domain: domain.to_string(),
        })
    }
}

/// Utility to check if a in the binary represantion of listflags
/// the bit at position bitindex is 1.
///
///
/// # Example
///
/// ```
/// use std::convert::TryInto;
/// use deltachat::dc_tools::listflags_has;
/// use deltachat::constants::{DC_GCL_ADD_SELF, DC_GCL_VERIFIED_ONLY};
/// let listflags: u32 = 0x1101;
/// assert!(listflags_has(listflags, 0x1) == true);
/// assert!(listflags_has(listflags, 0x10) == false);
/// assert!(listflags_has(listflags, 0x100) == true);
/// assert!(listflags_has(listflags, 0x1000) == true);
/// let listflags: u32 = (DC_GCL_ADD_SELF | DC_GCL_VERIFIED_ONLY).try_into().unwrap();
/// assert!(listflags_has(listflags, DC_GCL_VERIFIED_ONLY) == true);
/// assert!(listflags_has(listflags, DC_GCL_ADD_SELF) == true);
/// let listflags: u32 = DC_GCL_VERIFIED_ONLY.try_into().unwrap();
/// assert!(listflags_has(listflags, DC_GCL_ADD_SELF) == false);
/// ```
pub fn listflags_has(listflags: u32, bitindex: usize) -> bool {
    let listflags = listflags as usize;
    (listflags & bitindex) == bitindex
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::ffi::CStr;

    #[test]
    fn test_dc_strdup() {
        unsafe {
            let str_a = b"foobar\x00" as *const u8 as *const libc::c_char;
            let str_a_copy = dc_strdup(str_a);

            // Value of str_a_copy should equal foobar
            assert_eq!(
                CStr::from_ptr(str_a_copy),
                CString::new("foobar").unwrap().as_c_str()
            );
            // Address of str_a should be different from str_a_copy
            assert_ne!(str_a, str_a_copy);

            let str_a = std::ptr::null() as *const libc::c_char;
            let str_a_copy = dc_strdup(str_a);
            // Value of str_a_copy should equal ""
            assert_eq!(
                CStr::from_ptr(str_a_copy),
                CString::new("").unwrap().as_c_str()
            );
            assert_ne!(str_a, str_a_copy);
        }
    }

    #[test]
    fn test_dc_strdup_keep_null() {
        unsafe {
            let str_a = b"foobar\x00" as *const u8 as *const libc::c_char;
            let str_a_copy = dc_strdup_keep_null(str_a);
            assert_eq!(
                CStr::from_ptr(str_a_copy),
                CString::new("foobar").unwrap().as_c_str()
            );
            assert_ne!(str_a, str_a_copy);

            let str_a = ptr::null();
            let str_a_copy = dc_strdup_keep_null(str_a);
            assert_eq!(str_a.is_null(), true);
            assert_eq!(str_a_copy.is_null(), true);
        }
    }

    #[test]
    fn test_dc_ltrim() {
        unsafe {
            let html: *const libc::c_char =
                b"\r\r\nline1<br>\r\n\r\n\r\rline2\n\r\x00" as *const u8 as *const libc::c_char;
            let out: *mut libc::c_char = strndup(html, strlen(html) as libc::c_ulong);

            dc_ltrim(out);

            assert_eq!(
                CStr::from_ptr(out as *const libc::c_char).to_str().unwrap(),
                "line1<br>\r\n\r\n\r\rline2\n\r"
            );
        }
    }

    #[test]
    fn test_dc_rtrim() {
        unsafe {
            let html: *const libc::c_char =
                b"\r\r\nline1<br>\r\n\r\n\r\rline2\n\r\x00" as *const u8 as *const libc::c_char;
            let out: *mut libc::c_char = strndup(html, strlen(html) as libc::c_ulong);

            dc_rtrim(out);

            assert_eq!(
                CStr::from_ptr(out as *const libc::c_char).to_str().unwrap(),
                "\r\r\nline1<br>\r\n\r\n\r\rline2"
            );
        }
    }

    #[test]
    fn test_dc_trim() {
        unsafe {
            let html: *const libc::c_char =
                b"\r\r\nline1<br>\r\n\r\n\r\rline2\n\r\x00" as *const u8 as *const libc::c_char;
            let out: *mut libc::c_char = strndup(html, strlen(html) as libc::c_ulong);

            dc_trim(out);

            assert_eq!(
                CStr::from_ptr(out as *const libc::c_char).to_str().unwrap(),
                "line1<br>\r\n\r\n\r\rline2"
            );
        }
    }

    #[test]
    fn test_rust_ftoa() {
        assert_eq!("1.22", format!("{}", 1.22));
    }

    #[test]
    fn test_dc_str_replace() {
        unsafe {
            let mut str: *mut libc::c_char = strdup(b"aaa\x00" as *const u8 as *const libc::c_char);
            dc_str_replace(
                &mut str,
                b"a\x00" as *const u8 as *const libc::c_char,
                b"ab\x00" as *const u8 as *const libc::c_char,
            );
            assert_eq!(
                CStr::from_ptr(str as *const libc::c_char).to_str().unwrap(),
                "ababab"
            );
            free(str as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_truncate_1() {
        let s = "this is a little test string";
        assert_eq!(dc_truncate(s, 16, false), "this is a [...]");
        assert_eq!(dc_truncate(s, 16, true), "this is a ...");
    }

    #[test]
    fn test_dc_truncate_2() {
        assert_eq!(dc_truncate("1234", 2, false), "1234");
        assert_eq!(dc_truncate("1234", 2, true), "1234");
    }

    #[test]
    fn test_dc_truncate_3() {
        assert_eq!(dc_truncate("1234567", 1, false), "1[...]");
        assert_eq!(dc_truncate("1234567", 1, true), "1...");
    }

    #[test]
    fn test_dc_truncate_4() {
        assert_eq!(dc_truncate("123456", 4, false), "123456");
        assert_eq!(dc_truncate("123456", 4, true), "123456");
    }

    #[test]
    fn test_dc_truncate_edge() {
        assert_eq!(dc_truncate("", 4, false), "");
        assert_eq!(dc_truncate("", 4, true), "");

        assert_eq!(dc_truncate("\n  hello \n world", 4, false), "\n  [...]");
        assert_eq!(dc_truncate("\n  hello \n world", 4, true), "\n  ...");

        assert_eq!(
            dc_truncate("𐠈0Aᝮa𫝀®!ꫛa¡0A𐢧00𐹠®A  丽ⷐએ", 1, false),
            "𐠈[...]"
        );
        assert_eq!(
            dc_truncate("𐠈0Aᝮa𫝀®!ꫛa¡0A𐢧00𐹠®A  丽ⷐએ", 0, false),
            "𐠈0Aᝮa𫝀®!ꫛa¡0A𐢧00𐹠®A  丽ⷐએ"
        );

        // 9 characters, so no truncation
        assert_eq!(
            dc_truncate("𑒀ὐ￠🜀\u{1e01b}A a🟠", 6, false),
            "𑒀ὐ￠🜀\u{1e01b}A a🟠",
        );

        // 12 characters, truncation
        assert_eq!(
            dc_truncate("𑒀ὐ￠🜀\u{1e01b}A a🟠bcd", 6, false),
            "𑒀ὐ￠🜀\u{1e01b}A[...]",
        );
    }

    #[test]
    fn test_dc_null_terminate_1() {
        unsafe {
            let str: *mut libc::c_char =
                dc_null_terminate(b"abcxyz\x00" as *const u8 as *const libc::c_char, 3);
            assert_eq!(
                CStr::from_ptr(str as *const libc::c_char).to_str().unwrap(),
                "abc"
            );
            free(str as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_null_terminate_2() {
        unsafe {
            let str: *mut libc::c_char =
                dc_null_terminate(b"abcxyz\x00" as *const u8 as *const libc::c_char, 0);
            assert_eq!(
                CStr::from_ptr(str as *const libc::c_char).to_str().unwrap(),
                ""
            );
            free(str as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_null_terminate_3() {
        unsafe {
            let str: *mut libc::c_char =
                dc_null_terminate(0 as *const u8 as *const libc::c_char, 0);
            assert_eq!(
                CStr::from_ptr(str as *const libc::c_char).to_str().unwrap(),
                ""
            );
            free(str as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_str_to_clist_1() {
        unsafe {
            let list = dc_str_to_clist(ptr::null(), b" \x00" as *const u8 as *const libc::c_char);
            assert_eq!((*list).count, 0);
            clist_free_content(list);
            clist_free(list);
        }
    }

    #[test]
    fn test_dc_str_to_clist_2() {
        unsafe {
            let list: *mut clist = dc_str_to_clist(
                b"\x00" as *const u8 as *const libc::c_char,
                b" \x00" as *const u8 as *const libc::c_char,
            );
            assert_eq!((*list).count, 1);
            clist_free_content(list);
            clist_free(list);
        }
    }

    #[test]
    fn test_dc_str_to_clist_3() {
        unsafe {
            let list: *mut clist = dc_str_to_clist(
                b" \x00" as *const u8 as *const libc::c_char,
                b" \x00" as *const u8 as *const libc::c_char,
            );
            assert_eq!((*list).count, 2);
            clist_free_content(list);
            clist_free(list);
        }
    }

    #[test]
    fn test_dc_str_to_clist_4() {
        unsafe {
            let list: *mut clist = dc_str_to_clist(
                b"foo bar test\x00" as *const u8 as *const libc::c_char,
                b" \x00" as *const u8 as *const libc::c_char,
            );
            assert_eq!((*list).count, 3);
            let str: *mut libc::c_char =
                dc_str_from_clist(list, b" \x00" as *const u8 as *const libc::c_char);

            assert_eq!(
                CStr::from_ptr(str as *const libc::c_char).to_str().unwrap(),
                "foo bar test"
            );

            clist_free_content(list);
            clist_free(list);
            free(str as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_replace_bad_utf8_chars_1() {
        unsafe {
            let buf1 = strdup(b"ol\xc3\xa1 mundo <>\"\'& \xc3\xa4\xc3\x84\xc3\xb6\xc3\x96\xc3\xbc\xc3\x9c\xc3\x9f foo\xc3\x86\xc3\xa7\xc3\x87 \xe2\x99\xa6&noent;\x00" as *const u8 as *const libc::c_char);
            let buf2 = strdup(buf1);

            dc_replace_bad_utf8_chars(buf2);

            assert_eq!(strcmp(buf1, buf2), 0);

            free(buf1 as *mut libc::c_void);
            free(buf2 as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_replace_bad_utf8_chars_2() {
        unsafe {
            let buf1 = strdup(b"ISO-String with Ae: \xc4\x00" as *const u8 as *const libc::c_char);
            let buf2 = strdup(buf1);

            dc_replace_bad_utf8_chars(buf2);

            assert_eq!(
                CStr::from_ptr(buf2 as *const libc::c_char)
                    .to_str()
                    .unwrap(),
                "ISO-String with Ae: _"
            );

            free(buf1 as *mut libc::c_void);
            free(buf2 as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_replace_bad_utf8_chars_3() {
        unsafe {
            let buf1 = strdup(b"\x00" as *const u8 as *const libc::c_char);
            let buf2 = strdup(buf1);

            dc_replace_bad_utf8_chars(buf2);

            assert_eq!(*buf2.offset(0), 0);

            free(buf1 as *mut libc::c_void);
            free(buf2 as *mut libc::c_void);
        }
    }

    #[test]
    fn test_dc_replace_bad_utf8_chars_4() {
        unsafe {
            dc_replace_bad_utf8_chars(ptr::null_mut());
        }
    }

    #[test]
    fn test_dc_create_id() {
        let buf = dc_create_id();
        assert_eq!(buf.len(), 11);
    }

    #[test]
    fn test_encode_66bits_as_base64() {
        assert_eq!(
            encode_66bits_as_base64(0x01234567, 0x89abcdef, 0),
            "ASNFZ4mrze8"
        );
        assert_eq!(
            encode_66bits_as_base64(0x01234567, 0x89abcdef, 1),
            "ASNFZ4mrze9"
        );
        assert_eq!(
            encode_66bits_as_base64(0x01234567, 0x89abcdef, 2),
            "ASNFZ4mrze-"
        );
        assert_eq!(
            encode_66bits_as_base64(0x01234567, 0x89abcdef, 3),
            "ASNFZ4mrze_"
        );
    }

    #[test]
    fn test_os_str_to_c_string_cwd() {
        let some_dir = std::env::current_dir().unwrap();
        some_dir.as_os_str().to_c_string().unwrap();
    }

    #[test]
    fn test_os_str_to_c_string_unicode() {
        let some_str = String::from("/some/valid/utf8");
        let some_dir = std::path::Path::new(&some_str);
        assert_eq!(
            some_dir.as_os_str().to_c_string().unwrap(),
            CString::new("/some/valid/utf8").unwrap()
        );
    }

    #[test]
    fn test_os_str_to_c_string_nul() {
        let some_str = std::ffi::OsString::from("foo\x00bar");
        assert_eq!(
            some_str.to_c_string().err().unwrap(),
            CStringError::InteriorNullByte
        )
    }

    #[test]
    fn test_path_to_c_string_cwd() {
        let some_dir = std::env::current_dir().unwrap();
        some_dir.to_c_string().unwrap();
    }

    #[test]
    fn test_path_to_c_string_unicode() {
        let some_str = String::from("/some/valid/utf8");
        let some_dir = std::path::Path::new(&some_str);
        assert_eq!(
            some_dir.as_os_str().to_c_string().unwrap(),
            CString::new("/some/valid/utf8").unwrap()
        );
    }

    #[test]
    fn test_os_str_to_c_string_unicode_fn() {
        let some_str = std::ffi::OsString::from("foo");
        assert_eq!(
            os_str_to_c_string_unicode(&some_str).unwrap(),
            CString::new("foo").unwrap()
        );
    }

    #[test]
    fn test_path_to_c_string_unicode_fn() {
        let some_str = String::from("/some/path");
        let some_path = std::path::Path::new(&some_str);
        assert_eq!(
            os_str_to_c_string_unicode(&some_path).unwrap(),
            CString::new("/some/path").unwrap()
        );
    }

    #[test]
    fn test_os_str_to_c_string_unicode_fn_nul() {
        let some_str = std::ffi::OsString::from("fooz\x00bar");
        assert_eq!(
            os_str_to_c_string_unicode(&some_str).err().unwrap(),
            CStringError::InteriorNullByte
        );
    }

    #[test]
    fn test_as_path() {
        let some_path = CString::new("/some/path").unwrap();
        let ptr = some_path.as_ptr();
        assert_eq!(as_path(ptr), std::ffi::OsString::from("/some/path"))
    }

    #[test]
    fn test_as_path_unicode_fn() {
        let some_path = CString::new("/some/path").unwrap();
        let ptr = some_path.as_ptr();
        assert_eq!(as_path_unicode(ptr), std::ffi::OsString::from("/some/path"));
    }

    #[test]
    fn test_cstring_yolo() {
        assert_eq!(CString::new("hello").unwrap(), CString::yolo("hello"));
    }

    #[test]
    fn test_strdup_str() {
        unsafe {
            let s = "hello".strdup();
            let cmp = strcmp(s, b"hello\x00" as *const u8 as *const libc::c_char);
            free(s as *mut libc::c_void);
            assert_eq!(cmp, 0);
        }
    }

    #[test]
    fn test_strdup_string() {
        unsafe {
            let s = String::from("hello").strdup();
            let cmp = strcmp(s, b"hello\x00" as *const u8 as *const libc::c_char);
            free(s as *mut libc::c_void);
            assert_eq!(cmp, 0);
        }
    }

    #[test]
    fn test_dc_extract_grpid_from_rfc724_mid() {
        // Should return None if we pass invalid mid
        let mid = "foobar";
        let grpid = dc_extract_grpid_from_rfc724_mid(mid);
        assert_eq!(grpid, None);

        // Should return None if grpid has a length which is not 11 or 16
        let mid = "Gr.12345678.morerandom@domain.de";
        let grpid = dc_extract_grpid_from_rfc724_mid(mid);
        assert_eq!(grpid, None);

        // Should return extracted grpid for grpid with length of 11
        let mid = "Gr.12345678901.morerandom@domain.de";
        let grpid = dc_extract_grpid_from_rfc724_mid(mid);
        assert_eq!(grpid, Some("12345678901"));

        // Should return extracted grpid for grpid with length of 11
        let mid = "Gr.1234567890123456.morerandom@domain.de";
        let grpid = dc_extract_grpid_from_rfc724_mid(mid);
        assert_eq!(grpid, Some("1234567890123456"));
    }

    #[test]
    fn test_emailaddress_parse() {
        assert_eq!(EmailAddress::new("").is_ok(), false);
        assert_eq!(
            EmailAddress::new("user@domain.tld").unwrap(),
            EmailAddress {
                local: "user".into(),
                domain: "domain.tld".into(),
            }
        );
        assert_eq!(EmailAddress::new("uuu").is_ok(), false);
        assert_eq!(EmailAddress::new("dd.tt").is_ok(), false);
        assert_eq!(EmailAddress::new("tt.dd@uu").is_ok(), false);
        assert_eq!(EmailAddress::new("u@d").is_ok(), false);
        assert_eq!(EmailAddress::new("u@d.").is_ok(), false);
        assert_eq!(EmailAddress::new("u@d.t").is_ok(), false);
        assert_eq!(
            EmailAddress::new("u@d.tt").unwrap(),
            EmailAddress {
                local: "u".into(),
                domain: "d.tt".into(),
            }
        );
        assert_eq!(EmailAddress::new("u@.tt").is_ok(), false);
        assert_eq!(EmailAddress::new("@d.tt").is_ok(), false);
    }

    use proptest::prelude::*;

    proptest! {
        #[test]
        fn test_dc_truncate(
            buf: String,
            approx_chars in 0..10000usize,
            do_unwrap: bool,
        ) {
            let res = dc_truncate(&buf, approx_chars, do_unwrap);
            let el_len = if do_unwrap { 3 } else { 5 };
            let l = res.chars().count();
            if approx_chars > 0 {
                assert!(
                    l <= approx_chars + el_len,
                    "buf: '{}' - res: '{}' - len {}, approx {}",
                    &buf, &res, res.len(), approx_chars
                );
            } else {
                assert_eq!(&res, &buf);
            }

            if approx_chars > 0 && buf.chars().count() > approx_chars + el_len {
                let l = res.len();
                if do_unwrap {
                    assert_eq!(&res[l-3..l], "...", "missing ellipsis in {}", &res);
                } else {
                    assert_eq!(&res[l-5..l], "[...]", "missing ellipsis in {}", &res);
                }
            }
        }
    }

    #[test]
    fn test_dc_create_incoming_rfc724_mid() {
        let res = dc_create_incoming_rfc724_mid(123, 45, &vec![6, 7]);
        assert_eq!(as_str(res), "123-45-7@stub");

        unsafe {
            free(res.cast());
        }
    }
}