use crate::dehtml::*;
#[derive(Copy, Clone)]
pub struct Simplify {
pub is_forwarded: bool,
}
/// Return index of footer line in vector of message lines, or vector length if
/// no footer is found.
///
/// Also return whether not-standard (rfc3676, §4.3) footer is found.
fn find_message_footer(lines: &[&str]) -> (usize, bool) {
for (ix, &line) in lines.iter().enumerate() {
// quoted-printable may encode `-- ` to `-- =20` which is converted
// back to `-- `
match line {
"-- " | "-- " => return (ix, false),
"--" | "---" | "----" => return (ix, true),
_ => (),
}
}
(lines.len(), false)
}
impl Simplify {
pub fn new() -> Self {
Simplify {
is_forwarded: false,
}
}
/// Simplify and normalise text: Remove quotes, signatures, unnecessary
/// lineends etc.
/// The data returned from simplify() must be free()'d when no longer used.
pub fn simplify(&mut self, input: &str, is_html: bool, is_msgrmsg: bool) -> String {
let mut out = if is_html {
dehtml(input)
} else {
input.to_string()
};
out.retain(|c| c != '\r');
out = self.simplify_plain_text(&out, is_msgrmsg);
out.retain(|c| c != '\r');
out
}
/**
* Simplify Plain Text
*/
#[allow(non_snake_case, clippy::mut_range_bound)]
fn simplify_plain_text(&mut self, buf_terminated: &str, is_msgrmsg: bool) -> String {
/* This function ...
... removes all text after the line `-- ` (footer mark)
... removes full quotes at the beginning and at the end of the text -
these are all lines starting with the character `>`
... remove a non-empty line before the removed quote (contains sth. like "On 2.9.2016, Bjoern wrote:" in different formats and lanugages) */
/* split the given buffer into lines */
let lines: Vec<_> = buf_terminated.split('\n').collect();
let mut l_first: usize = 0;
let mut is_cut_at_begin = false;
let (mut l_last, mut is_cut_at_end) = find_message_footer(&lines);
if l_last > l_first + 2 {
let line0 = lines[l_first];
let line1 = lines[l_first + 1];
let line2 = lines[l_first + 2];
if line0 == "---------- Forwarded message ----------"
&& line1.starts_with("From: ")
&& line2.is_empty()
{
self.is_forwarded = true;
l_first += 3
}
}
for l in l_first..l_last {
let line = lines[l];
if line == "-----"
|| line == "_____"
|| line == "====="
|| line == "*****"
|| line == "~~~~~"
{
l_last = l;
is_cut_at_end = true;
/* done */
break;
}
}
if !is_msgrmsg {
let mut l_lastQuotedLine = None;
for l in (l_first..l_last).rev() {
let line = lines[l];
if is_plain_quote(line) {
l_lastQuotedLine = Some(l)
} else if !is_empty_line(line) {
break;
}
}
if let Some(last_quoted_line) = l_lastQuotedLine {
l_last = last_quoted_line;
is_cut_at_end = true;
if l_last > 1 && is_empty_line(lines[l_last - 1]) {
l_last -= 1
}
if l_last > 1 {
let line = lines[l_last - 1];
if is_quoted_headline(line) {
l_last -= 1
}
}
}
}
if !is_msgrmsg {
let mut l_lastQuotedLine_0 = None;
let mut hasQuotedHeadline = 0;
for l in l_first..l_last {
let line = lines[l];
if is_plain_quote(line) {
l_lastQuotedLine_0 = Some(l)
} else if !is_empty_line(line) {
if is_quoted_headline(line)
&& 0 == hasQuotedHeadline
&& l_lastQuotedLine_0.is_none()
{
hasQuotedHeadline = 1i32
} else {
/* non-quoting line found */
break;
}
}
}
if let Some(last_quoted_line) = l_lastQuotedLine_0 {
l_first = last_quoted_line + 1;
is_cut_at_begin = true
}
}
/* re-create buffer from the remaining lines */
let mut ret = String::new();
if is_cut_at_begin {
ret += "[...]";
}
/* we write empty lines only in case and non-empty line follows */
let mut pending_linebreaks = 0;
let mut content_lines_added = 0;
for l in l_first..l_last {
let line = lines[l];
if is_empty_line(line) {
pending_linebreaks += 1
} else {
if 0 != content_lines_added {
if pending_linebreaks > 2i32 {
pending_linebreaks = 2i32
}
while 0 != pending_linebreaks {
ret += "\n";
pending_linebreaks -= 1
}
}
// the incoming message might contain invalid UTF8
ret += line;
content_lines_added += 1;
pending_linebreaks = 1i32
}
}
if is_cut_at_end && (!is_cut_at_begin || 0 != content_lines_added) {
ret += " [...]";
}
ret
}
}
/**
* Tools
*/
fn is_empty_line(buf: &str) -> bool {
// XXX: can it be simplified to buf.chars().all(|c| c.is_whitespace())?
//
// Strictly speaking, it is not equivalent (^A is not whitespace, but less than ' '),
// but having control sequences in email body?!
//
// See discussion at: https://github.com/deltachat/deltachat-core-rust/pull/402#discussion_r317062392
for c in buf.chars() {
if c > ' ' {
return false;
}
}
true
}
fn is_quoted_headline(buf: &str) -> bool {
/* This function may be called for the line _directly_ before a quote.
The function checks if the line contains sth. like "On 01.02.2016, xy@z wrote:" in various languages.
- Currently, we simply check if the last character is a ':'.
- Checking for the existence of an email address may fail (headlines may show the user's name instead of the address) */
buf.len() <= 80 && buf.ends_with(':')
}
fn is_plain_quote(buf: &str) -> bool {
buf.starts_with('>')
}
#[cfg(test)]
mod tests {
use super::*;
use proptest::prelude::*;
proptest! {
#[test]
// proptest does not support [[:graphical:][:space:]] regex.
fn test_simplify_plain_text_fuzzy(input in "[!-~\t \n]+") {
let output = Simplify::new().simplify_plain_text(&input, true);
assert!(output.split('\n').all(|s| s != "-- "));
}
}
#[test]
fn test_simplify_trim() {
let mut simplify = Simplify::new();
let html = "\r\r\nline1
\r\n\r\n\r\rline2\n\r";
let plain = simplify.simplify(html, true, false);
assert_eq!(plain, "line1\nline2");
}
#[test]
fn test_simplify_parse_href() {
let mut simplify = Simplify::new();
let html = "text");
}
#[test]
fn test_simplify_html_encoded() {
let mut simplify = Simplify::new();
let html =
"<>"'& äÄöÖüÜß fooÆçÇ ♦&noent;";
let plain = simplify.simplify(html, true, false);
assert_eq!(
plain,
"<>\"\'& äÄöÖüÜß fooÆçÇ \u{2666}\u{200e}\u{200f}\u{200c}&noent;\u{200d}"
);
}
#[test]
fn test_simplify_utilities() {
assert!(is_empty_line(" \t"));
assert!(is_empty_line(""));
assert!(is_empty_line(" \r"));
assert!(!is_empty_line(" x"));
assert!(is_plain_quote("> hello world"));
assert!(is_plain_quote(">>"));
assert!(!is_plain_quote("Life is pain"));
assert!(!is_plain_quote(""));
}
}