newsletter-to-web/bin/src/main.rs

use std::{
    collections::HashMap,
    error::Error,
    fs::{read_dir, OpenOptions},
    io::Write,
    net::TcpStream,
    path::{Path, PathBuf},
};

use imap::Session;
use mail_parser::Message;
use rustls_connector::RustlsConnector;

use sanitize_html::{rules::Element, sanitize_str};
use sha2::{Digest, Sha256};

extern crate imap;
extern crate mail_parser;
extern crate rustls_connector;
extern crate sanitize_html;
extern crate sha2;

fn main() {
    let dir = Path::new("data");
    if !dir.exists() {
        std::fs::create_dir(&dir).expect("Could not create directory");
    }

    let messsages = messages_from_tests(&Path::new("tests/data")) //connect("my.kiers.eu", 993, "newsletters@kie.rs", "Jjkcloudron1!")
        .expect("A list of messages");

    for (uid, message) in messsages {
        println!("Processing message {}", &uid);

        let parsed = Message::parse(&message).expect("A parsed messsage.");
        let title = parsed.get_subject().expect("Expected a subject");

        println!("{}", &title);

        let html_body = parsed.get_html_body(0).expect("Could not read html body");
        let processed_html = process_html(&html_body).expect("Could not process the HTML");
        let html_bytes = processed_html.as_bytes();

        let hash = base16ct::lower::encode_string(&Sha256::digest(&html_bytes));
        println!("{}", hash);

        let html_path: PathBuf = [dir, Path::new(&format!("{}.html", &title))]
            .iter()
            .collect();

        OpenOptions::new()
            .write(true)
            .create(true)
            .open(&html_path)
            .expect(format!("Could not open file '{}' for writing", &html_path.display()).as_str())
            .write_all(&html_bytes)
            .expect(format!("Could not write html to file '{}'.", &html_path.display()).as_str());

        println!();
    }
}

fn connect(
    server: &str,
    port: u16,
    username: &str,
    password: &str,
) -> Result<HashMap<String, Vec<u8>>, Box<dyn Error>> {
    let mut session = open_session(server, port, username, password)?;

    session.examine("INBOX")?;

    let items = match session.uid_search("ALL") {
        Ok(i) => i,
        Err(e) => return Err(Box::new(e)),
    };

    let mut msgs = HashMap::<String, Vec<u8>>::with_capacity(items.len());

    //println!("# of messages: {}", &items.len());

    for item in items {
        let msg = session.uid_fetch(&item.to_string(), "(BODY.PEEK[] UID)")?;

        let message = if let Some(m) = msg.iter().next() {
            m
        } else {
            continue;
        };

        let body = message.body().expect("Message did not have a body.");

        msgs.insert(item.to_string(), body.to_owned());
    }

    session.logout().expect("Could not log out");

    Ok(msgs)
}

fn open_session(
    server: &str,
    port: u16,
    username: &str,
    password: &str,
) -> Result<
    Session<
        rustls_connector::rustls::StreamOwned<
            rustls_connector::rustls::ClientConnection,
            TcpStream,
        >,
    >,
    Box<dyn Error + 'static>,
> {
    let stream = TcpStream::connect((server, port))?;
    let tls = RustlsConnector::new_with_webpki_roots_certs();
    let tls_stream = tls.connect(server, stream)?;

    let client = imap::Client::new(tls_stream);

    Ok(client.login(username, password).map_err(|e| e.0)?)
}

fn process_html(input: &str) -> Result<String, sanitize_html::errors::SanitizeError> {
    let mut rules = sanitize_html::rules::predefined::relaxed().delete("style");

    rules
        .allowed_elements
        .get_mut("img")
        .unwrap()
        .attribute_rules
        .rename("src", "data-source");

    let mut span = Element::new("span");

    span.attribute_rules
        .modify("style", Box::new(|_i| "".to_string()));

    let rules = rules.element(span);

    //rules.allowed_elements.remove_entry("img");

    sanitize_str(&rules, input)
    //Ok(input.to_owned())
}

fn messages_from_tests(path: &Path) -> Result<HashMap<String, Vec<u8>>, Box<dyn Error>> {
    let mut messages = HashMap::<String, Vec<u8>>::new();

    let items = match read_dir(path) {
        Ok(i) => i,
        Err(e) => return Err(Box::new(e)),
    };

    for item in items {
        if let Ok(item) = item {
            if let Some(extension) = item.path().extension() {
                if extension != "eml" {
                    continue;
                }

                let uid = item.path().file_stem().unwrap().to_owned();
                if let Ok(data) = std::fs::read(item.path()) {
                    messages.insert(uid.into_string().unwrap(), data);
                }
            }
        }
    }

    Ok(messages)
}

fn write_to_test_path(uid: &str, message: &[u8]) {
    let test_path: PathBuf = [Path::new("tests/data"), Path::new(&format!("{}.eml", &uid))]
        .iter()
        .collect();

    let _ = OpenOptions::new()
        .write(true)
        .create(true)
        .open(test_path)
        .expect("Could not open file fir writing")
        .write_all(&message);
}