use std::collections::HashSet;
use mastodon_async::helpers::toml; // requires `features = ["toml"]`
use mastodon_async::prelude::*;
use mastodon_async::{entities::visibility::Visibility};
use mastodon_async::{helpers::cli, Result};
use reqwest;
use std::io::Cursor;
use std::io::Write;

#[tokio::main] // requires `features = ["mt"]
async fn main() -> Result<()> {
    let mastodon = if let Ok(data) = toml::from_file("mastodon-data.toml") {
        Mastodon::from(data)
    } else {
        register().await?
    };

    match get_next_url() {
        Some(url) => post_image(&mastodon, &url).await,
        None => post(&mastodon, "@Sugui@awoo.fai.st @MeDueleLaTeta@awoo.fai.st me quedé sin chicas").await
    };

    Ok(())
}

fn get_next_url() -> Option<String> {
    let binding = std::fs::read("./posted.csv").expect("File not found").iter().map(|c| *c as char).collect::<String>();
    let posted = binding.lines().collect::<HashSet<_>>();
    let binding = std::fs::read("./urls.csv").expect("File not found").iter().map(|c| *c as char).collect::<String>();
    let urls = binding.lines().collect::<HashSet<_>>();
    let urls = urls.difference(&posted).collect::<Vec<_>>();
    if urls.is_empty() {
        None
    } else {
        let mut file = std::fs::OpenOptions::new()
            .write(true)
            .append(true) // This is needed to append to file
            .open("./posted.csv")
            .unwrap();
            write!(file, "{}\n", urls[0]).unwrap();
        Some(urls[0].to_string().clone())
    }
}

async fn post_image(account: &Mastodon, url: &String) {
    fetch_url(url.to_string(), ".tmp".to_string()).await.unwrap();
    let attachment = account.media("./.tmp", Some(url.to_string())).await.expect("upload");
    let attachment = account.wait_for_processing(attachment, Default::default()).await.expect("processing");
    let status = StatusBuilder::new()
        .media_ids(&[attachment.id])
        .visibility(Visibility::Unlisted)
        .sensitive(true)
        .build()
        .unwrap();
    account.new_status(status).await.unwrap();
}

async fn post(account: &Mastodon, msg: &str) {
    let status = StatusBuilder::new()
    .visibility(Visibility::Direct)
    .status(msg)
    .build()
    .unwrap();
    account.new_status(status).await.unwrap();
}

async fn fetch_url(url: String, file_name: String) -> Result<()> {
    let response = reqwest::get(url).await?;
    let mut file = std::fs::File::create(file_name)?;
    let mut content =  Cursor::new(response.bytes().await?);
    std::io::copy(&mut content, &mut file)?;
    Ok(())
}

async fn register() -> Result<Mastodon> {
    let registration = Registration::new("https://awoo.fai.st")
        .client_name("sleeping-girls-bot")
        .scopes(Scopes::all())
        .build()
        .await?;
    let mastodon = cli::authenticate(registration).await?;

    // Save app data for using on the next run.
    toml::to_file(&mastodon.data, "mastodon-data.toml")?;

    Ok(mastodon)
}