discord-bot/src/commands/link_email.rs

use lettre::{
  message::{header, MultiPart, SinglePart},
  transport::smtp::{self, authentication::Credentials},
  Message, SmtpTransport, Transport,
};
use maud::html;
use serenity::{
  builder::CreateApplicationCommand,
  client::Context,
  model::{
    application::interaction::application_command::ApplicationCommandInteraction,
    prelude::{command::CommandOptionType, interaction::application_command::CommandDataOptionValue},
  },
};
use skynet_discord_bot::{get_now_iso, random_string, Config, DataBase, Wolves, WolvesVerify};
use sqlx::{Pool, Sqlite};

pub(crate) mod link {
  use super::*;

  pub async fn run(command: &ApplicationCommandInteraction, ctx: &Context) -> String {
    let db_lock = {
      let data_read = ctx.data.read().await;
      data_read.get::<DataBase>().expect("Expected Databse in TypeMap.").clone()
    };
    let db = db_lock.read().await;

    let config_lock = {
      let data_read = ctx.data.read().await;
      data_read.get::<Config>().expect("Expected Config in TypeMap.").clone()
    };
    let config = config_lock.read().await;

    if get_server_member_discord(&db, &command.user.name).await.is_some() {
      return "Already linked".to_string();
    }

    db_pending_clear_expired(&db).await;

    if get_verify_from_db(&db, &command.user.name).await.is_some() {
      return "Linking already in process, please check email.".to_string();
    }

    let option = command
      .data
      .options
      .get(0)
      .expect("Expected email option")
      .resolved
      .as_ref()
      .expect("Expected email object");

    let email = if let CommandDataOptionValue::String(email) = option {
      email
    } else {
      return "Please provide a valid user".to_string();
    };

    // check if email exists
    let details = match get_server_member_email(&db, email).await {
      None => return "Please check is the same as on https://ulwolves.ie/".to_string(),
      Some(x) => x,
    };

    if details.verified {
      return "Email already verified".to_string();
    }

    // generate a auth key
    let auth = random_string(20);
    match send_mail(&config, &details, &auth, &command.user.name) {
      Ok(_) => match save_to_db(&db, &details, &auth, &command.user.name).await {
        Ok(_) => {}
        Err(e) => {
          return format!("Unable to save to db {}  {e:?}", &details.email);
        }
      },
      Err(e) => {
        return format!("Unable to send mail to {}  {e:?}", &details.email);
      }
    }

    format!("Verification email sent to {}", email)
  }

  pub fn register(command: &mut CreateApplicationCommand) -> &mut CreateApplicationCommand {
    command
      .name("link")
      .description("Set Wolves Email")
      .create_option(|option| option.name("email").description("UL Wolves Email").kind(CommandOptionType::String).required(true))
  }

  async fn get_server_member_discord(db: &Pool<Sqlite>, user: &str) -> Option<Wolves> {
    sqlx::query_as::<_, Wolves>(
      r#"
      SELECT * 
      FROM wolves
      WHERE discord = ?
      "#,
    )
    .bind(user)
    .fetch_one(db)
    .await
    .ok()
  }

  async fn get_server_member_email(db: &Pool<Sqlite>, email: &str) -> Option<Wolves> {
    sqlx::query_as::<_, Wolves>(
      r#"
      SELECT * 
      FROM wolves
      WHERE email = ?
      "#,
    )
    .bind(email)
    .fetch_one(db)
    .await
    .ok()
  }

  fn send_mail(config: &Config, email: &Wolves, auth: &str, user: &str) -> Result<smtp::response::Response, smtp::Error> {
    let mail = &email.email;
    let discord = "https://discord.skynet.ie";
    let sender = format!("UL Computer Society <{}>", &config.mail_user);

    // Create the html we want to send.
    let html = html! {
        head {
            title { "Hello from Skynet!" }
            style type="text/css" {
                "h2, h4 { font-family: Arial, Helvetica, sans-serif; }"
            }
        }
        div style="display: flex; flex-direction: column; align-items: center;" {
            h2 { "Hello from Skynet!" }
            // Substitute in the name of our recipient.
            p { "Hi " (user) "," }
            p {
                "Please use " pre { "/verify code:" (auth)} " to verify your discord account."
            }
            p {
                "If you have issues please refer to our Discord server:"
                br;
                a href=(discord) { (discord) }
            }
            p {
                "Skynet Team"
                br;
                "UL Computer Society"
            }
        }
    };

    let body_text = format!(
      r#"
        Hi {user}
        
        Please use "/verify code:{auth}" to verify your discord account.
        
        If you have issues please refer to our Discord server:
        {discord}
        
        Skynet Team
        UL Computer Society
        "#
    );

    // Build the message.
    let email = Message::builder()
      .from(sender.parse().unwrap())
      .to(mail.parse().unwrap())
      .subject("Skynet-Discord: Link Wolves.")
      .multipart(
        // This is composed of two parts.
        // also helps not trip spam settings (uneven number of url's
        MultiPart::alternative()
          .singlepart(SinglePart::builder().header(header::ContentType::TEXT_PLAIN).body(body_text))
          .singlepart(SinglePart::builder().header(header::ContentType::TEXT_HTML).body(html.into_string())),
      )
      .expect("failed to build email");

    let creds = Credentials::new(config.mail_user.clone(), config.mail_pass.clone());

    // Open a remote connection to gmail using STARTTLS
    let mailer = SmtpTransport::starttls_relay(&config.mail_smtp).unwrap().credentials(creds).build();

    // Send the email
    mailer.send(&email)
  }

  pub async fn db_pending_clear_expired(pool: &Pool<Sqlite>) -> Option<WolvesVerify> {
    sqlx::query_as::<_, WolvesVerify>(
      r#"
        DELETE 
        FROM wolves_verify
        WHERE date_expiry < ?
        "#,
    )
    .bind(get_now_iso(true))
    .fetch_one(pool)
    .await
    .ok()
  }

  pub async fn get_verify_from_db(db: &Pool<Sqlite>, user: &str) -> Option<WolvesVerify> {
    sqlx::query_as::<_, WolvesVerify>(
      r#"
      SELECT * 
      FROM wolves_verify
      WHERE discord = ?
      "#,
    )
    .bind(user)
    .fetch_one(db)
    .await
    .ok()
  }

  async fn save_to_db(db: &Pool<Sqlite>, record: &Wolves, auth: &str, user: &str) -> Result<Option<WolvesVerify>, sqlx::Error> {
    sqlx::query_as::<_, WolvesVerify>(
      "
        INSERT INTO wolves_verify (email, discord, auth_code, date_expiry)
        VALUES (?1, ?2, ?3, ?4)
        ",
    )
    .bind(record.email.to_owned())
    .bind(user)
    .bind(auth.to_owned())
    .bind(get_now_iso(false))
    .fetch_optional(db)
    .await
  }
}

pub(crate) mod verify {
  use super::*;
  use crate::commands::link_email::link::{db_pending_clear_expired, get_verify_from_db};
  use sqlx::Error;
  pub async fn run(command: &ApplicationCommandInteraction, ctx: &Context) -> String {
    let db_lock = {
      let data_read = ctx.data.read().await;
      data_read.get::<DataBase>().expect("Expected Databse in TypeMap.").clone()
    };
    let db = db_lock.read().await;

    // check if user has used /link
    let details = if let Some(x) = get_verify_from_db(&db, &command.user.name).await {
      x
    } else {
      return "Please use /link first".to_string();
    };

    let option = command
      .data
      .options
      .get(0)
      .expect("Expected code option")
      .resolved
      .as_ref()
      .expect("Expected code object");

    let code = if let CommandDataOptionValue::String(code) = option {
      code
    } else {
      return "Please provide a verification code".to_string();
    };

    db_pending_clear_expired(&db).await;

    if &details.auth_code != code {
      return "Invalid verification code".to_string();
    }

    match db_pending_clear_successful(&db, &command.user.name).await {
      Ok(_) => {
        return match set_discord(&db, &command.user.name, &details.email).await {
          Ok(_) => "Discord username linked to Wolves".to_string(),
          Err(e) => {
            println!("{:?}", e);
            "Failed to save, please try /link again".to_string()
          }
        }
      }
      Err(e) => println!("{:?}", e),
    }

    "Failed to verify".to_string()
  }

  pub fn register(command: &mut CreateApplicationCommand) -> &mut CreateApplicationCommand {
    command.name("verify").description("Verify Wolves Email").create_option(|option| {
      option
        .name("code")
        .description("Code from verification email")
        .kind(CommandOptionType::String)
        .required(true)
    })
  }

  async fn db_pending_clear_successful(pool: &Pool<Sqlite>, user: &str) -> Result<Option<WolvesVerify>, Error> {
    sqlx::query_as::<_, WolvesVerify>(
      r#"
        DELETE 
        FROM wolves_verify
        WHERE discord = ?
        "#,
    )
    .bind(user)
    .fetch_optional(pool)
    .await
  }

  async fn set_discord(db: &Pool<Sqlite>, discord: &str, email: &str) -> Result<Option<Wolves>, Error> {
    sqlx::query_as::<_, Wolves>(
      "
      UPDATE wolves
      SET discord = ?
      WHERE email = ?
    ",
    )
    .bind(discord)
    .bind(email)
    .fetch_optional(db)
    .await
  }
}