use chrono::{Datelike, Utc};
use dotenv::dotenv;
use ldap3::{LdapConn, Mod, Scope, SearchEntry};
use skynet_ldap_backend::{get_config, Config};
use std::collections::{HashMap, HashSet};
use std::env;
use std::error::Error;

#[async_std::main]
async fn main() -> tide::Result<()> {
    let config = get_config();

    update_users(&config).await?;
    update_admin(&config).await?;
    update_committee(&config).await?;

    Ok(())
}

async fn update_users(config: &Config) -> tide::Result<()> {
    let mut users_tmp = HashSet::new();
    // default user to ensure group is never empty
    users_tmp.insert(String::from("compsoc"));

    if let Ok(x) = env::var("USERS_LIFETIME") {
        for user in x.split(',').collect::<Vec<&str>>() {
            users_tmp.insert(user.to_string());
        }
    }

    /*
    pull in data from wolves (csv or api (hopefully api)
    pull entire ldap data

    for every valid user in wolves match to ldap
    add to users
    */
    println!("{:#?}", users_tmp);
    // pull from wolves csv
    for user in from_csv(config).await.unwrap_or_default() {
        users_tmp.insert(user);
    }

    // sorting makes it easier/faster
    if let Ok(x) = env::var("USERS_BANNED") {
        for user in x.split(',').collect::<Vec<&str>>() {
            users_tmp.remove(user);
        }
    }

    println!("{:#?}", users_tmp);

    // easier to work with Strings above but easier to work with &str below
    let users: Vec<&str> = users_tmp.iter().map(|s| &**s).collect();

    update_group(config, "skynet-users", &users, true).await?;

    Ok(())
}

fn uid_to_dn(uid: &str) -> String {
    format!("uid={},ou=users,dc=skynet,dc=ie", uid)
}

async fn update_admin(config: &Config) -> tide::Result<()> {
    dotenv().ok();

    // read from teh env
    if let Ok(x) = env::var("USERS_ADMIN") {
        let users = x.split(',').collect::<Vec<&str>>();

        update_group(config, "skynet-admins", &users, true).await?;
        // admins automatically get added as users
        update_group(config, "skynet-users", &users, false).await?;
    }
    Ok(())
}

async fn update_committee(config: &Config) -> tide::Result<()> {
    dotenv().ok();

    // read from teh env
    if let Ok(x) = env::var("USERS_COMMITTEE") {
        let users = x.split(',').collect::<Vec<&str>>();

        update_group(config, "skynet-committee", &users, true).await?;
        // admins automatically get added as users
        update_group(config, "skynet-users", &users, false).await?;
    }
    Ok(())
}

async fn update_group(config: &Config, group: &str, users: &[&str], replace: bool) -> tide::Result<()> {
    if users.is_empty() {
        return Ok(());
    }

    let mut ldap = LdapConn::new(&config.ldap_host)?;

    // use the admin account
    ldap.simple_bind(&config.ldap_admin, &config.ldap_admin_pw)?.success()?;

    let dn = format!("cn={},ou=groups,dc=skynet,dc=ie", group);
    let members = users.iter().map(|uid| uid_to_dn(uid)).collect();
    let mods = if replace {
        vec![Mod::Replace("member".to_string(), members)]
    } else {
        vec![Mod::Add("member".to_string(), members)]
    };

    if let Err(x) = ldap.modify(&dn, mods) {
        println!("{:?}", x);
    }

    let dn_linux = format!("cn={}-linux,ou=groups,dc=skynet,dc=ie", group);
    let members_linux = users.iter().map(|uid| uid.to_string()).collect();
    let mods = if replace {
        vec![Mod::Replace("memberUid".to_string(), members_linux)]
    } else {
        vec![Mod::Add("memberUid".to_string(), members_linux)]
    };
    if let Err(x) = ldap.modify(&dn_linux, mods) {
        println!("{:?}", x);
    };

    // tidy up
    ldap.unbind()?;

    Ok(())
}

async fn ldap_get_accounts(config: &Config) -> Result<(HashMap<String, String>, HashMap<String, String>), Box<dyn Error>> {
    // connect to ldap
    let mut ldap = LdapConn::new(&config.ldap_host)?;
    ldap.simple_bind(&config.ldap_admin, &config.ldap_admin_pw)?.success()?;

    let mut uid_idstudent: HashMap<String, String> = HashMap::new();
    let mut uid_email: HashMap<String, String> = HashMap::new();

    let (rs, _res) = ldap
        .search("ou=users,dc=skynet,dc=ie", Scope::OneLevel, "(objectClass=*)", vec!["uid", "mail", "skID", "skSecure"])
        .unwrap()
        .success()
        .unwrap();

    for entry in rs {
        let tmp = SearchEntry::construct(entry);

        // skSecure is a standin for teh password, only 1 if the password is SSHA512
        if !tmp.attrs.contains_key("skSecure") {
            continue;
        }
        if tmp.attrs["skSecure"].is_empty() {
            continue;
        }

        // make sure there is an id;
        let uid = if !tmp.attrs["uid"].is_empty() {
            tmp.attrs["uid"][0].clone()
        } else {
            continue;
        };

        if !tmp.attrs["skID"].is_empty() {
            let skid = tmp.attrs["skID"][0].clone();
            if &skid != "00000000" {
                uid_idstudent.insert(skid, uid.clone());
            }
        }

        if !tmp.attrs["mail"].is_empty() {
            let mail = tmp.attrs["mail"][0].clone();
            if &mail != "nomail@skynet.ie" {
                uid_email.insert(mail, uid.clone());
            }
        }
    }
    ldap.unbind()?;

    Ok((uid_idstudent, uid_email))
}

async fn from_csv(config: &Config) -> Result<HashSet<String>, Box<dyn Error>> {
    let mut uids = HashSet::new();

    let (uid_idstudent, uid_email) = ldap_get_accounts(config).await?;
    let records = read_csv()?;

    let now = Utc::now();
    let today = format!("{}-{:02}-{:02}", now.year(), now.month(), now.day());

    for record in records {
        // only import users if it is actually active.
        if record.expiry < today {
            continue;
        }

        if let Some(uid) = uid_email.get(&record.email) {
            uids.insert(uid.clone());
        }
        if let Some(uid) = uid_idstudent.get(&record.id_student) {
            uids.insert(uid.clone());
        }
    }

    Ok(uids)
}

#[derive(Debug, serde::Deserialize)]
struct Record {
    // #[serde(rename = "MemID")]
    // id_wolves: String,
    #[serde(rename = "Student Num")]
    id_student: String,
    #[serde(rename = "Contact Email")]
    email: String,
    #[serde(rename = "Expiry")]
    expiry: String,
}

fn read_csv() -> Result<Vec<Record>, Box<dyn Error>> {
    let mut records: Vec<Record> = vec![];

    if let Ok(mut rdr) = csv::Reader::from_path("tmp.csv") {
        for result in rdr.deserialize() {
            // Notice that we need to provide a type hint for automatic
            // deserialization.
            let record: Record = result?;
            records.push(record);
        }
    }

    Ok(records)
}