use crate::config_manager::{get_peachcloud_domain, load_peach_config,
                            set_admin_password_hash, get_admin_password_hash,
                            get_temporary_password_hash, set_temporary_password_hash};
use crate::error::PeachError;
use crate::sbot_client;
use log::info;
use rand::distributions::Alphanumeric;
use rand::{thread_rng, Rng};
use std::iter;
use crypto::digest::Digest;
use crypto::sha3::Sha3;

/// Returns Ok(()) if the supplied password is correct,
/// and returns Err if the supplied password is incorrect.
pub fn verify_password(password: &str) -> Result<(), PeachError> {
    let real_admin_password_hash = get_admin_password_hash()?;
    let password_hash = hash_password(&password.to_string());
    if real_admin_password_hash == password_hash {
        Ok(())
    } else {
        Err(PeachError::InvalidPassword)
    }
}

/// Checks if the given passwords are valid, and returns Ok() if they are and
/// a PeachError otherwise.
/// Currently this just checks that the passwords are the same,
/// but could be extended to test if they are strong enough.
pub fn validate_new_passwords(new_password1: &str, new_password2: &str) -> Result<(), PeachError> {
    if new_password1 == new_password2 {
        Ok(())
    } else {
        Err(PeachError::PasswordsDoNotMatch)
    }
}

/// Sets a new password for the admin user
pub fn set_new_password(new_password: &str) -> Result<(), PeachError> {
    let new_password_hash = hash_password(&new_password.to_string());
    let result = set_admin_password_hash(&new_password_hash);
    match result {
        Ok(_) => {
            Ok(())
        },
        Err(_err) => {
            Err(PeachError::FailedToSetNewPassword { msg: "failed to save password hash".to_string() })
        }
    }
}

/// Creates a hash from a password string
pub fn hash_password(password: &str) -> String {
    let mut hasher = Sha3::sha3_256();
    hasher.input_str(password);
    hasher.result_str()
}

/// Sets a new temporary password for the admin user
/// which can be used to reset the permanent password
pub fn set_new_temporary_password(new_password: &str) -> Result<(), PeachError> {
    let new_password_hash = hash_password(&new_password.to_string());
    let result = set_temporary_password_hash(&new_password_hash);
    match result {
        Ok(_) => {
            Ok(())
        },
        Err(_err) => {
            Err(PeachError::FailedToSetNewPassword { msg: "failed to save temporary password hash".to_string() })
        }
    }
}

/// Returns Ok(()) if the supplied temp_password is correct,
/// and returns Err if the supplied temp_password is incorrect
pub fn verify_temporary_password(password: &str) -> Result<(), PeachError> {
    let temporary_admin_password_hash = get_temporary_password_hash()?;
    let password_hash = hash_password(&password.to_string());
    if temporary_admin_password_hash == password_hash {
        Ok(())
    } else {
        Err(PeachError::InvalidPassword)
    }
}

/// Generates a temporary password and sends it via ssb dm
/// to the ssb id configured to be the admin of the peachcloud device
pub fn send_password_reset() -> Result<(), PeachError> {
    // first generate a new random password of ascii characters
    let mut rng = thread_rng();
    let temporary_password: String = iter::repeat(())
        .map(|()| rng.sample(Alphanumeric))
        .map(char::from)
        .take(10)
        .collect();
    // save this string as a new temporary password
    set_new_temporary_password(&temporary_password)?;
    let domain = get_peachcloud_domain()?;

    // then send temporary password as a private ssb message to admin
    let mut msg = format!(
        "Your new temporary password is: {}

If you are on the same WiFi network as your PeachCloud device you can reset your password \
using this link: http://peach.local/reset_password",
        temporary_password
    );
    // if there is an external domain, then include remote link in message
    // otherwise dont include it
    let remote_link = match domain {
        Some(domain) => {
            format!(
                "\n\nOr if you are on a different WiFi network, you can reset your password \
            using the the following link: {}/reset_password",
                domain
            )
        }
        None => "".to_string(),
    };
    msg += &remote_link;
    // finally send the message to the admins
    let peach_config = load_peach_config()?;
    for ssb_admin_id in peach_config.ssb_admin_ids {
        sbot_client::private_message(&msg, &ssb_admin_id)?;
    }
    Ok(())
}