use std::path::PathBuf;

use crypto::digest::Digest;
use crypto::sha2::Sha256;
use sodiumoxide::crypto::pwhash::argon2id13;
use uuid::Uuid;

pub fn hash_secret(secret: &str) -> String {
    sodiumoxide::init().unwrap();
    let hash = argon2id13::pwhash(
        secret.as_bytes(),
        argon2id13::OPSLIMIT_INTERACTIVE,
        argon2id13::MEMLIMIT_INTERACTIVE,
    )
    .unwrap();
    let texthash = std::str::from_utf8(&hash.0).unwrap().to_string();

    // postgres hates null chars. don't do that to postgres
    texthash.trim_end_matches('\u{0}').to_string()
}

pub fn hash_str(string: &str) -> String {
    let mut hasher = Sha256::new();
    hasher.input_str(string);

    hasher.result_str()
}

pub fn uuid_v4() -> String {
    Uuid::new_v4().to_simple().to_string()
}

// TODO: more reliable, more tested
// I don't want to use ProjectDirs, it puts config in awkward places on
// mac. Data too. Seems to be more intended for GUI apps.
pub fn home_dir() -> PathBuf {
    let home = std::env::var("HOME").expect("$HOME not found");
    PathBuf::from(home)
}

pub fn config_dir() -> PathBuf {
    let config_dir =
        std::env::var("XDG_CONFIG_HOME").map_or_else(|_| home_dir().join(".config"), PathBuf::from);
    config_dir.join("atuin")
}

pub fn data_dir() -> PathBuf {
    let data_dir = std::env::var("XDG_DATA_HOME")
        .map_or_else(|_| home_dir().join(".local").join("share"), PathBuf::from);

    data_dir.join("atuin")
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::env;

    #[test]
    fn test_config_dir_xdg() {
        env::remove_var("HOME");
        env::set_var("XDG_CONFIG_HOME", "/home/user/custom_config");
        assert_eq!(
            config_dir(),
            PathBuf::from("/home/user/custom_config/atuin")
        );
    }

    #[test]
    fn test_config_dir() {
        env::set_var("HOME", "/home/user");
        env::remove_var("XDG_CONFIG_HOME");
        assert_eq!(config_dir(), PathBuf::from("/home/user/.config/atuin"));
    }

    #[test]
    fn test_data_dir_xdg() {
        env::remove_var("HOME");
        env::set_var("XDG_DATA_HOME", "/home/user/custom_data");
        assert_eq!(data_dir(), PathBuf::from("/home/user/custom_data/atuin"));
    }

    #[test]
    fn test_data_dir() {
        env::set_var("HOME", "/home/user");
        env::remove_var("XDG_DATA_HOME");
        assert_eq!(data_dir(), PathBuf::from("/home/user/.local/share/atuin"));
    }
}