use crate::app_config::AppConfig;
use crate::utils::time_utils::time_secs;
use jwt_simple::reexports::serde_json;
use std::cmp::min;
use std::str::FromStr;

/// Matrix Gateway user errors
#[derive(thiserror::Error, Debug)]
enum MatrixGWUserError {
    #[error("Failed to load user metadata: {0}")]
    LoadUserMetadata(std::io::Error),
    #[error("Failed to decode user metadata: {0}")]
    DecodeUserMetadata(serde_json::Error),
    #[error("Failed to save user metadata: {0}")]
    SaveUserMetadata(std::io::Error),
    #[error("Failed to delete API token: {0}")]
    DeleteToken(std::io::Error),
    #[error("Failed to load API token: {0}")]
    LoadApiToken(std::io::Error),
    #[error("Failed to decode API token: {0}")]
    DecodeApiToken(serde_json::Error),
    #[error("API Token does not exists!")]
    ApiTokenDoesNotExists,
    #[error("Failed to save API token: {0}")]
    SaveAPIToken(std::io::Error),
}

#[derive(serde::Serialize, serde::Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
pub struct UserEmail(pub String);

impl UserEmail {
    pub fn is_valid(&self) -> bool {
        mailchecker::is_valid(&self.0)
    }
}

#[derive(serde::Serialize, serde::Deserialize, Debug, Clone, Eq, PartialEq)]
pub struct APITokenID(pub uuid::Uuid);

impl Default for APITokenID {
    fn default() -> Self {
        Self(uuid::Uuid::new_v4())
    }
}

impl FromStr for APITokenID {
    type Err = uuid::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Ok(Self(uuid::Uuid::from_str(s)?))
    }
}

#[derive(serde::Serialize, serde::Deserialize, Debug, Clone)]
pub struct User {
    pub email: UserEmail,
    pub name: String,
    pub time_create: u64,
    pub last_login: u64,
}

impl User {
    /// Get a user by its mail
    pub async fn get_by_mail(mail: &UserEmail) -> anyhow::Result<Self> {
        let path = AppConfig::get().user_metadata_file_path(mail);
        let data = std::fs::read_to_string(path).map_err(MatrixGWUserError::LoadUserMetadata)?;
        Ok(serde_json::from_str(&data).map_err(MatrixGWUserError::DecodeUserMetadata)?)
    }

    /// Update user metadata on disk
    pub async fn write(&self) -> anyhow::Result<()> {
        let path = AppConfig::get().user_metadata_file_path(&self.email);
        std::fs::write(&path, serde_json::to_string(&self)?)
            .map_err(MatrixGWUserError::SaveUserMetadata)?;
        Ok(())
    }

    /// Create or update user information
    pub async fn create_or_update_user(mail: &UserEmail, name: &str) -> anyhow::Result<User> {
        let storage_dir = AppConfig::get().user_directory(mail);
        let mut user = if !storage_dir.exists() {
            std::fs::create_dir_all(storage_dir)?;

            User {
                email: mail.clone(),
                name: name.to_string(),
                time_create: time_secs(),
                last_login: time_secs(),
            }
        } else {
            Self::get_by_mail(mail).await?
        };

        // Update some user information
        user.name = name.to_string();
        user.last_login = time_secs();
        user.write().await?;

        Ok(user)
    }
}

/// Single API client information
#[derive(serde::Serialize, serde::Deserialize, Debug, Clone)]
pub struct APIToken {
    /// Token unique ID
    pub id: APITokenID,

    /// Client description
    pub description: String,

    /// Restricted API network for token
    pub network: Option<ipnet::IpNet>,

    /// Client secret
    pub secret: String,

    /// Client creation time
    pub created: u64,

    /// Client last usage time
    pub last_used: u64,

    /// Read only access
    pub read_only: bool,

    /// Token max inactivity
    pub max_inactivity: u64,
}

impl APIToken {
    /// Get a token information
    pub async fn load(email: &UserEmail, id: &APITokenID) -> anyhow::Result<Self> {
        let token_file = AppConfig::get().user_api_token_metadata_file(email, id);
        match token_file.exists() {
            true => Ok(serde_json::from_str::<Self>(
                &std::fs::read_to_string(&token_file).map_err(MatrixGWUserError::LoadApiToken)?,
            )
            .map_err(MatrixGWUserError::DecodeApiToken)?),
            false => Err(MatrixGWUserError::ApiTokenDoesNotExists.into()),
        }
    }

    /// Write this token information
    pub async fn write(&self, mail: &UserEmail) -> anyhow::Result<()> {
        let path = AppConfig::get().user_api_token_metadata_file(mail, &self.id);
        std::fs::write(&path, serde_json::to_string(&self)?)
            .map_err(MatrixGWUserError::SaveAPIToken)?;
        Ok(())
    }

    /// Delete this token
    pub async fn delete(self, email: &UserEmail) -> anyhow::Result<()> {
        let token_file = AppConfig::get().user_api_token_metadata_file(email, &self.id);
        std::fs::remove_file(&token_file).map_err(MatrixGWUserError::DeleteToken)?;
        Ok(())
    }

    pub fn shall_update_time_used(&self) -> bool {
        let refresh_interval = min(600, self.max_inactivity / 10);

        (self.last_used) < time_secs() - refresh_interval
    }

    pub fn is_expired(&self) -> bool {
        (self.last_used + self.max_inactivity) < time_secs()
    }
}

#[derive(serde::Serialize, Debug, Clone)]
pub struct ExtendedUserInfo {
    #[serde(flatten)]
    pub user: User,
    pub matrix_user_id: Option<String>,
}

impl ExtendedUserInfo {
    pub async fn from_user(user: User) -> anyhow::Result<Self> {
        Ok(Self {
            user,
            matrix_user_id: None, // TODO
        })
    }
}