use crate::app_config::AppConfig;
use crate::broadcast_messages::{BroadcastMessage, BroadcastSender};
use crate::constants;
use crate::controllers::server_controller::ServerConstraints;
use crate::matrix_connection::matrix_client::EncryptionRecoveryState;
use crate::utils::rand_utils::rand_string;
use crate::utils::time_utils::time_secs;
use anyhow::Context;
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 create API token directory: {0}")]
    CreateApiTokensDirectory(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)
    }
}

/// Base API token information
#[derive(serde::Serialize, serde::Deserialize, Debug, Clone)]
pub struct BaseAPIToken {
    /// Token name
    pub name: String,

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

    /// Token max inactivity
    pub max_inactivity: u32,

    /// Token expiration
    pub expiration: Option<u64>,

    /// Read only access
    pub read_only: bool,
}

impl BaseAPIToken {
    /// Check API token information validity
    pub fn check(&self) -> Option<&'static str> {
        let constraints = ServerConstraints::default();

        if !lazy_regex::regex!("^[a-zA-Z0-9 :-]+$").is_match(&self.name) {
            return Some("Token name contains invalid characters!");
        }

        if !constraints.token_name.check_str(&self.name) {
            return Some("Invalid token name length!");
        }

        if !constraints
            .token_max_inactivity
            .check_u32(self.max_inactivity)
        {
            return Some("Invalid token max inactivity!");
        }

        if let Some(expiration) = self.expiration
            && expiration <= time_secs()
        {
            return Some("Given expiration time is in the past!");
        }

        None
    }
}

/// Single API token information
#[derive(serde::Serialize, serde::Deserialize, Debug, Clone)]
pub struct APIToken {
    #[serde(flatten)]
    pub base: BaseAPIToken,

    /// Token unique ID
    pub id: APITokenID,

    /// Client secret
    pub secret: String,

    /// Client creation time
    pub created: u64,

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

impl APIToken {
    /// Get the list of tokens of a user
    pub async fn list_user(email: &UserEmail) -> anyhow::Result<Vec<Self>> {
        let tokens_dir = AppConfig::get().user_api_token_directory(email);

        if !tokens_dir.exists() {
            return Ok(vec![]);
        }

        let mut list = vec![];
        for u in std::fs::read_dir(&tokens_dir)? {
            let entry = u?;
            list.push(
                Self::load(
                    email,
                    &APITokenID::from_str(
                        entry
                            .file_name()
                            .to_str()
                            .context("Cannot decode API Token ID as string!")?,
                    )?,
                )
                .await?,
            );
        }
        Ok(list)
    }

    /// Create a new token
    pub async fn create(email: &UserEmail, base: BaseAPIToken) -> anyhow::Result<Self> {
        let tokens_dir = AppConfig::get().user_api_token_directory(email);

        if !tokens_dir.exists() {
            std::fs::create_dir_all(tokens_dir)
                .map_err(MatrixGWUserError::CreateApiTokensDirectory)?;
        }

        let token = APIToken {
            base,
            id: Default::default(),
            secret: rand_string(constants::TOKENS_LEN),
            created: time_secs(),
            last_used: time_secs(),
        };

        token.write(email).await?;

        Ok(token)
    }

    /// 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, tx: &BroadcastSender) -> 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)?;

        if let Err(e) = tx.send(BroadcastMessage::APITokenDeleted(self)) {
            log::error!("Failed to notify API token deletion! {e}");
        }

        Ok(())
    }

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

        (self.last_used) < time_secs() - refresh_interval as u64
    }

    pub fn is_expired(&self) -> bool {
        // Check for hard coded expiration
        if let Some(exp_time) = self.base.expiration
            && exp_time < time_secs()
        {
            return true;
        }

        // Control max token inactivity
        (self.last_used + self.base.max_inactivity as u64) < time_secs()
    }
}

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