// ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
// ┃ Copyright: (c) 2023, Mike 'PhiSyX' S. (https://github.com/PhiSyX)         ┃
// ┃ SPDX-License-Identifier: MPL-2.0                                          ┃
// ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
// ┃                                                                           ┃
// ┃  This Source Code Form is subject to the terms of the Mozilla Public      ┃
// ┃  License, v. 2.0. If a copy of the MPL was not distributed with this      ┃
// ┃  file, You can obtain one at https://mozilla.org/MPL/2.0/.                ┃
// ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

use std::path;

use super::Error;
use crate::routing;

// --------- //
// Interface //
// --------- //

/// Interface d'application web.
pub trait Application {
	/// Routeur de l'application.
	type Router: routing::interface::RouterExt<State = Self::State>;

	/// État utilisateur de l'application.
	type State;

	fn register_extension(
		_: &crate::state::State<Self::State>,
		router: routing::AxumRouter<Self::State>,
	) -> routing::AxumRouter<Self::State> {
		router
	}

	fn register_layer(
		_: &crate::state::State<Self::State>,
		router: routing::AxumRouter<Self::State>,
	) -> routing::AxumRouter<Self::State> {
		router
	}

	fn register_middleware(
		_: &crate::state::State<Self::State>,
		router: routing::AxumRouter<Self::State>,
	) -> routing::AxumRouter<Self::State> {
		router
	}

	fn register_service(
		server: crate::server::Server<Self::State>,
	) -> crate::server::Server<Self::State> {
		server
	}
}

#[async_trait::async_trait]
pub trait ApplicationExt {
	type CLI: ApplicationCLIInterface;
	type ENV: ApplicationEnvInterface;

	/// Définit le mode d'exécution du programme.
	fn define_process_mode(self, mode: super::env::EnvProcessMode) -> Self
	where
		Self: Sized;

	/// Définit les arguments de la CLI, filtrés par les champs de la structure
	/// implémentant l'interface [CLI_Interface].
	fn with_cli_args(self) -> Self
	where
		Self: Sized;

	/// Définit les variables d'environnement, filtrés par les champs de la
	/// structure implémentant l'interface [ENV_Interface].
	fn with_env_vars(self) -> Result<Self, Error>
	where
		Self: Sized;

	/// Arguments de la CLI.
	fn cli_args(&self) -> &Self::CLI;

	/// Variables d'environnement.
	fn env_vars(&self) -> &Self::ENV;
}

pub trait ApplicationCLIInterface:
	std::fmt::Debug + Clone + Send + Sync
{
	fn arguments() -> Self
	where
		Self: Sized;

	fn shared(self) -> std::sync::Arc<Self>
	where
		Self: Sized,
	{
		std::sync::Arc::new(self)
	}
}

pub trait ApplicationEnvInterface:
	std::fmt::Debug + Clone + Send + Sync
{
	// NOTE(phisyx): ici typiquement un maybe async aurait été vraiment
	// sympa.
	// Dans le cas où l'on voudrait récupérer les variables d'environnement
	// depuis une URL distant.
	/* #[async] */
	fn setup(_: &crate::application::Settings) -> Result<Self, Error>
	where
		Self: Sized;

	/// Récupère les variables d'environnement à partir du contenu d'un fichier
	/// et retourne une structure avec les données du contenu du fichier en
	/// guise de valeurs pour chaque champ.
	fn fetch_from_file<T>(
		env_filepath: impl AsRef<path::Path>,
	) -> Result<T, Error>
	where
		T: serde::de::DeserializeOwned,
	{
		Ok(lexa_env::from_file(env_filepath)?)
	}
}

pub trait ApplicationLoggerInterface {
	fn using_logger(self) -> Result<Self, Error>
	where
		Self: Sized,
	{
		eprintln!(
			"WARN: You need to implement the method \
			 `ApplicationLoggerInterface#using_logger` for `{}`.",
			std::any::type_name::<Self>()
		);
		Ok(self)
	}

	fn using_logger_with_settings(
		self,
		_: super::settings::LoggerSettings,
	) -> Result<Self, Error>
	where
		Self: Sized,
	{
		eprintln!(
			"WARN: You need to implement the method \
			 `ApplicationLoggerInterface#using_logger_with_settings` for `{}`.",
			std::any::type_name::<Self>()
		);
		Ok(self)
	}
}

#[async_trait::async_trait]
pub trait Service: Send + Sync {
	type Payload;

	async fn subscribe(_: &Self::Payload) -> Result<Self, super::ServiceError>
	where
		Self: Sized;
}

// -------------- //
// Implémentation // -> Interface
// -------------- //

impl ApplicationCLIInterface for () {
	fn arguments() -> Self
	where
		Self: Sized,
	{
	}
}

impl ApplicationEnvInterface for () {
	fn setup(_: &crate::application::Settings) -> Result<Self, Error>
	where
		Self: Sized,
	{
		Ok(())
	}
}