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//! Fama provides a series of functionalities that makes it easy to layout the steps
//! require to accomplish a task.
//! Each step in the process is refer to as a pipe. The data or content is passed through
//! the "pipes". At any stage the flow can be stopped.
//!
//! This pattern is usually refer to as the "pipeline" pattern. It is very similar to the
//! middleware pattern.
//!
//! This implementation remove the responsibility of the current "pipe" calling the next pipe like
//! in the middleware patten. A "pipe" can apply it's changes/logic or stop the flow. It is the "pipeline"
//! that initiates the next call.
//!
//! The following example is illustrating a "New User" flow through the pipeline.
//!
//! ```rust
//!# #![allow(dead_code)]
//!
//! #[tokio::main]
//! async fn main() {
//! // A new user instance is being passed through the pipeline
//! let new_user = fama::Pipeline::pass(NewUser::default()) // The input/content
//! .through(ValidateUserName).await // pipe "ValidateUserName" will stop the flow if the user does not have a "username"
//! .through(GenerateUserId).await // pipe "GenerateUserId" generates and set the user ID.
//! .through(ApplyDefaultRole).await // pipe "ApplyDefaultRole" will give the user the "Basic" role if the list of roles is empty
//! .through(SaveNewUserData).await // pipe "SaveNewUserData" saves the data to the database. At this stage, we know all is well
//! .through_fn(|_pipe: fama::PipeContent| async {
//! println!("yep, you can pass a closure or function too");
//! }).await
//! .deliver(); // starts the process or use
//! // .confirm() // Return true when the content passes throug all the pipes
//!
//! // Fails because "new user" does not have a "username"
//! println!("fails validation: {:#?}", &new_user);
//!
//! println!("----------------------------------------");
//!
//! let new_user2 = fama::Pipeline::pass(NewUser {
//! username: Some("user1".into()), // "new user" has a username
//! ..NewUser::default()
//! })
//! .through(ValidateUserName).await
//! .through(GenerateUserId).await
//! .through(ApplyDefaultRole).await
//! .through(SaveNewUserData).await
//! .deliver();
//!
//! println!(
//! "passes validation and all fields are set : {:#?}",
//! &new_user2
//! );
//! }
//!
//! // The content or the pipeline input. Could be any type
//! #[derive(Debug, Clone)]
//! struct NewUser {
//! internal_id: i32,
//! id: Option<String>,
//! username: Option<String>,
//! role: Option<Vec<UserRole>>,
//! }
//!
//! impl Default for NewUser {
//! fn default() -> Self {
//! Self {
//! internal_id: 0,
//! id: None,
//! username: None,
//! role: None,
//! }
//! }
//! }
//!
//! // making the pipe input type injectable
//! #[fama::async_trait]
//! impl busybody::Injectable for NewUser {
//! async fn inject(c: &busybody::ServiceContainer) -> Self {
//! // get the instance of the type in the current scope or
//! // create a new instance
//! c.proxy_value().unwrap_or_else(|| Self::default())
//! }
//! }
//!
//! // The various roles a user can have
//! #[derive(Debug, Clone)]
//! enum UserRole {
//! Admin,
//! ContentCreator,
//! Moderator,
//! Basic,
//! }
//!
//! struct ValidateUserName;
//!
//! // A struct becomes a pipe when it implements "fama::FamaPipe"
//! #[fama::async_trait]
//! impl fama::FamaPipe<(NewUser, fama::PipeContent), ()> for ValidateUserName {
//!
//! // The only requirement is to implement "receive_pipe_content" method
//! async fn receive_pipe_content(&self, (new_user, mut content): (NewUser, fama::PipeContent)) {
//!
//1 // When the username is "none", stop the flow
//! if new_user.username.is_none() {
//! println!("User name cannot be empty");
//! content.stop_the_flow(); // Stop the pipeline flow. Pipes below this pipe will not get call
//! }
//!
//! }
//! }
//!
//! struct GenerateUserId;
//!
//! #[fama::async_trait]
//! impl fama::FamaPipe<(NewUser, fama::PipeContent), Option<fama::PipeContent>> for GenerateUserId {
//! async fn receive_pipe_content(&self, (mut new_user, content): (NewUser,fama::PipeContent)) -> Option<fama::PipeContent> {
//!
//! if new_user.id.is_none() {
//! new_user.id = Some(uuid::Uuid::new_v4().to_string()); // Generate and set the ID
//! content.store(new_user);
//! }
//!
//! None
//! }
//! }
//!
//! struct ApplyDefaultRole;
//!
//! #[fama::async_trait]
//! impl fama::FamaPipe<(NewUser, fama::PipeContent), Option<fama::PipeContent>> for ApplyDefaultRole {
//! async fn receive_pipe_content(&self, (mut new_user, content): (NewUser,fama::PipeContent)) -> Option<fama::PipeContent> {
//!
//! if new_user.role.is_none() {
//! new_user.role = Some(vec![UserRole::Basic]); // Apply default role
//! content.store(new_user);
//! }
//!
//! Some(content)
//! }
//! }
//!
//! struct SaveNewUserData;
//! #[fama::async_trait]
//! impl fama::FamaPipe<(NewUser, fama::PipeContent), Option<fama::PipeContent>> for SaveNewUserData {
//! async fn receive_pipe_content(&self, (mut new_user, content): (NewUser,fama::PipeContent)) -> Option<fama::PipeContent> {
//!
//! println!(">> saving new user: {:?}", &new_user);
//!
//! new_user.internal_id = 1; // pretend we persisted the data to a database
//! content.store(new_user);
//!
//! Some(content)
//! }
//! }
//! ```
//!
mod content;
mod pipeline;
pub use content::PipeContent;
pub use pipeline::FamaPipe;
pub use pipeline::Pipeline;
pub use async_trait::async_trait;