From 9076ab2be9cbc4b0ed13740bb00e2743cc4b1bf4 Mon Sep 17 00:00:00 2001
From: Bat <baptiste@gelez.xyz>
Date: Sat, 15 Sep 2018 18:11:39 +0100
Subject: [PATCH] Initial commit

---
 .gitignore |  3 ++
 Cargo.toml |  7 +++++
 README.md  | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs | 75 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 167 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.toml
 create mode 100644 README.md
 create mode 100644 src/lib.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6936990
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/target
+**/*.rs.bk
+Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..6aa9f6d
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "canapi"
+version = "0.1.0"
+authors = ["Bat' <baptiste@gelez.xyz>"]
+
+[dependencies]
+serde = "1.0"
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b6f2045
--- /dev/null
+++ b/README.md
@@ -0,0 +1,82 @@
+# Canapi
+
+Common Canapi traits.
+
+Canapi is a collection of Rust crate to make it possible to share a REST API definition between
+clients and servers. You define your endpoints (`Endpoint` trait), bind them to your databse (`Provider` trait),
+and you can re-use these endpoints in your client (`Fetch` trait).
+
+This requires three separate crates: one for your API defintion, one for your server, and one for the client.
+
+## Example
+
+`my-api`, where you define the API.
+
+```rust
+use canapi::Endpoint;
+
+#[derive(Default, Serialize, Deserialize)]
+struct UserEndpoint {
+    id: Option<i32>,
+    name: Option<String>,
+    bio: Option<String>,
+}
+
+impl Endpoint for PostEndpoint {
+    type Id = i32;
+
+    fn endpoint() -> &'static str {
+        "/api/v1/users"
+    }
+}
+```
+
+`my-server`, to bind endpoints to database (and expose them to the rest of the world)
+
+```rust
+use canapi::Provider;
+use diesel::*; // Example with Diesel
+use my_api::UserEndpoint;
+
+/// Define the User model…
+
+impl Provider<PgConnection> for User {
+    type Data = UserEndpoint;
+
+    fn get(conn: &PgConnection, id: i32) -> Option<Post> {
+        posts::table.filter(posts::id.eq(id))
+            .limit(1)
+            .get_result::<Post>(conn)
+            .ok()
+    }
+}
+
+// Use rocket, actix-web, iron, gotham or whatever you want to expose your endpoints…
+```
+
+`my-client`, to use your API (here with a potential WASM `Fetch` impl)
+
+```rust
+use canapi_wasm::WasmFetch;
+use plume_api;
+
+#[derive(Default)]
+pub struct Api {
+    users: UserEndpoint
+}
+
+fn fetch_first_post() {
+    let api = Api::default();
+    let post = api.users.get::<WasmFetch>(1);
+    assert_eq(post.id, Some(1));
+}
+
+fn find_hello() {
+    let api = Api::default();
+    let post = api.users.find::<WasmFetch>(PostEndpoint {
+        name: Some(String::new("Jane")),
+        ..PostEndpoint::default()
+    });
+    assert_eq!(post.title, Some(String::new("Jane")));
+}
+```
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..95b5a8b
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,75 @@
+extern crate serde;
+
+use serde::{Serialize, de::DeserializeOwned};
+use std::fmt::Display;
+
+pub enum Error {
+    Fetch(String),
+    SerDe(String),
+    NotFound(String),
+    Authorization(String),
+}
+
+/// API to DB link
+/// 
+/// `E` is the endpoint (API)
+/// `P` is the provider (DB)
+pub trait Provider<P> {
+    type Data: Endpoint;
+
+    /// Get a single result by ID
+    fn get(provider: &P, id: <Self::Data as Endpoint>::Id) -> Result<Self::Data, Error>;
+
+    /// List all matching results
+    fn list(provider: &P, query: Self::Data) -> Vec<Self::Data>;
+
+    /// Save a new object, and returns it
+    fn create(provider: &P, query: Self::Data) -> Result<Self::Data, Error>;
+
+    /// Update an object
+    fn update(provider: &P, id: <Self::Data as Endpoint>::Id, new_data: Self::Data) -> Result<Self::Data, Error>;
+
+    /// Delete an object
+    fn delete(provider: &P, id: <Self::Data as Endpoint>::Id);
+}
+
+/// API Endpoint, common to the server and the front
+pub trait Endpoint: Default + Serialize + DeserializeOwned {
+    type Id: Display;
+
+    /// The URL on which this endpoint is mounted.
+    /// 
+    /// It should start with a /, and end without.
+    fn endpoint() -> &'static str;
+
+    fn get<F: Fetch>(&self, id: Self::Id) -> Result<Self, Error> {
+        F::fetch("GET", format!("{}/{}", Self::endpoint(), id), None)
+    }
+
+    fn list<F: Fetch>(&self) -> Result<Self, Error> {
+        F::fetch("GET", format!("{}", Self::endpoint()), None)
+    }
+
+    fn find<F: Fetch>(&self, query: Self) -> Result<Self, Error> {
+        F::fetch("GET", format!("{}", Self::endpoint()), Some(query))
+    }
+
+    fn create<F: Fetch>(&self, new: Self) -> Result<Self, Error> {
+        F::fetch("POST", format!("{}", Self::endpoint()), Some(new))
+    }
+
+    fn update<F: Fetch>(&self, id: Self::Id, data: Self) -> Result<Self, Error> {
+        F::fetch("PUT", format!("{}/{}", Self::endpoint(), id), Some(data))
+    }
+    
+    fn delete<F: Fetch>(&self, id: Self::Id) -> Result<Self, Error> {
+        F::fetch("DELETE", format!("{}/{}", Self::endpoint(), id), None)
+    }
+}
+
+/// Anything that can perform a network request to fetch an endpoint
+pub trait Fetch {
+
+    /// Fetch a given endpoint
+    fn fetch<T: Endpoint>(method: &'static str, url: String, query: Option<T>) -> Result<T, Error>;    
+}