Add code to authenticate to NextCloud server

.cspell/custom-dictionary-workspace.txt

@@ -0,0 +1,6 @@
+# SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+# SPDX-License-Identifier: CC0-1.0
+# Custom Dictionary Words
+montecristosoftware
+reqwest
+webbrowser

.vscode/settings.json

@@ -0,0 +1,12 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: CC0-1.0
+{
+    "cSpell.customDictionaries": {
+        "custom-dictionary-workspace": {
+            "name": "custom-dictionary-workspace",
+            "path": "${workspaceFolder:cooking-schedule}/.cspell/custom-dictionary-workspace.txt",
+            "addWords": true,
+            "scope": "workspace"
+        }
+    }
+}

Cargo.lock

@@ -2,6 +2,23 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "anyhow"
+version = "1.0.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb07d2053ccdbe10e2af2995a2f116c1330396493dc1269f6a91d0ae82e19704"
+
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -38,6 +55,12 @@ version = "1.0.73"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
 
+[[package]]
+name = "cesu8"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d43a04d8753f35258c91f8ec639f792891f748a1edbd759cf1dcea3382ad83c"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -53,14 +76,55 @@ dependencies = [
  "envmnt",
 ]
 
+[[package]]
+name = "clap"
+version = "3.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "190814073e85d238f31ff738fcb0bf6910cedeb73376c87cd69291028966fd83"
+dependencies = [
+ "atty",
+ "bitflags",
+ "clap_lex",
+ "indexmap",
+ "once_cell",
+ "strsim",
+ "termcolor",
+ "textwrap",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2850f2f5a82cbf437dd5af4d49848fbdfc27c157c3d010345776f952765261c5"
+dependencies = [
+ "os_str_bytes",
+]
+
+[[package]]
+name = "combine"
+version = "4.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a604e93b79d1808327a6fca85a6f2d69de66461e7620f5a4cbf5fb4d1d7c948"
+dependencies = [
+ "bytes",
+ "memchr",
+]
+
 [[package]]
 name = "cooking-schedule"
 version = "0.0.0"
 dependencies = [
+ "anyhow",
+ "clap",
+ "directories",
  "reqwest",
  "rusty-hook",
+ "serde",
  "serde_json",
  "tokio",
+ "toml",
+ "webbrowser",
 ]
 
 [[package]]
@@ -79,6 +143,61 @@ version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5827cebf4670468b8772dd191856768aedcb1b0278a04f989f7766351917b9dc"
 
+[[package]]
+name = "darling"
+version = "0.13.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a01d95850c592940db9b8194bc39f4bc0e89dee5c4265e4b1807c34a9aba453c"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.13.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "859d65a907b6852c9361e3185c862aae7fafd2887876799fa55f5f99dc40d610"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.13.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c972679f83bdf9c42bd905396b6c3588a843a17f0f16dfcfa3e2c5d57441835"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "directories"
+version = "4.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f51c5d4ddabd36886dd3e1438cb358cdcb0d7c499cb99cb4ac2e38e18b5cb210"
+dependencies = [
+ "dirs-sys",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b1d1d91c932ef41c0f2663aa8b0ca0342d444d842c06914aa0a7e352d0bada6"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "encoding_rs"
 version = "0.8.31"
@@ -159,6 +278,12 @@ version = "0.3.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c09fd04b7e4073ac7156a9539b57a484a8ea920f79c7c675d05d289ab6110d3"
 
+[[package]]
+name = "futures-io"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc4045962a5a5e935ee2fdedaa4e08284547402885ab326734432bed5d12966b"
+
 [[package]]
 name = "futures-sink"
 version = "0.3.21"
@@ -178,9 +303,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8b7abd5d659d9b90c8cba917f6ec750a74e2dc23902ef9cd4cc8c8b22e6036a"
 dependencies = [
  "futures-core",
+ "futures-io",
  "futures-task",
+ "memchr",
  "pin-project-lite",
  "pin-utils",
+ "slab",
 ]
 
 [[package]]
@@ -192,6 +320,17 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4eb1a864a501629691edf6c15a593b7a51eebaa1e8468e9ddc623de7c9b58ec6"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "h2"
 version = "0.3.13"
@@ -297,6 +436,12 @@ dependencies = [
  "tokio-native-tls",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "idna"
 version = "0.2.3"
@@ -339,6 +484,26 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "112c678d4050afce233f4f2852bb2eb519230b3cf12f33585275537d7e41578d"
 
+[[package]]
+name = "jni"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c6df18c2e3db7e453d3c6ac5b3e9d5182664d28788126d39b91f2d1e22b017ec"
+dependencies = [
+ "cesu8",
+ "combine",
+ "jni-sys",
+ "log",
+ "thiserror",
+ "walkdir",
+]
+
+[[package]]
+name = "jni-sys"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8eaf4bc02d17cbdd7ff4c7438cafcdf7fb9a4613313ad11b4f8fefe7d3fa0130"
+
 [[package]]
 name = "js-sys"
 version = "0.3.58"
@@ -417,6 +582,62 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "ndk"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2032c77e030ddee34a6787a64166008da93f6a352b629261d0fee232b8742dd4"
+dependencies = [
+ "bitflags",
+ "jni-sys",
+ "ndk-sys",
+ "num_enum",
+ "thiserror",
+]
+
+[[package]]
+name = "ndk-context"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27b02d87554356db9e9a873add8782d4ea6e3e58ea071a9adb9a2e8ddb884a8b"
+
+[[package]]
+name = "ndk-glue"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d0c4a7b83860226e6b4183edac21851f05d5a51756e97a1144b7f5a6b63e65f"
+dependencies = [
+ "lazy_static",
+ "libc",
+ "log",
+ "ndk",
+ "ndk-context",
+ "ndk-macro",
+ "ndk-sys",
+]
+
+[[package]]
+name = "ndk-macro"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0df7ac00c4672f9d5aece54ee3347520b7e20f158656c7db2e6de01902eb7a6c"
+dependencies = [
+ "darling",
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "ndk-sys"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e5a6ae77c8ee183dcbbba6150e2e6b9f3f4196a7666c02a715a95692ec1fa97"
+dependencies = [
+ "jni-sys",
+]
+
 [[package]]
 name = "nias"
 version = "0.5.0"
@@ -433,6 +654,27 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "num_enum"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf5395665662ef45796a4ff5486c5d41d29e0c09640af4c5f17fd94ee2c119c9"
+dependencies = [
+ "num_enum_derive",
+]
+
+[[package]]
+name = "num_enum_derive"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b0498641e53dd6ac1a4f22547548caa6864cc4933784319cd1775271c5a46ce"
+dependencies = [
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.12.0"
@@ -484,6 +726,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "os_str_bytes"
+version = "6.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21326818e99cfe6ce1e524c2a805c189a99b5ae555a35d19f9a284b427d86afa"
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -508,6 +756,16 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1df8c4ec4b0627e53bdf214615ad287367e482558cf84b109250b37464dc03ae"
 
+[[package]]
+name = "proc-macro-crate"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e17d47ce914bf4de440332250b0edd23ce48c005f59fab39d3335866b114f11a"
+dependencies = [
+ "thiserror",
+ "toml",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.40"
@@ -535,6 +793,17 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "redox_users"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b033d837a7cf162d7993aded9304e30a83213c648b6e389db233191f891e5c2b"
+dependencies = [
+ "getrandom",
+ "redox_syscall",
+ "thiserror",
+]
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"
@@ -599,6 +868,15 @@ version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f3f6f92acf49d1b98f7a81226834412ada05458b7364277387724a237f062695"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "schannel"
 version = "0.1.20"
@@ -637,6 +915,20 @@ name = "serde"
 version = "1.0.137"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61ea8d54c77f8315140a05f4c7237403bf38b72704d031543aa1d16abbf517d1"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.137"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f26faba0c3959972377d3b2d306ee9f71faee9714294e41bb777f83f88578be"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
 
 [[package]]
 name = "serde_json"
@@ -677,6 +969,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "syn"
 version = "1.0.98"
@@ -702,6 +1000,41 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "termcolor"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bab24d30b911b2376f3a13cc2cd443142f0c81dda04c118693e35b3835757755"
+dependencies = [
+ "winapi-util",
+]
+
+[[package]]
+name = "textwrap"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1141d4d61095b28419e22cb0bbf02755f5e54e0526f97f1e3d1d160e60885fb"
+
+[[package]]
+name = "thiserror"
+version = "1.0.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd829fe32373d27f76265620b5309d0340cb8550f523c1dda251d6298069069a"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0396bc89e626244658bef819e22d0cc459e795a5ebe878e6ec336d1674a8d79a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.6.0"
@@ -856,6 +1189,17 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
 
+[[package]]
+name = "walkdir"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
+dependencies = [
+ "same-file",
+ "winapi",
+ "winapi-util",
+]
+
 [[package]]
 name = "want"
 version = "0.3.0"
@@ -948,6 +1292,26 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webbrowser"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc6a3cffdb686fbb24d9fb8f03a213803277ed2300f11026a3afe1f108dc021b"
+dependencies = [
+ "jni",
+ "ndk-glue",
+ "url",
+ "web-sys",
+ "widestring",
+ "winapi",
+]
+
+[[package]]
+name = "widestring"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17882f045410753661207383517a6f62ec3dbeb6a4ed2acce01f0728238d1983"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -964,6 +1328,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"

Cargo.toml

@@ -3,6 +3,7 @@
 
 [package]
 name = "cooking-schedule"
+description = "Build a schedule of dishes to cook with the help of NextCloud Cookbook"
 version = "0.0.0"
 edition = "2021"
 authors = ["Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>"]
@@ -15,13 +16,33 @@ path = "src/main.rs"
 [dev-dependencies.rusty-hook]
 version = "0.11"
 
+[dependencies.anyhow]
+version = "1.0"
+
+[dependencies.clap]
+version = "3.2"
+features = ["cargo"]
+
+[dependencies.directories]
+version = "4.0"
+
 [dependencies.reqwest]
 version = "0.11"
-features = ["json"]
+features = ["json", "blocking"]
+
+[dependencies.serde]
+version = "1.0"
+features = ["derive"]
 
 [dependencies.serde_json]
 version = "1.0"
 
+[dependencies.toml]
+version = "0.5"
+
 [dependencies.tokio]
 version = "1"
 features = ["rt-multi-thread", "net", "macros"]
+
+[dependencies.webbrowser]
+version = "0.7"

src/config/credentials.rs

@@ -0,0 +1,118 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use {
+    anyhow::{anyhow, Result},
+    reqwest::{StatusCode, Url},
+    serde::{Deserialize, Serialize},
+    std::collections::HashMap,
+    std::io::ErrorKind,
+    std::path::{Path, PathBuf},
+    std::time::Duration,
+};
+
+#[derive(Deserialize, Serialize, Default)]
+pub struct Credentials {
+    #[serde(skip)]
+    config_file: PathBuf,
+
+    servers: HashMap<String, Server>,
+}
+
+#[derive(Deserialize, Serialize)]
+pub struct Server {
+    url: String,
+    login_name: String,
+    password: String,
+}
+
+impl Credentials {
+    pub fn from_directory(config_dir: &Path) -> Result<Self> {
+        let credentials_file = config_dir.join("credentials.toml");
+        match std::fs::read_to_string(&credentials_file) {
+            Ok(content) => {
+                let mut credentials: Credentials = toml::from_str(&content)?;
+                credentials.config_file = credentials_file;
+                Ok(credentials)
+            }
+            Err(err) if err.kind() == ErrorKind::NotFound => {
+                let mut credentials = Credentials::default();
+                credentials.config_file = credentials_file;
+                credentials.write_back()?;
+                Ok(credentials)
+            }
+            Err(err) => Err(anyhow!(err)),
+        }
+    }
+
+    pub fn add(&mut self, server: Url) -> Result<()> {
+        let http_client = reqwest::blocking::Client::new();
+
+        #[derive(Deserialize)]
+        struct LoginFlow {
+            poll: LoginPollEndpoint,
+            login: String,
+        }
+        #[derive(Deserialize)]
+        struct LoginPollEndpoint {
+            token: String,
+            endpoint: String,
+        }
+        #[derive(Deserialize)]
+        #[serde(rename_all = "camelCase")]
+        struct LoginResult {
+            server: String,
+            login_name: String,
+            app_password: String,
+        }
+
+        let login_url = server.join("index.php/login/v2")?;
+
+        let login_flow = http_client
+            .post(login_url.clone())
+            .send()?
+            .json::<LoginFlow>()?;
+
+        // User auth flow happens in browser
+        webbrowser::open(&login_flow.login)?;
+
+        // We start polling for the end of the flow
+        loop {
+            let response = http_client
+                .post(&login_flow.poll.endpoint)
+                .form(&[("token", &login_flow.poll.token)])
+                .send()?;
+
+            match response.status() {
+                StatusCode::OK => {
+                    let login_result = response.json::<LoginResult>()?;
+                    let new_server = Server {
+                        url: login_result.server,
+                        login_name: login_result.login_name,
+                        password: login_result.app_password,
+                    };
+
+                    let host_name = server
+                        .host_str()
+                        .ok_or(anyhow!("No hostname for provided URL, is it valid?"))?;
+                    self.servers.insert(host_name.to_owned(), new_server);
+                    break;
+                }
+                StatusCode::NOT_FOUND => {
+                    std::thread::sleep(Duration::from_secs(1));
+                    // ...then keep polling
+                }
+                _ => {
+                    response.error_for_status()?;
+                }
+            }
+        }
+
+        self.write_back()
+    }
+
+    fn write_back(&self) -> Result<()> {
+        std::fs::write(&self.config_file, toml::to_string(self)?)?;
+        Ok(())
+    }
+}

src/config/mod.rs

@@ -0,0 +1,40 @@
+// SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+pub mod credentials;
+
+use {
+    self::credentials::Credentials,
+    anyhow::Result,
+    directories::ProjectDirs,
+    serde::Deserialize,
+    std::io::{Error, ErrorKind},
+    std::path::PathBuf,
+};
+
+#[derive(Deserialize)]
+pub struct Config {
+    #[serde(skip_deserializing)]
+    pub credentials: Credentials,
+}
+
+impl Config {
+    pub fn new() -> Self {
+        let config_dir = Self::ensure_config_dir().unwrap();
+        Config {
+            credentials: Credentials::from_directory(&config_dir).unwrap(),
+        }
+    }
+
+    fn ensure_config_dir() -> Result<PathBuf> {
+        let config_dir = ProjectDirs::from("eu", "montecristosoftware", "cooking-schedule")
+            .ok_or(Error::new(
+                ErrorKind::Other,
+                "Unable to determine application configuration folder",
+            ))?
+            .config_dir()
+            .to_path_buf();
+        std::fs::create_dir_all(&config_dir)?;
+        Ok(config_dir)
+    }
+}

src/main.rs

@@ -1,6 +1,47 @@
 // SPDX-FileCopyrightText: 2022 Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
-fn main() {
+mod config;
-    println!("Hello, world!");
+
+use {
+    self::config::Config,
+    clap::{arg, command, ArgMatches, Command},
+    reqwest::Url,
+};
+
+fn parse_args() -> ArgMatches {
+    command!()
+        .propagate_version(true)
+        .subcommand_required(true)
+        .arg_required_else_help(true)
+        .subcommand(
+            Command::new("init")
+                .about("Authenticate against the provided NextCloud server")
+                .arg(arg!(<server> "NextCloud server to connect to")),
+        )
+        .get_matches()
+}
+
+#[tokio::main(flavor = "multi_thread")]
+async fn main() -> anyhow::Result<()> {
+    let args = parse_args();
+    let mut configuration = Config::new();
+
+    match args.subcommand() {
+        Some(("init", sub_matches)) => {
+            let server = sub_matches
+                .get_one::<String>("server")
+                .expect("Mandatory parameter <server>");
+            tokio::task::block_in_place(move || -> anyhow::Result<()> {
+                configuration
+                    .credentials
+                    .add(Url::parse(server)?)
+                    .expect("Unable to authenticate to NextCloud instance");
+                Ok(())
+            })?;
+        }
+        _ => unreachable!("Exhausted list of subcommands and subcommand_required prevents `None`"),
+    };
+
+    Ok(())
 }