util.rs

use anyhow::Context;
use base64::{engine::general_purpose::STANDARD_NO_PAD as BASE_64_STD_NO_PAD, Engine as _};
use reqwest::{RequestBuilder, Url};
use spacetimedb_auth::identity::{IncomingClaims, SpacetimeIdentityClaims};
use spacetimedb_client_api_messages::name::GetNamesResponse;
use spacetimedb_lib::Identity;
use std::io::Write;
use std::path::{Path, PathBuf};

use crate::config::Config;
use crate::login::{spacetimedb_login_force, DEFAULT_AUTH_HOST};

pub const UNSTABLE_WARNING: &str = "WARNING: This command is UNSTABLE and subject to breaking changes.";

/// Determine the identity of the `database`.
pub async fn database_identity(
    config: &Config,
    name_or_identity: &str,
    server: Option<&str>,
) -> Result<Identity, anyhow::Error> {
    if let Ok(identity) = Identity::from_hex(name_or_identity) {
        return Ok(identity);
    }
    spacetime_dns(config, name_or_identity, server)
        .await?
        .with_context(|| format!("failed to find database `{name_or_identity}`."))
}

pub(crate) trait ResponseExt: Sized {
    /// Ensure that this response has the given content-type, especially if it's
    /// a success response.
    ///
    /// This checks the response status for you, so you shouldn't call
    /// `error_for_status()` beforehand.
    ///
    /// If the response does not have the given content type, assume it's an error message
    /// and return it as such. Success responses with the wrong content type are treated
    /// as a bug in the API implementation, since that makes it harder to tell what's
    /// meant to be a structured response and what's a plain-text error message.
    async fn ensure_content_type(self, content_type: &str) -> anyhow::Result<Self>;

    /// Like [`reqwest::Response::json()`], but handles non-JSON error messages gracefully.
    async fn json_or_error<T: serde::de::DeserializeOwned>(self) -> anyhow::Result<T>;

    /// Transforms a status of `NOT_FOUND` into `None`.
    fn found(self) -> Option<Self>;
}

fn err_status_desc(status: http::StatusCode) -> Option<&'static str> {
    if status.is_success() {
        None
    } else if status.is_client_error() {
        Some("HTTP status client error")
    } else if status.is_server_error() {
        Some("HTTP status server error")
    } else {
        Some("unexpected HTTP status code")
    }
}

impl ResponseExt for reqwest::Response {
    async fn ensure_content_type(self, content_type: &str) -> anyhow::Result<Self> {
        let status = self.status();
        if self
            .headers()
            .get(http::header::CONTENT_TYPE)
            .is_some_and(|ty| ty == content_type)
        {
            return Ok(self);
        }
        let url = self.url();
        let Some(status_desc) = err_status_desc(status) else {
            anyhow::bail!("HTTP response from url ({url}) was success but did not have content-type: {content_type}");
        };
        let url = url.to_string();
        let status_err = match self.error_for_status_ref() {
            Err(e) => anyhow::Error::from(e),
            Ok(_) => anyhow::anyhow!("{status_desc} ({status}) from url ({url})"),
        };
        let err = match self.text().await {
            Ok(text) => status_err.context(text),
            Err(err) => anyhow::Error::from(err)
                .context(format!("{status_desc} ({status})"))
                .context("failed to get response text"),
        };
        Err(err)
    }

    async fn json_or_error<T: serde::de::DeserializeOwned>(self) -> anyhow::Result<T> {
        let status = self.status();
        self.ensure_content_type("application/json")
            .await?
            .json()
            .await
            .map_err(|err| {
                let mut err = anyhow::Error::from(err);
                if let Some(desc) = err_status_desc(status) {
                    err = err.context(format!("malformed json payload for {desc} ({status})"))
                }
                err
            })
    }

    fn found(self) -> Option<Self> {
        (self.status() != http::StatusCode::NOT_FOUND).then_some(self)
    }
}

/// Converts a name to a database identity.
pub async fn spacetime_dns(
    config: &Config,
    domain: &str,
    server: Option<&str>,
) -> Result<Option<Identity>, anyhow::Error> {
    let client = reqwest::Client::new();
    let url = format!("{}/v1/database/{}/identity", config.get_host_url(server)?, domain);
    let Some(res) = client.get(url).send().await?.found() else {
        return Ok(None);
    };
    let text = res.error_for_status()?.text().await?;
    text.parse()
        .map(Some)
        .context("identity endpoint did not return an identity")
}

pub async fn spacetime_server_fingerprint(url: &str) -> anyhow::Result<String> {
    let builder = reqwest::Client::new().get(format!("{url}/v1/identity/public-key").as_str());
    let res = builder.send().await?.error_for_status()?;
    let fingerprint = res.text().await?;
    Ok(fingerprint)
}

/// Returns all known names for the given identity.
pub async fn spacetime_reverse_dns(
    config: &Config,
    identity: &str,
    server: Option<&str>,
) -> Result<GetNamesResponse, anyhow::Error> {
    let client = reqwest::Client::new();
    let url = format!("{}/v1/database/{}/names", config.get_host_url(server)?, identity);
    client.get(url).send().await?.json_or_error().await
}

/// Add an authorization header, if provided, to the request `builder`.
pub fn add_auth_header_opt(mut builder: RequestBuilder, auth_header: &AuthHeader) -> RequestBuilder {
    if let Some(token) = &auth_header.token {
        builder = builder.bearer_auth(token);
    }
    builder
}

/// Gets the `auth_header` for a request to the server depending on how you want
/// to identify yourself.  If you specify `anon_identity = true` then no
/// `auth_header` is returned. If you specify an identity this function will try
/// to find the identity in the config file. If no identity can be found, the
/// program will `exit(1)`. If you do not specify an identity this function will
/// either get the default identity if one exists or create and save a new
/// default identity returning the one that was just created.
///
/// # Arguments
///  * `config` - The config file reference
///  * `anon_identity` - Whether or not to just use an anonymous identity (no identity)
///  * `identity_or_name` - The identity to try to lookup, which is typically provided from the command line
pub async fn get_auth_header(
    config: &mut Config,
    anon_identity: bool,
    target_server: Option<&str>,
    interactive: bool,
) -> anyhow::Result<AuthHeader> {
    let token = if anon_identity {
        None
    } else {
        Some(get_login_token_or_log_in(config, target_server, interactive).await?)
    };
    Ok(AuthHeader { token })
}

#[derive(Debug, Clone)]
pub struct AuthHeader {
    token: Option<String>,
}
impl AuthHeader {
    pub fn to_header(&self) -> Option<http::HeaderValue> {
        self.token.as_ref().map(|token| {
            let mut val = http::HeaderValue::try_from(["Bearer ", token].concat()).unwrap();
            val.set_sensitive(true);
            val
        })
    }
}

pub const VALID_PROTOCOLS: [&str; 2] = ["http", "https"];

#[derive(Clone, Copy, PartialEq, Debug)]
pub enum ModuleLanguage {
    Csharp,
    Rust,
    Javascript,
}
impl clap::ValueEnum for ModuleLanguage {
    fn value_variants<'a>() -> &'a [Self] {
        &[Self::Csharp, Self::Rust, Self::Javascript]
    }
    fn to_possible_value(&self) -> Option<clap::builder::PossibleValue> {
        match self {
            Self::Csharp => Some(clap::builder::PossibleValue::new("csharp").aliases(["c#", "cs", "C#", "CSharp"])),
            Self::Rust => Some(clap::builder::PossibleValue::new("rust").aliases(["rs", "Rust"])),
            Self::Javascript => Some(clap::builder::PossibleValue::new("typescript").aliases([
                "JavaScript",
                "javascript",
                "js",
                "TypeScript",
                "ts",
                "ECMAScript",
                "ecmascript",
                "es",
            ])),
        }
    }
}

pub fn detect_module_language(path_to_project: &Path) -> anyhow::Result<ModuleLanguage> {
    // TODO: Possible add a config file durlng spacetime init with the language
    // check for Cargo.toml
    if path_to_project.join("Cargo.toml").exists() {
        Ok(ModuleLanguage::Rust)
    } else if path_to_project
        .read_dir()
        .unwrap()
        .any(|entry| entry.unwrap().path().extension() == Some("csproj".as_ref()))
    {
        Ok(ModuleLanguage::Csharp)
    } else if path_to_project.join("package.json").exists() {
        Ok(ModuleLanguage::Javascript)
    } else {
        anyhow::bail!("Could not detect the language of the module. Are you in a SpacetimeDB project directory?")
    }
}

pub fn url_to_host_and_protocol(url: &str) -> anyhow::Result<(&str, &str)> {
    if contains_protocol(url) {
        let protocol = url.split("://").next().unwrap();
        let host = url.split("://").last().unwrap();

        if !VALID_PROTOCOLS.contains(&protocol) {
            Err(anyhow::anyhow!("Invalid protocol: {protocol}"))
        } else {
            Ok((host, protocol))
        }
    } else {
        Err(anyhow::anyhow!("Invalid url: {url}"))
    }
}

pub fn contains_protocol(name_or_url: &str) -> bool {
    name_or_url.contains("://")
}

pub fn host_or_url_to_host_and_protocol(host_or_url: &str) -> (&str, Option<&str>) {
    if contains_protocol(host_or_url) {
        let (host, protocol) = url_to_host_and_protocol(host_or_url).unwrap();
        (host, Some(protocol))
    } else {
        (host_or_url, None)
    }
}

/// Prompt the user for `y` or `n` from stdin.
///
/// Return `false` unless the input is `y`.
pub fn y_or_n(force: bool, prompt: &str) -> anyhow::Result<bool> {
    if force {
        println!("Skipping confirmation due to --yes");
        return Ok(true);
    }
    let mut input = String::new();
    print!("{prompt} [y/N]");
    std::io::stdout().flush()?;
    std::io::stdin().read_line(&mut input)?;
    let input = input.trim().to_lowercase();
    Ok(input == "y" || input == "yes")
}

pub fn decode_identity(token: &String) -> anyhow::Result<String> {
    // Here, we manually extract and decode the claims from the json web token.
    // We do this without using the `jsonwebtoken` crate because it doesn't seem to have a way to skip signature verification.
    // But signature verification would require getting the public key from a server, and we don't necessarily want to do that.
    let token_parts: Vec<_> = token.split('.').collect();
    if token_parts.len() != 3 {
        return Err(anyhow::anyhow!("Token does not look like a JSON web token: {token}"));
    }
    let decoded_bytes = BASE_64_STD_NO_PAD.decode(token_parts[1])?;
    let decoded_string = String::from_utf8(decoded_bytes)?;

    let claims_data: IncomingClaims = serde_json::from_str(decoded_string.as_str())?;
    let claims_data: SpacetimeIdentityClaims = claims_data.try_into()?;

    Ok(claims_data.identity.to_string())
}

pub async fn get_login_token_or_log_in(
    config: &mut Config,
    target_server: Option<&str>,
    interactive: bool,
) -> anyhow::Result<String> {
    if let Some(token) = config.spacetimedb_token() {
        return Ok(token.clone());
    }

    // Note: We pass `force: false` to `y_or_n` because if we're running non-interactively we want to default to "no", not yes!
    let full_login = interactive
        && y_or_n(
            false,
            // It would be "ideal" if we could print the `spacetimedb.com` by deriving it from the `default_auth_host` constant,
            // but this will change _so_ infrequently that it's not even worth the time to write that code and test it.
            "You are not logged in. Would you like to log in with spacetimedb.com?",
        )?;

    if full_login {
        let host = Url::parse(DEFAULT_AUTH_HOST)?;
        spacetimedb_login_force(config, &host, false, true).await
    } else {
        let host = Url::parse(&config.get_host_url(target_server)?)?;
        spacetimedb_login_force(config, &host, true, true).await
    }
}

pub fn resolve_sibling_binary(bin_name: &str) -> anyhow::Result<PathBuf> {
    let resolved_exe = std::env::current_exe().context("could not retrieve current exe")?;
    let bin_path = resolved_exe
        .parent()
        .unwrap()
        .join(bin_name)
        .with_extension(std::env::consts::EXE_EXTENSION);
    Ok(bin_path)
}