pocketstation 1.0.1

use std::collections::BTreeMap;

pub use crate::graph::OperatorId;
use crate::graph::{EdgeContract, NodeTypeId};

use crate::session::SessionError;

pub const CONNECTOR_NODE_TYPE_ID: &str = "endpoint.connector.external";
pub const BROWSER_NODE_TYPE_ID: &str = "endpoint.browser.remote";
pub const BROWSER_OPERATOR_ID: &str = "io.pocketstation.browser.webrtc.v1";

#[derive(Debug, Clone, Default, PartialEq, Eq)]
pub struct EndpointConfiguration {
    values: BTreeMap<String, String>,
}

impl EndpointConfiguration {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn with(mut self, key: impl Into<String>, value: impl Into<String>) -> Self {
        self.values.insert(key.into(), value.into());
        self
    }

    pub fn get(&self, key: &str) -> Option<&str> {
        self.values.get(key).map(String::as_str)
    }

    pub fn iter(&self) -> impl Iterator<Item = (&str, &str)> {
        self.values
            .iter()
            .map(|(key, value)| (key.as_str(), value.as_str()))
    }

    pub(crate) fn validate(&self) -> Result<(), SessionError> {
        if let Some((key, _)) = self.values.iter().find(|(key, _)| key.trim().is_empty()) {
            return Err(SessionError::InvalidEndpoint {
                reason: format!("configuration key {key:?} cannot be empty"),
            });
        }
        Ok(())
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct EndpointDescriptor {
    node_type_id: NodeTypeId,
    operator_id: OperatorId,
    configuration: EndpointConfiguration,
    input_edge: Option<EdgeContract>,
}

impl EndpointDescriptor {
    pub fn new(node_type_id: NodeTypeId, operator_id: OperatorId) -> Self {
        Self {
            node_type_id,
            operator_id,
            configuration: EndpointConfiguration::new(),
            input_edge: None,
        }
    }

    pub fn with_configuration(mut self, configuration: EndpointConfiguration) -> Self {
        self.configuration = configuration;
        self
    }

    /// Declares the bounded delivery policy for routes entering this endpoint.
    ///
    /// Endpoint packages own this policy. The Session compiler validates and
    /// lowers it without recognizing provider, recorder, or transport names.
    pub fn with_input_edge(mut self, input_edge: EdgeContract) -> Self {
        self.input_edge = Some(input_edge);
        self
    }

    pub fn node_type_id(&self) -> &NodeTypeId {
        &self.node_type_id
    }

    pub fn operator_id(&self) -> &OperatorId {
        &self.operator_id
    }

    pub fn configuration(&self) -> &EndpointConfiguration {
        &self.configuration
    }

    pub const fn input_edge(&self) -> Option<EdgeContract> {
        self.input_edge
    }

    pub(crate) fn validate(&self) -> Result<(), SessionError> {
        if self.node_type_id.as_str().trim().is_empty() {
            return Err(SessionError::InvalidEndpoint {
                reason: "node type id cannot be empty".to_owned(),
            });
        }
        if self.operator_id.as_str().trim().is_empty() {
            return Err(SessionError::InvalidEndpoint {
                reason: "operator id cannot be empty".to_owned(),
            });
        }
        self.configuration.validate()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn given_endpoint_operator_id_when_imported_from_session_then_endpoint_contract_type_is_reexported(
    ) {
        let operator_id: OperatorId = crate::graph::OperatorId::new("connector.example");

        assert_eq!(operator_id.as_str(), "connector.example");
        assert_eq!(OperatorId::syntax_version(), 1);
    }
}