//! Manages MCP server connections — start, stop, list, and dispatch
//! tool calls to remote MCP servers.

use std::collections::HashMap;

/// Metadata for a connected MCP server.
#[derive(Debug, Clone)]
pub struct McpServerHandle {
    pub name: String,
    pub transport: String,
}

/// Manages MCP server connections.
#[derive(Clone)]
pub struct McpManager {
    servers: HashMap<String, McpServerHandle>,
}

impl McpManager {
    pub fn new() -> Self {
        McpManager {
            servers: HashMap::new(),
        }
    }
}

impl Default for McpManager {
    fn default() -> Self {
        Self::new()
    }
}

impl McpManager {
    /// Register an MCP server by name and transport string.
    ///
    /// Returns an error if a server with the same name is already registered.
    pub fn register(&mut self, name: &str, transport: &str) -> anyhow::Result<()> {
        if self.servers.contains_key(name) {
            anyhow::bail!("MCP server '{name}' is already registered");
        }
        self.servers.insert(
            name.to_string(),
            McpServerHandle {
                name: name.to_string(),
                transport: transport.to_string(),
            },
        );
        Ok(())
    }

    /// Remove a registered MCP server and return its handle, if it existed.
    pub fn unregister(&mut self, name: &str) -> Option<McpServerHandle> {
        self.servers.remove(name)
    }

    pub fn list(&self) -> Vec<McpServerHandle> {
        self.servers.values().cloned().collect()
    }

    pub fn get(&self, name: &str) -> Option<&McpServerHandle> {
        self.servers.get(name)
    }

    pub fn is_empty(&self) -> bool {
        self.servers.is_empty()
    }
}