use std::collections::BTreeMap;
use std::sync::Arc;
use rmcp::model::ReadResourceRequestParams;
use serde_json::{Map, Value, json};
use super::ServerConn;
use crate::tool::{Tool, ToolHints, ToolResult, ToolSource};
fn ro() -> Option<ToolHints> {
Some(ToolHints {
read_only: true,
..Default::default()
})
}
fn conn<'a>(
servers: &'a BTreeMap<String, ServerConn>,
name: &str,
) -> Result<&'a ServerConn, String> {
servers.get(name).ok_or_else(|| {
format!(
"no connected MCP server {name:?} (connected: {})",
servers.keys().cloned().collect::<Vec<_>>().join(", ")
)
})
}
fn s(v: &Value, k: &str) -> String {
v.get(k).and_then(Value::as_str).unwrap_or("").to_owned()
}
pub(crate) fn resource_tools(servers: BTreeMap<String, ServerConn>) -> Vec<Tool> {
let servers = Arc::new(servers);
let ls = servers.clone();
let list = Tool {
name: "list_mcp_resources".into(),
description: "List the resources MCP servers offer (uri, name, description, mimeType). Optionally for one server.".into(),
input_schema: json!({"type": "object", "properties": {
"server": {"type": "string", "description": "Only this server (default: all)"}
}, "additionalProperties": false}),
source: ToolSource::Mcp,
hints: ro(),
execute: Arc::new(move |args, ctx| {
let servers = ls.clone();
Box::pin(async move {
let mut names: Vec<String> = servers.keys().cloned().collect();
if let Some(one) = args.get("server").and_then(Value::as_str).filter(|x| !x.is_empty()) {
if let Err(e) = conn(&servers, one) {
return ToolResult::error(format!("list_mcp_resources: {e}"));
}
names = vec![one.to_owned()];
}
let mut lines = Vec::new();
let mut items = Vec::new();
for name in names {
let Ok(c) = conn(&servers, &name) else { continue };
let res = tokio::select! {
r = tokio::time::timeout(c.timeout, c.peer.list_all_resources()) => match r {
Ok(Ok(v)) => Ok(v),
Ok(Err(e)) => Err(e.to_string()),
Err(_) => Err("context deadline exceeded".to_owned()),
},
_ = ctx.cancel.cancelled() => Err("context canceled".to_owned()),
};
let resources = match res {
Ok(r) => r,
Err(e) => {
lines.push(format!("{name}: error: {e}"));
continue;
}
};
for r in resources {
let v = serde_json::to_value(&r).unwrap_or_default();
let (uri, rname, mime, desc) =
(s(&v, "uri"), s(&v, "name"), s(&v, "mimeType"), s(&v, "description"));
let mut line = format!("{name} {uri}");
if !rname.is_empty() {
line.push_str(&format!(" — {rname}"));
}
if !mime.is_empty() {
line.push_str(&format!(" ({mime})"));
}
if !desc.is_empty() {
line.push_str(&format!(": {desc}"));
}
lines.push(line);
items.push(json!({"server": name, "uri": uri, "name": rname, "mimeType": mime, "description": desc}));
}
}
let mut meta = Map::new();
if lines.is_empty() {
meta.insert("count".into(), json!(0));
return ToolResult::ok("No resources.").with_metadata(meta);
}
meta.insert("count".into(), json!(items.len()));
meta.insert("resources".into(), Value::Array(items));
ToolResult::ok(lines.join("\n")).with_metadata(meta)
})
}),
};
let rs = servers;
let read = Tool {
name: "read_mcp_resource".into(),
description: "Read one MCP resource by server and uri. Text comes back as text; binary content is described, not inlined.".into(),
input_schema: json!({"type": "object", "properties": {
"server": {"type": "string", "description": "The MCP server name"},
"uri": {"type": "string", "description": "The resource uri"}
}, "required": ["server", "uri"], "additionalProperties": false}),
source: ToolSource::Mcp,
hints: ro(),
execute: Arc::new(move |args, ctx| {
let servers = rs.clone();
Box::pin(async move {
let server = args.get("server").and_then(Value::as_str).unwrap_or("").to_owned();
let uri = args.get("uri").and_then(Value::as_str).unwrap_or("").to_owned();
let c = match conn(&servers, &server) {
Ok(c) => c,
Err(e) => return ToolResult::error(format!("read_mcp_resource: {e}")),
};
if uri.is_empty() {
return ToolResult::error("read_mcp_resource: uri is required");
}
let res = tokio::select! {
r = tokio::time::timeout(c.timeout, c.peer.read_resource(ReadResourceRequestParams::new(uri.clone()))) => match r {
Ok(Ok(v)) => Ok(v),
Ok(Err(e)) => Err(e.to_string()),
Err(_) => Err("context deadline exceeded".to_owned()),
},
_ = ctx.cancel.cancelled() => Err("context canceled".to_owned()),
};
let res = match res {
Ok(r) => r,
Err(e) => return ToolResult::error(format!("read_mcp_resource: {e}")),
};
let v = serde_json::to_value(&res).unwrap_or_default();
let mut parts = Vec::new();
for rc in v.get("contents").and_then(Value::as_array).cloned().unwrap_or_default() {
if let Some(t) = rc.get("text").and_then(Value::as_str) {
parts.push(t.to_owned());
} else if let Some(b) = rc.get("blob").and_then(Value::as_str) {
parts.push(format!("[binary {}, {} base64 chars]", s(&rc, "mimeType"), b.len()));
}
}
let mut meta = Map::new();
meta.insert("server".into(), json!(server));
meta.insert("uri".into(), json!(uri));
ToolResult::ok(parts.join("\n")).with_metadata(meta)
})
}),
};
vec![list, read]
}