//! Connect to an LSP language server.
//!
//! Starts a new language server process and registers it in the
//! shared LSP manager for subsequent tool invocations.

use crate::tools::{Tool, ToolCtx};
use anyhow::Result;
use serde_json::{json, Value};
use tracing::{info, error, instrument};

/// Tool that connects to an LSP language server for a given language.
///
/// Flow: parse language + command + args → lock LSP manager → call
/// `manager.start()` → confirm connection in the response string.
pub struct LspConnect;

impl Tool for LspConnect {
    fn name(&self) -> &'static str {
        "lsp_connect"
    }

    fn description(&self) -> &'static str {
        "Connect to an LSP language server for a given language"
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "language": {
                    "type": "string",
                    "description": "Language identifier (e.g. 'rust', 'python')"
                },
                "command": {
                    "type": "string",
                    "description": "Command to start the language server"
                },
                "args": {
                    "type": "array",
                    "items": {"type": "string"},
                    "description": "Arguments for the language server command"
                }
            },
            "required": ["language", "command"]
        })
    }

    #[instrument(skip(self, ctx, args))]
    fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
        let language = crate::tools::arg_str(args, "language")?;
        let command = crate::tools::arg_str(args, "command")?;
        let extra_args: Vec<String> = args
            .get("args")
            .and_then(|v| v.as_array())
            .map(|arr| arr.iter().filter_map(|v| v.as_str().map(String::from)).collect())
            .unwrap_or_default();

        info!(language, command, extra_args = ?extra_args, "LSP connect requested");

        let mut manager = match ctx.lsp_manager.lock() {
            Ok(g) => g,
            Err(poisoned) => {
                error!("LSP manager mutex poisoned, recovering");
                poisoned.into_inner()
            }
        };
        manager.start(&language, &command, &extra_args)?;

        info!(language, "LSP connected successfully");
        Ok(format!("Connected LSP for '{language}'"))
    }
}