use crate::server_handler::{McpServerHandler, McpServerHandlerError};
use chrono::{Datelike, Local, Utc};
use rmcp::handler::server::tool::ToolRouter;
use rmcp::model::{Implementation, ServerCapabilities, ServerInfo};
use rmcp::{ServerHandler, tool, tool_handler, tool_router};
use toml::Value;
use toml::map::Map;

#[derive(Debug, Clone)]
pub(crate) struct DateTimeHandler {
    tool_router: ToolRouter<Self>,
}

impl McpServerHandler for DateTimeHandler {
    async fn new(
        _additional_properties: Map<String, Value>,
    ) -> Result<Self, McpServerHandlerError> {
        Ok(DateTimeHandler {
            tool_router: Self::tool_router(),
        })
    }
}

#[tool_router]
impl DateTimeHandler {
    #[tool(
        description = "returns the local datetime in ISO 8601",
        annotations(read_only_hint = true)
    )]
    fn get_local_datetime() -> String {
        Local::now().format("%+").to_string()
    }

    #[tool(
        description = "returns the utc datetime in ISO 8601",
        annotations(read_only_hint = true)
    )]
    fn get_utc_datetime() -> String {
        Utc::now().format("%+").to_string()
    }

    #[tool(
        description = "return current week number in year",
        annotations(read_only_hint = true)
    )]
    fn get_week() -> String {
        Local::now().iso_week().week().to_string()
    }

    #[tool(
        description = "return current weekday",
        annotations(read_only_hint = true)
    )]
    fn get_weekday() -> String {
        use chrono::Weekday::*;

        match Local::now().weekday() {
            Mon => "Monday",
            Tue => "Tuesday",
            Wed => "Wednesday",
            Thu => "Thursday",
            Fri => "Friday",
            Sat => "Saturday",
            Sun => "Sunday",
        }.to_string()
    }
}

#[tool_handler]
impl ServerHandler for DateTimeHandler {
    fn get_info(&self) -> ServerInfo {
        ServerInfo::new(ServerCapabilities::builder().enable_tools().build())
            .with_instructions(
                "A simple clock/datetime provider. It is read only and thus safe to use."
                    .to_string(),
            )
            .with_server_info(Implementation::new("datetime", env!("CARGO_PKG_VERSION")))
    }
}