//! A simple logger used from lua,

//! but initialization is opaque for the user.

use chrono::Utc;

use mlua::{Lua, Result as LuaResult, Value};

pub fn setup(lua: &Lua) -> LuaResult<()> {

lua.globals().set(

"logger_init",

lua.create_function(|lua, file_name: Option<String>| {

let logger: Value = lua.globals().get("__INTERNAL_LOGGER__")?;

if logger != Value::Nil {

// Already initialized, do nothing.

return Ok(logger);

}

let date = Utc::now().format("%A, %B %e, %Y %H:%M:%S").to_string();

let logfile = file_name.unwrap_or("kipt.out".to_string());

lua.load(format!(

"__INTERNAL_LOGGER__ = io.open(\"{}\", \"w\")

__INTERNAL_LOGGER__:write(\"-- {} --\", \"\\n\\n\")

",

logfile, date,

))

.exec()?;

let logger: mlua::Value = lua.globals().get("__INTERNAL_LOGGER__")?;

Ok(logger)

})?,

)?;

Ok(())

}

pub fn write(lua: &Lua, data: &str) -> LuaResult<()> {

lua.load(format!("__INTERNAL_LOGGER__:write(\"{}\", \"\\n\")", data))

.exec()?;

Ok(())

}

pub fn close(lua: &Lua) -> LuaResult<()> {

lua.load("__INTERNAL_LOGGER__:close()").exec()?;

Ok(())

}