use std::ffi::c_char;

use dlopen::raw::Library;

use super::{context::PluginContext, Plugin, PluginInfo};


#[derive(Debug, Clone, Copy)]
pub struct PluginSyms {
    pub(super) init:        unsafe extern "C" fn(ctx: *const PluginContext),
    pub(super) pre_reload:  unsafe extern "C" fn() -> *const (),
    pub(super) post_reload: unsafe extern "C" fn(state: *const ()),
    pub(super) poll:        unsafe extern "C" fn(buf: *mut c_char, len: usize),
    pub(super) free:        unsafe extern "C" fn(),
    pub(super) get_info:    unsafe extern "C" fn() -> *const PluginInfo,
}

impl Plugin {
    pub fn reload_symbols(&mut self) -> Result<(), dlopen::Error> {
        log::debug!("Loading {:?}", self.path);
        let lib = Library::open(&self.path)?;
        let symbols = PluginSyms { 
            init: unsafe { lib.symbol("plug_init")? },
            pre_reload: unsafe { lib.symbol("plug_pre_reload")? },
            post_reload: unsafe { lib.symbol("plug_post_reload")? },
            poll: unsafe { lib.symbol("plug_poll")? },
            free: unsafe { lib.symbol("plug_free")? },

            get_info: unsafe { lib.symbol("plug_get_info")? },
        };
        unsafe {
            if (symbols.get_info)().is_null() {
                log::error!("Info fields for plugin {:?} are null", self.path);
                self.disable();
            }
        }

        self.syms = Some(symbols);
        self.lib = Some(lib);
        Ok(())
    }
}