use std::{
    collections::HashMap,
    sync::{Arc, RwLock},
};

use {
    crate::expr::LTExpr
};

pub struct SymbolEntry {
    link_addr: tisc::VM_Word,

    in_types: Vec< laddertypes::TypeTerm >,
    out_types: Vec< laddertypes::TypeTerm >
}

pub struct SymbolTable {
    symbols: HashMap< String, SymbolEntry >,
    linker: tisc::Linker
}

impl SymbolTable {
    pub fn new() -> Self {
        SymbolTable {
            symbols: HashMap::new(),
            linker: tisc::Linker::new(0x100)
        }
    }

    pub fn get_link_addr(&self, symbol: &str) -> Option< tisc::VM_Word > {
        self.symbols.get(&String::from(symbol)).map(|e| e.link_addr)
    }

    pub fn call_symbol(&self, typectx: &Arc<RwLock<laddertypes::TypeDict>>, symbol: &str) -> LTExpr {
        let entry = self.symbols.get(&String::from(symbol)).unwrap();
        LTExpr::call_symbol(
            /*
            &laddertypes::TypeTerm::App(vec![
                typectx.write().unwrap().parse("Fn").expect("parse typeterm"),
                laddertypes::TypeTerm::App( entry.in_types.clone() ),
                laddertypes::TypeTerm::App( entry.out_types.clone() )
            ]),
            */
            typectx,
            entry.out_types.len(),
            entry.link_addr
        )
    }

    pub fn define(
        &mut self,
        vm: &mut tisc::VM,
        typectx: &Arc<RwLock<laddertypes::TypeDict>>,
        symbol: &str,
        in_types: Vec<&str>,
        out_types: Vec<&str>,
        asm: tisc::Assembler
    ) {
        self.linker.link( vm, String::from(symbol), asm.build() );

        self.symbols.insert(
            String::from(symbol),
            SymbolEntry {
                link_addr: self.linker.resolve_symbol(&String::from(symbol)).expect("cant find symbol"),
                in_types: in_types.into_iter().map(|t| typectx.write().unwrap().parse(t).expect("parse typeterm")).collect(),                
                out_types: out_types.into_iter().map(|t| typectx.write().unwrap().parse(t).expect("parse typeterm")).collect()
            }
        );
    }
}