#[macro_use]
extern crate log;

use crsn::asm::error::CrsnError;
use crsn::asm::instr::op::OpKind;
use crsn::asm::parse::arg_parser::TokenParser;
use crsn::module::{CrsnExtension, ParseRes};
use crsn::sexp::SourcePosition;
use crsn::asm::data::literal::Value;
use crate::exec::{OPT_AUTO_BLIT, OPT_FRAME_RATE, OPT_UPSCALE};

mod defs;
mod parse;
mod exec;

#[derive(Debug, Clone)]
pub struct ScreenOps;

impl ScreenOps {
    pub fn new() -> Box<dyn CrsnExtension> {
        Box::new(Self)
    }
}

impl CrsnExtension for ScreenOps {
    fn name(&self) -> &'static str {
        "screen"
    }

    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
        parse::parse(pos, keyword, args)
    }

    /// Get value of an extension-provided constant.
    /// This constant may be an object handle, or a constant value used as argument in some other instruction.
    fn get_constant_value<'a>(&self, name: &str) -> Option<Value>
    {
        match name {
            "SCREEN_AUTO_BLIT" => Some(OPT_AUTO_BLIT),
            "SCREEN_FPS" => Some(OPT_FRAME_RATE),
            "SCREEN_UPSCALE" => Some(OPT_UPSCALE),
            _ => None
        }
    }
}