use crate::{
    brush::Brush,
    lisp::{
        error::{EvalError, LispError},
        expr::{is_ident, Arity, LispExpr},
        number::LispNumber,
        Environment,
    },
    primitive,
};

use std::{convert::TryInto, fs::File, io::Write};

use log::info;

#[macro_export]
macro_rules! primitive {
    ($env:expr, $arity:expr, $name:expr, $closure:expr) => {
        let val = crate::lisp::expr::LispExpr::PrimitiveFunc(crate::lisp::expr::PrimitiveFunc {
            arity: $arity,
            closure: $closure,
        });
        let _ = $env.insert($name.to_string(), val);
    };
}

pub fn new_env() -> Environment {
    let mut env = Environment::new();

    primitive!(env, Arity::Atleast(2), "+", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        return Ok(LispExpr::Number(
            nums.iter().fold(LispNumber::Integer(0), |acc, &x| acc + *x),
        ));
    });

    primitive!(env, Arity::Atleast(2), "-", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let mut acc = nums[0].clone();
        for arg in nums.into_iter().skip(1) {
            acc = acc - *arg;
        }
        Ok(LispExpr::Number(acc))
    });

    primitive!(env, Arity::Atleast(2), "*", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        return Ok(LispExpr::Number(
            nums.iter().fold(LispNumber::Integer(1), |acc, &x| acc * *x),
        ));
    });

    primitive!(env, Arity::Atleast(2), "/", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let mut acc = nums[0].clone();
        for arg in nums.into_iter().skip(1) {
            acc = acc.div(*arg)?;
        }
        Ok(LispExpr::Number(acc))
    });

    primitive!(env, Arity::Exact(0), "toggle-grid", |_, app| {
        app.toggle_grid();
        Ok(LispExpr::Unit)
    });

    primitive!(env, Arity::Atleast(2), "and", |args, _| {
        if args
            .iter()
            .any(|arg| matches!(arg, LispExpr::BoolLit(false)))
        {
            Ok(LispExpr::BoolLit(false))
        } else {
            Ok(LispExpr::BoolLit(true))
        }
    });

    primitive!(env, Arity::Atleast(2), "or", |args, _| {
        if args
            .iter()
            .any(|arg| matches!(arg, LispExpr::BoolLit(true)))
        {
            Ok(LispExpr::BoolLit(true))
        } else {
            Ok(LispExpr::BoolLit(false))
        }
    });

    primitive!(env, Arity::Exact(1), "not", |args, _| {
        if matches!(&args[0], LispExpr::BoolLit(false)) {
            Ok(LispExpr::BoolLit(true))
        } else {
            Ok(LispExpr::BoolLit(false))
        }
    });

    primitive!(env, Arity::Atleast(1), "begin", |args, _| {
        if args.is_empty() {
            Err(EvalError::ArgumentCount(Arity::Atleast(1)).into())
        } else {
            Ok(args.into_iter().last().unwrap().clone())
        }
    });

    primitive!(env, Arity::Exact(0), "quit", |_, app| {
        app.quit();
        Ok(LispExpr::Unit)
    });

    primitive!(env, Arity::Exact(2), "eq?", |args, app| {
        let s = &args[0];
        let o = &args[1];
        info!("comparing {} {}", s, o);
        let result = s.compare(o, &app.lisp_env);
        result.map(LispExpr::BoolLit)
    });

    primitive!(env, Arity::Exact(2), ">", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let acc = nums[0].clone();
        Ok(LispExpr::BoolLit(
            nums.into_iter().skip(1).all(|&arg| acc > arg),
        ))
    });

    primitive!(env, Arity::Exact(2), ">=", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let acc = nums[0].clone();
        Ok(LispExpr::BoolLit(
            nums.into_iter().skip(1).all(|&arg| acc >= arg),
        ))
    });

    primitive!(env, Arity::Exact(2), "<", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let acc = nums[0].clone();
        Ok(LispExpr::BoolLit(
            nums.into_iter().skip(1).all(|&arg| acc < arg),
        ))
    });

    primitive!(env, Arity::Exact(2), "<=", |args, _| {
        let nums = args
            .into_iter()
            .map(|arg| arg.try_into())
            .collect::<Result<Vec<&LispNumber>, LispError>>()?;
        let acc = nums[0].clone();
        Ok(LispExpr::BoolLit(
            nums.into_iter().skip(1).all(|&arg| acc <= arg),
        ))
    });

    primitive!(env, Arity::Exact(1), "string-len", |args, _| {
        match &args[0] {
            LispExpr::StringLit(s) => Ok(LispExpr::Number(LispNumber::Integer(s.len() as i64))),
            _ => Err(EvalError::TypeMismatch.into()),
        }
    });

    primitive!(env, Arity::Atmost(1), "save", |args, app| {
        let image = app.export().encode().unwrap();
        if args.len() == 1 && matches!(&args[0], LispExpr::StringLit(_)) {
            let mut buffer = File::create(&args[0].as_ref()).unwrap();
            buffer.write_all(&image[..]).unwrap();
        } else if let Some(p) = app.file_name {
            let file_name = p;
            let mut buffer = File::create(&file_name).unwrap();
            buffer.write_all(&image[..]).unwrap();
        } else {
            return Err(EvalError::NoFileName.into());
        }

        return Ok(LispExpr::Unit);
    });

    primitive!(env, Arity::Atmost(1), "brush", |args, app| {
        info!("brush {}", &args[0]);
        let old_size = if matches!(app.brush, Brush::Line { .. } | Brush::Circle { .. }) {
            app.brush.size().unwrap()
        } else {
            0
        };
        if let [LispExpr::Quote(kind, _)] = args {
            if is_ident(kind) {
                match (&**kind).as_ref() {
                    "fill" => app.brush = Brush::Fill,
                    "circle" => app.brush = Brush::new(old_size),
                    "line" => app.brush = Brush::line(old_size, false),
                    "line-extend" => app.brush = Brush::line(old_size, true),
                    _ => return Err(EvalError::CustomInternal("unknown brush type").into()),
                }
            }
        } else {
            return Err(EvalError::TypeMismatch.into());
        }
        return Ok(LispExpr::Unit);
    });

    env
}