/* relish: versatile lisp shell
 * Copyright (C) 2021 Aidan Hahn
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

use crate::segment::{Ctr, Seg, Type};
use crate::sym::{Args, SymTable, Symbol, ValueType};
use std::rc::Rc;

pub mod append;
pub mod boolean;
pub mod control;
pub mod decl;
pub mod math;
//pub mod str;

/// static_stdlib
/// inserts all stdlib functions that can be inserted without
/// any kind of further configuration data into a symtable
pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
    syms.insert(
        "append".to_string(),
        Symbol {
            name: String::from("append"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: append::APPEND_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(append::append_callback)),
        },
    );

    syms.insert(
        "echo".to_string(),
        Symbol {
            name: String::from("echo"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: ECHO_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(_echo_callback)),
        },
    );

    syms.insert(
        "if".to_string(),
        Symbol {
            name: String::from("if"),
            args: Args::Lazy(3),
            conditional_branches: true,
            docs: control::IF_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(control::if_callback)),
        },
    );

    syms.insert(
        "let".to_string(),
        Symbol {
            name: String::from("let"),
            args: Args::Infinite,
            conditional_branches: true,
            docs: control::LET_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(control::let_callback)),
        },
    );

    syms.insert(
        "while".to_string(),
        Symbol {
            name: String::from("while"),
            args: Args::Infinite,
            conditional_branches: true,
            docs: control::WHILE_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(control::while_callback)),
        },
    );

    syms.insert(
        "circuit".to_string(),
        Symbol {
            name: String::from("circuit"),
            args: Args::Infinite,
            conditional_branches: true,
            docs: control::CIRCUIT_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(control::circuit_callback)),
        },
    );

    syms.insert(
        "and".to_string(),
        Symbol {
            name: String::from("and"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: boolean::AND_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(boolean::and_callback)),
        },
    );

    syms.insert(
        "or".to_string(),
        Symbol {
            name: String::from("or"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: boolean::OR_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(boolean::or_callback)),
        },
    );

    syms.insert(
        "not".to_string(),
        Symbol {
            name: String::from("not"),
            args: Args::Strict(vec![Type::Bool]),
            conditional_branches: false,
            docs: boolean::NOT_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(boolean::not_callback)),
        },
    );

    syms.insert(
        "eq?".to_string(),
        Symbol {
            name: String::from("eq?"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: boolean::ISEQ_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(boolean::iseq_callback)),
        },
    );

    syms.insert(
        "toggle".to_string(),
        Symbol {
            name: String::from("toggle"),
            args: Args::Lazy(1),
            conditional_branches: true,
            docs: boolean::TOGGLE_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(boolean::toggle_callback)),
        },
    );

    syms.insert(
        "help".to_string(),
        Symbol {
            name: String::from("help"),
            args: Args::Strict(vec![Type::Symbol]),
            conditional_branches: true,
            docs: decl::HELP_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(decl::help_callback)),
        },
    );

    syms.insert(
        "set?".to_string(),
        Symbol {
            name: String::from("set?"),
            args: Args::Strict(vec![Type::Symbol]),
            conditional_branches: true,
            docs: decl::ISSET_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(decl::isset_callback)),
        },
    );

    syms.insert(
        "env".to_string(),
        Symbol {
            name: String::from("env"),
            args: Args::None,
            conditional_branches: false,
            docs: decl::ENV_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(decl::env_callback)),
        },
    );

    syms.insert(
        "add".to_string(),
        Symbol {
            name: String::from("add"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: math::ADD_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::add_callback)),
        },
    );

    syms.insert(
        "sub".to_string(),
        Symbol {
            name: String::from("sub"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: math::SUB_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::sub_callback)),
        },
    );

    syms.insert(
        "div".to_string(),
        Symbol {
            name: String::from("div"),
            args: Args::Lazy(2),
            conditional_branches: false,
            docs: math::DIV_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::div_callback)),
        },
    );

    syms.insert(
        "mul".to_string(),
        Symbol {
            name: String::from("mul"),
            args: Args::Infinite,
            conditional_branches: false,
            docs: math::MUL_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::mul_callback)),
        },
    );

    syms.insert(
        "int".to_string(),
        Symbol {
            name: String::from("int"),
            args: Args::Lazy(1),
            conditional_branches: false,
            docs: math::INTCAST_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::intcast_callback)),
        },
    );

    syms.insert(
        "float".to_string(),
        Symbol {
            name: String::from("float"),
            args: Args::Lazy(1),
            conditional_branches: false,
            docs: math::FLOATCAST_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(math::floatcast_callback)),
        },
    );

    Ok(())
}

/// dynamic_stdlib
/// takes configuration data and uses it to insert dynamic
/// callbacks with configuration into a symtable
pub fn dynamic_stdlib(syms: &mut SymTable) -> Result<(), String> {
    //get CFG_RELISH_ENV from syms
    let env_cfg_user_form = syms
        .call_symbol(&"CFG_RELISH_ENV".to_string(), &Seg::new(), true)
        .unwrap_or_else(|_: String| Box::new(Ctr::None))
        .to_string()
        .ne("");

    syms.insert(
        "def".to_string(),
        Symbol {
            name: String::from("define"),
            args: Args::Infinite,
            conditional_branches: true,
            docs: decl::STORE_DOCSTRING.to_string(),
            value: ValueType::Internal(Rc::new(
                move |ast: &Seg, syms: &mut SymTable| -> Result<Ctr, String> {
                    decl::store_callback(ast, syms, env_cfg_user_form)
                },
            )),
        },
    );

    Ok(())
}

pub const ECHO_DOCSTRING: &str =
    "traverses any number of arguments. Prints their evaluated values on a new line for each.";

fn _echo_callback(ast: &Seg, _syms: &mut SymTable) -> Result<Ctr, String> {
    if ast.len() == 1 {
        println!("{}", ast.car);
    } else {
        ast.circuit(&mut |arg: &Ctr| print!("{}", arg) == ());
    }

    Ok(Ctr::None)
}