use super::parser::{Parser, TokenSet};
use SyntaxKind;
use syntax_kinds::*;

mod items;
mod attributes;
mod expressions;
mod types;
mod paths;
mod type_params;

pub(crate) fn file(p: &mut Parser) {
    let file = p.start();
    p.eat(SHEBANG);
    items::mod_contents(p, false);
    file.complete(p, FILE);
}

fn visibility(p: &mut Parser) {
    if p.at(PUB_KW) {
        let vis = p.start();
        p.bump();
        if p.at(L_PAREN) {
            match p.nth(1) {
                CRATE_KW | SELF_KW | SUPER_KW => {
                    p.bump();
                    p.bump();
                    p.expect(R_PAREN);
                }
                IN_KW => {
                    p.bump();
                    p.bump();
                    paths::use_path(p);
                    p.expect(R_PAREN);
                }
                _ => (),
            }
        }
        vis.complete(p, VISIBILITY);
    }
}

fn alias(p: &mut Parser) -> bool {
    if p.at(AS_KW) {
        let alias = p.start();
        p.bump();
        name(p);
        alias.complete(p, ALIAS);
    }
    true //FIXME: return false if three are errors
}

fn abi(p: &mut Parser) {
    assert!(p.at(EXTERN_KW));
    let abi = p.start();
    p.bump();
    match p.current() {
        STRING | RAW_STRING => p.bump(),
        _ => (),
    }
    abi.complete(p, ABI);
}

fn fn_value_parameters(p: &mut Parser) {
    assert!(p.at(L_PAREN));
    p.bump();
    p.expect(R_PAREN);
}

fn fn_ret_type(p: &mut Parser) {
    if p.at(THIN_ARROW) {
        p.bump();
        types::type_(p);
    }
}

fn name(p: &mut Parser) {
    if p.at(IDENT) {
        let m = p.start();
        p.bump();
        m.complete(p, NAME);
    } else {
        p.error("expected a name");
    }
}

fn name_ref(p: &mut Parser) {
    if p.at(IDENT) {
        let m = p.start();
        p.bump();
        m.complete(p, NAME_REF);
    } else {
        p.error("expected identifier");
    }
}

fn error_block(p: &mut Parser, message: &str) {
    assert!(p.at(L_CURLY));
    let err = p.start();
    p.error(message);
    p.bump();
    let mut level: u32 = 1;
    while level > 0 && !p.at(EOF) {
        match p.current() {
            L_CURLY => level += 1,
            R_CURLY => level -= 1,
            _ => (),
        }
        p.bump();
    }
    err.complete(p, ERROR);
}