use unicode_id_start::{is_id_continue_unicode, is_id_start_unicode};

pub const EOF: char = '\0';

// 11.1 Unicode Format-Control Characters

/// U+200C ZERO WIDTH NON-JOINER, abbreviated in the spec as `<ZWNJ>`.
/// Specially permitted in identifiers.
pub const ZWNJ: char = '\u{200c}';

/// U+200D ZERO WIDTH JOINER, abbreviated as `<ZWJ>`.
/// Specially permitted in identifiers.
pub const ZWJ: char = '\u{200d}';

/// U+FEFF ZERO WIDTH NO-BREAK SPACE, abbreviated `<ZWNBSP>`.
/// Considered a whitespace character in JS.
pub const ZWNBSP: char = '\u{feff}';

// 11.2 White Space
/// U+0009 CHARACTER TABULATION, abbreviated `<TAB>`.
pub const TAB: char = '\u{9}';

/// U+000B VERTICAL TAB, abbreviated `<VT>`.
pub const VT: char = '\u{b}';

/// U+000C FORM FEED, abbreviated `<FF>`.
pub const FF: char = '\u{c}';

/// U+00A0 NON-BREAKING SPACE, abbreviated `<NBSP>`.
pub const NBSP: char = '\u{a0}';

pub fn is_irregular_whitespace(c: char) -> bool {
    matches!(
        c,
        VT | FF | NBSP | ZWNBSP | '\u{85}' | '\u{1680}' | '\u{2000}'
            ..='\u{200a}' | '\u{202f}' | '\u{205f}' | '\u{3000}'
    )
}

// 11.3 Line Terminators

///  U+000A LINE FEED, abbreviated in the spec as `<LF>`.
pub const LF: char = '\u{a}';

/// U+000D CARRIAGE RETURN, abbreviated in the spec as `<CR>`.
pub const CR: char = '\u{d}';

/// U+2028 LINE SEPARATOR, abbreviated `<LS>`.
pub const LS: char = '\u{2028}';

/// U+2029 PARAGRAPH SEPARATOR, abbreviated `<PS>`.
pub const PS: char = '\u{2029}';

pub fn is_regular_line_terminator(c: char) -> bool {
    matches!(c, LF | CR)
}

pub fn is_irregular_line_terminator(c: char) -> bool {
    matches!(c, LS | PS)
}

pub fn is_line_terminator(c: char) -> bool {
    is_regular_line_terminator(c) || is_irregular_line_terminator(c)
}

const T: bool = true;
const F: bool = false;

#[repr(C, align(64))]
pub struct Align64<T>(pub(crate) T);

// This contains `$` (36) and `_` (95)
pub const ASCII_START: Align64<[bool; 128]> = Align64([
    F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F,
    F, F, F, F, T, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F,
    F, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, F, F, F, T,
    F, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, F, F, F, F,
]);

// This contains `$` (36)
pub const ASCII_CONTINUE: Align64<[bool; 128]> = Align64([
    F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F, F,
    F, F, F, F, T, F, F, F, F, F, F, F, F, F, F, F, T, T, T, T, T, T, T, T, T, T, F, F, F, F, F, F,
    F, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, F, F, F, T,
    F, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, F, F, F, F,
]);

#[inline]
pub fn is_identifier_start_ascii(c: char) -> bool {
    ASCII_START.0[c as usize]
}

/// Section 12.6 Detect `IdentifierStartChar`
#[inline]
pub fn is_identifier_start_all(c: char) -> bool {
    if c.is_ascii() {
        return is_identifier_start_ascii(c);
    }
    is_id_start_unicode(c)
}

/// Section 12.6 Detect `IdentifierPartChar`
/// NOTE 2: The nonterminal `IdentifierPart` derives _ via `UnicodeIDContinue`.
#[inline]
pub fn is_identifier_part(c: char) -> bool {
    if c.is_ascii() {
        return ASCII_CONTINUE.0[c as usize];
    }
    is_id_continue_unicode(c) || c == ZWNJ || c == ZWJ
}
