# http://ruby-lang.org
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾

# require commenting.kak

# Detection
# ‾‾‾‾‾‾‾‾‾

hook global BufSetOption mimetype=text/x-ruby %{
    set buffer filetype ruby
}

hook global BufCreate .*(([.](rb))|(irbrc)|(pryrc)|(Capfile|[.]cap)|(Gemfile)|(Guardfile)|(Rakefile|[.]rake)|(Thorfile|[.]thor)|(Vagrantfile)) %{
    set buffer filetype ruby
}

# Highlighters
# ‾‾‾‾‾‾‾‾‾‾‾‾

addhl -group / regions -default code ruby       \
    double_string '"' (?<!\\)(\\\\)*"        '' \
    single_string "'" "'"                    '' \
    backtick      '`' (?<!\\)(\\\\)*`        '' \
    regex         '/' (?<!\\)(\\\\)*/[imox]* '' \
    comment       '#' '$'                    '' \
    comment       ^begin= ^=end              '' \
    literal       '%[iqrswxIQRSWX]\(' \)     \( \
    literal       '%[iqrswxIQRSWX]\{' \}     \{ \
    literal       '%[iqrswxIQRSWX]\[' \]     \[ \
    literal       '%[iqrswxIQRSWX]<'   >      <

# Regular expression flags are: i → ignore case, m → multi-lines, o → only interpolate #{} blocks once, x → extended mode (ignore white spaces)
# Literals are: i → array of symbols, q → string, r → regular expression, s → symbol, w → array of words, x → capture shell result

addhl -group /ruby/double_string fill string
addhl -group /ruby/double_string regions regions interpolation \Q#{ \} \{
addhl -group /ruby/double_string/regions/interpolation fill meta

addhl -group /ruby/single_string fill string

addhl -group /ruby/backtick fill meta
addhl -group /ruby/backtick regions regions interpolation \Q#{ \} \{
addhl -group /ruby/backtick/regions/interpolation fill meta

addhl -group /ruby/regex fill meta
addhl -group /ruby/regex regions regions interpolation \Q#{ \} \{
addhl -group /ruby/regex/regions/interpolation fill meta

addhl -group /ruby/comment fill comment

addhl -group /ruby/literal fill meta

addhl -group /ruby/code regex \<([A-Za-z]\w+:)|([$@][A-Za-z]\w+)|(\W\K:[A-Za-z]\w+[=?!]?) 0:identifier
addhl -group /ruby/code regex \<(require|include)\> 0:meta
addhl -group /ruby/code regex \<(attr_(reader|writer|accessor))\> 0:attribute

# Keywords are collected searching for keyword_ at
# https://github.com/ruby/ruby/blob/trunk/parse.y
addhl -group /ruby/code regex \<(alias|and|begin|break|case|class|def|defined|do|else|elsif|end|ensure|false|for|if|in|module|next|nil|not|or|redo|rescue|retry|return|self|super|then|true|undef|unless|until|when|while|yield)\> 0:keyword

# Commands
# ‾‾‾‾‾‾‾‾

def -hidden _ruby_filter_around_selections %{
    eval -draft -itersel %{
        exec <a-x>
        # remove trailing white spaces
        try %{ exec -draft s \h + $ <ret> d }
    }
}

def -hidden _ruby_indent_on_char %{
    eval -draft -itersel %{
        # align middle and end structures to start
        try %{ exec -draft <a-x> <a-k> ^ \h * (else|elsif) $ <ret> <a-\;> <a-?> ^ \h * (if)                                                       <ret> s \A | \Z <ret> \' <a-&> }
        try %{ exec -draft <a-x> <a-k> ^ \h * (when)       $ <ret> <a-\;> <a-?> ^ \h * (case)                                                     <ret> s \A | \Z <ret> \' <a-&> }
        try %{ exec -draft <a-x> <a-k> ^ \h * (rescue)     $ <ret> <a-\;> <a-?> ^ \h * (begin)                                                    <ret> s \A | \Z <ret> \' <a-&> }
        try %{ exec -draft <a-x> <a-k> ^ \h * (end)        $ <ret> <a-\;> <a-?> ^ \h * (begin|case|class|def|do|for|if|module|unless|until|while) <ret> s \A | \Z <ret> \' <a-&> }
    }
}

def -hidden _ruby_indent_on_new_line %{
    eval -draft -itersel %{
        # preserve previous line indent
        try %{ exec -draft K <a-&> }
        # filter previous line
        try %{ exec -draft k : _ruby_filter_around_selections <ret> }
        # copy _#_ comment prefix and following white spaces
        try %{ exec -draft k x s ^ \h * \K \# \h * <ret> y j p }
        # indent after start structure
        try %{ exec -draft k x <a-k> ^ \h * (begin|case|class|def|do|else|elsif|ensure|for|if|module|rescue|unless|until|when|while) \b <ret> j <a-gt> }
        # wisely add end structure
        eval -save-regs x %{
            try %{ exec -draft k x s ^ \h + <ret> \" x y } catch %{ reg x '' }
            try %{ exec -draft k x <a-k> ^ <c-r> x (begin|case|class|def|do|for|if|module|unless|until|while) <ret> j <a-a> i X <a-\;> K <a-K> ^ <c-r> x (for|function|if|while) . * \n <c-r> x end $ <ret> j x y p j a end <esc> <a-lt> }
        }
    }
}

# Initialization
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾

hook global WinSetOption filetype=ruby %{
    addhl ref ruby

    hook window InsertEnd  .* -group ruby-hooks  _ruby_filter_around_selections
    hook window InsertChar .* -group ruby-indent _ruby_indent_on_char
    hook window InsertChar \n -group ruby-indent _ruby_indent_on_new_line

    set window comment_line_chars '#'
    set window comment_selection_chars '^begin=:^=end'
}

hook global WinSetOption filetype=(?!ruby).* %{
    rmhl ruby
    rmhooks window ruby-indent
    rmhooks window ruby-hooks
}