# http://moonscript.org
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾

# Detection
# ‾‾‾‾‾‾‾‾‾

hook global BufCreate .*[.](moon) %{
    set-option buffer filetype moon
}

# Highlighters
# ‾‾‾‾‾‾‾‾‾‾‾‾

add-highlighter shared/moon regions
add-highlighter shared/moon/code default-region group
add-highlighter shared/moon/double_string region '"'  (?<!\\)(\\\\)*" regions
add-highlighter shared/moon/single_string region "'"  (?<!\\)(\\\\)*' fill string
add-highlighter shared/moon/comment       region '--' '$'             fill comment

add-highlighter shared/moon/double_string/base default-region fill string
add-highlighter shared/moon/double_string/interpolation region -recurse \{ \Q#{ \} fill meta

add-highlighter shared/moon/code/ regex ([.\\](?=[A-Za-z]))|(\b[A-Za-z]\w*:)|(\b[A-Za-z]\w*\K!+)|(\W\K[@:][A-Za-z]\w*) 0:variable
add-highlighter shared/moon/code/ regex \b(and|break|catch|class|continue|do|else(if)?|export|extends|false|finally|for|from|if|import|in|local|nil|not|or|return|super|switch|then|true|try|unless|using|when|while|with)\b 0:keyword

# Commands
# ‾‾‾‾‾‾‾‾

define-command moon-alternative-file -docstring 'Jump to the alternate file (implementation ↔ test)' %{ evaluate-commands %sh{
    case $kak_buffile in
        *spec/*_spec.moon)
            altfile=$(eval printf %s\\n $(printf %s\\n $kak_buffile | sed s+spec/+'*'/+';'s/_spec//))
            [ ! -f $altfile ] && echo "echo -markup '{Error}implementation file not found'" && exit
        ;;
        *.moon)
            path=$kak_buffile
            dirs=$(while [ $path ]; do printf %s\\n $path; path=${path%/*}; done | tail -n +2)
            for dir in $dirs; do
                altdir=$dir/spec
                if [ -d $altdir ]; then
                    altfile=$altdir/$(realpath $kak_buffile --relative-to $dir | sed s+[^/]'*'/++';'s/.moon$/_spec.moon/)
                    break
                fi
            done
            [ ! -d $altdir ] && echo "echo -markup '{Error}spec/ not found'" && exit
        ;;
        *)
            echo "echo -markup '{Error}alternative file not found'" && exit
        ;;
    esac
    printf %s\\n "edit $altfile"
}}

define-command -hidden moon-filter-around-selections %{
    evaluate-commands -draft -itersel %{
        execute-keys <a-x>
        # remove trailing white spaces
        try %{ execute-keys -draft s \h + $ <ret> d }
    }
}

define-command -hidden moon-indent-on-char %{
    evaluate-commands -draft -itersel %{
        # align _else_ statements to start
        try %{ execute-keys -draft <a-x> <a-k> ^ \h * (else(if)?) $ <ret> <a-\;> <a-?> ^ \h * (if|unless|when) <ret> s \A | \z <ret> ) <a-&> }
        # align _when_ to _switch_ then indent
        try %{ execute-keys -draft <a-x> <a-k> ^ \h * (when) $ <ret> <a-\;> <a-?> ^ \h * (switch) <ret> s \A | \z <ret> ) <a-&> ) <space> <gt> }
        # align _catch_ and _finally_ to _try_
        try %{ execute-keys -draft <a-x> <a-k> ^ \h * (catch|finally) $ <ret> <a-\;> <a-?> ^ \h * (try) <ret> s \A | \z <ret> ) <a-&> }
    }
}

define-command -hidden moon-indent-on-new-line %{
    evaluate-commands -draft -itersel %{
        # copy -- comment prefix and following white spaces
        try %{ execute-keys -draft k <a-x> s ^ \h * \K -- \h * <ret> y gh j P }
        # preserve previous line indent
        try %{ execute-keys -draft \; K <a-&> }
        # filter previous line
        try %{ execute-keys -draft k : moon-filter-around-selections <ret> }
        # indent after start structure
        try %{ execute-keys -draft k <a-x> <a-k> ^ \h * (class|else(if)?|for|if|switch|unless|when|while|with) \b | ([:=]|[-=]>) $ <ret> j <a-gt> }
        # deindent after return statements
        try %{ execute-keys -draft k <a-x> <a-k> ^ \h * (break|return) \b <ret> j <a-lt> }
    }
}

# Initialization
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾

hook -group moon-highlight global WinSetOption filetype=moon %{
    add-highlighter window/moon ref moon
    hook -once -always window WinSetOption filetype=(?!moon).* %{ remove-highlighter window/moon }
}

hook global WinSetOption filetype=moon %{
    hook window ModeChange insert:.* -group moon-hooks  moon-filter-around-selections
    hook window InsertChar .* -group moon-indent moon-indent-on-char
    hook window InsertChar \n -group moon-indent moon-indent-on-new-line

    alias window alt moon-alternative-file

    hook global WinSetOption filetype=(?!moon).* %{
        remove-hooks window moon-.+
        unalias window alt moon-alternative-file
    }
}