# http://handlebarsjs.com/
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾

# Detection
# ‾‾‾‾‾‾‾‾‾

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

hook global WinSetOption filetype=hbs %{
    require-module hbs

    hook window ModeChange pop:insert:.* -group hbs-trim-indent hbs-trim-indent
    hook window InsertChar \n -group hbs-insert hbs-insert-on-new-line
    hook window InsertChar \n -group hbs-indent hbs-indent-on-new-line
    hook window InsertChar .* -group hbs-indent hbs-indent-on-char
    hook window InsertChar '>' -group hbs-indent html-indent-on-greater-than
    hook window InsertChar \n -group hbs-indent html-indent-on-new-line

    hook -once -always window WinSetOption filetype=.* %{ remove-hooks window hbs-.+ }
}

hook -group hbs-highlight global WinSetOption filetype=hbs %{
    maybe-add-hbs-to-html
    add-highlighter window/hbs-file ref hbs-file
    hook -once -always window WinSetOption filetype=.* %{ remove-highlighter window/hbs-file }
}


provide-module hbs %[

require-module html

# Highlighters
# ‾‾‾‾‾‾‾‾‾‾‾‾

add-highlighter shared/hbs regions
add-highlighter shared/hbs/comment          region \{\{!--  --\}\} fill comment
add-highlighter shared/hbs/comment_alt      region \{\{!      \}\} fill comment
add-highlighter shared/hbs/block-expression region \{\{[#/]   \}\} regions
add-highlighter shared/hbs/expression       region \{\{       \}\} regions

define-command -hidden add-mutual-highlighters -params 1 %~
    add-highlighter "shared/hbs/%arg{1}/code" default-region group
    add-highlighter "shared/hbs/%arg{1}/single-quote" region '"'    (?<!\\)(\\\\)*" fill string
    add-highlighter "shared/hbs/%arg{1}/double-quote" region "'"    (?<!\\)(\\\\)*' fill string
    add-highlighter "shared/hbs/%arg{1}/code/variable" regex \b([\w-]+)\b 1:variable
    add-highlighter "shared/hbs/%arg{1}/code/attribute" regex \b([\w-]+)= 1:attribute
    add-highlighter "shared/hbs/%arg{1}/code/helper" regex (?:(?:\{\{)|\()([#/]?[\w-]+(?:/[\w-]+)*) 1:keyword
~

add-mutual-highlighters expression
add-mutual-highlighters block-expression

add-highlighter shared/hbs/block-expression/code/yield regex \b(as)\s|[\w-]+|\}\} 1:keyword


# wrapper around shared/html highlighter.  The shared/hbs highlighter will be
# added into shared/html when a buffer of filetype 'hbs' is actively displayed in the window.
add-highlighter shared/hbs-file regions
add-highlighter shared/hbs-file/html default-region ref html

# Commands
# ‾‾‾‾‾‾‾‾

define-command -hidden hbs-trim-indent %{
    # remove trailing white spaces
    try %{ execute-keys -draft -itersel x s \h+$ <ret> d }
}

define-command -hidden hbs-indent-on-char %[
    evaluate-commands -draft -itersel %[
        # de-indent after closing a yielded block tag
        try %[ execute-keys -draft , <a-h> s ^\h+\{\{/([\w-.]+(?:/[\w-.]+)*)\}\}$ <ret> {c\{\{#<c-r>1,\{\{/<c-r>1\}\} <ret> s \A|.\z <ret> 1<a-&> ]
    ]
]

define-command -hidden hbs-insert-on-new-line %{
    evaluate-commands -draft -itersel %{
        # copy '/' comment prefix and following white spaces
        try %{ execute-keys -draft k x s ^\h*\K/\h* <ret> y j p }
    }
}

define-command -hidden hbs-indent-on-new-line %{
    evaluate-commands -draft -itersel %{
        # preserve previous line indent
        try %{ execute-keys -draft <semicolon> K <a-&> }
        # filter previous line
        try %{ execute-keys -draft k : hbs-trim-indent <ret> }
        # indent after lines beginning with : or -
        try %{ execute-keys -draft k x <a-k> ^\h*[:-] <ret> j <a-gt> }
    }
}

# Initialization
# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾

declare-option bool hbs_highlighters_enabled false

define-command -hidden maybe-add-hbs-to-html %{ evaluate-commands %sh{
    if [ "$kak_opt_hbs_highlighters_enabled" == "false" ]; then
        printf %s "
            add-highlighter shared/html/hbs region '\{\{' '\}\}' ref hbs
            add-highlighter shared/html/tag/hbs region '\{\{' '\}\}' ref hbs
            set-option global hbs_highlighters_enabled true
        "
    fi
} }

]