md2man

#!/bin/sh

set -euo pipefail

get_name() {
	sed -En '/^---$/,/^---$/{
	/^slug:/{
		s/\//./g
		s/^slug: Web\.(API|JavaScript\.Reference\.Global_Objects)\.//p
		q
	}
	}' "$1"
}

get_title() {
	sed -n '/^---$/,/^---$/{
		/^title:/{
			s/^title:[[:space:]]*//
			s/^"//g
			s/"$//g
			p
			q
		}
	}' "$1"
}

get_date() (
	export LC_ALL=C
	ls -dog "$1" |
	awk -v abmon="$(locale abmon)" \
		-v cmonth="$(date +%m)" \
		-v cyear="$(date +%Y)" '
	BEGIN {
		n = split(abmon, months, ";")
		while (++i <= n) months[months[i]] = i
	}
	{
		month = months[$4]
		day = $5
		year = ($6 ~ /:/) ? (month > cmonth ? cyear-1 : cyear) : $6
		printf "%04d-%02d-%02d\n", year, month, day
	}'
)

yn() {
	case $1 in
	0) echo no;;
	1) echo yes;;
	esac
}

js_property_attributes() {
	for i in 0 1; do
	for j in 0 1; do
	for k in 0 1; do
		printf '/^{{js_property_attributes\(%d, %d, %d\)}}$/c\\\n| | |\\\n|-|-|\\\n|Writable|%s|\\\n|Enumerable|%s|\\\n|Configurable|%s|\\\n\n' \
			"$i" "$j" "$k" "$(yn "$i")" "$(yn "$j")" "$(yn "$k")"
	done
	done
	done
}

space="[[:space:]]*"
str="(\"([^\"]+)\"|'([^']+)')"
empty="(\"\"|'')"

ref() {
	printf '%s\n' "
	s/{{$1\($str\)}}/\`\2\3\`/ig
	s/{{$1\($str,$space$str\)}}/\`\5\6\`/ig
	s/{{$1\($str,$space$empty,$space$str\)}}/\`\2\3\`/ig
	s/{{$1\($str,$space$str,$space$str\)}}/\`\5\6\`/ig
	s/{{$1\($str,$space$empty,$space$empty,[^)]+\)}}/\2\3/ig
	s/{{$1\($str,$space$str,$space$empty,[^)]+\)}}/\5\6/ig
	s/{{$1\($str,$space$empty,$space$str,[^)]+\)\)}}/\2\3/ig
	s/{{$1\($str,$space$str,$space$str,[^)]+\)}}/\5\6/ig
	"
}

text() {
	printf '%s\n' "
	s/{{$1\($str\)}}/\2\3/ig
	s/{{$1\($str,$space$str\)}}/\5\6/ig
	"
}

element() {
	printf '%s\n' "
	s/{{$1\($space$str$space\)}}/\`<\2\3>\`/ig
	s/{{$1\($str,$space$str\)}}/\`\5\6\`/ig
	"
}

info() {
	printf '%s\n' "s/{{$1(\(\))?}}/$2/ig"
}

ignore() {
	printf '%s\n' "s/{{$1(\(($str|$empty|[^)'\"]*)*\))?}}//ig"
}

clean() {
	sed -E "
	/^---$/,/^---$/c\\
---\\
title: $(get_name "$1")\\
section: JS\\
header: JavaScript Reference Manual\\
footer: JavaScript\\
date: $(get_date "$1")\\
---\\
# Name\\
$(get_name "$1") - $(get_title "$1")\\
\\
# Synopsis

	/^## Specifications/,/{{Specifications}}/d
	/^## Browser compatibility/,/{{Compat}}/d
	/^[>[:space:]]*\`\`\`[^[:space:]]+ hidden$/,/^[>[:space:]]*\`\`\`$/d

	s/^([>[:space:]]*)(\`\`\`[^[:space:]]+) example-bad$/\1**Bad**\n\1\2/
	s/^([>[:space:]]*)(\`\`\`[^[:space:]]+) example-good$/\1**Good**\n\1\2/

	s/^#//

	/{{[^}]*$/N
	/{{[^}]*$/N
	/{{[^}]*$/N
	s/{{[[:space:]]*([^}]*[^}[:space:]])[[:space:]]*}}/{{\1}}/g

	$(js_property_attributes)

	$(ignore APIRef)
	$(ignore DefaultAPISidebar)
	$(ignore DOMAttributeMethods)
	$(ignore EmbedInteractiveExample)
	$(ignore EmbedGHLiveSample)
	$(ignore EmbedLiveSample)
	$(ignore InheritanceDiagram)
	$(ignore JSRef)
	$(ignore jsSidebar)
	$(ignore HTTPSidebar)
	$(ignore SeeCompatTable)

	$(ref CSP)
	$(ref cssxref)
	$(ref domxref)
	$(ref HTTPHeader)
	$(ref HTTPMethod)
	$(ref HTTPStatus)
	$(ref jsxref)
	$(ref SVGAttr)
	$(ref WebExtAPIRef)

	$(info AvailableInWorkers '\n\n**Note:** This feature is available in Web Workers.')
	$(info deprecated_header '\n\n**Deprecated:** This feature is no longer recommended.')
	$(info Deprecated_Inline '*(deprecated)*')
	$(info Experimental_Inline '*(experimental)*')
	$(info NonStandardBadge '*(non-standard)*')
	$(info non-standard_header '\n\n**Non-standard:** This feature is non-standard and is not on a standards track.')
	$(info non-standard_inline '*(non-standard)*')
	$(info optional_inline '*(optional)*')
	$(info ReadOnlyInline '*(read-only)*')
	$(info securecontext_header '\n\n**Secure context:** This feature is available only in secure contexts (HTTPS).')
	$(info SecureContext_Inline '*(secure context)*')

	$(element HTMLElement)
	$(element MathMLElement)
	$(element SVGElement)

	$(text Glossary)
	$(text LiveSampleLink)

	s/{{AvailableInWorkers\(\"dedicated\"\)}}/\n\n**Note:** This feature is only available in Dedicated Web Workers./ig
	s/{{AvailableInWorkers\(\"service\"\)}}/\n\n**Note:** This feature is only available in Service Workers./ig
	s/{{AvailableInWorkers\(\"window_and_dedicated\"\)}}/\n\n**Note:** This feature is available in Dedicated Web Workers./ig
	s/{{AvailableInWorkers\(\"window_and_service\"\)}}/\n\n**Note:** This feature is available in Service Workers./ig
	s/{{AvailableInWorkers\(\"window_and_worker_except_service\"\)}}/\n\n**Note:** This feature is available in Web Workers, except for Service Workers./ig
	s/{{AvailableInWorkers\(\"worker\"\)}}/\n\n**Note:** This feature is only available in Web Workers./ig
	s/{{AvailableInWorkers\(\"worker_except_service\"\)}}/\n\n**Note:** This feature is only available in Web Workers, except for Service Workers./ig
	s/{{RFC\(\"?([0-9]+)\"?\)}}/RFC \1/ig
	s/{{RFC\(([0-9]+),$space$str\)}}/RFC \1: \3\4/ig
	s/{{RFC\(([0-9]+),$space$empty,$space([0-9.]+)\)}}/RFC \1, section \3/ig
	s/{{RFC\(\"?([0-9]+)\"?,$space$empty,$space$str\)}}/RFC \1, section \4\5)/ig
	s/{{RFC\(\"?([0-9]+)\"?,$space$str,$space$str\)}}/RFC \1, section \6\7: \3\4/ig

	s/\[!CALLOUT]//g
	s/\[!NOTE]/**Note:**/g
	s/\[!WARNING]/**Warning:**/g
	" "$1"
}

convert() {
	pandoc --fail-if-warnings --lua-filter=filter.lua -s \
		-f markdown-table_captions-markdown_in_html_blocks -t man
}

cleaned="$(clean $1)"

unknown=$(printf %s "$cleaned" | { grep -o '{{[^}]*}}' || :; } | sort | uniq)

if [ "$unknown" ]; then
	printf >&2 'unknown macros: %s\n' "$unknown"
	exit 1
fi

printf %s "$cleaned" | convert