#!/bin/bash

set -e

# Converts a raw collectd template to a go file with the template as a variable
# named "CollectdTemplate".  Should be called from the directory of the monitor
# package.

template_filename=$1
target_file=${2:-template.go}

package=$(basename $(pwd))

old_content=$(cat $target_file 2>/dev/null || echo -n "")

# A bunch of hacks so that we can render the template into the collectd package
# and not have an import from the same package.
collectd_package="collectd."
collectd_package_import='

	"github.com/signalfx/signalfx-agent/internal/monitors/collectd"'
if [[ $package == "collectd" ]]; then
  collectd_package_import=
  collectd_package=
fi

new_content=$(cat <<-EOH
// +build linux

package $package

// AUTOGENERATED BY scripts/collectd-template-to-go.  DO NOT EDIT!!

import (
	"text/template"$collectd_package_import
)

// CollectdTemplate is a template for a $package collectd config file
var CollectdTemplate = template.Must(${collectd_package}InjectTemplateFuncs(template.New("$package")).Parse(\`
$(cat $template_filename)
\`)).Option("missingkey=error")
EOH
)

# Don't write content if it's the same so we don't trigger a recompilation.
[[ $old_content == $new_content ]] || echo -n "$new_content" | gofmt > $target_file