#!/bin/sh

# Author: Preston Pan
# Date: 05/10/2022
# Description: Script called from `find` in build.sh. $1 is the file that `find` is currently on.

if [ $# -eq 0 ]; then
	printf "Error: This script must be ran from a find command or build.sh!\n"
	exit 1
fi

# This function recursively resolves the $$INCLUDE calls
template_replacement()
{
	r_templates="$(< "$TEMPLATE_BUILD_DIR/$(basename "$1")" grep "\$\$INCLUDE")" # this is the future built version of our template.
																				 # We are finding the $$INCLUDE lines.
	if [ -z "$r_templates" ] # Base case of recursion: there are no more $$INCLUDE calls.
	then
		return 0
	fi

	echo "$r_templates" | while read -r i
	do
		# Escapes special characters from line containing $$INCLUDE call
		keyword_regexp="$(printf '%s' "$i" | -e sed 's/[]\/$*.^|[]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
		r_tname="$TEMPLATE_DIR/$(echo "$i" | cut -d ' ' -f 2).html"
		# Get contents of file then escapes special characters
		f_contents="$(cat "$r_tname")"
		replacement_regexp="$(printf '%s' "$f_contents" | sed -e 's/[\/&]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
		#Finally do the sed replace to replace the $$INCLUDE line with the contents of the included template file
		sed -i "s/$keyword_regexp/$replacement_regexp/g" "$TEMPLATE_BUILD_DIR/$(basename "$1")" # BUG: This shit does not work
		# Then we do it all again on the same file.
		template_replacement "$1"
	done
}

fname="$(basename "$1")" # gets the name of file in question
if [ "${fname##*.}" != "html" ] # If it is not an html file, just copy it over to the build directory, the script does nothing.
then
	cp "$1" "$BUILD_DIR/$1"
	exit 0
fi

# We want the first specified template to be the template
template_name="$(< "$1" grep "\$\$TEMPLATE" | head -1)"


# Location of the template that is to be built from template_replacement

if [ -n "$template_name" ] # We get the path of the template and if no template is specified it uses the default.
then
	template="$TEMPLATE_DIR/$(echo "$template_name" | cut -d ' ' -f 2 | tr -d '\n').html"
else
	template="$DEFAULT_TEMPLATE"
fi

built_template="$TEMPLATE_BUILD_DIR/$(basename "$template")"
template_replacement "$template" # replace all the $$TEMPLATE calls.

vars="$(< "$1" grep "\$\$START")"

# now we prepare to do the variable substitutions.
cp "$built_template" "$BUILD_DIR/$1"

echo "$vars" | while read -r var;
do
	# Get the name of the variable
	name="$(echo "$var" | cut -d ' ' -f 2 | tr -d '\n')"
	keyword_regexp="$(printf '%s' "$var" | sed -e 's/[]\/$*.^|[]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
	# Get the endpoint of the variable
	var_end="\$\$END $name"
	end_regexp="$(printf '%s' "$var_end" | sed -e 's/[\/&]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
	# Get the value of the variable
	value="$(< "$BUILD_DIR/$1" sed -n "/$keyword_regexp/,/$end_regexp/p" "$1")"
	value_regexp="$(printf '%s' "$value" | sed -e 's/[]\/$*.^|[]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
	# Get the string to replace
	replacement="\$\$VAR $name"
	replacement_regexp="$(printf '%s' "$replacement" | sed -e 's/[\/&]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
	# Then do the replacement
	sed -i "s/$replacement_regexp/$value_regexp/g" "$BUILD_DIR/$1" # BUG: Doesn't work on openBSD
done

# For some reason I can't trim these inside the loop (i tried) so this works.
sed -i '/\$\$START/d' "$BUILD_DIR/$1"
sed -i '/\$\$END/d' "$BUILD_DIR/$1"

debug="$(< "$BUILD_DIR/$1" grep "\$\$SCRIPT")"
printf "$debug\n"

if [ -n "$debug" ]
then
	echo "$debug" | while read -r line;
	do
		name="$(echo "$line" | cut -d ' ' -f 2 | tr -d '\n')"
		output="$(./"$PLUG_DIR/$name" "$1" "$template")"
		keyword_regexp="$(printf '%s' "$line" | sed -e 's/[]\/$*.^|[]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"
		replacement_regexp="$(printf '%s' "$output" | sed -e 's/[\/&]/\\&/g' | sed ':a;N;$!ba;s,\n,\\n,g')"

		sed -i "s/$keyword_regexp/$replacement_regexp/g" "$BUILD_DIR/$1" # BUG: doesn't work with openBSD
	done
fi