#!/bin/bash

# Validates input arguments
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <file> <replacement_text_file>"
    exit 1
fi

file=$1
replacement_text_file=$2

# Read replacement text
replacement=$(<"$replacement_text_file")

# Initialize flag to detect when inside the help section
inside=0

# Buffer for storing processed content
buffer=""

# Process the file
while IFS= read -r line || [[ -n "$line" ]]; do
    if [ "$line" = "<!--help-->" ] && [ "$inside" -eq 0 ]; then
        # Append opening tag and replacement text
        buffer+="${line%%<!--help-->*}<!--help-->"$'\n'"$replacement"$'\n'
        inside=1
    elif [ "$line" = "<!--/help-->" ] && [ "$inside" -eq 1 ]; then
        # Append closing tag and reset flag
        buffer+="<!--/help-->"$'\n'
        inside=0
    elif [ "$inside" -eq 1 ]; then
        # Inside help section, do nothing (skip original content)
        :
    else
        # Outside help section, append the line
        buffer+="$line"$'\n'
    fi
done <"$file"

# Write buffer to the file, correctly handling new lines
printf "%s" "$buffer" >"$file"