#!/usr/bin/env bash
set -Eeuo pipefail

info () { printf "%b%s%b" "\E[1;34m❯ \E[1;36m" "$1" "\E[0m\n"; }
error () { printf "%b%s%b" "\E[1;31m❯ " "ERROR: $1" "\E[0m\n" >&2; }
warn () { printf "%b%s%b" "\E[1;31m❯ " "Warning: $1" "\E[0m\n" >&2; }

trap 'error "Status $? while: $BASH_COMMAND (line $LINENO/$BASH_LINENO)"' ERR

[ ! -f "/run/entry.sh" ] && error "Script must run inside Docker container!" && exit 11
[ "$(id -u)" -ne "0" ] && error "Script must be executed with root privileges." && exit 12

echo "❯ Starting $APP for Docker v$(</run/version)..."
echo "❯ For support visit $SUPPORT"
echo

# Docker environment variables

: "${BOOT:=""}"           # URL of the ISO file
: "${DEBUG:="N"}"         # Disable debugging
: "${ALLOCATE:=""}"       # Preallocate diskspace
: "${ARGUMENTS:=""}"      # Extra QEMU parameters
: "${CPU_CORES:="1"}"     # Amount of CPU cores
: "${RAM_SIZE:="1G"}"     # Maximum RAM amount
: "${DISK_SIZE:="16G"}"   # Initial data disk size
: "${BOOT_INDEX:="10"}"   # Boot index of CD drive
 
# Helper variables

STORAGE="/storage"
INFO="/run/shm/msg.html"
PAGE="/run/shm/index.html"
TEMPLATE="/var/www/index.html"
FOOTER1="$APP for Docker v$(</run/version)"
FOOTER2="<a href='$SUPPORT'>$SUPPORT</a>"

KERNEL=$(uname -r | cut -b 1)
MINOR=$(uname -r | cut -d '.' -f2)
ARCH=$(dpkg --print-architecture)
VERS=$(qemu-system-x86_64 --version | head -n 1 | cut -d '(' -f 1)

# Check system

if [ ! -d "/dev/shm" ]; then
  error "Directory /dev/shm not found!" && exit 14
else
  [ ! -d "/run/shm" ] && ln -s /dev/shm /run/shm
fi

# Check folder
[ ! -d "$STORAGE" ] && error "Storage folder ($STORAGE) not found!" && exit 13

# Helper functions

escape () {
    local s
    s=${1//&/\&amp;}
    s=${s//</\&lt;}
    s=${s//>/\&gt;}
    s=${s//'"'/\&quot;}
    printf -- %s "$s"
    return 0
}

html()
{
    local title
    local body
    local script
    local footer

    title=$(escape "$APP")
    title="<title>$title</title>"
    footer=$(escape "$FOOTER1")

    body=$(escape "$1")
    if [[ "$body" == *"..." ]]; then
      body="<p class=\"loading\">${body/.../}</p>"
    fi

    [ -n "${2:-}" ] && script="$2" || script=""

    local HTML
    HTML=$(<"$TEMPLATE")
    HTML="${HTML/\[1\]/$title}"
    HTML="${HTML/\[2\]/$script}"
    HTML="${HTML/\[3\]/$body}"
    HTML="${HTML/\[4\]/$footer}"
    HTML="${HTML/\[5\]/$FOOTER2}"

    echo "$HTML" > "$PAGE"
    echo "$body$script" > "$INFO"

    return 0
}

addPackage () {

  local pkg=$1
  local desc=$2

  if apt-mark showinstall | grep -qx "$pkg"; then
    return 0
  fi

  MSG="Installing $desc..."
  info "$MSG" && html "$MSG"

  DEBIAN_FRONTEND=noninteractive apt-get -qq update
  DEBIAN_FRONTEND=noninteractive apt-get -qq --no-install-recommends -y install "$pkg" > /dev/null

  return 0
}

# Start webserver
cp -r /var/www/* /run/shm
html "Starting $APP for Docker..."
nginx -e stderr

return 0