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

# cURL configurations applied to all requests
CURL_ARGS=(--silent --max-time 6)

# Color definitions
COLOR_DANGER=$(tput setaf 1)
COLOR_SUCCESS=$(tput setaf 2)
COLOR_RESET=$(tput sgr0)

show_usage () {
  echo "Usage: $0 [COMMAND] [OPTIONS]"
  echo ""
  echo "Commands:"
  echo "  make:playlist     Make a playlist file"
  echo "  make:epg          Make an EPG file"
  echo "  decrypt:authinfo  Find a possible IPTV key"
  echo ""
  echo "Run '$0 COMMAND -h' for help on a specific command."
}

show_make_playlist_usage () {
  echo "Usage: $0 make:playlist -u <user-id> -p <password> -d <device-id> --mac <mac-address>"
  echo ""
  echo "Options:"
  echo "  -u | --user       User ID"
  echo "  -p | --password   Password"
  echo "  -d | --device     Device ID"
  echo "  --ip              Device IP address (default: 127.0.0.1)"
  echo "  --mac             Device MAC address"
  echo "  --udpxy           Udpxy endpoint (default: http://127.0.0.1:4022)"
  echo "  -o | --output     Playlist file name (default: playlist.M3U8)"
  echo "  -I | --interface  Network interface for cURL requests (optional)"
}

show_make_epg_usage () {
  echo "Usage: $0 make:epg"
  echo ""
  echo "Options:"
  echo "  --endpoint        EPG index endpoint (default: http://120.87.12.38:8083/epg/api/page/biz_59417088.json)"
  echo "  -o | --output     EPG file name (default: epg.xml)"
  echo "  -I | --interface  Network interface for cURL requests (optional)"
}

show_decrypt_authinfo_usage () {
  echo "Usage: $0 decrypt:authinfo <authinfo>"
}

step () { printf '%s==> %s%s\n' "$COLOR_SUCCESS" "$1" "$COLOR_RESET"; }

fatal () { printf '%s!!! %s%s\n' "$COLOR_DANGER" "$1" "$COLOR_RESET" >&2; exit 1; }

ensure_curl_is_installed () {
  if ! command -v curl &>/dev/null; then
    fatal "The cURL package that handles HTTP requests is not installed."
  fi
}

ensure_jq_is_installed () {
  if ! command -v jq &>/dev/null; then
    fatal "The jq package that handles HTTP JSON response is not installed."
  fi
}

ensure_openssl_is_installed () {
  if ! command -v openssl &>/dev/null; then
    fatal "The OpenSSL package that handles token computation is not installed."
  fi
}

categorize_by_channel_name () {
  result="720P"

  case "$1" in
    *4K*) result="4K" ;;
    *"超清"*|*"高清"*) result="1080P" ;;
  esac

  echo "$result"
}

retrieve_endpoint () {
  local user_id="$1"
  local url="http://eds1.unicomgd.com:8082/EDS/jsp/AuthenticationURL?Action=Login&UserID=$user_id&return_type=1"
  local response
  local epgurl
  response=$(curl "${CURL_ARGS[@]}" "$url") || return 1
  epgurl=$(printf '%s' "$response" | jq -r '.epgurl')
  printf '%s\n' "$(extract_hostname "$epgurl")"
}

extract_hostname () {
  local url="$1"
  local res
  res="${url#*//}"
  res="${res%%/*}"
  printf '%s\n' "$res"
}

retrieve_encry_token () {
  local endpoint="$1"
  local user_id="$2"
  local url="http://$endpoint/EPG/oauth/v2/authorize?response_type=EncryToken&client_id=jiulian&userid=$user_id"
  local response
  local token
  response=$(curl "${CURL_ARGS[@]}" "$url") || return 1
  token=$(printf '%s' "$response" | jq -r '.EncryToken') || return 1
  [[ -n "$token" && "$token" != "null" ]] || return 1
  printf '%s\n' "$token"
}

build_authinfo () {
  local encry_token="$1"
  local user_id="$2"
  local device_id="$3"
  local ip_address="$4"
  local mac_address="$5"

  local random_num=$(( (RANDOM << 15 | RANDOM) % 99999999 + 1 ))
  local parts=("$random_num" "$encry_token" "$user_id" "$device_id" "$ip_address" "$mac_address" "Reserved" "OTT")
  local joined
  joined=$(IFS='$'; printf '%s' "${parts[*]}")

  printf '%s\n' "$joined"
}

encrypt_authinfo () {
  local data="$1"
  local key="$2"
  local res
  res=$(printf '%s' "$data" | openssl enc -e -des-ede3 -K "$key" -nosalt 2>/dev/null | xxd -p -u -c 0)

  printf '%s\n' "$res"
}

retrieve_access_token () {
  local endpoint="$1"
  local user_id="$2"
  local authinfo="$3"
  local url="http://$endpoint/EPG/oauth/v2/token?grant_type=EncryToken&client_id=jiulian&UserID=$user_id&DeviceType=UNT400G&DeviceVersion=5.5.021&authinfo=$authinfo&issmarthomestb=1&tvdesktopid="
  local response
  local token
  response=$(curl "${CURL_ARGS[@]}" "$url") || return 1
  token=$(printf '%s' "$response" | jq -r '.access_token') || return 1
  [[ -n "$token" && "$token" != "null" ]] || return 1
  printf '%s\n' "$token"
}

build_channel_logos () {
  local -n ref=$1
  [[ -n "$1" ]] || return 1

  local url='http://120.87.12.38:8083/epg/api/custom/getAllChannel.json'
  local response
  response=$(curl "${CURL_ARGS[@]}" "$url") || return 1
  [[ -n "$response" ]] || return 1

  local channel
  local hwcode
  local icon
  while read -r channel; do
    hwcode=$(printf '%s' "$channel" | jq -r '.params.hwcode') || return 1
    icon=$(printf '%s' "$channel" | jq -r '.icon') || return 1
    [[ -n "$hwcode" && "$hwcode" != "null" ]] || continue
    [[ -n "$icon" && "$icon" != "null" ]] || continue
    ref["$hwcode"]="$icon"
  done < <(printf '%s' "$response" | jq -c '.channels[]') || return 1
}

make_epg () {
  # Check dependencies
  ensure_curl_is_installed
  ensure_jq_is_installed

  # Default variables
  local output_file='epg.xml'
  local endpoint='http://120.87.12.38:8083/epg/api/page/biz_59417088.json'

  while [ $# -gt 0 ]; do
    case "$1" in
      -o | --output ) output_file="$2"; shift 2;;
      --endpoint ) endpoint="$2"; shift 2;;
      -I | --interface ) CURL_ARGS+=(--interface "$2"); shift 2;;
      -h | --help ) show_make_epg_usage; exit 0;;
      *) echo "Unknown option: $1"; exit 1;;
    esac
  done

  step "Request channel index"
  response=$(curl "${CURL_ARGS[@]}" "$endpoint")

  step "Create the EPG XML file"
  echo '<?xml version="1.0" encoding="UTF-8"?>' > "$output_file"
  echo '<!DOCTYPE tv SYSTEM "xmltv.dtd">' >> "$output_file"
  echo "<tv date=\"$(date +"%Y%m%d%H%M%S %z")\">" >> "$output_file"

  while read -r item; do
    item_title=$(echo "$item" | jq -r '.itemTitle')
    item_type=$(echo "$item" | jq -r '.itemType')
    data_link=$(echo "$item" | jq -r '.dataLink')

    if [[ "$item_type" == "channel" ]]; then
      step "Process: $item_title"

      response=$(curl "${CURL_ARGS[@]}" "$data_link")
      channel_icon=$(echo "$response" | jq -r '.channel.icon')
      channel_title=$(echo "$response" | jq -r '.channel.title')
      hwcode=$(echo "$response" | jq -r '.channel.params.hwcode')

      echo "  <channel id=\"$hwcode\">" >> "$output_file"
      echo "    <display-name lang=\"zh\"><![CDATA[$channel_title]]></display-name>" >> "$output_file"
      echo "    <icon src=\"$channel_icon\"/>" >> "$output_file"
      echo "  </channel>" >> "$output_file"

      while read -r schedule; do
        schedule_title=$(echo "$schedule" | jq -r '.title')
        schedule_starttime=$(echo "$schedule" | jq -r '.starttime')
        schedule_endtime=$(echo "$schedule" | jq -r '.endtime')

        echo "  <programme start=\"$schedule_starttime +0800\" stop=\"$schedule_endtime +0800\" channel=\"$hwcode\">" >> "$output_file"
        echo "    <title lang=\"zh\"><![CDATA[$schedule_title]]></title>" >> "$output_file"
        echo "  </programme>" >> "$output_file"
      done < <(echo "$response" | jq -c '.schedules[]')
    fi
  done < <(echo "$response" | jq -c '.areaDatas[].items[]')

  echo '</tv>' >> "$output_file"

  step "EPG built sucessfully!"

  exit 0
}

make_playlist () {
  # Check dependencies
  ensure_curl_is_installed
  ensure_jq_is_installed
  ensure_openssl_is_installed

  # Default values
  local user_id=''
  local password=''
  local device_id=''
  local mac_address=''
  local ip_address='127.0.0.1'
  local udpxy_endpoint='http://127.0.0.1:4022'
  local output_file='playlist.M3U8'

  while [ $# -gt 0 ]; do
    case "$1" in
      -u | --user) user_id="$2"; shift 2;;
      -p | --password) password="$2"; shift 2;;
      -d | --device) device_id="$2"; shift 2;;
      --ip) ip_address="$2"; shift 2;;
      --mac) mac_address="$2"; shift 2;;
      --udpxy) udpxy_endpoint="$2"; shift 2;;
      -o | --output) output_file="$2"; shift 2;;
      -I | --interface) CURL_ARGS+=(--interface "$2"); shift 2;;
      -h | --help ) show_make_playlist_usage; exit 0;;
      *) echo "Unknown option: $1"; exit 1;;
    esac
  done

  # Validate user input
  if [[ -z "$user_id" ]]; then
    fatal "Requires an IPTV user ID with -u or --user"
  fi

  if [[ -z "$password" ]]; then
    fatal "Requires an IPTV password with -p or --password"
  fi

  if [[ -z "$device_id" ]]; then
    fatal "Requires a device ID with -d or --device"
  fi

  if [[ -z "$mac_address" ]]; then
    fatal "Requires a device MAC address with --mac"
  fi

  step "Authenticate"

  local host
  host=$(retrieve_endpoint "$user_id") || fatal 'Failed to retrieve endpoint'

  local encry_token
  encry_token=$(retrieve_encry_token "$host" "$user_id") || fatal 'Failed to retrieve encry token'

  local key
  key=$(printf "%-24s" "$password" | tr ' ' 0 | xxd -p)

  local authinfo
  authinfo=$(build_authinfo "$encry_token" "$user_id" "$device_id" "$ip_address" "$mac_address") || fatal 'Failed to build authinfo'
  authinfo=$(encrypt_authinfo "$authinfo" "$key") || fatal 'Failed to encrypt authinfo'

  local access_token
  access_token=$(retrieve_access_token "$host" "$user_id" "$authinfo") || fatal 'Failed to retrieve access token'

  step "Request channel logos"
  local -A logos
  build_channel_logos logos

  step "Request channels from the batch API"
  response=$(curl "${CURL_ARGS[@]}" \
    --data '{"channelcodes":""}' \
    --header 'Content-Type: application/json;charset=utf-8' \
    --header "Authorization: $access_token" \
    http://$host/EPG/interEpg/channellist/batch)

  step "Decode channels from the HTTP response"
  echo '#EXTM3U' > "$output_file"
  echo '#EXT-X-VERSION:3' >> "$output_file"

  echo "$response" | jq -c '.channellist[]' | while read -r channel; do
    channelcode=$(echo "$channel" | jq -r '.channelcode')
    channelname=$(echo "$channel" | jq -r '.channelname')
    channelurl=$(echo "$channel" | jq -r '.channelurl')
    IFS='|' read -ra channelurls <<< "$channelurl"

    step "Process: $channelname"

    pattern="://([^/]+)"
    if [[ "${channelurls[0]}" =~ $pattern ]]; then
      host=${BASH_REMATCH[1]}

      group=$(categorize_by_channel_name "$channelname")

      printf '#EXTINF:-1 tvg-id="%s" tvg-name="%s" tvg-logo="%s" group-name="%s",%s\n' \
        "$channelcode" \
        "$channelname" \
        "${logos[$channelcode]-}" \
        "$group" \
        "$channelname" >> "$output_file"
      echo "$udpxy_endpoint/udp/$host" >> "$output_file"
    fi
  done

  step "Extract IPTV channels successfully!"

  exit 0
}

decrypt_authinfo () {
  if [[ "$1" == '-h' || "$1" == "--help" ]]; then
    show_decrypt_authinfo_usage
    exit 0
  fi

  local authinfo="$1"

  if [[ -z "$authinfo" ]]; then
    fatal "Requires authinfo data from /EPG/oauth/v2/token"
  fi

  authinfo=$(echo -n "$authinfo" | xxd -r -p)

  local loading=("Still working." "Still working.." "Still working...")

  local key
  for ((i=0; i<1000000; i++)); do
    key=$(printf "%06d" "$i")

    if (( i % 100 == 0 )); then
      echo -ne "\r\033[K${loading[i % 3]} $((i / 1000000 * 100))%"
    fi

    local result=$(echo -n "$authinfo" | \
      openssl enc -d -des-ede3 -K "$(echo -n "${key}000000000000000000" | xxd -p -c 0)" 2>/dev/null | \
      tr -d '\0')

    if echo -n "$result" | grep -q OTT; then
      IFS='$' read -ra components <<< "$result"

      echo -e "\n"
      echo "========================================"
      echo "Found key: $key"
      echo "========================================"
      echo "$result"
      echo "========================================"
      echo "      random:  ${components[0]}"
      echo " encry token:  ${components[1]}"
      echo "     user id:  ${components[2]}"
      echo "   device id:  ${components[3]}"
      echo "  ip address:  ${components[4]}"
      echo " mac address:  ${components[5]}"
      echo "    reserved:  ${components[6]}"
      echo "         ott:  ${components[7]}"

      exit 0
    fi
  done

  fatal "Could not find a possible key."
}

##
## Main
##

while [ $# -gt 0 ]; do
  case "$1" in
    make:playlist) shift 1; make_playlist "$@";;
    make:epg) shift 1; make_epg "$@";;
    decrypt:authinfo) shift 1; decrypt_authinfo "$@";;
    -h | --help) show_usage; exit 0;;
    *) echo "Unknown command: $1"; exit 1;;
  esac
done