#!/bin/bash

# .env contains a line like
# BASE64_BEARER_TOKEN='<literal base64 encoded string>'
# Retrieve that base64 token from a request from the browser
# network tab network tabfrom a logged in MS Stream (Classic) tab
source .env

OUTDIR="./videos"

read -r -d '' API_URL <<- 'EOM'
https://euwe-1.api.microsoftstream.com/api/videos?
$top=100
&
$skip=0
&
$orderby=metrics/trendingScore asc
&
$filter=
		published{SPACE}
		and{SPACE}
		(
				(
						state eq 'Completed' and contentSource ne 'livestream'
				){SPACE}
				or{SPACE}
				(
						contentSource eq 'livestream'{SPACE}
						and not 
						(
								state eq 'Completed'{SPACE}
								and not 
								liveEvent/LiveEventOptions/OnDemandOptions/EnablePlayback
						)
				)
		)
&
api-version=1.4-private
EOM

API_URL="$(tr -d -- '\n' <<< "${API_URL//\{SPACE\}/ }")"

mkdir -p "${OUTDIR}" || {
  printf '\033[31m%s\033[m\n' 'Aborting'
  exit 2
}

# '>' without quotes is delimiter, since it's one of the few chars disallowed in a URL. Title must not include this char
# https://www.ietf.org/rfc/rfc2396.txt
# 2.4.3. Excluded US-ASCII Characters
m3u8_manifest_urls_and_metadata=$(
    # shellcheck disable=SC2312
    wget --no-verbose --quiet -O- --header="authorization: Bearer ${BASE64_BEARER_TOKEN}" "${API_URL}" |
      jq -r '.value[] | .name + ">" + .media.duration[2:] + ">" + (.playbackUrls | map(select(.mimeType == "application/vnd.apple.mpegurl")) | .[].playbackUrl)'
)

[[ -z "${m3u8_manifest_urls_and_metadata}" ]] && {
  printf '\033[31m%s\033[m\n' 'Error GETting manifest urls (response empty) or Bearer token invalid/expired. Exiting.'
  exit 3
}

idx=1
total="$(wc -l <<< "${m3u8_manifest_urls_and_metadata}")"

IFS=$'\n'
for m3u8_manifest_url_and_metadata in ${m3u8_manifest_urls_and_metadata}; do
    IFS='>' read -r title length m3u8_manifest_url <<< "${m3u8_manifest_url_and_metadata}"

    length="$(sed -e 's/\..*S/S/g' -e 's/M/:/g' -e 's/H/:/g' <<< "${length}")"

    filepath="${OUTDIR}/${title}.mp4"

    printf '\033[32m%s\033[m\n' "Download '${filepath}' (${idx}/${total})"

    # shellcheck disable=SC2312
    ffmpeg -hide_banner                                        \
      -loglevel error                                          \
      -headers "authorization: Bearer ${BASE64_BEARER_TOKEN}"  \
      -i "${m3u8_manifest_url}"                                \
      -progress -                                              \
      -codec copy                                              \
      "${filepath}"                                            |
        grep --line-buffered 'out_time='                       |
        sed -u -e 's/out_time=//g' -e 's/\..*//g' -e 's/^-//g' |
        xargs -I{} printf "{} of ${length}       \r"

    printf '\n\033[33m%s\033[m\n' "Done"

    idx=$(( idx + 1 ))
done