#!/usr/bin/env bash

# encode - Encode for streaming and schedule cron job
# Usage:  encode
#   Called by cron every minute; process oldest .upload file in ./uploadpage/streams)
# Required: file coreutils(readlink ls head mv tail rm) cron(crontab) date ffmpeg
#   mailer[gitlab.com/pepa65/mailer]

# Check for oldest uploaded file
_=$(readlink -f -- "${BASH_SOURCE:-$0}") repopath=${_%/*}
log=$repopath/process.log dir=$repopath/uploadpage/streams
upload=$(ls -tr "$dir"/*.upload 2>/dev/null |head -1)

# Finished if no uploadpage/streams/*.upload files found
[[ $upload ]] || exit 0

Log(){ # 1:message 2:returncode(empty: no exit) I:file
	echo "$1">>"$log"
	[[ $2 ]] && exit $2 || return 0
}

Mail(){ # 1:kind(0:done, 1:wrong type, 2:encoding error) 2:logline I:repopath,email,username,name,type,start,finish
	source "$repopath/vars"  # I:user,password,smtp,port,ssltls
	local sbj msg to from="Stream Upload server"
	mapfile -t <"$repopath/mailhash"
	for line in "${MAPFILE[@]}"
	do [[ ${line:0:1} = '#' ]] && continue
		[[ $username = ${line%%$'\t'*} ]] && _=${line#*$'\t'} to=${_%$'\t'*} && break
	done
	# If email given, strip ':'
	[[ $email ]] && to=${email:1}
	[[ $port ]] || port=587
	# If ssltls is not empty, switch to SSL/TLS
	[[ $ssltls ]] && $ssltls='-T'
	sbj[0]="Stream Upload encoding done for ${name##*@}"
	sbj[1]="Stream Upload file wrong type: $type"
	sbj[2]="Stream Upload error encoding"
	msg[0]="Heya,\n\nEncoded video with tag '$name'.\nEncoding started on $start and finished on $finish.\n\nStream Upload server"
	msg[1]="Heya,\n\nThe file '$name' from $start is of type '$type' and could not be used.\n\nStream Upload server\n"
	msg[2]="Heya,\n\nThe file '$name' started encoding on $start but ran into an error on $finish.\n\nStream Upload server\n"
	if [[ $to && $user && $password && $smtp && $port ]]
	then # All ingredients for a mail present
		/usr/local/bin/mailer -m "$(echo -e "${msg[$1]}")" -t "$to" -s "${sbj[$1]}" -u "$user" -p "$password" -S "$smtp" -P "$port" $ssltls -f "$from" 2>"$repopath/mailer.log" &&
			Log "== Mail with subject '${sbj[$1]}' sent to $to" ||
			Log "== Mail with subject '${sbj[$1]}' failed to send to: $to"
		Log "Start encoding on $start, finished on $finish"
	else # Can't send
		Log "== Mail with subject '${sbj[$1]}' could not be sent"
		(($1==2)) && Log "Start encoding on $start, error on $finish"
	fi
	Log "$2" $1
}

# Rename upload and check type
file=${upload%.upload} video=$file.mp4 name=${file##*/} key=${name%%.*}
rest=${name#*.} date=${rest:0:15} id=${rest:15:1} _=${rest:16} _=${_%@*} username=${_%%:*} email=${_#$username}
mv "$upload" "$file"

type=$(file -bL --mime-type "$file")
[[ ! ${type:0:5} = video ]] && Mail 1 "File $name is of type $type"

# Encode video
start=$(date +'%Y-%m-%d at %H:%M:%S') error=0
## Single pass
#ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -force_key_frames 'expr:gte(t,n_forced*2)' -c:a copy -tune zerolatency -f mp4 "$video"  |tail -n 20 >"$file.0log" || error=1
# Double pass
set -o pipefail  # to get ffmpeg's returncode
ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -vf "format=yuv420p,scale=1920x1080,setdar=16/9,fps=25" -video_track_timescale 18000 -b:v 6M -maxrate 6M -bufsize 12M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 1 -passlogfile "$file" -f mp4 "$video" 2>&1 |tail -n 20 >"$file.1log" &&
	ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -vf "format=yuv420p,scale=1920x1080,setdar=16/9,fps=25" -video_track_timescale 18000 -b:v 6M -maxrate 6M -bufsize 12M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 2 -passlogfile "$file" -f mp4 "$video" 2>&1 |tail -n 20 >"$file.2log" ||
	error=1

# Remove logfiles
rm "$file"-*
finish=$(date +'%Y-%m-%d at %H:%M:%S')
((error)) && Mail 2 "Error encoding $name"

# concatenate countdown
if [[ ! $id = _ ]]
then
	countdown=$(ls -tr "$dir/.$id"*.mp4 2>/dev/null |head -1)
	ffmpeg -f concat -safe 0 -i <(echo -e "file '$countdown'\nfile '$video'") -c copy "${video%.mp4}_.mp4" 2>&1 |tail -n 20 >"$file.3log"
	mv "${video%.mp4}_.mp4" "$video"
fi
Log ".. $id $countdown $video"

# Remove tailfiles if no errors
rm -- "$file".?log

# Schedule cron job
m=${date:13:2} m=${m#0} h=${date:11:2} h=${h#0}
D=${date:8:2} D=${D#0} M=${date:5:2} M=${M#0}
crontab -l >/dev/null || echo -e "# m h dom mon dow  command\n" |crontab -
line="$m $h $D $M "'*'"  $repopath/stream '$name'"
echo -e "$(crontab -l)\n$line" |crontab -

Mail 0 "crontab: '$line'"