#!/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)

# Check for oldest uploaded file
_=$(realpath -- "${BASH_SOURCE:-$0}") repopath=${_%/*}
log=$repopath/process.log dir=$repopath/uploadpage/streams
upload=$(/usr/bin/ls -1tr "$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:email,name,type,start,finish
	local sbj msg from="Stream Upload server"
	source "$repopath/mailvars"  # I:to,user,password,smtp,port
	[[ $email ]] && to=$email
	sbj[0]="Stream upload done for ${name##*@}"
	sbj[1]="Stream upload wrong type: $type"
	sbj[2]="Stream upload error encoding"
	msg[0]="Heya,\n\nVideo file 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"
	[[ $to && $user && $password && $smtp && $port ]] &&
		mailer -m "$(echo -e "${msg[$1]}")" -t "$to" -s "${sbj[$1]}" -u "$user" -p "$password" -S "$smtp" -P "$port" -f "$from" &&
		Log "Mail with subject '${sbj[$1]}' sent to $to" ||
		Log "Mail with subject '${sbj[$1]}' could not be sent"
	Log "$2" $1
}

# Rename upload and check type
file=${upload%.upload} video=$file.mp4 name=${file##*/} key=${name%%.*}
rest=${name#*.} date=${rest:0:15} _=${rest:15} email=${_%@*}
# If email embedded, strip the '='
[[ $email ]] && email=${email:1}
/usr/bin/mv "$upload" "$file"

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

# Encode video
start=$(date +'%Y-%m-%d at %H:%M') error=0
## Single pass
#/usr/bin/ffmpeg -y -i "$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 "$video" ||
# Double pass
/usr/bin/ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -maxrate 6M -bufsize 1M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 1 -f mp4 "$video" &&
	/usr/bin/ffmpeg -y -i "$file" -c:v libx264 -x264opts no-scenecut -b:v 6M -maxrate 6M -bufsize 1M -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart -c:a copy -tune zerolatency -pass 2 -f mp4 "$video" ||
	error=1

finish=$(date +'%Y-%m-%d at %H:%M')
((error)) && Mail 2 "Error encoding $name"

# 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}
/usr/bin/crontab -l ||
	echo -e "# m h dom mon dow  command\n" |/usr/bin/crontab -
line="$m $h $D $M "'*'"  $repopath/stream '$name'"
echo -e "$(/usr/bin/crontab -l)\n$line" |/usr/bin/crontab -

Mail 0 "crontab:  '$line'"