#!/mod/bin/jimsh

source /mod/webif/lib/setup
require lock system.class ts.class tdelete pretty_size browse.class \
    safe_delete settings.class

set loglevel [[settings] autolog]

if {![acquire_lock webif_auto]} {
	puts "Cannot acquire exclusive lock, terminating."
	exit
}

set logfile "/mod/tmp/auto.log"
# Rotate log file if large enough.
if {[file exists $logfile] && [file size $logfile] > 2097152} {
	file copy -force $logfile "/mod/tmp/auto_old.log"
	file delete $logfile
}

set logfd [open "/mod/tmp/auto.log" "a+"]
proc log {msg {level 1}} {
	if {$level > $::loglevel} return
	puts $::logfd "[\
	    clock format [clock seconds] -format "%d/%m/%Y %H:%M"\
	    ] - $msg"
	flush $::logfd
}

proc elapsed {start} {
	return $(([clock milliseconds] - $start) / 1000.0)
}

proc startclock {} {
	set ::startclock_s [clock milliseconds]
}

proc endclock {size} {
	set el [elapsed $::startclock_s]
	set rate $($size / $el)
	return "[pretty_size $size] in $el seconds - [pretty_size $rate]/s"
}

set scanstart [clock milliseconds]
log "-------------------------------------------------------"

# is_listening is relatively expensive so it is checked once globally at
# the start and then if the server is not listening then no decrypt
# operations will be attempted for this run, even if the server starts
# up halfway through. Otherwise the server is checked for every decryption
# and if it goes away then decryption will not be attempted for the rest
# of the run.
if {[system is_listening 9000]} {
	set dlnaok 1
	log "DLNA Server is running." 2
} else {
	set dlnaok 0
	log "DLNA Server is NOT running." 2
}

log "Media scan starting, DLNA server status: $dlnaok"

proc dsc {{size 0}} {
	set free [system diskfree]

	# Required disk space is 1GiB + 3 times the file size.
	set req $($size * 3 + 1073741824)

	if {$free < $req} {
		log "Insufficient disk space. Require=$req, Free=$free" 0
		exit
	}
}

dsc

set tmp "/mod/tmp/webif_auto"
if {![file exists $tmp]} {
	if {[catch {file mkdir $tmp} msg]} {
		log "Cannot create temporary directory - $tmp ($msg)" 0
		exit
	}
} elseif {![file isdirectory $tmp]} {
	log "Cannot create temporary directory - $tmp (file exists)" 0
	exit
}

# Clean-up the temporary directory
foreach file [readdir -nocomplain $tmp] { tdelete "$tmp/$file" }

if {[system pkginst undelete]} {
	set dustbin "[system dustbin]"
} else {
	set dustbin ""
}

log "Dustbin: $dustbin" 2

proc dedup {dir} {
	log "DEDUP: \[$dir]" 2
	loop i 0 1 {
		foreach line [split \
		    [exec /mod/webif/html/dedup/dedup -yes -auto $dir] "\n"] {
			log $line 2
		}
	}
}

proc do_expire {ts} {
	global ax_days
	set file [$ts get file]

	# Calculate the age of the file in days.
	set age $(([clock seconds] - [$ts get start]) / 86400.0)
	log "  EXPIRE: $file (age = $age)" 2

	if {$age > $ax_days} {
		if {[$ts inuse]} {
			log "     EXPIRE: $file ($age > $ax_days)"
			log "          In use."
			return
		}
		if {[safe_delete $file]} {
			log "     EXPIRE: $file ($age > $ax_days)" 0
			log "          Deleted." 0
		}
	}
}

proc do_shrink {ts} {
	global tmp dustbin tsgroup
	set file [$ts get file]

	if {[$ts flag "Shrunk"]} {
		log "  $file - already shrunk." 2
		return
	}

	set file [file rootname [$ts get file]]

	if {[$ts inuse]} {
		log "  $file - in use." 2
		return
	}

	if {[catch {
		set perc [exec /mod/bin/stripts -aq $file]
	    } msg]} {
		log "          Error: $msg" 0
		return
	}
	if {[string match {*%} $perc]} {
		set perc [string range $perc 0 end-1]
	} else {
		set perc 0
	}

	if {$perc == 0} {
		log "  $file - already shrunk." 2
		$ts set_shrunk
		return
	}
	set size [$ts size]
	dsc $size
	startclock
	log "  SHRINK: $file" 0
	log "          Estimate $perc% saving." 0
	log "          Shrinking..." 0
	if {[catch {
		foreach line [split \
		    [exec nice -n 19 /mod/bin/stripts -q $file $tmp/shrunk] \
		    "\n"] {
			log $line 0
		}
	    } msg]} {
		log "Error during shrink: $msg" 0
		return
	}

	# The following steps are structured to minimise the risk of
	# things being left in an inconsistent state if the system goes
	# into standby. Renames within the same filesystem are very
	# quick so the risk is small, but even so...

	# Move the shrunken version back to the local directory.
	foreach f [glob "$tmp/shrunk.*"] {
		set ext [file extension $f]
		file rename $f "${file}_shrunk${ext}"
	}

	# Remove the old recording (-> bin if undelete is installed)
	safe_delete [$ts get file] "webif_autoshrink"

	# Finally, rename the shrunken recording again.
	foreach ext $tsgroup {
		set f "${file}_shrunk.$ext"
		if {[file exists $f]} {
			file rename $f "${file}.$ext"
		}
	}
	$ts set_shrunk
	log "Done... [endclock $size]" 0
}

proc do_decrypt {ts} {
	global tmp dustbin

	set file [$ts get file]
	set rfile [file rootname $file]
	set bfile [file tail $file]

	if {![$ts flag "ODEncrypted"]} {
		log "  $file - Already decrypted." 2
		return
	}

	lassign [$ts dlnaloc "127.0.0.1"] url
	if {$url eq ""} {
		log "  $file - Not yet indexed."
		return
	}

	if {![system is_listening 9000]} {
		log "  $file - DLNA Server not running." 2
		set ::dlnaok 0
		return
	}

	if {[$ts inuse]} {
		log "  $file - In use."
		return
	}

	# Check that the file is not already decrypted by analysing it.
	set anencd [exec /mod/bin/stripts -qE $rfile]
	if {$anencd != "1"} {
		log "  $file - already decrypted but the HMT flag is wrong." 0
		system notify "$file - auto-decrypt - file is already decrypted but the HMT flag is wrong."
		return
	}

	# Perform the decryption by requesting the file from the DLNA server.
	set size [$ts size]
	dsc $size
	set flagfile "$tmp/decrypting.$bfile"
	exec /mod/bin/busybox/touch $flagfile
	startclock
	log "  DECRYPT: $rfile" 0
	log "  DLNA: $url" 0
	exec wget -O "$tmp/$bfile" $url

	if {[file size $file] != [file size "$tmp/$bfile"]} {
		log "  $file - File size mismatch." 0
		file delete "$tmp/$bfile"
		file delete $flagfile
		return
	}

	# Check if the file is in use. It is possible that the file is
	# now being played even though it was free when decryption started.
	if {[$ts inuse]} {
		log "  $file - In use."
		file delete "$tmp/$bfile"
		file delete $flagfile
		return
	}

	# Copy the HMT file over for stripts
	set thmt "$tmp/[file rootname $bfile].hmt"
	file copy "$rfile.hmt" $thmt
	# Check that the file is no longer encrypted by analysing it.
	set anencd [exec /mod/bin/stripts -qE "$tmp/[file rootname $bfile]"]
	file delete $thmt

	if {$anencd != "0"} {
		log "  $file - File did not decrypt properly." 0
		system notify "$file - auto-decrypt failed."
		file delete "$tmp/$bfile"
		file delete $flagfile
		return
	}

	# Move the encrypted file out of the way.
	file rename $file "$rfile.encrypted"
	# Move the decrypted copy into place.
	file rename "$tmp/$bfile" $file
	# Patch the HMT - quickest way to get back to a playable file.
	exec /mod/bin/hmt -encrypted "$rfile.hmt"

	log "  Removing/binning old copy." 0
	# Move the old recording to the bin if undelete is installed.
	if {$dustbin ne ""} {
		set bin [_del_bindir $file "webif_autodecrypt"]
		set tail [file tail $rfile]
		file rename "$rfile.encrypted" "$bin/$tail.ts"
		foreach ext {nts hmt thm} {
			if {[file exists "$rfile.$ext"]} {
				file copy $rfile.$ext "$bin/$tail.$ext"
				if {$ext eq "hmt"} {
					# Patch the binned HMT back
					exec /mod/bin/hmt +encrypted \
					    "$bin/$tail.hmt"
				}
			}
		}
	} else {
		tdelete "$rfile.encrypted"
	}
	log "Done... [endclock $size]" 0
	file delete $flagfile
}

proc do_mpg {ts} {
	global tmp tsgroup

	set file [file rootname [$ts get file]]

	if {[file exists $file.mpg]} {
		# Already done.
		return
	}

	if {[$ts flag "ODEncrypted"]} {
		log "  $file - Not decrypted." 2
		return
	}

	if {[$ts get definition] eq "HD"} {
		# Cannot extract a useful MPG from a HD recording.
		return
	}

	if {[$ts inuse]} {
		log "  $file - In use."
		return
	}
	dsc [$ts size]

	log "     MPG: $file" 0
	log "          Converting..." 0
	if {[catch {
		foreach line [split \
		    [exec nice -n 19 /mod/bin/ffmpeg -y -benchmark -v 0 \
		    -i $file.ts \
		    -map 0:0 -map 0:1 \
		    -vcodec copy -acodec copy $tmp/mpg.mpg] "\n"] {
			log $line 0
		}
	    } msg]} {
		log "Error during mpg extract: $msg" 0
		return
	}

	# Move the MPG into the local directory
	file rename $tmp/mpg.mpg $file.mpg
}

proc do_mp3 {ts} {
	global tmp tsgroup

	set file [file rootname [$ts get file]]

	if {[file exists $file.mp3]} {
		# Already done.
		return
	}

	if {[$ts flag "ODEncrypted"]} {
		log "  $file - Not decrypted." 2
		return
	}

	if {[$ts get definition] eq "HD"} {
		# Cannot extract a useful MP3 from a HD recording.
		log "  $file - High definition." 2
		return
	}

	if {[$ts inuse]} {
		log "  $file - In use."
		return
	}
	dsc [$ts size]

	log "     MP3: $file" 0
	log "          Converting..." 0
	if {[catch {
		foreach line [split \
		    [exec nice -n 19 /mod/bin/ffmpeg -y -benchmark -v 0 \
		    -i $file.ts \
		    -f mp3 -vn -acodec copy $tmp/mp3.mp3] "\n"] {
			log $line 0
		}
	    } msg]} {
		log "Error during mp3 extract: $msg" 0
		return
	}

	if {[system pkginst id3v2]} {
		log [exec /mod/bin/id3v2 \
		    --song "[$ts get title]" \
		    --comment "[$ts get synopsis]" \
		    --album "[$ts get channel_name]" \
		    --year "[clock format [$ts get start] -format {%Y}]" \
		    "$tmp/mp3.mp3"] 0
	}

	# Move the MP3 into the local directory
	file rename $tmp/mp3.mp3 $file.mp3
}

proc entries {dir callback} {
	foreach entry [readdir -nocomplain $dir] {
		if {![string match {*.ts} $entry} continue
		if {[catch {set ts [ts fetch "$dir/$entry"]}]} continue
		if {$ts == 0} continue
		$callback $ts
	}
}

proc shrink {dir} {
	log "SHRINK: \[$dir]" 2
	entries $dir do_shrink
}

proc decrypt {dir} {
	log "DECRYPT: \[$dir]" 2
	if {$::dlnaok} { entries $dir do_decrypt }
}

proc mpg {dir} {
	log "MPG: \[$dir]" 2
	entries $dir do_mpg
}

proc mp3 {dir} {
	log "MP3: \[$dir]" 2
	entries $dir do_mp3
}

proc expire {dir} {
	global ax_days
	log "EXPIRE: \[$dir]" 2
	
	set ax_days [{dir expiry} $dir]
	entries $dir do_expire
}

proc scan {dir attr {force 0}} {{indent 0}} {
	global dustbin

	incr indent 2

	log "[string repeat " " $indent]\[$dir]" 2

	if {$dir eq $dustbin} {
		log "Dustbin, skipping." 2
		return
	}

	if {[string match {\[*} [file tail $dir]]} {
		# Special folder
		file stat "$dir/" st
		if {$st(dev) != $::rootdev} {
			log "Special folder on different device, skipping." 2
			return
		}
		if {$force} {
			set force 0
			log "Special folder, overriding recursion." 2
		}
	}

	# Recursion
	if {!$force && [file exists "$dir/.auto${attr}r"]} {
		log "[string repeat " " $indent]  (R)" 2
		set force 1
	}

	dsc

	if {$force || [file exists "$dir/.auto$attr"]} { $attr $dir }

	foreach entry [readdir -nocomplain $dir] {
		if {[file isdirectory "$dir/$entry"]} {
			scan "$dir/$entry" $attr $force
		}
	}

	incr indent -2
}

set root [system mediaroot]
file stat "$root/" rootstat
set rootdev $rootstat(dev)
log "Root device: $rootdev" 2

if {[llength $argv] > 0} {
	set loglevel 2
	foreach arg $argv { scan $root $arg }
} else {
	foreach arg {dedup decrypt shrink mpg mp3 expire} {
		set st [clock milliseconds]
		scan $root $arg
		log "$arg scan completed in [elapsed $st] seconds."
	}
}

release_lock webif_auto

log "Media scan completed in [elapsed $scanstart] seconds."