#!/bin/bash

#
# Copyright 2006 Ralf Mueller  ralf @ bj - ig . de
# 
# GPL v2
#
# Move vdr video files between different video disks
#
# Using this script only makes sense if you have more then one
# video directory for you vdr
#
# When stopping this script while moving data you may create
# lost files on the destination video directory - this should
# _not_ result in a lost recording but "only" in lost space! Have a look
# at you copy destination if you have to stop this script.
# 
# This script is provided as is - it may scare you pet, it may dry up
# plants, it may even clear your disk - you use it at your own risk. 
#

unset LANG
export LC_ALL=C

MIN_FREE=8000 # GB
VIDEO_DIR=/media/video0

#set -x

if [ "$1" == "" -o "$1" == "--help" ]; then
    echo "Usage:"
    echo "$(basename $0) <recording>"
    echo "    check consistency of links to other video disks for <recording>"
    echo
    echo "$(basename $0) <recording> <dstVideoDir>"
    echo "    move <recording> to <dstVideoDir>"
    echo
    echo "$(basename $0) <recording> <srcVideoDir> <dstVideoDir>"
    echo "    move <recording> from <srcVideoDir> to <dstVideoDir>"
    echo
    echo "<recording> may be a single recording or a complete recording tree"
    exit 0
fi

if [ '!' -d "$VIDEO_DIR" ]; then
    VIDEO_DIR=/media/video.0
fi
if [ '!' -d "$VIDEO_DIR" ]; then
    VIDEO_DIR=/video0
fi
if [ '!' -d "$VIDEO_DIR" ]; then
    VIDEO_DIR=/video.0
fi
if [ '!' -d "$VIDEO_DIR" ]; then
    echo "You may want to adapt the VIDEO_DIR variable on top of this script"
    exit 1
fi

IONICE=$(type -p ionice)

VIDEO_BASE=$(echo $VIDEO_DIR | sed 's/[0-9]*$//')

if [ "$TIME_REF" == "" -o '!' -r "$TIME_REF" ]; then
    export TIME_REF="/tmp/mvvideo-timeref.$$"
    touch "$TIME_REF"
    MY_TIME_REF="$TIME_REF"
    sleep 2
fi

if [ "$VIDEO_DIR" == "$VIDEO_BASE" ]; then
    echo "$VIDEO_DIR is not base of a distributed video directory" >/dev/stderr
    exit 1
fi

RECORDING="$1"
RECORDING="${RECORDING%/}"

if [ "${RECORDING#/}" == "$RECORDING" ]; then
    RECORDING="$(pwd)/$RECORDING"
fi

if [ '!' -d "$RECORDING" ]; then
    echo "'$RECORDING' is not a recording directory" >/dev/stderr
    exit 1
fi

absPath() {
    local DIR="$1"
    if [ -d "$DIR" ]; then
        (cd "$DIR"; pwd)
    else
        (cd $(dirname "$DIR"); pwd)
    fi
}

RECORDING_BASE=$(absPath "$RECORDING")
RECORDING_BASE="${RECORDING_BASE#$VIDEO_DIR}"
if [ "$RECORDING_BASE" == "$RECORDING" ]; then
    echo "The base of '$RECORDING' is not on '$VIDEO_DIR'" >/dev/stderr
    exit 1
fi
RECORDING_BASE="${RECORDING_BASE#/}"

if [ "${RECORDING%.rec}" == "$RECORDING" ]; then
    find "$RECORDING" -xtype d -name "*.rec" -exec "$0" "{}" "$2" "$3" \;
    exit 0
fi

P_DST_VIDEO_DIR="$2"
if [ "$3" != "" ]; then
    P_SRC_VIDEO_DIR="$2"
    P_SRC_VIDEO_DIR="${P_SRC_VIDEO_DIR%/}"
    P_DST_VIDEO_DIR="$3"
fi
P_DST_VIDEO_DIR="${P_DST_VIDEO_DIR%/}"

checkSize() {
    local DIR="$1"
    local MEDIA M_SIZE M_USE M_FREE M_PERCENT M_MOUNT

    read MEDIA M_SIZE M_USE M_FREE M_PERCENT M_MOUNT < <(df -kP -B1M "$DIR" | tail -1 )
    if [ "$M_FREE" -gt "$MIN_FREE" ]; then
#        echo "enough space left: $M_FREE"
        return 0
    fi
#    echo "not enough space left: $M_FREE"
    return 1
}

mvFile() {
    local RECORDING="$1"
    local SRC_FILE="$2"
    local DST_DIR="$3"

    local FILE_NAME="$(basename "$SRC_FILE")"
    if [ '!' -h "$DST_DIR/$FILE_NAME" -a -f "$DST_DIR/$FILE_NAME" ]; then
        echo "there already is a file called '$DST_DIR/$FILE_NAME'. bailing out." >/dev/stderr
        exit 1
    fi
    mkdir -p "$DST_DIR"
    if checkSize $DST_DIR; then
        if [ -x "$IONICE" ]; then 
            "$IONICE" -c3 mv "$SRC_FILE" "$DST_DIR"
        else
            mv "$SRC_FILE" "$DST_DIR"
        fi
        # remove old symbolic links
        if [ -h "$RECORDING/$FILE_NAME" ]; then
            rm "$RECORDING/$FILE_NAME"
        fi
        # don't create links if we moved the file to video0
        if [ '!' -r "$RECORDING/$FILE_NAME" ]; then
            ln -s "$DST_DIR/$FILE_NAME" "$RECORDING/$FILE_NAME"
        fi
        rmdir -p "$(dirname "$SRC_FILE")" 2>/dev/null
    else
        echo "not enough space on '$DST_DIR'" >/dev/stderr
        exit 1
    fi
}

i=1

echo "processing: $RECORDING_BASE" >/dev/stderr
while true; do
    REC="00$i"
    REC="${REC: -3:3}.vdr"

    if [ '!' -r "$RECORDING/$REC" ]; then
        if [ "$i" -le "1" -a '!' -r "$RECORDING/dvd.vdr" ]; then
            echo "no data in '$RECORDING'" >/dev/stderr
        fi
        exit 0
    fi
    if [ -h "$RECORDING/$REC" ]; then
        LINK="$(readlink "$RECORDING/$REC")"
        REC_DIR="${LINK%/[0-9][0-9][0-9].vdr}"
        REC_DIR="$(absPath "$REC_DIR")"
    else
        REC_DIR="$(absPath "$RECORDING")"
    fi
    REC_VIDEO_DIR=$(echo "$REC_DIR" | sed "s#^\\($VIDEO_BASE[0-9]*\\)/.*"#\\1#)

    if [ "${REC_VIDEO_DIR#$VIDEO_BASE}" == "$REC_VIDEO_DIR" ]; then
        echo "'$REC_DIR' is not on a valid video directory" >/dev/stderr
        exit 1
    fi

    if [ "$P_SRC_VIDEO_DIR" != "" -a "$P_SRC_VIDEO_DIR" != "$REC_VIDEO_DIR" ]; then
        i=$(( $i + 1 ))
        continue;
    fi

    if [ "$REC_DIR/$REC" -nt "$TIME_REF" ]; then
        echo "skipping active recording '$RECORDING'" > /dev/stderr
        i=$(( $i + 1 ))
        continue;
    fi

    REC_BASE=${REC_DIR#$REC_VIDEO_DIR/}

    if [ "$REC_BASE" != "$RECORDING_BASE" ]; then
        echo "reorder: mvFile '$REC_BASE/$REC' to '$RECORDING_BASE/$REC'"
        mvFile "$RECORDING" "$REC_DIR/$REC" "$REC_VIDEO_DIR/$RECORDING_BASE"
        continue;
    fi

    if [ "$P_DST_VIDEO_DIR" != "" ]; then
        if [ "${P_DST_VIDEO_DIR#$VIDEO_BASE}" != "$P_DST_VIDEO_DIR" ]; then
            DST_VIDEO_DIR="$P_DST_VIDEO_DIR"
        else
            echo "'$P_DST_VIDEO_DIR' is not a valid video directory" >/dev/stderr
            exit 1
        fi
    fi

    if [ "$DST_VIDEO_DIR" == "" ]; then
        DST_VIDEO_DIR="$REC_VIDEO_DIR"
    fi

    if [ "$DST_VIDEO_DIR" != "$REC_VIDEO_DIR" ]; then
        echo "new disk: mvFile '$REC_DIR/$REC' to '$DST_VIDEO_DIR'"
        mvFile "$RECORDING" "$REC_DIR/$REC" "$DST_VIDEO_DIR/$RECORDING_BASE"
    fi
    echo "done: $REC"
    i=$(( $i + 1 ))

    touch "$VIDEO_DIR/.update"
done

if [ "$MY_TIME_REF" != "" ]; then
    rm "$MY_TIME_REF"
fi