#!/bin/bash
#  $HeadURL$ $LastChangedRevision$
set -e
{ [[ $0 =~ ^/ ]] && PROGNAME_FULL=$0; } || PROGNAME_FULL=$(cd $PWD/$(dirname $0) && pwd)/$(basename $0)
PROGNAME=$(basename $0)
#PROGNAME=${PROGNAME_FULL//\//_}

#  MODROOT
MODROOT=${MDI_MODROOT:-$(while [ ! -d lib/helpers -a $PWD != / ]; do cd ..; done; echo $PWD)}
[ -d $MODROOT/lib/helpers ] || { echo "$PROGNAME: ERROR: can't find components (do you need to set 'MDI_MODROOT'?)" >&2; exit 1; }

#  Load config and support functions
. $MODROOT/include/mdi.sh
. $MODROOT/etc/mdi.sh

#  Globals

main()
{
    #  Defaults for options
    VERBOSELEVEL=2
    HELPER_HOOKS_FILE=$PROGNAME_FULL-hooks
    DISPLAY_PROGNAME=$(basename $(dirname $PROGNAME_FULL))
    RECURSE_FLAG=true

    #  Process options
    while [ "X$1" != X ]; do
        case $1 in
            #  Application-specific options
            --helper-hooks=*)      HELPER_HOOKS_FILE=${1#*=} ;;
            --progname=*)          DISPLAY_PROGNAME=${1#*=} ;;
            --recurse=*)           RECURSE_FLAG=${1#*=} ;;
            #  General options
            -v|--verbose)          VERBOSELEVEL=3 ;;
            -d)                    VERBOSELEVEL=$2; shift ;;
            --debug=*)             VERBOSELEVEL=${1#*=} ;;
            -h|--help)             usage 0 ;;
            --)                    shift; break ;;
            -*)                    usage ;;
            *)                     break ;;
        esac
        shift
    done

    #  Process arguments
    [ $# -ge 1 ] || usage
    MODE=$1; shift
    debug 10 "main: MODE=$MODE"
    case $MODE in
        edit|create|delete|list|purge|init) : ;;
        *)                                  usage ;;
    esac

    #  Sanity checks and derivations
    debug 10 "main: sanity checks ..."
    [ $RECURSE_FLAG = true -o $RECURSE_FLAG = false ] || usage
    debug 10 "main: calling [. $HELPER_HOOKS_FILE] ..."
    . $HELPER_HOOKS_FILE
    debug 10 "main: after call"
    inherit MY_ID MY_ATTRIBUTES PARENT_ID

    #  Delegate
    debug 10 "main: delegating ..."
    $MODE "$@"

    return 0
}

init()
{
    local HELPER CMDLINE
    inherit MY_HELPER_IDS MY_ID MY_PRIVATE_ATTRIBUTES MY_PUBLIC_ATTRIBUTES PARENT_ID

    #  Process arguments
    [ $# = 0 ] || usage

    #  Sanity checks and derivations

    #  Guts
    info "initialising ..."
    debug 10 "init: calling init_prologue() ..."
    init_prologue || return $?
    debug 10 "init: registering helper ..."
    $SQLITE_CMD $DB_FILE "insert into helpers (helper, parent_helper) values ('$MY_ID', '$PARENT_ID');"
    debug 10 "init: registering attributes ..."
    for ATTRIBUTE in $MY_PRIVATE_ATTRIBUTES; do
        $SQLITE_CMD $DB_FILE "insert into attributes (helper, attribute, public) values ('$MY_ID', '$ATTRIBUTE', 0);"
    done
    for ATTRIBUTE in $MY_PUBLIC_ATTRIBUTES; do
        $SQLITE_CMD $DB_FILE "insert into attributes (helper, attribute, public) values ('$MY_ID', '$ATTRIBUTE', 1);"
    done
    if [ $RECURSE_FLAG = true ]; then
        for HELPER in $MY_HELPER_IDS; do
            ( cd $HELPER && ./helper --progname=$DISPLAY_PROGNAME/$HELPER --debug=$VERBOSELEVEL init ) || return $?
        done
    fi
    debug 10 "init: calling init_epilogue() ..."
    init_epilogue || return $?

    return 0
}

init_prologue()
{
   return 0
}

init_epilogue()
{
   return 0
}

list()
{
    local HELPER
    inherit RECURSE_FLAG MY_HELPER_IDS

    #  Process arguments
    [ $# = 0 ] || usage
    debug 10 "list: "

    #  Sanity checks and derivations

    #  Guts
    debug 10 "list: calling list_prologue() ..."
    list_prologue || return $?
    if [ $RECURSE_FLAG = true ]; then
        for HELPER in $MY_HELPER_IDS; do
            debug 10 "list: calling $HELPER helper ..."
            ( cd $HELPER && ./helper --progname=$DISPLAY_PROGNAME/$HELPER --debug=$VERBOSELEVEL list ) || return $?
        done
    fi

    return 0
}

#  Stupid hook to dump the table.
list_prologue()
{
    inherit SQLITE_CMD DB_FILE MY_ID MY_ATTRIBUTES

    printf "%${#MY_ID}.${#MY_ID}s\n" "$MY_ID"
    printf "%${#MY_ID}.${#MY_ID}s\n" "==================================="
    echo
    $SQLITE_CMD $DB_FILE "select uname from attribute_values where helper == '$MY_ID' and attribute == 'status' and value == 'installing';"
    echo

    return 0
}

edit()
{
    #  arguments
    local UNAME
    #  my properties
    inherit MY_ID MY_HELPER_IDS MY_ATTRIBUTES
    #  globals
    inherit RECURSE_FLAG 
    #  real locals
    local HELPER

    #  Process arguments
    [ $# = 1 ] || usage
    UNAME=$1; shift
    debug 10 "edit: UNAME=$UNAME"

    #  Sanity checks and derivations

    #  Guts
    info "editing settings ..."
    debug 10 "edit: loading local (public and private) attribute values ..."
    load_local_attributes $MY_ID $UNAME "$MY_ATTRIBUTES"
    debug 10 "edit: loading inherited attribute names ..."
    MY_INHERITED_ATTRIBUTES=$(list_inherited_attributes $MY_ID)
    debug 10 "edit: MY_INHERITED_ATTRIBUTES=\"$MY_INHERITED_ATTRIBUTES\""
    if [ "X$MY_INHERITED_ATTRIBUTES" != X ]; then
        local ${MY_INHERITED_ATTRIBUTES^^}
        debug 10 "edit: loading inherited attribute values ..."
        load_inherited_attributes $MY_ID $UNAME "$MY_INHERITED_ATTRIBUTES"
    fi
    debug 10 "edit: setting any of my attributes that are blank to a default ..."
    for ATTRIBUTE in $MY_ATTRIBUTES; do
        eval "[ \"X\$${ATTRIBUTE^^}\" != X ] || ${ATTRIBUTE^^}=\"\$DFLT_${ATTRIBUTE^^}\""
    done

    #  Guts
    debug 10 "edit: calling edit_prologue() ..."
    edit_prologue || return $?
    STATUS="not installing"
    debug 10 "edit: saving new values ..."
    debug 10 "edit: UNAME=$UNAME"
    save_local_attributes $MY_ID $UNAME "$MY_ATTRIBUTES"
    if [ $RECURSE_FLAG = true ]; then
        for HELPER in $MY_HELPER_IDS; do
            debug 10 "edit: calling $HELPER helper ..."
            ( cd $HELPER && ./helper --progname=$DISPLAY_PROGNAME/$HELPER --debug=$VERBOSELEVEL edit $UNAME ) || return $?
        done
    fi

    return 0
}

edit_prologue()
{
    return 0
}

create()
{
    #  locals for parameters
    local UNAME 
    #  my properties
    inherit MY_HELPER_IDS MY_ID MY_ATTRIBUTES
    #  globals
    inherit RECURSE_FLAG 
    #  locals
    local HELPER COUNT MY_INHERITED_ATTRIBUTES

    #  Process arguments
    [ $# = 1 ] || usage
    UNAME=$1; shift
    debug 10 "create: UNAME=$UNAME, MY_ID=$MY_ID"

    #  Sanity checks and derivations
    debug 10 "create: loading local (public and private) attribute values ..."
    load_local_attributes $MY_ID $UNAME "$MY_ATTRIBUTES"
    debug 10 "create: loading inherited attribute values ..."
    MY_INHERITED_ATTRIBUTES=$(list_inherited_attributes $MY_ID)
    if [ "X$MY_INHERITED_ATTRIBUTES" != X ]; then
        local ${MY_INHERITED_ATTRIBUTES^^}
        debug 10 "edit: loading inherited attribute values ..."
        load_inherited_attributes $MY_ID $UNAME "$MY_INHERITED_ATTRIBUTES"
    fi
    if [ "X$STATUS" = X ]; then
        error "$UNAME: no config found (do you need to run 'mdi edit $UNAME'?)"
        return 1
    elif [ "X$STATUS" = Xinstalling ]; then
        error "$UNAME: appears to be being installed already"
        return 1
    elif [ "X$STATUS" = "Xnot installing" ]; then
        :
    else
        internal "create: $STATUS: invalid status"
    fi
    #  Guts

    debug 10 "create: marking installing ..."
    $SQLITE_CMD $DB_FILE "update attribute_values set value = 'installing' where helper == '$MY_ID' and attribute == 'status' and uname == '$UNAME';"

    #  From here on, if anything goes wrong then we call the delete() function to handler it.
    debug 10 "create: calling create_prologue() ..."
    create_prologue || { 
        RC=$?
        delete $UNAME || internal "create: create_prologue() failed, we tried to rollback by calling delete() but that failed too!"
        return $RC
    }
    #  create_prologue() may change MY_HELPER_IDS
    debug 10 "create: after calling create_prologue(), MY_HELPER_IDS=\"$MY_HELPER_IDS\""

    if [ $RECURSE_FLAG = true ]; then
        RC=0
        SUCCESSFULLY_COMPLETED_HELPERS=()
        for HELPER in $MY_HELPER_IDS; do
            debug 10 "create: calling sub-helper $HELPER ..."
            ( cd $HELPER && ./helper --progname=$DISPLAY_PROGNAME/$HELPER --debug=$VERBOSELEVEL create $UNAME ) || {
                RC=$?
                delete $UNAME || internal "create: sub-helper $HELPER failed, we tried to rollback by calling delete() but that failed too!"
                return $RC
            }
        done
    fi

    debug 10 "create: calling create_epilogue() ..."
    create_epilogue || {
        RC=$?
        delete $UNAME || internal "create: create_epilogue() failed, we tried to rollback by calling delete() but that failed too!"
        return $RC
    }
    #  No counterpart to lock code above.

    return 0
}    

create_prologue()
{
    return 0
}

create_epilogue()
{
    return 0
}

delete()
{
    #  arguments
    local UNAME 
    #  my properties
    inherit MY_HELPER_IDS MY_ID
    #  globals
    inherit RECURSE_FLAG 
    #  real locals
    local HELPER 

    #  Process arguments
    [ $# = 1 ] || usage
    UNAME=$1; shift
    debug 10 "delete: UNAME=$UNAME, MY_ID=$MY_ID"

    delete_or_purge delete $UNAME
}

purge()
{
    #  arguments
    local UNAME 
    #  my properties
    inherit MY_HELPER_IDS MY_ID
    #  globals
    inherit RECURSE_FLAG 
    #  real locals
    local HELPER 

    #  Process arguments
    [ $# = 1 ] || usage
    UNAME=$1; shift
    debug 10 "purge: UNAME=$UNAME, MY_ID=$MY_ID"

    delete_or_purge purge $UNAME
}

delete_or_purge()
{
    #  arguments
    local UNAME 
    #  my properties
    inherit MY_HELPER_IDS MY_ID
    #  globals
    inherit RECURSE_FLAG 
    #  real locals
    local MODE HELPER 

    #  Process arguments
    [ $# = 2 ] || usage
    MODE=$1; shift
    UNAME=$1; shift
    debug 10 "delete_or_purge: MODE=$MODE, UNAME=$UNAME, MY_ID=$MY_ID"

    #  Sanity checks and derivations
    debug 10 "delete_or_purge: loading local (public and private) attribute values ..."
    load_local_attributes $MY_ID $UNAME "$MY_ATTRIBUTES"
    debug 10 "delete_or_purge: loading inherited attribute values ..."
    MY_INHERITED_ATTRIBUTES=$(list_inherited_attributes $MY_ID)
    if [ "X$MY_INHERITED_ATTRIBUTES" != X ]; then
        local ${MY_INHERITED_ATTRIBUTES^^}
        debug 10 "edit: loading inherited attribute values ..."
        load_inherited_attributes $MY_ID $UNAME "$MY_INHERITED_ATTRIBUTES"
    fi
    if [ $MODE = delete ];then
        if [ "X$STATUS" = X ]; then
            return 0
        elif [ "X$STATUS" = Xinstalling ]; then
            :
        elif [ "X$STATUS" = "Xnot installing" ]; then
            return 0
        else
            internal "delete_or_purge: $STATUS: invalid status"
        fi
    fi
    
    #  Guts
    debug 10 "delete_or_purge: calling delete_prologue() ..."
    delete_prologue || internal "delete_or_purge: delete_prologue() failed; it is illegal for any delete operation to fail!"
    debug 10 "delete_or_purge: after calling delete_prologue(), MY_HELPER_IDS=\"$MY_HELPER_IDS\""

    if [ $RECURSE_FLAG = true ]; then
        for HELPER in $(echo $MY_HELPER_IDS | xargs -n 1 echo | tac | xargs echo); do
            debug 10 "delete_or_purge: calling $HELPER helper ..."
            ( cd $HELPER && ./helper --progname=$DISPLAY_PROGNAME/$HELPER --debug=$VERBOSELEVEL $MODE $UNAME ) || {
                internal "delete_or_purge: sub-helper $HELPER failed; it is illegal for any delete operation to fail!"
            }
        done
    fi

    debug 10 "delete_or_purge: calling delete_epilogue() ..."
    delete_epilogue || internal "delete_or_purge: delete_epilogue() failed; it is illegal for any delete operation to fail!"

    debug 10 "delete_or_purge: marking not installing ..."
    $SQLITE_CMD $DB_FILE "update attribute_values set value = 'not installing' where helper == '$MY_ID' and attribute == 'status' and uname == '$UNAME';"

    return 0
}    

delete_prologue()
{
    return 0
}

delete_epilogue()
{
    return 0
}

usage()
{
    local RC

    RC=${1:-1}

    {
        echo "Usage:   $DISPLAY_PROGNAME [ <options> ] { edit <host> | create <host> | delete <host> | purge | init | list }"
        echo
    } | if [ $RC = 0 ]; then
        cat
    else
        cat >&2
    fi

    exit $RC
}

main "$@"