#!/bin/bash
#  $HeadURL$ $LastChangedRevision$

#  Modules
. $(miniade) || { echo "${0##*/}: ERROR: miniade failed (hint: run 'miniade' to see error)" >&2; exit 1; }

#  Configurable stuff

#  Other globals

main()
{
    local MY_ARGS
    #  Defaults for options

    #  Process options
    miniade_process_options --help-handler=help MY_ARGS "$@" && set -- "${MY_ARGS[@]}"

    #  Process arguments
    [ $# = 1 ] || miniade_bad_usage
    type encode > /dev/null 2>&1 || miniade_internal "encode: command not found (hint: is PATH set correctly?)"
    ENCODE_OUTPUT=$(encode --decode "$1") || miniade_internal "encode: failed (hint: see messages above)"
    eval set -- "$ENCODE_OUTPUT"
    [ $# -eq 3 ] || miniade_bad_usage
    SYMLINK="$1"
    TARGET="$2"
    MKDIR_FLAG="$3"
    miniade_debug 10 "main: SYMLINK=$SYMLINK, TARGET=$TARGET, MKDIR_FLAG=$MKDIR_FLAG"

    #  Sanity checks and derivations
    [[ $MKDIR_FLAG =~ ^(true|false)$ ]] || miniade_error "$MKDIR_FLAG: invalid value for MKDIR_FLAG"
    [[ $SYMLINK =~ ^/ ]] || miniade_error "$SYMLINK: not absolute"
    ! [[ $TARGET =~ ^/ ]] || miniade_error "$SYMLINK: not relative"

    #  Guts
    #  Symlink
    if [ ! -h $SYMLINK -a ! -e $SYMLINK ]; then
        ln -s $TARGET $SYMLINK
    elif { [ ! -h $SYMLINK -a -e $SYMLINK ]; }; then
        miniade_error "$SYMLINK: exists but is not a symlink (hint: fix this manually)"
    elif { [ -h $SYMLINK ] && [ $(readlink $SYMLINK) != $TARGET ]; }; then
        miniade_warning "$SYMLINK: exists and is a symlink but points to $(readlink $SYMLINK) instead of $TARGET; removing ..."
        rm -f $SYMLINK
        ln -s $TARGET $SYMLINK
    fi
    #  Mkdir
    if $MKDIR_FLAG; then
        ABSOLUTE_TARGET=$(realpath -m $SYMLINK)
        if [ ! -h $ABSOLUTE_TARGET -a ! -e $ABSOLUTE_TARGET ]; then
            mkdir -p $ABSOLUTE_TARGET
        elif [ -h $ABSOLUTE_TARGET -o \( -e $ABSOLUTE_TARGET -a ! -d $ABSOLUTE_TARGET \) ]; then
            miniade_error "$ABSOLUTE_TARGET: exists but is not a directory (hint: fix this manually)"
        fi
    else
        #  It'd be nice to do this "if link's targer doesn't exist then error" test before we even create the
        #  symlink, but $ABSOLUTE_TARGET depends on the realpath command and I suspect that that won't work
        #  in the above call unless $SYMLINK actually exists. But perhaps it would e..g:
        #
        #      lagane# realpath /etc/a             #  where /etc/a does not exist!
        #      /etc/a
        #      lagane#
        #
        #  Nonetheless, for the time being, we do it this way: undo the just created symlink
        #  and return an error.
        if [ ! -e $ABSOLUTE_TARGET ]; then
            rm -f $SYMLINK
            miniade_error "$ABSOLUTE_TARGET: does not exist and you didn't request me to create it (as a directory); symlink has been removed"
        fi
    fi
}

help()
{
    local PROGNAME

    miniade_get_progname PROGNAME
    echo "Usage: $PROGNAME [ <standard-options> ] <symlink>@<target>@<mkdir-flag"
    exit 0
}

main "$@"