#!/bin/sh
#
# %CopyrightBegin%
#
# Copyright Ericsson AB 2010. All Rights Reserved.
#
# The contents of this file are subject to the Erlang Public License,
# Version 1.1, (the "License"); you may not use this file except in
# compliance with the License. You should have received a copy of the
# Erlang Public License along with this software. If not, it can be
# retrieved online at http://www.erlang.org/.
#
# Software distributed under the License is distributed on an "AS IS"
# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
# the License for the specific language governing rights and limitations
# under the License.
#
# %CopyrightEnd%
#
# Author: Rickard Green
#

#
# NOTE! This script needs to be portable since it is run on all platforms
# (besides win32). Keep this in mind when updating it.
#

## set `INST_BIN_DEBUG=true' in environment when debugging the script to
## avoid removing, and creating stuff etc...

##
## We do not reset these variables, since values may be passed either via
## environment, or command line arguments.
##
#bindir=
#exec_prefix=
#erlang_bindir=
#DESTDIR=
#EXTRA_PREFIX=
#BINDIR_SYMLINKS=
#LN_S=
tst=

#
# When this script communicates with the user it talks of the parameters
# as they are given to configure if such exist (currently --bindir, and
# --exec-prefix); otherwise, as the variable names used in the top
# Makefile (which calls this script).
#

path_variables="DESTDIR EXTRA_PREFIX exec_prefix bindir erlang_bindir"
DQ=

dbg=
test "$INST_BIN_DEBUG" != "true" || dbg=true

while [ $# -gt 1 ]; do
    case "$1" in
	--bindir) bindir="$2";;
	--exec-prefix) exec_prefix="$2";;
	--erlang-bindir) erlang_bindir="$2";;
	--destdir) DESTDIR="$2";;
	--extra-prefix) EXTRA_PREFIX="$2";;
	--bindir-symlinks) BINDIR_SYMLINKS="$2";;
	--ln_s) LN_S="$2";;
	--test-file) tst="$2";;
	*) break;;
    esac
    shift
    shift
done


test $# -gt 0 || {
    echo " ERROR: Missing files to install" 1>&2
    test "$tst" = "" || echo "{error,{arg,missing_files}}." > $tst
    exit 1;
}
test "$bindir" != "" || {
    echo " ERROR: Missing --bindir" 1>&2
    test "$tst" = "" || echo "{error,{arg,missing_bindir}}." > $tst
    exit 1
}
test "$exec_prefix" != "" || {
    echo " ERROR: Missing --exec-prefix" 1>&2
    test "$tst" = "" || echo "{error,{arg,missing_exec_prefix}}." > $tst
    exit 1
}
test "$erlang_bindir" != "" || {
    echo " ERROR: Missing erlang_bindir" 1>&2
    test "$tst" = "" || echo "{error,{arg,missing_erlang_bindir}}." > $tst
    exit 1
}

# Make sure all paths are absolute
for dir_var in $path_variables; do
    eval "dir_path=\"\$$dir_var\""

    case "$dir_path" in
	/*) ;;
	"")
	    # Empty DESTDIR or EXTRA_PREFIX which is ok
	    case $dir_var in
		DESTDIR|EXTRA_PREFIX) ;;
		*)
		    echo " ERROR: Internal error: \$$dir_var is empty" 1>&2
		    test "$tst" = "" || echo "{error,{empty,$dir_var}}." > $tst
		    exit 1;;
	    esac
	    continue;;
	*)
	    case $dir_var in
		bindir) flag="--bindir=";;
		exec_prefix) flag="--exec-prefix=";;
		erlang_bindir) flag="erlang_bindir=";;
		DESTDIR) flag="DESTDIR=";;
		EXTRA_PREFIX) flag="EXTRA_PREFIX=";;
		*) flag="";; # Need to update the script...
	    esac
	    cat 1>&2 <<EOF
 ERROR: Found path to a directory which was not absolute. All paths needs to
        be absolute.

        $flag"$dir_path"
EOF
	    test "$tst" = "" || echo "{error,{not_abs,'$dir_var'}}." > $tst
	    exit 1;;
    esac
    case "$dir_path" in
	*[!A-Za-z0-9/=_.-]*) DQ="\"";;
	*) ;;
    esac
done

# We place temporary check files in the source dir and the target dir. These
# can later be used to verify that our modifications of the paths are
# successful.

test "$dbg" = "true" || {
    bchk_file="tmp-erlang-install-bin.$$"
    ebchk_file="tmp-erlang-install-erl-bin.$$"
    bchk="$DESTDIR$EXTRA_PREFIX$bindir/$bchk_file"
    ebchk="$DESTDIR$EXTRA_PREFIX$erlang_bindir/$ebchk_file"
    chk_txt="Temporary Erlang/OTP install file."
    chk_err=no

    # Make sure we haven't got any old ones...
    rm -f "$bchk" "$ebchk"

    { { echo "$chk_txt" > "$ebchk"; } 2>/dev/null && test -r "$ebchk"; } || {
	cat 1>&2 <<EOF
  ERROR: Cannot create files in 'erlang_bindir'.

EOF
	chk_err=no_create_erlang_bindir
    }

    { { echo "$chk_txt" > "$bchk"; } 2>/dev/null && test -r "$bchk"; } || {
	cat 1>&2 <<EOF
 ERROR: Cannot create files in '--bindir'.

EOF
	chk_err=no_create_bindir
    }


    { test $chk_err != no ||
	test ! -f "$DESTDIR$EXTRA_PREFIX$bindir/$ebchk_file"; } || {
	# Refuse to install in the same directory as the source...
	cat 1>&2 <<EOF
 ERROR: '--bindir' and 'erlang_bindir' both points to the same directory. This
        can be due to symbolic directory links.

EOF
	chk_err=target_and_source_same_dir
    }

    test $chk_err = no || {
	cat 1>&2 <<EOF
         --bindir="$bindir"
         erlang_bindir="$erlang_bindir"
         EXTRA_PREFIX="$EXTRA_PREFIX"
         DESTDIR="$DESTDIR"

         Note that all absolute directory paths are prefixed by
         \$DESTDIR\$EXTRA_PREFIX when accessed.
EOF
	rm -f "$bchk" "$ebchk"
	test "$tst" = "" || echo "{error,$chk_err}." > $tst
	exit 1
    }
}

dirty=no

# Make all paths look good (remove all `.' dirs, `//', and trailing `/').
for dir_var in $path_variables; do
    eval "dir_path=\"\$$dir_var\""
    test "$dir_path" != "" || continue

    ndp=
    save_IFS=$IFS
    IFS=/
    for dir in $dir_path; do
	case "$dir" in
	    "" | ".") continue;;
	    "..")
		case $dir_var in
		    bindir|erlang_bindir|exec_prefix) dirty=yes;;
		    *) ;;
		esac;;
	    *) ;;
	esac
	ndp="$ndp/$dir"
    done
    IFS=$save_IFS
    test "$ndp" != "" || ndp="/"
    eval "$dir_var=\"$ndp\""
done

iprfx="$DESTDIR$EXTRA_PREFIX"

# Make sure we didn't mess up
{   $dbg test -f "$iprfx$bindir/$bchk_file" &&
    $dbg test -f "$iprfx$erlang_bindir/$ebchk_file"; } || {
    cat 1>&2 <<EOF
 ERROR: Internal error: Unsuccessfully trimmed the paths

        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
EOF
    $dbg rm -f "$bchk" "$ebchk"
    test "$tst" = "" || echo "{error,bad_trim}." > $tst
    exit 1
}

# Now all paths look good...


# $ln_s should be either 'ln -s', 'ln', or 'cp -p'. We don't want to
# maks hard links, so make sure we got 'ln -s'; otherwise, use 'cp -p'

# This is the fallback if we haven't got 'ln -s'
ln_s="cp -p"
type=copy
paths=absolute
abspath_reason=no_ln_s
src_dir="$iprfx$erlang_bindir"

case "X${LN_S}X" in
    Xln[\ \	]*X|X*[\ \	]ln[\ \	]*X)
	# Got `ln'; check that we also got `-s' flag
	case "X${LN_S}X" in
	    X*[\ \	]-sX|X*[\ \	]-s[\ \	]*X)
		# Ok; seems like we got `ln -s'
		ln_s="ln -s"
		type=link
		paths="$BINDIR_SYMLINKS"
		test "$BINDIR_SYMLINKS" = "absolute" && abspath_reason=request
		# $DESTDIR should *not* be part of src_dir when linking
		src_dir="$EXTRA_PREFIX$erlang_bindir"
		;;
	    *) ;;
	esac;;
	*) ;;
esac

case "$paths" in
    absolute|relative) ;;
    *) paths=undetermined;;
esac

# Determine if we should use absolute or relative paths for links
test $paths != absolute && {
    # If $paths is undetermined, use absolute paths unless both $bindir
    # and $erlang_bindir are prefixed by $exec_prefix (which is the normal
    # case)
    test $paths = relative || paths=absolute
    abspath_reason=not_prefix
    resolved_bindir="$bindir"
    resolved_erlang_bindir="$erlang_bindir"
    resolved_exec_prefix="$exec_prefix"
    case "$bindir" in
	"$exec_prefix"*)
	    case "$erlang_bindir" in
		"$exec_prefix"*) paths=relative;;
		*) ;;
	    esac;;
	*);;
    esac
    # Now paths=absolute|relative

    # If we got dirty paths (contains ..) and are going for relative links,
    # we need to resolve the paths
    test $dirty-$paths = yes-relative && {
	# Need to resolve $bindir and $erlang_bindir paths
	for dir_var in bindir erlang_bindir exec_prefix; do
	    eval "dir_path=\"\$$dir_var\""

	    ndp="/"
	    save_IFS=$IFS
	    IFS=/
	    for dir in $dir_path; do
		case "$dir" in
		    "") ;;
		    "..")
			test "$ndp" != "/" || {
			    IFS=$save_IFS
			    paths=absolute
			    abspath_reason=unreasonable_path
			    break 2
			}
			ndp=`dirname "$ndp" 2>/dev/null` || {
			    IFS=$save_IFS
			    paths=absolute
			    abspath_reason=dirname_failed
			    break 2
			};;
		    *)
			if test "$ndp" = "/"; then
			    ndp="/$dir"
			else
			    ndp="$ndp/$dir"
			fi;;
		    esac
	    done
	    IFS=$save_IFS
	    test "$ndp" != "" || ndp="/"
	    eval "resolved_$dir_var=\"$ndp\""
	done
    }

    # If we still are going for relative and relative symbolic links have
    # not been explicitly requested check that the resolved paths still
    # are prefixed by exec_prefix
    test $paths = relative && test "$BINDIR_SYMLINKS" != "relative" && {
	paths=absolute
	abspath_reason=not_prefix
	case "$resolved_bindir" in
	    "$resolved_exec_prefix"*)
		case "$resolved_erlang_bindir" in
		    "$resolved_exec_prefix"*)
			paths=relative;;
		    *) ;;
		esac;;
	    *) ;;
	esac
    }

    # If we still are going for relative check that resolved paths are
    # reachable (might not be if the directory structure contains symbolic
    # directory links).
    test $paths = relative && {
	($dbg test -r "$iprfx$resolved_bindir/$bchk_file" &&
	    $dbg test -r "$iprfx$resolved_erlang_bindir/$ebchk_file" &&
	    $dbg cd "$iprfx$resolved_bindir" &&
	    $dbg test -r "./$bchk_file" &&
	    $dbg cd "$iprfx$resolved_erlang_bindir" &&
	    $dbg test -r "./$ebchk_file") || {
	    paths=absolute
	    abspath_reason=unreachable_absolute
	}
    }


    # If we still are going for relative, calculate the relative path from
    # $resolved_bindir to $resolved_erlang_bindir and verify that we
    # can reach $erlang_bindir from $bindir via calculated relative path
    test $paths = relative && {
	relpath=
	common=

	save_IFS=$IFS
	IFS=/

	build=false
	for dir in $resolved_erlang_bindir; do
	    test "$dir" != "" || continue
	    test $build = false || { relpath="$relpath/$dir"; continue; }
	    cand="${common}/$dir"
	    case "$resolved_bindir" in
		"$cand"*) common="$cand";;
		*) relpath="$dir"; build=true;;
	    esac
	done

	check=
	build=false
	test "$common" != "" || build=true

	for dir in $resolved_bindir; do
	    test "$dir" != "" || continue
	    test $build = true || {
		check="${check}/$dir"
		test "$check" != "$common" || build=true
		continue
	    }
	    if test "$relpath" = ""; then
		relpath=".."
	    else
		relpath="../$relpath"
	    fi
	done

	IFS=$save_IFS

	test "$relpath" != "" || {
	    cat 1>&2 <<EOF
 ERROR: Internal error: Computed relative path: .

        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
        BINDIR_SYMLINKS="$BINDIR_SYMLINKS"
EOF
	    $dbg rm -f "$bchk" "$ebchk"
	    test "$tst" = "" || echo "{error,empty_relpath}." > $tst
	    exit 1
	}

	# Verify that it works otherwise go for absolute links
	if ($dbg cd "$iprfx$bindir" 2>/dev/null && \
	    $dbg test -r "$relpath/$ebchk_file"); then
	    src_dir="$relpath"
	else
	    abspath_reason=unreachable_relative
	    paths=absolute
	fi
    }
}

# Don't need the temporary check files anymore
$dbg rm -f "$bchk" "$ebchk"

# If we reverted to absolute paths we may have to abort or notify the user
# about this...
case "$paths-$BINDIR_SYMLINKS" in
    absolute-absolute)  # User requested absolute and got it
	case "$abspath_reason" in
	    no_ln_s)
		cat <<EOF
 ERROR: Cannot install absolute symbolic links in the '--bindir' directory,
        since 'ln -s' does not work. If you want to install using 'cp -p'
        invoke 'make install' without setting BINDIR_SYMLINKS.

        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
        BINDIR_SYMLINKS="$BINDIR_SYMLINKS"

        Note that all absolute directory paths are prefixed by
        \$DESTDIR\$EXTRA_PREFIX when accessed.
EOF
		test "$tst" = "" || echo "{error,$abspath_reason}." > $tst
		exit 1;; # Abort...
	    *)
		;;
	esac;;

    absolute-relative)  # User forced relative symbolic links, but we need
			# to revert to absolute symbolic links. Print error
			# message and abort.

	case "$abspath_reason" in
	    no_ln_s)
		cat 1>&2 <<EOF
 ERROR: Cannot install relative symbolic links in the '--bindir' directory,
        since 'ln -s' does not work. If you want to install using 'cp -p' do
        not set BINDIR_SYMLINKS, and invoke 'make install' again.

EOF
		;;
	    not_prefix)
		cat 1>&2 <<EOF
 ERROR: Internal error: Should not have reverted to absolute paths just
        because '--exec-prefix' was not a prefix of '--bindir' and/or
        'erlang_bindir' since relative symbolic links were forced.

EOF
		;;
	    unreasonable_path)
		cat 1>&2 <<EOF
 ERROR: Refusing to install relative symbolic links, since the relative path
        potentially could go via \$DESTDIR\$EXTRA_PREFIX/. Make your install
        paths a bit more reasonable (preferably) or, do not invoke
        'make install' with 'BINDIR_SYMLINKS=relative'.

EOF
		;;
	    unreachable_absolute)
		cat 1>&2 <<EOF
 ERROR: Could not find '--bindir' and/or 'erlang_bindir' after resolving paths.
        The directory structure probably consists of symbolic directory links.
        Refusing to install obviously incorrect relative symbolic links. In
        order to install absolute symbolic links, invoke 'make install' without
        'BINDIR_SYMLINKS=relative'.

EOF
		;;
	    unreachable_relative)
		cat 1>&2 <<EOF
 ERROR: Could not find 'erlang_bindir' from '--bindir' via computed relative
        path. This probably due to symbolic directory links. Refusing to install
        obviously incorrect relative symbolic links. In order to install
        absolute symbolic links, invoke 'make install' without
        'BINDIR_SYMLINKS=relative'.

        Computed relative path="$relpath"
EOF
		;;
	    dirname_failed)
		cat 1>&2 <<EOF
 ERROR: Cannot install relative symbolic links since the 'dirname' command
        failed while computing the relative path. The 'dirname' command is only
        needed when '--bindir', 'erlang_bindir', and/or '--exec-prefix' contain
        relative parts, i.e., '..' parts. If you modify your install paths, it
        may be possible to install relative symbolic links. In order to install
        absolute symbolic links, invoke 'make install' without
        'BINDIR_SYMLINKS=relative'.

EOF
		;;
	    *)
		cat 1>&2 <<EOF
 ERROR: Refusing to install relative symbolic links. The error description for
        \"$abspath_reason\" is however missing.

EOF
		;;
	esac
	cat 1>&2 <<EOF
        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
        BINDIR_SYMLINKS="$BINDIR_SYMLINKS"

        Note that all absolute directory paths are prefixed by
        \$DESTDIR\$EXTRA_PREFIX when accessed.
EOF
	test "$tst" = "" || echo "{error,$abspath_reason}." > $tst
	exit 1;; # Abort...

    absolute-*)  # Notify the user that we reverted to absolute symbolic links
	cat <<EOF
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
EOF
	case "$abspath_reason" in
	    no_ln_s)
		cat <<EOF
  NOTE: Cannot install symbolic links in the '--bindir' directory, since
        'ln -s' does not work. Will create copies using 'cp -p' instead.

EOF
		;;
	    not_prefix)
		cat <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory to the
        'erlang_bindir' directory instead of relative ones. This since at least
        one of these directories is not prefixed by '--exec-prefix'. It is
        possible to force relative symbolic links if you want that by invoking
        the install as 'make BINDIR_SYMLINKS=relative install'.

EOF
		;;

	    unreasonable_path)
		cat <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory to the
        'erlang_bindir' directory instead of relative ones. This since it
        potentially would pass outside of '\$DESTDIR\$EXTRA_PREFIX/'.

EOF
		;;
	    unreachable_absolute)
		cat <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory to the
        'erlang_bindir' instead of relative ones. This since at least one of
        these directory could not be found after resolving paths. This is
        probably due to symbolic directory links.

EOF
		;;
	    unreachable_relative)
		cat <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory to the
        'erlang_bindir' directory instead of relative ones. This since the
        'erlang_bindir' directory could not be found from the '--bindir'
        directory using the computed relative path. This is probably due
        to symbolic directory links.

        Computed relative path="$relpath"
EOF
		;;
	    dirname_failed)
		cat 1>&2 <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory to the
        'erlang_bindir' directory instead of relative ones. This since the
        'dirname' command failed while computing the relative path. The
        'dirname' command is only needed when '--bindir', 'erlang_bindir',
        and/or '--exec-prefix' contain relative parts, i.e., '..' parts. If
        you modify your install paths, it may be possible to install relative
        symbolic links.

EOF
		;;
	    *)
		cat 1>&2 <<EOF
  NOTE: Installing absolute symbolic links in the '--bindir' directory
        to the 'erlang_bindir' instead of relative ones. The notification
        description for "$abspath_reason" is however missing.

EOF
		;;
	esac

	cat <<EOF
        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
        BINDIR_SYMLINKS="$BINDIR_SYMLINKS"

        Note that all absolute directory paths are prefixed by
        \$DESTDIR\$EXTRA_PREFIX when accessed.
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
EOF
	;;

    *) # relative links
	;;
esac

# Now paths=absolute|relative and src_dir is correct (relative bindir)

# cd into "$iprfx$bindir" and do it from there...
echo cd "$DQ$iprfx$bindir$DQ"
$dbg cd    "$iprfx$bindir" || {
    test "$tst" = "" || echo "{error,cd_bin_failed}." > $tst
    exit 1
}

# Verify that the source files actually exist (done in a separate pass
# before we modify anything, so we leave it untouched if it should fail).
# Note that we will not find them under $src_dir if we use absolute symbolic
# links and $DESTDIR != "". In this case (actually all cases) they can then
# be found under $iprfx$erlang_bindir
test_src_dir="$src_dir"
test "$paths-$type" != "absolute-link" || test_src_dir="$iprfx$erlang_bindir"

for file in "$@"; do
    test "$file" != "" || continue
    src_file="$test_src_dir/$file"
    $dbg test -f "$src_file" || {
	cat 1>&2 <<EOF
 ERROR: Missing source file: $src_file

        --bindir="$bindir"
        erlang_bindir="$erlang_bindir"
        --exec-prefix="$exec_prefix"
        EXTRA_PREFIX="$EXTRA_PREFIX"
        DESTDIR="$DESTDIR"
        BINDIR_SYMLINKS="$BINDIR_SYMLINKS"

        Note that all absolute directory paths are prefixed by
        \$DESTDIR\$EXTRA_PREFIX when accessed.
EOF
	test "$tst" = "" || echo "{error,{no_srcfile,\"$src_file\"}}." > $tst
	exit 1
    }
done

# Remove after possible old install (done in a separate pass since I think
# the output looks nicer than if mixed). Note that we cannot test for existance
# in a portable way, so force remove.
for file in "$@"; do
    test "$file" != "" || continue
    echo rm -f "$file"
    $dbg rm -f "$file"
done

# do it
for file in "$@"; do
    echo $ln_s "$DQ$src_dir/$file$DQ" "$file"
    $dbg $ln_s    "$src_dir/$file"    "$file" || {
	test "$tst" = "" || echo "{error,{$type,\"$file\",failed}}." > $tst
	exit 1
    }
done

test "$tst" = "" || echo "{ok,{$paths,\"$iprfx$bindir\",\"$src_dir\"}}." > $tst

exit 0 # Done
