#!/bin/sh -e

## e.g.
#
#   $ ./scripts/setup
#   $ ./scripts/deplist system | ./scripts/depsort
#

HERE="$(dirname $(readlink -f ${0}))";
BASE="${HERE}/..";

##
# Usage
#
if test ${#} = 0; then
    cat <<EOF
Usage: ${0} REPO [REPO ...]
EOF
fi

##
# Sanity check. The specified repositories exist.
#
for repo in ${@}; do
    if ! test -d "${BASE}/${repo}"; then
        printf "E: '%s' is not a valid repository!\n" "${repo}" 1>&2;
        exit 1;
    fi
done

##
# Find a package by name or find the parent package of a subpackage.
# Note that the index is padded by a space on either side for easy grep.
#
# Usage: parent PACKAGE
#
parent ()
{
    a=$("${HERE}"/sgrep " ${1} " "${HERE}"/.index | cut -d' ' -f2 | xargs);
    if ! test -z "${a}"; then
        r=${a};
    else
        b=$(grep " ${1} " "${HERE}"/.index | cut -d' ' -f2 | xargs);
        if ! test -z "${b}"; then
            r=${b};
        else
            r=${1};
        fi
    fi
    printf "%s" "${r}";
}

##
# Prints a fatal error and exits.
#
nxdepf ()
{
    printf "E: dependency '%s' not found or excepted (needed by '%s')\n" "${1}" "${2}" 1>&2;
    exit 1;
}

##
# Do everything at once.
#
for repo in ${@}; do
    find "${BASE}/${repo}" -mindepth 1 -maxdepth 1 -type d | while read k; do
    (
        ##
        # Source APKBUILD in a subshell to avoid contamination.
        #
        . "${k}/APKBUILD";

        ##
        # Special-case some options. For example, '!check' means
        # that the 'checkdepends=' variable is not used. Ignore.
        #
        for m in ${options}; do
            case ${m} in
                !check) checkdepends=; ;;
            esac
        done

        ##
        # Aggregate all possible depends. Obviously if something
        # is not specified, it will be empty anyway.
        #
        # FIXME: Clean this up somehow.
        #
        cats=$(tr ' ' '\n' <<EOF | sort | uniq
${checkdepends}
${depends}
${depends_dev}
${makedepends}
${makedepends_build}
${makedepends_host}
${_core_depends}
EOF
);

        ##
        # Construct canonical repository/package name.
        #
        p="${repo}/${k##*/}";

        ##
        # Column 1 output.
        #
        printf "%s " "${p}";
        test -z "${cats}" && printf "\n" && continue; # skip when empty; we are done

        for d in ${cats}; do

            ##
            # Trim out most of the qualifiers.
            #
            _d=${d};            # formatting

            _d=${_d%=*};        # remove =version
            _d=${_d%>*};        # remove >version
            _d=${_d%<*};        # remove <version
            _d=${_d%~*};        # remove ~version

            ##
            # Handle cases where a dependency is provided by another package.
            #
            case "${_d}" in
                !*) continue; ;;

                # override: system
                /bin/sh)        _d=dash; ;;
                /sbin/init)     _d=s6-linux-init; ;;
                cmd:sendmail)   _d=ssmtp; ;;
                cmd:which)      _d=debianutils; ;;
                libc-utils)     _d=musl; ;;

                # override: user (FIXME: incomplete)
                cmd:byacc)      _d=$(parent ${d#cmd:*}); ;;
                cmd:cpio)       _d=$(parent libarchive-tools); ;;
                cmd:gzip)       _d=$(parent ${d#cmd:*}); ;;
                cmd:yacc)       _d=bison; ;;
                cmd:lex)        _d=flex; ;;
                cmd:locale)     _d=musl-locales; ;;
                cmd:mcookie)    _d=$(parent ${d#cmd:*}); ;;
                cmd:pkg-config) _d=pkgconf; ;;
                cmd:unix2dos)   _d=dos2unix; ;;
                cmd:xsltproc)   _d=libxslt; ;;
                cargo-*)        _d=rust; ;;
                guile-dev)      _d=guile; ;;
                llvm-dev)       _d=$(parent llvm14-dev); ;;
                llvm-static)    _d=$(parent llvm14-static); ;;
                llvm-test-*)    _d=$(parent llvm14-test-utils); ;;

                # automatic search
                *)              _d=$(parent $_d); ;;
            esac

            ##
            # Determine relative path to dependency. It might be
            # in the wrong repository, in which case must fix.
            #
            # TODO: Clean up to accommodate any number of repos
            # and their policies. For example, 'kernel' if we do
            # end up creating that someday.
            #
            case "${repo}" in
                system) # nothing in system may depend on anything outside of system
                    if ! test -f "${BASE}/${repo}/${_d}/APKBUILD"; then
                        nxdepf "${_d}" "${p}";
                    fi
                    path="${repo}/${_d}";
                    ;;
                user) # packages in user might depend on something in system
                    if ! test -f "${BASE}/${repo}/${_d}/APKBUILD"; then
                        if test -f "${BASE}/system/${_d}/APKBUILD"; then
                            path="system/${_d}";
                        else
                            nxdepf "${_d}" "${p}";
                        fi
                    else
                        path="${repo}/${_d}";
                    fi
                    ;;
            esac

            ##
            # Print remaining columns of output if not parent.
            #
            printf " %s" "${path}";
        done | tr ' ' '\n' | sed -e "\@${p}\$@d" | sort -u | xargs; # sort and remove duplicates
    )
    done | sort; # sort only within a repo
done