#----------------------------------*-sh-*--------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2018-2020 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     sysFunctions
#
# Description
#     General system helper functions
#
# Functions provided
#     isNone, isSystem, isAbsdir, hasAbsdir
#     isDarwin, isWindows
#     findFirstFile
#     findSystemInclude
#     findLibrary
#     findExtLib
#     versionCompare
#
# Internal variables used
#     extLibraries
#
# External variables used
#     WM_OSTYPE  (is set for Windows)
#     WM_COMPILER_LIB_ARCH
#     DEB_TARGET_MULTIARCH
#
#------------------------------------------------------------------------------

if [ -z "$WMAKE_SCRIPTS_SYSFUNCTIONS" ]
then
    # Load once, but do not rely on this variable elsewhere
    WMAKE_SCRIPTS_SYSFUNCTIONS=loaded

    # Debian multi-arch, ignore missing/bad dpkg-architecture.
    if [ -z "$DEB_TARGET_MULTIARCH" ]
    then
        DEB_TARGET_MULTIARCH=$(dpkg-architecture -qDEB_TARGET_MULTIARCH 2>/dev/null || true)
    fi

    # True if OS is Darwin.
    isDarwin()
    {
        test Darwin = "$(uname -s 2>/dev/null || true)"
    }

    # True if target OS is Windows
    isWindows()
    {
        test MSwindows = "$WM_OSTYPE"
    }

    # Static, dynamic library extensions
    extLibraries=".a .so"

    if isDarwin
    then
        extLibraries=".a .dylib"
    elif isWindows
    then
        extLibraries=".a .dll .dll.a"  # including cross-compiling
    fi

    # True if '$1' begins with '/'
    isAbsdir()
    {
        test "$1" = "/${1#/}"
    }


    # True if '$1' begins with '/' and also exists as a directory
    hasAbsdir()
    {
        test "$1" = "/${1#/}" -a -d "$1"
    }


    # True if '$1' is an empty string, "none" or ends in "-none"
    # Eg,
    #    if isNone "$BOOST_ARCH_PATH" ...
    isNone()
    {
        test -z "$1" -o "${1##*-}" = none
    }


    # True if '$1' is "system" or ends in "-system"
    # Eg,
    #    if isSystem "$BOOST_ARCH_PATH"
    isSystem()
    {
        test "${1##*-}" = system
    }


    # True if '$1' and '$2' have the same directory basename
    # Eg,
    #    equalBaseName "/usr/include/scotch-int32" "scotch-int32"
    equalBaseName()
    {
        test "${1##*/}" = "${2##*/}"
    }


    # Simple output for -query
    # $1 = software
    # $2 = setting
    _process_query()
    {
        if isNone "$2"
        then
            echo "$1=none"
        elif isAbsdir "$2"    ## not hasAbsdir
        then
            echo "$1=${2##*/}"
        elif isSystem "$2"
        then
            echo "$1=system"
        else
            echo "$1=unknown"
        fi
    }


    # Return system prefix (/usr, /usr/local, ...) based on hint provided
    # Eg,
    #    sysPrefix "/usr/local/include/fftw3.h"  -> "/usr/local"
    #
    # Without a hint, echoes "/usr"
    sysPrefix()
    {
        case "$1" in
        /usr/local/*)
            echo "/usr/local"
            ;;
        *)
            echo "/usr"
            ;;
        esac
    }


    # Check existence of any of the files
    # On success, echoes the file found and returns 0, otherwise returns 2
    findFirstFile()
    {
        local file

        for file
        do
            if [ -f "$file" ] && [ -r "$file" ]
            then
                echo "$file"  # Found
                return 0
            fi
        done
        return 2
    }

    # Check system /usr/local/include /usr/include paths
    #
    # On success, echoes the resolved file and returns 0, otherwise returns 2
    #
    # Specify -name=incName to search for
    #
    findSystemInclude()
    {
        local searchName

        case "$1" in
        -name=*)
            searchName="${1#*=}"
            ;;
        esac

        if [ -z "$searchName" ]
        then
            return 1
        fi

        findFirstFile \
            "/usr/local/include/$searchName" \
            "/usr/include/$searchName" \
            ;
    }

    # Check existence of library with ending '.a', '.so' ...
    #
    # On success, echoes the resolved file and returns 0, otherwise returns 2
    #
    # This function has two modes of operation.
    #
    # 1) Automated search.
    #    Specify -prefix=dirName -name=libName, optionally -local=subdirName
    #    and search for (lib, lib64, lib/x86_64..) etc.
    #
    # 2) Directed search.
    #    specify the fully qualified names to search on the parameter list
    #
    findLibrary()
    {
        local prefixDir localDir searchDir searchName
        local file ext

        searchDir=true

        while [ "$searchDir" = true ] && [ "$#" -gt 0 ]
        do
            case "$1" in
            -prefix=*)
                prefixDir="${1#*=}"
                shift
                ;;

            -local=*)
                # Prefix with directory separator
                localDir="/${1#*=}"
                shift
                ;;

            -name=*)
                searchName="${1#*=}"
                shift
                ;;

            (*)
                unset searchDir
                ;;
            esac
        done

        if [ -n "$searchName" ]
        then
            # Automated search (eg, lib/ lib64/, lib/x86_64-linux-gnu)
            # but also handle possible local versions (eg, lib/scotch-int32)

            : "${prefixDir:=/usr}"  # A reasonable default
            [ -d "$prefixDir" ] || return 2

            # Local and regular search paths
            set -- \
                "lib${localDir}" \
                "${WM_COMPILER_LIB_ARCH:+lib${WM_COMPILER_LIB_ARCH}${localDir}}" \
                "${DEB_TARGET_MULTIARCH:+lib/${DEB_TARGET_MULTIARCH}${localDir}}" \
                "lib" \
                "${WM_COMPILER_LIB_ARCH:+lib${WM_COMPILER_LIB_ARCH}}" \
                "${DEB_TARGET_MULTIARCH:+lib/${DEB_TARGET_MULTIARCH}}" \
                ;

            # Ignore empty local search path ("/")
            [ "${#localDir}" -gt 1 ] || shift 3

            ## echo "search: $# $@" 1>&2

            for searchDir in "$@"
            do
                [ -n "$searchDir" ] || continue
                for ext in '' $extLibraries
                do
                    file="$prefixDir/$searchDir/$searchName$ext"
                    if [ -f "$file" ] && [ -r "$file" ]
                    then
                        echo "$file"  # Found
                        return 0
                    fi
                done
            done

        else
            # Directed search

            for file
            do
                [ -n "$file" ] || continue
                for ext in '' $extLibraries
                do
                    if [ -f "$file$ext" ] && [ -r "$file$ext" ]
                    then
                        echo "$file$ext"  # Found
                        return 0
                    fi
                done
            done
        fi

        return 2
    }


    # Check existence of library in FOAM_EXT_LIBBIN, but conditional
    # on FOAM_EXT_LIBBIN being located in the ThirdParty directory
    #
    # On success, echoes the resolved file and returns 0, otherwise returns 2
    findExtLib()
    {
        local file

        if [ -n "$FOAM_EXT_LIBBIN" ] && \
           [ -n "$WM_THIRD_PARTY_DIR" ] && \
           [ "${FOAM_EXT_LIBBIN#$WM_THIRD_PARTY_DIR}" != "$FOAM_EXT_LIBBIN" ]
        then
            for file
            do
                if file="$(findLibrary "$FOAM_EXT_LIBBIN/$file")"
                then
                    echo "$file"
                    return 0
                fi
            done
        fi

        return 2
    }


    # Compare version tuples with syntax similar to POSIX shell,
    # but respecting dot separators.
    #
    # arg1 OP arg2
    #   OP is one of -eq, -ne, -lt, -le, -gt, or -ge.
    #   Returns true for a successful comparison.
    #   Arg1 and arg2 normally comprise positive integers, but leading content
    #   before a '-' is stripped.
    #   Missing digits are treated as '0'.
    #
    # Eg,
    #    versionCompare "software-1.2.3" -gt 1.1 && echo True
    #
    # Ad hoc handling of "git" version as always newest.
    #    "git" -gt "1.2.3" : True
    #    "1.2.3" -lt "git" : True
    versionCompare()
    {
        [ "$#" -eq 3 ] || {
            echo "Compare needs 3 arguments (was given $#)" 1>&2
            return 2
        }

        local arg1="${1#*-}"    # Strip leading prefix-
        local op="${2}"
        local arg2="${3#*-}"    # Strip leading prefix-
        local result=''         # Empty represents 'equal'

        arg1="${arg1:-0}."
        arg2="${arg2:-0}."

        if   [ "$arg1" = "$arg2" ];        then unset arg1 arg2 # Identical
        elif [ "${arg1#git}" != "$arg1" ]; then result='more'   # (git > arg2)
        elif [ "${arg2#git}" != "$arg2" ]; then result='less'   # (arg1 < git)
        fi

        while [ -z "$result" ] && [ -n "${arg1}${arg2}" ]
        do
            local digits1="${arg1%%.*}"
            local digits2="${arg2%%.*}"

            arg1="${arg1#*.}"
            arg2="${arg2#*.}"

            : "${digits1:=0}"
            : "${digits2:=0}"

            # Other handling of non-integer values?
            if   [ "$digits1" -lt "$digits2" ]; then result='less'
            elif [ "$digits1" -gt "$digits2" ]; then result='more'
            fi
        done

        case "$op" in
        (-eq | eq)  [ -z "$result" ] ;;
        (-ne | ne)  [ -n "$result" ] ;;
        (-lt | lt)  [ 'less' = "$result" ] ;;
        (-gt | gt)  [ 'more' = "$result" ] ;;
        (-le | le)  [ 'less' = "${result:-less}" ] ;;
        (-ge | ge)  [ 'more' = "${result:-more}" ] ;;
        (*)
            echo "Unknown operator: '$op'" 1>&2
            return 2
            ;;
        esac
    }
fi


#------------------------------------------------------------------------------