#!/bin/sh
# Configure script by blankhex

# Global variables
source_path=""
cc=$CC
ar=$AR
staticlib=libbh.a
dynamiclib=libbh.so
exe=""
enable_dynamic="no"
enable_mt="yes"
enable_lfs="no"
enable_tests="yes"
use_clock_gettime="no"

if [ -z "$cc" ]; then cc="gcc"; fi
if [ -z "$ld" ]; then ld="gcc"; fi
if [ -z "$ar" ]; then ar="ar"; fi

# Internal functions
assign_option() {
    set -- "${1#--}" "$2"
    set -- "${2:-${1%%=*}}" "${1#*=}"
    eval "$1=\"$2\""
}

assign_toggle() {
    set -- "${1#--}" "$2" "$3"
    set -- "${2:-${1%%=*}}" "${1#*=}" "$3" "$1"
    if test "$4" = "$2"; then set -- "$1" "$3"; fi
    eval "$1=$2"
}

add_trailing_slash() {
    set -- "$1" "$(printf "%s" "$1" | tail -c 1)"
    if [ "$2" = "/" ]; then echo "$1";
    else echo "$1/"; fi
}

# Option parsing
for option do
    case $option in
        --cc=*) assign_option "$option"; ;;
        --ar=*) assign_option "$option"; ;;
        --extra-cflags=*) assign_option "$option" extra_cflags; ;;
        --extra-ldflags=*) assign_option "$option" extra_ldflags; ;;
        --extra-ldlibs=*) assign_option "$option" extra_ldlibs; ;;
        --platform=*) assign_option "$option"; ;;
        --enable-dynamic|--enable-dynamic=*) assign_toggle "$option" enable_dynamic yes; ;;
        --enable-mt|--enable-mt=*) assign_toggle "$option" enable_mt yes; ;;
        --enable-lfs|--enable-lfs=*) assign_toggle "$option" enable_lfs yes; ;;
        --enable-tests|--enable-tests=*) assign_toggle "$option" enable_tests yes; ;;
        --use-clock_gettime|--use-clock_gettime=*) assign_toggle "$option" use_clock_gettime yes; ;;
        --source=*) assign_option "$option" source_path; ;;
        --help|-h) display_help="yes"; ;;
        *) echo "configure: WARNING: unrecognized option $option"; ;;
    esac
done

# Help message
show_help() {
cat << EOF
Usage: configure [OPTIONS]

Options:
  --help                            Print this message
  --source=                         Path to the source code
  --cc=CC                           C compiler
  --ar=AR                           Library archiver
  --extra-cflags=                   Extra compiler flags
  --extra-ldflags=                  Extra linker flags
  --extra-ldlibs=                   Extra libraries
  --platform=[Posix|Win32|Dummy]    Specify target platform
  --enable-dynamic[=yes|no]         Make dynamic library
  --enable-mt[=yes|no]              Enable multithreading support
  --enable-lfs[=yes|no]             Enable large file support
  --enable-tests[=yes|no]           Enable unit tests
  --use-clock_gettime[=yes|no]      Use of clock_gettime regardless of the support
EOF
exit 1
}

if [ -n "$display_help" ]; then show_help; fi

# Add trailing slash if needed
if [ -n "$source_path" ]; then
    source_path=$(add_trailing_slash "$source_path")
fi

# Detect OS and platform, because it wasn't specified
os="Unknown"
if [ -z "$platform" ]; then
    case $(uname) in
        Darwin) os="MacOS"; platform="Posix"; ;;
        Linux) os="Linux"; platform="Posix"; ;;
        *BSD) os="BSD"; platform="Posix"; ;;
        CYGWIN*|MINGW*|MSYS*) os="Windows"; platform="Win32"; ;;
        *) os="Unknown"; platform="Dummy"; ;;
    esac
fi

# Validate platforms
case $platform in
    Posix) ;;
    Win32) ;;
    Dummy) ;;
    *) echo "configure: WARNING: unrecognized platform $platform"; platform=Dummy; ;;
esac

# Make build magic
cflags="-fPIC -I${source_path}include -I."
ldflags=""
ldlibs="-lm"

cflags="$cflags $extra_cflags"
ldflags="$ldflags $extra_ldflags"
ldlibs="$ldlibs $extra_ldlibs"

# Make sure that build directories exist
mkdir src src/Platform src/Math src/String 2> /dev/null

# Build source list
sources="${source_path}src/Platform/Spinlock.c"

# Platform dependant sources
if [ "$platform" = "Posix" ]; then
    sources="$sources:${source_path}src/Platform/Posix/File.c"
    mkdir src/Platform/Posix 2> /dev/null
elif [ "$platform" = "Win32" ]; then
    exe=".exe"
    dynamiclib="bh.dll"
    sources="$sources:${source_path}src/Platform/Win32/File.c"
    mkdir src/Platform/Win32 2> /dev/null
else
    sources="$sources:${source_path}src/Platform/Dummy/File.c"
    mkdir src/Platform/Dummy 2> /dev/null
fi

if [ "$platform" = "Posix" ] && [ "$enable_mt" = "yes" ]; then
    sources="$sources:${source_path}src/Platform/Posix/Condition.c"
    sources="$sources:${source_path}src/Platform/Posix/Mutex.c"
    sources="$sources:${source_path}src/Platform/Posix/Semaphore.c"
    sources="$sources:${source_path}src/Platform/Posix/Thread.c"
    sources="$sources:${source_path}src/Platform/Posix/Tss.c"
    ldlibs="$ldlibs -pthread"
    mkdir src/Platform/Posix 2> /dev/null
elif [ "$platform" = "Win32" ] && [ "$enable_mt" = "yes" ]; then
    sources="$sources:${source_path}src/Platform/Win32/Condition.c"
    sources="$sources:${source_path}src/Platform/Win32/Mutex.c"
    sources="$sources:${source_path}src/Platform/Win32/Semaphore.c"
    sources="$sources:${source_path}src/Platform/Win32/Thread.c"
    sources="$sources:${source_path}src/Platform/Win32/Tss.c"
    mkdir src/Platform/Win32 2> /dev/null
else
    sources="$sources:${source_path}src/Platform/Dummy/Condition.c"
    sources="$sources:${source_path}src/Platform/Dummy/Mutex.c"
    sources="$sources:${source_path}src/Platform/Dummy/Semaphore.c"
    sources="$sources:${source_path}src/Platform/Dummy/Thread.c"
    sources="$sources:${source_path}src/Platform/Dummy/Tss.c"
    mkdir src/Platform/Dummy 2> /dev/null
fi

# Platform independant sources
for file in "${source_path}src"/*.c; do
    sources="$sources:$file"
done

for file in "${source_path}src/Math"/*.c; do
    sources="$sources:$file"
done

for file in "${source_path}src/String"/*.c; do
    sources="$sources:$file"
done

# Tests
if [ "$enable_tests" = "yes" ]; then
    tests=""
    mkdir test test/src 2> /dev/null
    for file in "${source_path}test/src"/*.c; do
        if [ -n "$tests" ]; then tests="$tests:$file"
        else tests="$file"; fi
    done
fi

# Makefile generation
{
    # Generate variables
    echo "CC=$cc"
    echo "AR=$ar"
    echo "CFLAGS=$cflags"
    echo "LDFLAGS=$ldflags"
    echo "LDLIBS=$ldlibs"
    echo "STATICLIB=$staticlib"

    if [ "$enable_dynamic" = "yes" ]; then
        echo "DYNAMICLIB=$dynamiclib"
    fi

    # Set a list of objects
    printf "\nOBJS="
    (
        IFS=":"
        for source in $sources; do
            object=${source%%.c}.o
            object=${object#${source_path}}
            echo " \\"
            printf "  %s" "$object"
        done
    )
    printf "\n\n"

    # Check if dynamic linking is enabled and add rules
    if [ "$enable_dynamic" = "yes" ]; then
        printf "all: static dynamic\n\n"
        printf "dynamic: \$(DYNAMICLIB)\n\n"
        printf "\$(DYNAMICLIB): \$(OBJS)\n"
        printf "\t\$(CC) \$(LDFLAGS) -shared \$(OBJS) -o \$(DYNAMICLIB) \$(LDLIBS)\n\n"
    else
        printf "all: static\n\n"
    fi

    # Add rules for static linking
    printf "static: \$(STATICLIB)\n\n"
    printf "\$(STATICLIB): \$(OBJS)\n"
    printf "\t\$(AR) r \$(STATICLIB) \$(OBJS)\n\n"

    # Generate rules for tests
    if [ "$enable_tests" = "yes" ]; then
    (
        IFS=":"
        for source in $tests; do
            object=${source%%.c}${exe}
            object=${object#${source_path}}
            printf "%s: %s \$(STATICLIB)\n" $object $source
            printf "\t\$(CC) \$(CFLAGS) -I${source_path}unit/include \$(LDFLAGS) %s %s \$(STATICLIB) -o %s \$(LDLIBS)\n\n" "$source" "${source_path}unit/src/Unit.c" "$object"
        done
    )
    printf "tests: "
    (
        IFS=":"
        for source in $tests; do
            object=${source%%.c}${exe}
            object=${object#${source_path}}
            echo " \\"
            printf "  %s" "$object"
        done
    )
    printf "\n\n"
    fi

    # Generate rules for main objects
    (
        IFS=":"
        for source in $sources; do
            object=${source%%.c}.o
            object=${object#${source_path}}
            printf "$object: $source\n"
            printf "\t\$(CC) -c \$(CFLAGS) %s -o %s\n\n" "$source" "$object"
        done
    )
    printf "\n\n"

    # Generate clean rules
    printf "clean:\n"
    printf "\t-rm -f \$(OBJS) \$(STATICLIB)"
    if [ "$enable_dynamic" = "yes" ]; then
        printf " \$(DYNAMICLIB)"
    fi

    if [ "$enable_tests" = "yes" ]; then
    (
        IFS=":"
        for source in $tests; do
            object=${source%%.c}${exe}
            object=${object#${source_path}}
            printf " %s" "$object"
        done
    )
    fi
    printf "\n\n"
} > Makefile

# Generate internal config.h
{
    printf "#ifndef BH_SRC_CONFIG_H\n#define BH_SRC_CONFIG_H\n\n"
    if [ "$use_clock_gettime" ]; then printf "#define BH_USE_CLOCK_GETTIME\n"; fi
    if [ "$enable_lfs" ]; then printf "#define BH_ENABLE_LFS\n"; fi
    printf "\n#endif /* BH_SRC_CONFIG_H */\n"
} > Config.h

echo "OS:                       $os"
echo "Platform:                 $platform"
echo "Source path:              $source_path"
echo "CC:                       $cc"
echo "AR:                       $ar"
echo "CFLAGS:                   $cflags"
echo "LDFLAGS:                  $ldflags"
echo "LDLIBS:                   $ldlibs"
echo "Enable multithreading:    $enable_mt"
echo "Enable long file support: $enable_lfs"
echo "Enable tests:             $enable_tests"
echo "Build dynamic library:    $enable_dynamic"
echo "Use clock_gettime:        $use_clock_gettime"