#!/bin/sh

msg() {
    echo "configure: $1"
}

step_msg() {
    msg
    msg "$1"
    msg
}

warn() {
    echo "configure: WARNING: $1"
}

err() {
    echo "configure: error: $1"
    exit 1
}


need_cmd() {
    if which $1 >/dev/null 2>&1
    then msg "found $1"
    else err "need $1"
    fi
}

make_dir() {
    if [ ! -d $1 ]
    then
        msg "mkdir -p $1"
        mkdir -p $1
    fi
}

copy() {
    msg "cp $1 $2"
    cp $1 $2
}

putvar() {
    local T
    eval T=\$$1
    eval TLEN=\${#$1}
    if [ $TLEN -gt 35 ]
    then
        printf "configure: %-20s := %.35s ...\n" $1 "$T"
    else
        printf "configure: %-20s := %s\n" $1 "$T"
    fi
    printf "%-20s := %s\n" $1 "$T" >>config.mk
}

probe() {
    local V=$1
    local P=$2
    local T
    T=$(which $P 2>&1)
    if [ $? -ne 0 ]
    then
        T=""
    fi
    eval $V=\$T
    putvar $V
}

probe_need() {
    local V=$1
    local P=$2
    probe $V $P
    eval VV=\$$V
    if [ -z "$VV" ]
    then
        err "required program '$P' not found"
    fi
}

opt() {
    local OP=$1
    local DEFAULT=$2
    shift
    shift
    local DOC="$*"
    local FLAG=""

    if [ $DEFAULT -eq 0 ]
    then
        FLAG="enable"
    else
        FLAG="disable"
        DOC="don't $DOC"
    fi

    if [ $HELP -eq 0 ]
    then
        for arg in $CFG_CONFIGURE_ARGS
        do
            if [ "$arg" = "--${FLAG}-${OP}" ]
            then
                OP=$(echo $OP | tr 'a-z-' 'A-Z_')
                FLAG=$(echo $FLAG | tr 'a-z' 'A-Z')
                local V="CFG_${FLAG}_${OP}"
                eval $V=1
                putvar $V
            fi
        done
    else
        if [ ! -z "$META" ]
        then
            OP="$OP=<$META>"
        fi
        printf "    --%-30s %s\n" "$FLAG-$OP" "$DOC"
     fi
}

msg "looking for configure programs"
need_cmd mkdir
need_cmd printf
need_cmd cut
need_cmd grep
need_cmd xargs
need_cmd cp
need_cmd find
need_cmd uname
need_cmd date
need_cmd tr
need_cmd sed

msg "inspecting environment"

CFG_OSTYPE=$(uname -s)
CFG_CPUTYPE=$(uname -m)

if [ $CFG_OSTYPE = Darwin -a $CFG_CPUTYPE = i386 ]
then
    # Darwin's `uname -s` lies and always returns i386. We have to use sysctl
    # instead.
    if sysctl hw.optional.x86_64 | grep ': 1'
    then
        CFG_CPUTYPE=x86_64
    fi
fi


# The goal here is to come up with the same triple as LLVM would,
# at least for the subset of platforms we're willing to target.

case $CFG_OSTYPE in

    Linux)
        CFG_OSTYPE=unknown-linux-gnu
        ;;

    FreeBSD)
        CFG_OSTYPE=unknown-freebsd
        ;;

    Darwin)
        CFG_OSTYPE=apple-darwin
        ;;

    MINGW32*)
        CFG_OSTYPE=pc-mingw32
        ;;

    *)
        err "unknown OS type: $CFG_OSTYPE"
        ;;
esac


case $CFG_CPUTYPE in

    i386 | i486 | i686 | i786 | x86)
        CFG_CPUTYPE=i686
        ;;

    xscale | arm)
        CFG_CPUTYPE=arm
        ;;

    x86_64 | x86-64 | x64)
        CFG_CPUTYPE=x86_64
        ;;

    *)
        err "unknown CPU type: $CFG_CPUTYPE"
esac

CFG_HOST_TRIPLE="${CFG_CPUTYPE}-${CFG_OSTYPE}"

CFG_SELF=$(echo $0 | tr '\\' '/')
CFG_SRC_DIR=${CFG_SELF%${CFG_SELF##*/}}
CFG_BUILD_DIR=$(echo $PWD | tr '\\' '/')
CFG_CONFIGURE_ARGS="$@"

OPTIONS=""
HELP=0
if [ "$1" = "--help" ]
then
    HELP=1
    shift
    echo ""
    echo "Usage: $CFG_SELF [options]"
    echo ""
    echo "Options:"
    echo ""
else
    msg "recreating config.mk"
    echo '' >config.mk

    step_msg "processing $CFG_SELF args"
fi

opt sharedstd 1 "build libstd as a shared library"
opt valgrind 1 "run tests with valgrind"
opt docs     1 "build documentation"
opt optimize 1 "build optimized rust code"
opt mingw-cross 0 "cross-compile for win32 using mingw"


if [ $HELP -eq 1 ]
then
    echo ""
    exit 0
fi

step_msg "writing out basic parameters"
putvar CFG_SRC_DIR
putvar CFG_BUILD_DIR
putvar CFG_OSTYPE
putvar CFG_CPUTYPE
putvar CFG_CONFIGURE_ARGS

step_msg "looking for build programs"
probe_need CFG_PERL         perl
probe_need CFG_PYTHON       python
probe_need CFG_CURL         curl

probe CFG_GIT              git
probe CFG_CLANG            clang++
probe CFG_GCC              gcc
probe CFG_LLVM_CONFIG      llvm-config
probe CFG_VALGRIND         valgrind
probe CFG_PERF             perf
probe CFG_MAKEINFO         makeinfo
probe CFG_TEXI2PDF         texi2pdf
probe CFG_TEX              tex
probe CFG_MAKENSIS         makensis

if [ -z "$CFG_CLANG" -a -z "$CFG_GCC" ]
then
    err "either clang or gcc is required"
fi

if head -n 1 ${CFG_SRC_DIR}src/snapshots.txt | grep -q '^T'
then
    CFG_IN_TRANSITION=1
    putvar CFG_IN_TRANSITION
fi

# Valgrind is only reliable on Linux. On Windows it doesn't work at all, and
# on the Mac the dynamic linker causes Valgrind to emit a huge stream of
# errors.
if [ $CFG_OSTYPE != unknown-linux-gnu ] && [ $CFG_OSTYPE != apple-darwin ]
then
    CFG_BAD_VALGRIND=1
    putvar CFG_BAD_VALGRIND
fi

if [ ! -z "$CFG_LLVM_ROOT" -a -e "$CFG_LLVM_ROOT/bin/llvm-config" ]
then
    CFG_LLVM_CONFIG="$CFG_LLVM_ROOT/bin/llvm-config"
fi

if [ ! -z "$CFG_LLVM_ROOT" -a -z "$CFG_LLVM_CONFIG" ]
then
    CFG_LLVM_INCDIR="$CFG_LLVM_ROOT/include"
    CFG_LLVM_BINDIR="$CFG_LLVM_ROOT/bin"
    CFG_LLVM_LIBDIR="$CFG_LLVM_ROOT/lib"
    CFG_LLVM_CXXFLAGS="-I$CFG_LLVM_INCDIR"
    CFG_LLVM_LDFLAGS=""
    CFG_LLVM_LIBS=$(find "$CFG_LLVM_LIBDIR" \
                    -name '*.lib' \
                    -exec echo '\"{}\"' ';' \
                    | xargs echo)
    CFG_LLVM_VERSION=$("$CFG_LLVM_BINDIR/llc" \
                       --version \
                       | grep version \
                       | cut -d ' ' -f 5-)
    CFG_LLVM_TRIPLE=$("$CFG_LLVM_BINDIR/llc" \
                      --version \
                      | grep Host: \
                      | cut -d ' ' -f 4-)
elif [ ! -z "$CFG_LLVM_CONFIG" ]
then
    CFG_LLVM_VERSION=$($CFG_LLVM_CONFIG --version)
    CFG_LLVM_INCDIR=$($CFG_LLVM_CONFIG --includedir)
    CFG_LLVM_BINDIR=$($CFG_LLVM_CONFIG --bindir)
    CFG_LLVM_LIBDIR=$($CFG_LLVM_CONFIG --libdir)
    CFG_LLVM_CXXFLAGS=$($CFG_LLVM_CONFIG --cxxflags)
    CFG_LLVM_LDFLAGS=$($CFG_LLVM_CONFIG --ldflags)
    CFG_LLVM_LIBS=$($CFG_LLVM_CONFIG --libs)
    CFG_LLVM_TRIPLE=$($CFG_LLVM_CONFIG --host-target)
else
    err "either the \"CFG_LLVM_ROOT\" environment variable must be set, or a \
\"llvm-config\" script must be present"
fi

case $CFG_LLVM_VERSION in
    (3.0svn | 3.0)
    step_msg "found ok version of LLVM: $CFG_LLVM_VERSION"
    ;;
    (*)
    err "bad LLVM version: $CFG_LLVM_VERSION, need >=3.0svn"
    ;;
esac

if [ ! -z "$CFG_CLANG" ]
then
    CFG_CLANG_VERSION=$("$CFG_CLANG" \
                      --version \
                      | grep version \
                      | cut -d ' ' -f 3)

    case $CFG_CLANG_VERSION in
        (3.0svn | 3.0)
        step_msg "found ok version of CLANG: $CFG_CLANG_VERSION"
        CFG_C_COMPILER="clang"
        ;;
        (*)
        msg "bad CLANG version: $CFG_CLANG_VERSION, need >=3.0svn; disabling"
        CFG_C_COMPILER="gcc"
        ;;
    esac
else
    CFG_C_COMPILER="gcc"
fi

if [ ! -z "$CFG_LLVM_TRIPLE" ]
then
    if [ $CFG_HOST_TRIPLE != $CFG_LLVM_TRIPLE ]
    then
        warn "LLVM host-triple $CFG_LLVM_TRIPLE differs from"
        warn "detected host triple $CFG_HOST_TRIPLE"
        warn "choosing LLVM host-triple instead"
        msg ""
        CFG_HOST_TRIPLE=$CFG_LLVM_TRIPLE
    fi
fi

# FIXME: add support for extending the target-triples list
CFG_TARGET_TRIPLES="${CFG_HOST_TRIPLE}"

putvar CFG_HOST_TRIPLE
putvar CFG_TARGET_TRIPLES


putvar CFG_C_COMPILER

putvar CFG_LLVM_ROOT
putvar CFG_LLVM_INCDIR
putvar CFG_LLVM_BINDIR
putvar CFG_LLVM_LIBDIR
putvar CFG_LLVM_CXXFLAGS
putvar CFG_LLVM_LDFLAGS
putvar CFG_LLVM_LIBS
putvar CFG_LLVM_TRIPLE

# Munge any paths that appear in config.mk back to posix-y
perl -i.bak -p -e 's@ ([a-zA-Z]):[/\\]@ /\1/@go;' \
               -e 's@\\@/@go;' config.mk
rm -f config.mk.bak

step_msg "making directories"
for i in \
    doc \
    rt rt/isaac rt/bigint rt/sync rt/test rt/arch/i386 \
    rt/libuv rt/libuv/src/ares rt/libuv/src/eio rt/libuv/src/ev \
    rustllvm dl \
    test/run-pass test/run-fail test/compile-fail \
    test/bench test/perf test/pretty
do
    make_dir $i
done

for t in $CFG_TARGET_TRIPLES
do
    for i in 0 1 2 3
    do
        # host bin dir
        make_dir stage$i/bin

        # host lib dir
        make_dir stage$i/lib

        # target bin dir
        make_dir stage$i/lib/rustc/$t/bin

        # target lib dir
        make_dir stage$i/lib/rustc/$t/lib
    done
done

copy ${CFG_SRC_DIR}Makefile.in ./Makefile

step_msg "complete"