#!/usr/bin/env bash

PYTHON_BUILD_VERSION="20130518"

set -E
exec 3<&2 # preserve original stderr at fd 3


lib() {
  parse_options() {
    OPTIONS=()
    ARGUMENTS=()
    local arg option index

    for arg in "$@"; do
      if [ "${arg:0:1}" = "-" ]; then
        if [ "${arg:1:1}" = "-" ]; then
          OPTIONS[${#OPTIONS[*]}]="${arg:2}"
        else
          index=1
          while option="${arg:$index:1}"; do
            [ -n "$option" ] || break
            OPTIONS[${#OPTIONS[*]}]="$option"
            index=$(($index+1))
          done
        fi
      else
        ARGUMENTS[${#ARGUMENTS[*]}]="$arg"
      fi
    done
  }

  if [ "$1" == "--$FUNCNAME" ]; then
    declare -f "$FUNCNAME"
    echo "$FUNCNAME \"\$1\";"
    exit
  fi
}
lib "$1"


resolve_link() {
  $(type -p greadlink readlink | head -1) "$1"
}

abs_dirname() {
  local cwd="$(pwd)"
  local path="$1"

  while [ -n "$path" ]; do
    cd "${path%/*}"
    local name="${path##*/}"
    path="$(resolve_link "$name" || true)"
  done

  pwd
  cd "$cwd"
}

capitalize() {
  printf "%s" "$1" | tr a-z A-Z
}

sanitize() {
  printf "%s" "$1" | sed "s/[^A-Za-z0-9.-]/_/g; s/__*/_/g"
}

build_failed() {
  { echo
    echo "BUILD FAILED"
    echo

    if ! rmdir "${BUILD_PATH}" 2>/dev/null; then
      echo "Inspect or clean up the working tree at ${BUILD_PATH}"

      if file_is_not_empty "$LOG_PATH"; then
        echo "Results logged to ${LOG_PATH}"
        echo
        echo "Last 10 log lines:"
        tail -n 10 "$LOG_PATH"
      fi
    fi
  } >&3
  exit 1
}

file_is_not_empty() {
  local filename="$1"
  local line_count="$(wc -l "$filename" 2>/dev/null || true)"

  if [ -n "$line_count" ]; then
    words=( $line_count )
    [ "${words[0]}" -gt 0 ]
  else
    return 1
  fi
}

install_package() {
  install_package_using "tarball" 1 "$@"
}

install_git() {
  install_package_using "git" 2 "$@"
}

install_hg() {
  install_package_using "hg" 2 "$@"
}

install_svn() {
  install_package_using "svn" 2 "$@"
}

install_jar() {
  install_package_using "jar" 1 "$@"
}

install_zip() {
  install_package_using "zip" 1 "$@"
}

install_package_using() {
  local package_type="$1"
  local package_type_nargs="$2"
  local package_name="$3"
  shift 3

  local fetch_args=( "$package_name" "${@:1:$package_type_nargs}" )
  local make_args=( "$package_name" )
  local arg last_arg

  for arg in "${@:$(( $package_type_nargs + 1 ))}"; do
    if [ "$last_arg" = "--if" ]; then
      "$arg" || return 0
    elif [ "$arg" != "--if" ]; then
      make_args["${#make_args[@]}"]="$arg"
    fi
    last_arg="$arg"
  done

  pushd "$BUILD_PATH" >&4
  "fetch_${package_type}" "${fetch_args[@]}"
  make_package "${make_args[@]}"
  popd >&4

  { echo "Installed ${package_name} to ${PREFIX_PATH}"
    echo
  } >&2
}

apply_patches() {
  local package_name="$1"
  local patches_path="${PYTHON_BUILD_ROOT}/share/python-build/patches/${DEFINITION_PATH##*/}"

  # Support PYTHON_PATCH_STRIP, etc.
  local package_var_name="$(capitalize "${package_name%%-*}")"
  local PACKAGE_PATCH_STRIP="${package_var_name}_PATCH_STRIP"

  for patch in "${patches_path}/${package_name}/"*; do
    if [ -f "$patch" ]; then
      {
        echo "Applying ${patch##*/} to ${package_name}..."
        patch "-p${!PACKAGE_PATCH_STRIP:-0}" < "$patch"
      } >&4 2>&1
    fi
  done
}

make_package() {
  local package_name="$1"
  shift

  pushd "$package_name" >&4
  before_install_package "$package_name"
  apply_patches "$package_name"
  build_package "$package_name" $*
  after_install_package "$package_name"
  fix_directory_permissions
  popd >&4
}

compute_md5() {
  if type md5 &>/dev/null; then
    md5 -q
  elif type openssl &>/dev/null; then
    local output="$(openssl md5)"
    echo "${output##* }"
  elif type md5sum &>/dev/null; then
    local output="$(md5sum -b)"
    echo "${output% *}"
  else
    return 1
  fi
}

verify_checksum() {
  # If there's no MD5 support, return success
  [ -n "$HAS_MD5_SUPPORT" ] || return 0

  # If the specified filename doesn't exist, return success
  local filename="$1"
  [ -e "$filename" ] || return 0

  # If there's no expected checksum, return success
  local expected_checksum="$2"
  [ -n "$expected_checksum" ] || return 0

  # If the computed checksum is empty, return failure
  local computed_checksum="$(compute_md5 < "$filename")"
  [ -n "$computed_checksum" ] || return 1

  if [ "$expected_checksum" != "$computed_checksum" ]; then
    { echo
      echo "checksum mismatch: ${filename} (file is corrupt)"
      echo "expected $expected_checksum, got $computed_checksum"
      echo
    } >&4
    return 1
  fi
}

http() {
  local method="$1"
  local url="$2"
  local file="$3"
  [ -n "$url" ] || return 1

  if type curl &>/dev/null; then
    "http_${method}_curl" "$url" "$file"
  elif type wget &>/dev/null; then
    "http_${method}_wget" "$url" "$file"
  else
    echo "error: please install \`curl\` or \`wget\` and try again" >&2
    exit 1
  fi
}

http_head_curl() {
  curl -qsILf "$1" >&4 2>&1
}

http_get_curl() {
  curl -C - -o "${2:--}" -qsSLf "$1"
}

http_head_wget() {
  wget -q --spider "$1" >&4 2>&1
}

http_get_wget() {
  wget -nv -c -O "${2:--}" "$1"
}

fetch_tarball() {
  local package_name="$1"
  local package_url="$2"
  local mirror_url
  local checksum

  if [ "$package_url" != "${package_url/\#}" ]; then
    checksum="${package_url#*#}"
    package_url="${package_url%%#*}"

    if [ -n "$PYTHON_BUILD_MIRROR_URL" ]; then
      mirror_url="${PYTHON_BUILD_MIRROR_URL}/$checksum"
    fi
  fi

  local _package_filename="${package_url##*/}"
  local _package_suffix="${_package_filename##*.}"
  case "${_package_suffix}" in
  "Z" | "bz2" | "gz" | "xz" )
    local package_suffix="tar.${_package_suffix}"
  ;;
  * )
    local package_suffix="${_package_suffix}"
  ;;
  esac

  local package_filename="${package_name}.${package_suffix}"
  symlink_tarball_from_cache "$package_filename" "$checksum" || {
    echo "Downloading ${package_filename}..." >&2
    { http head "$mirror_url" &&
      download_tarball "$mirror_url" "$package_filename" "$checksum"
    } ||
    download_tarball "$package_url" "$package_filename" "$checksum"
  }

  { if tar xvf "$package_filename"; then
      if [ -z "$KEEP_BUILD_PATH" ]; then
        rm -f "$package_filename"
      else
        true
      fi
    fi
  } >&4 2>&1
}

symlink_tarball_from_cache() {
  [ -n "$PYTHON_BUILD_CACHE_PATH" ] || return 1

  local package_filename="$1"
  local cached_package_filename="${PYTHON_BUILD_CACHE_PATH}/$package_filename"
  local checksum="$2"

  [ -e "$cached_package_filename" ] || return 1
  verify_checksum "$cached_package_filename" "$checksum" >&4 2>&1 || return 1
  ln -s "$cached_package_filename" "$package_filename" >&4 2>&1 || return 1
}

download_tarball() {
  local package_url="$1"
  [ -n "$package_url" ] || return 1

  local package_filename="$2"
  local checksum="$3"

  echo "-> $package_url" >&2

  { http get "$package_url" "$package_filename"
    verify_checksum "$package_filename" "$checksum"
  } >&4 2>&1 || return 1

  if [ -n "$PYTHON_BUILD_CACHE_PATH" ]; then
    local cached_package_filename="${PYTHON_BUILD_CACHE_PATH}/$package_filename"
    { mv "$package_filename" "$cached_package_filename"
      ln -s "$cached_package_filename" "$package_filename"
    } >&4 2>&1 || return 1
  fi
}

fetch_git() {
  local package_name="$1"
  local git_url="$2"
  local git_ref="$3"

  echo "Cloning ${git_url}..." >&2

  if type git &>/dev/null; then
    if [ -n "$PYTHON_BUILD_CACHE_PATH" ]; then
      pushd "$PYTHON_BUILD_CACHE_PATH" >&4
      local clone_name="$(sanitize "$git_url")"
      if [ -e "${clone_name}" ]; then
        { cd "${clone_name}"
          git fetch --force "$git_url" "+${git_ref}:${git_ref}"
        } >&4 2>&1
      else
        git clone --bare --branch "$git_ref" "$git_url" "${clone_name}" >&4 2>&1
      fi
      git_url="$PYTHON_BUILD_CACHE_PATH/${clone_name}"
      popd >&4
    fi

    git clone --depth 1 --branch "$git_ref" "$git_url" "${package_name}" >&4 2>&1
  else
    echo "error: please install \`git\` and try again" >&2
    exit 1
  fi
}

fetch_hg() {
  local package_name="$1"
  local hg_url="$2"
  local hg_ref="$3"

  echo "Cloning ${hg_url}..." >&2

  if type hg &>/dev/null; then
    if [ -n "$PYTHON_BUILD_CACHE_PATH" ]; then
      pushd "$PYTHON_BUILD_CACHE_PATH" >&4
      local clone_name="$(sanitize "$hg_url")"
      if [ -e "${clone_name}" ]; then
        { cd "${clone_name}"
          hg pull --force "$hg_url"
        } >&4 2>&1
      else
        { hg clone --branch "$hg_ref" "$hg_url" "${clone_name}"
          cd "${clone_name}"
          hg update null
        } >&4 2>&1
      fi
      hg_url="$PYTHON_BUILD_CACHE_PATH/${clone_name}"
      popd >&4
    fi

    hg clone --branch "$hg_ref" "$hg_url" "${package_name}" >&4 2>&1
  else
    echo "error: please install \`hg\` and try again" >&2
    exit 1
  fi
}

fetch_svn() {
  local package_name="$1"
  local svn_url="$2"
  local svn_rev="$3"

  echo "Checking out ${svn_url}..." >&2

  if type svn &>/dev/null; then
    svn co -r "$svn_rev" "$svn_url" "${package_name}" >&4 2>&1
  else
    echo "error: please install \`svn\` and try again" >&2
    exit 1
  fi
}

fetch_jar() {
  local package_name="$1"
  local package_url="$2"
  local mirror_url
  local checksum

  if [ "$package_url" != "${package_url/\#}" ]; then
    checksum="${package_url#*#}"
    package_url="${package_url%%#*}"

    if [ -n "$PYTHON_BUILD_MIRROR_URL" ]; then
      mirror_url="${PYTHON_BUILD_MIRROR_URL}/$checksum"
    fi
  fi

  local package_filename="${package_name}.jar"
  symlink_jar_from_cache "$package_filename" "$checksum" || {
    echo "Downloading ${package_filename}..." >&2
    { http head "$mirror_url" &&
      download_jar "$mirror_url" "$package_filename" "$checksum"
    } ||
    download_jar "$package_url" "$package_filename" "$checksum"
  }
  { $JAVA -jar ${package_name}.jar -s -d ${package_name}
    rm -f "$package_filename"
  } >&4 2>&1
}

symlink_jar_from_cache() {
  symlink_tarball_from_cache "$@"
}

download_jar() {
  download_tarball "$@"
}

fetch_zip() {
  local package_name="$1"
  local package_url="$2"
  local mirror_url
  local checksum

  if [ "$package_url" != "${package_url/\#}" ]; then
    checksum="${package_url#*#}"
    package_url="${package_url%%#*}"

    if [ -n "$PYTHON_BUILD_MIRROR_URL" ]; then
      mirror_url="${PYTHON_BUILD_MIRROR_URL}/$checksum"
    fi
  fi

  local package_filename="${package_name}.zip"
  symlink_zip_from_cache "$package_filename" "$checksum" || {
    echo "Downloading ${package_filename}..." >&2
    { http head "$mirror_url" &&
      download_zip "$mirror_url" "$package_filename" "$checksum"
    } ||
    download_zip "$package_url" "$package_filename" "$checksum"
  }

  { if unzip "$package_filename"; then
      if [ -z "$KEEP_BUILD_PATH" ]; then
        rm -f "$package_filename"
      else
        true
      fi
    fi
  } >&4 2>&1
}

symlink_zip_from_cache() {
  symlink_tarball_from_cache "$@"
}

download_zip() {
  download_tarball "$@"
}

build_package() {
  local package_name="$1"
  shift

  if [ "$#" -eq 0 ]; then
    local commands="standard"
  else
    local commands="$*"
  fi

  echo "Installing ${package_name}..." >&2

  for command in $commands; do
    "build_package_${command}" "$package_name"
  done
}

package_option() {
  local package_name="$1"
  local command_name="$2"
  local variable="$(capitalize "${package_name}_${command_name}")_OPTS_ARRAY"
  local array="$variable[@]"
  shift 2
  local value=( "${!array}" "$@" )
  eval "$variable=( \"\${value[@]}\" )"
}

build_package_standard() {
  local package_name="$1"

  if [ "${MAKEOPTS+defined}" ]; then
    MAKE_OPTS="$MAKEOPTS"
  elif [ -z "${MAKE_OPTS+defined}" ]; then
    MAKE_OPTS="-j 2"
  fi

  # Support PYTHON_CONFIGURE_OPTS, etc.
  local package_var_name="$(capitalize "${package_name%%-*}")"
  local PACKAGE_CONFIGURE="${package_var_name}_CONFIGURE"
  local PACKAGE_PREFIX_PATH="${package_var_name}_PREFIX_PATH"
  local PACKAGE_CONFIGURE_OPTS="${package_var_name}_CONFIGURE_OPTS"
  local PACKAGE_CONFIGURE_OPTS_ARRAY="${package_var_name}_CONFIGURE_OPTS_ARRAY[@]"
  local PACKAGE_MAKE_OPTS="${package_var_name}_MAKE_OPTS"
  local PACKAGE_MAKE_OPTS_ARRAY="${package_var_name}_MAKE_OPTS_ARRAY[@]"
  local PACKAGE_CFLAGS="${package_var_name}_CFLAGS"

  ( if [ "${CFLAGS+defined}" ] || [ "${!PACKAGE_CFLAGS+defined}" ]; then
      export CFLAGS="$CFLAGS ${!PACKAGE_CFLAGS}"
    fi
    ${!PACKAGE_CONFIGURE:-./configure} --prefix="${!PACKAGE_PREFIX_PATH:-$PREFIX_PATH}" $CONFIGURE_OPTS ${!PACKAGE_CONFIGURE_OPTS} "${!PACKAGE_CONFIGURE_OPTS_ARRAY}"
  ) >&4 2>&1

  { "$MAKE" $MAKE_OPTS ${!PACKAGE_MAKE_OPTS} "${!PACKAGE_MAKE_OPTS_ARRAY}"
    "$MAKE" install
  } >&4 2>&1

  # Create `python` executable if missing
  if [[ "${package_name}" == "Python"* ]] || [[ "${package_name}" == "stackless"* ]]; then
    if [ ! -f "$PYTHON_BIN" ]; then
      local python
      for python in "${PREFIX_PATH}/bin/python"*; do
        if expr "$(basename "$python")" : '^python[0-9][0-9]*\.[0-9][0-9]*$' 2>&1 >/dev/null; then
          ( cd "${PREFIX_PATH}/bin" && ln -fs "$(basename "$python")" python )
          break
        fi
      done
    fi
  fi
}

build_package_autoconf() {
  { autoconf
  } >&4 2>&1
}

build_package_python() {
  local package_name="$1"

  { "$PYTHON_BIN" setup.py install
  } >&4 2>&1
}

build_package_jython() {
  build_package_copy
  { if [ -x "${PREFIX_PATH}/bin/jython" ] && [ ! -x "${PREFIX_PATH}/bin/python" ]; then
      ( cd "${PREFIX_PATH}/bin" && ln -fs jython python )
    fi
  } >&4 2>&1
}

build_package_pypy() {
  build_package_copy
  { if [ -x "${PREFIX_PATH}/bin/pypy" ] && [ ! -x "${PREFIX_PATH}/bin/python" ]; then
      ( cd "${PREFIX_PATH}/bin" && ln -fs pypy python )
    fi
  } >&4 2>&1
}

build_package_pypy_builder() {
  if [ -f "rpython/bin/rpython" ]; then # pypy 2.x
    python "rpython/bin/rpython" -Ojit "pypy/goal/targetpypystandalone.py" >&4 2>&1
  elif [ -f "pypy/translator/goal/translate.py" ]; then # pypy 1.x
    ( cd "pypy/translator/goal" && python "translate.py" --opt=jit "targetpypystandalone.py" ) 1>&4 2>&1
  else
    echo "not a pypy source tree" 1>&3
    return 1
  fi
  if [ -x "pypy-c" ] && [ ! -x "bin/pypy" ]; then
    mkdir -p "bin"
    mv -f "pypy-c" "bin/pypy"
  fi
  build_package_pypy
}

build_package_copy() {
  mkdir -p "$PREFIX_PATH"
  cp -R . "$PREFIX_PATH"
}

before_install_package() {
  local stub=1
}

after_install_package() {
  local stub=1
}

fix_directory_permissions() {
  # Ensure installed directories are not world-writable to avoid Bundler warnings
  find "$PREFIX_PATH" -type d \( -perm -020 -o -perm -002 \) -exec chmod go-w {} \;
}

require_gcc() {
  local gcc="$(locate_gcc || true)"

  if [ -z "$gcc" ]; then
    local esc=$'\033'
    { echo
      echo "${esc}[1mERROR${esc}[0m: This package must be compiled with GCC, but python-build couldn't"
      echo "find a suitable \`gcc\` executable on your system. Please install GCC"
      echo "and try again."
      echo

      if [ "$(uname -s)" = "Darwin" ]; then
        echo "${esc}[1mDETAILS${esc}[0m: Apple no longer includes the official GCC compiler with Xcode"
        echo "as of version 4.2. Instead, the \`gcc\` executable is a symlink to"
        echo "\`llvm-gcc\`, a modified version of GCC which outputs LLVM bytecode."
      fi
    } >&3
    return 1
  fi

  export CC="$gcc"
}

locate_gcc() {
  local gcc gccs
  IFS=: gccs=($(gccs_in_path))

  verify_gcc "$CC" ||
  verify_gcc "$(command -v gcc || true)" || {
    for gcc in "${gccs[@]}"; do
      verify_gcc "$gcc" && break || true
    done
  }

  return 1
}

gccs_in_path() {
  local gcc path paths
  local gccs=()
  IFS=: paths=($PATH)

  shopt -s nullglob
  for path in "${paths[@]}"; do
    for gcc in "$path"/gcc-*; do
      gccs["${#gccs[@]}"]="$gcc"
    done
  done
  shopt -u nullglob

  printf :%s "${gccs[@]}"
}

verify_gcc() {
  local gcc="$1"
  if [ -z "$gcc" ]; then
    return 1
  fi

  local version="$("$gcc" --version || true)"
  if [ -z "$version" ]; then
    return 1
  fi

  echo "$gcc"
}

has_broken_mac_openssl() {
  [ "$(uname -s)" = "Darwin" ] &&
  [ "$(openssl version 2>/dev/null || true)" = "OpenSSL 0.9.8r 8 Feb 2011" ] &&
  [[ "$PYTHON_CONFIGURE_OPTS" != *--with-openssl-dir=* ]]
}

build_package_mac_openssl() {
  # Install to a subdirectory since we don't want shims for bin/openssl.
  OPENSSL_PREFIX_PATH="${PREFIX_PATH}/openssl"

  # Put openssl.conf, certs, etc in ~/.pyenv/versions/*/openssl/ssl
  OPENSSLDIR="${OPENSSLDIR:-$OPENSSL_PREFIX_PATH/ssl}"

  # Tell Python to use this openssl for its extension.
  package_option python configure --with-openssl-dir="$OPENSSL_PREFIX_PATH"

  # Hint OpenSSL that we prefer a 64-bit build.
  export KERNEL_BITS="64"
  OPENSSL_CONFIGURE="${OPENSSL_CONFIGURE:-./config}"

  # Compile a shared lib with zlib dynamically linked, no kerberos.
  package_option openssl configure --openssldir="$OPENSSLDIR" zlib-dynamic no-krb5 shared

  # Default MAKE_OPTS are -j 2 which can confuse the build. Thankfully, make
  # gives precedence to the last -j option, so we can override that.
  package_option openssl make -j 1

  build_package_standard "$@"

  # Extract root certs from the system keychain in .pem format and rehash.
  local pem_file="$OPENSSLDIR/cert.pem"
  security find-certificate -a -p /Library/Keychains/System.keychain > "$pem_file"
  security find-certificate -a -p /System/Library/Keychains/SystemRootCertificates.keychain >> "$pem_file"
}

# Post-install check for Python 2.5.x
build_package_verify_py25() {
  build_package_verify_readline "$@"
  build_package_verify_sqlite3 "$@"
  build_package_verify_zlib "$@"
  build_package_verify_bz2 "$@"
}

# Post-install check for Python 2.6.x
build_package_verify_py26() {
  build_package_verify_py25 "$@"
  build_package_verify_ssl "$@"
}

# Post-install check for Python 2.7.x
build_package_verify_py27() {
  build_package_verify_py26 "$@"
}

# Post-install check for Python 3.0.x
build_package_verify_py30() {
  build_package_verify_readline "$@"
  build_package_verify_ssl "$@"
  build_package_verify_sqlite3 "$@"
  build_package_verify_zlib "$@"
  build_package_verify_bz2 "$@"
}

# Post-install check for Python 3.1.x
build_package_verify_py31() {
  build_package_verify_py30 "$@"
}

# Post-install check for Python 3.2.x
build_package_verify_py32() {
  build_package_verify_py31 "$@"
}

# Post-install check for Python 3.3.x
build_package_verify_py33() {
  build_package_verify_py32 "$@"
}

# Post-install check for Python 3.4.x
build_package_verify_py34() {
  build_package_verify_py33 "$@"
}

# Post-install check that the readline extension was built.
build_package_verify_readline() {
  "$PYTHON_BIN" -c 'try:
    import readline
except ImportError:
    raise(ImportError("The Python readline extension was not compiled. Missing the GNU readline lib?"))
  ' >&4 2>&1
}

# Post-install check that the ssl extension was built.
build_package_verify_ssl() {
  "$PYTHON_BIN" -c 'try:
    import ssl
except ImportError:
    raise(ImportError("The Python ssl extension was not compiled. Missing the OpenSSL lib?"))
  ' >&4 2>&1
}

# Post-install check that the sqlite3 extension was built.
build_package_verify_sqlite3() {
  "$PYTHON_BIN" -c 'try:
    import sqlite3
except ImportError:
    raise(ImportError("The Python sqlite3 extension was not compiled. Missing the SQLite3 lib?"))
  ' >&4 2>&1
}

# Post-install check that the zlib extension was built.
build_package_verify_zlib() {
  "$PYTHON_BIN" -c 'try:
    import zlib
except ImportError:
    raise(ImportError("The Python zlib extension was not compiled. Missing the zlib?"))
  ' >&4 2>&1
}

# Post-install check that the bz2 extension was built.
build_package_verify_bz2() {
  "$PYTHON_BIN" -c 'try:
    import bz2
except ImportError:
    raise(ImportError("The Python bz2 extension was not compiled. Missing the bzip2 lib?"))
  ' >&4 2>&1
}

require_java() {
  local java="$(locate_java || true)"

  if [ -z "$java" ]; then
    local esc=$'\033'
    { echo
      echo "${esc}[1mERROR${esc}[0m: This package must be installed with java, but python-build couldn't"
      echo "find a suitable \`java\` executable on your system. Please install Java"
      echo "and try again."
      echo
    } >&3
    return 1
  fi

  export JAVA="$java"
}

locate_java() {
  local java javas
  IFS=: javas=($(javas_in_path))

  verify_java "$JAVA" ||
  verify_java "$(command -v java || true)" || {
    for java in "${javas[@]}"; do
      verify_java "$java" && break || true
    done
  }

  return 1
}

javas_in_path() {
  local java path paths
  local javas=()
  IFS=: paths=($PATH)

  shopt -s nullglob
  for path in "${paths[@]}"; do
    local java="$path"/java
    if [ -x "$java" ]; then
      javas["${#javas[@]}"]="$java"
    fi
  done
  shopt -u nullglob

  printf :%s "${javas[@]}"
}

verify_java() {
  local java="$1"
  if [ -z "$java" ]; then
    return 1
  fi

  if [ ! -x "$java" ]; then
    return 1
  fi

  echo "$java"
}

version() {
  echo "python-build ${PYTHON_BUILD_VERSION}"
}

usage() {
  { version
    echo "usage: python-build [-g|--debug] [-k|--keep] [-v|--verbose] definition prefix"
    echo "       python-build --definitions"
  } >&2

  if [ -z "$1" ]; then
    exit 1
  fi
}

list_definitions() {
  { for definition in "${PYTHON_BUILD_ROOT}/share/python-build/"*; do
      [ -f "${definition}" ] && echo "${definition##*/}"
    done
  } | sort
}



unset VERBOSE
unset KEEP_BUILD_PATH
PYTHON_BUILD_ROOT="$(abs_dirname "$0")/.."
unset DEBUG

parse_options "$@"

for option in "${OPTIONS[@]}"; do
  case "$option" in
  "h" | "help" )
    usage without_exiting
    { echo
      echo "  -k/--keep        Do not remove source tree after installation"
      echo "  -g/--debug       Build a debug version"
      echo "  -v/--verbose     Verbose mode: print compilation status to stdout"
      echo "  --definitions    List all built-in definitions"
      echo
    } >&2
    exit 0
    ;;
  "definitions" )
    list_definitions
    exit 0
    ;;
  "k" | "keep" )
    KEEP_BUILD_PATH=true
    ;;
  "v" | "verbose" )
    VERBOSE=true
    ;;
  "g" | "debug" )
    DEBUG=true
    ;;
  "version" )
    version
    exit 0
    ;;
  esac
done

DEFINITION_PATH="${ARGUMENTS[0]}"
if [ -z "$DEFINITION_PATH" ]; then
  usage
elif [ ! -e "$DEFINITION_PATH" ]; then
  BUILTIN_DEFINITION_PATH="${PYTHON_BUILD_ROOT}/share/python-build/${DEFINITION_PATH}"
  if [ -e "$BUILTIN_DEFINITION_PATH" ]; then
    DEFINITION_PATH="$BUILTIN_DEFINITION_PATH"
  else
    echo "python-build: definition not found: ${DEFINITION_PATH}" >&2
    exit 2
  fi
fi

PREFIX_PATH="${ARGUMENTS[1]}"
if [ -z "$PREFIX_PATH" ]; then
  usage
fi

if [ -z "$TMPDIR" ]; then
  TMP="/tmp"
else
  TMP="${TMPDIR%/}"
fi

if [ -z "$MAKE" ]; then
  export MAKE="make"
fi

if [ -n "$PYTHON_BUILD_CACHE_PATH" ] && [ -d "$PYTHON_BUILD_CACHE_PATH" ]; then
  PYTHON_BUILD_CACHE_PATH="${PYTHON_BUILD_CACHE_PATH%/}"
else
  unset PYTHON_BUILD_CACHE_PATH
fi

if [ -z "$PYTHON_BUILD_MIRROR_URL" ]; then
  PYTHON_BUILD_MIRROR_URL="http://yyuu.github.io/pythons"
else
  PYTHON_BUILD_MIRROR_URL="${PYTHON_BUILD_MIRROR_URL%/}"
fi

if [ -n "$PYTHON_BUILD_SKIP_MIRROR" ]; then
  unset PYTHON_BUILD_MIRROR_URL
fi

if echo test | compute_md5 >/dev/null; then
  HAS_MD5_SUPPORT=1
else
  unset HAS_MD5_SUPPORT
  unset PYTHON_BUILD_MIRROR_URL
fi

if [ -n "$DEBUG" ]; then
  CONFIGURE_OPTS+=" --with-pydebug"
fi

SEED="$(date "+%Y%m%d%H%M%S").$$"
LOG_PATH="${TMP}/python-build.${SEED}.log"
PYTHON_BIN="${PREFIX_PATH}/bin/python"
CWD="$(pwd)"

if [ -z $PYTHON_BUILD_BUILD_PATH ]; then
  BUILD_PATH="${TMP}/python-build.${SEED}"
else
  BUILD_PATH="$PYTHON_BUILD_BUILD_PATH"
fi

exec 4<> "$LOG_PATH" # open the log file at fd 4
if [ -n "$VERBOSE" ]; then
  tail -f "$LOG_PATH" &
  TAIL_PID=$!
  trap "kill $TAIL_PID" SIGINT SIGTERM EXIT
fi

export LDFLAGS="-L'${PREFIX_PATH}/lib' ${LDFLAGS}"
export CPPFLAGS="-I'${PREFIX_PATH}/include' ${CPPFLAGS}"

unset PYTHONHOME
unset PYTHONPATH

trap build_failed ERR
mkdir -p "$BUILD_PATH"
source "$DEFINITION_PATH"
[ -z "${KEEP_BUILD_PATH}" ] && rm -fr "$BUILD_PATH"
trap - ERR