#!/bin/bash

################################################################
# Basic settings.
################################################################
VER_PYTHON="3.7.0"
VER_PYTHON_SHORT="3.7"
VER_OPENSSL="1.0.2p"
VER_SQLITE="3250000"
VER_ZLIB="1.2.11"
VER_PYTHON_LIB="${VER_PYTHON_SHORT}m"

################################################################
# DO NOT TOUCH FOLLOWING CODE
################################################################

FILE_PYTHON_STATIC_LIB="libpython${VER_PYTHON_LIB}.a"

PATH_ROOT=$(cd "$(dirname "$0")"/..; pwd)
PATH_EXT=${PATH_ROOT}/external
PATH_DOWNLOAD=${PATH_EXT}/_download_
PATH_TMP=${PATH_EXT}/linux/tmp
PATH_FIX=${PATH_EXT}/fix-external
PATH_RELEASE=${PATH_EXT}/linux/release


PY_PATH_SRC=${PATH_TMP}/Python-${VER_PYTHON}
OSSL_PATH_SRC=${PATH_TMP}/openssl-${VER_OPENSSL}
PATH_SRC_SQLITE=${PATH_TMP}/sqlite-autoconf-${VER_SQLITE}

function on_error()
{
	echo -e "\033[01m\033[31m"
	echo "==================[ !! ERROR !! ]=================="
	echo -e $1
	echo "==================================================="
	echo -e "\033[0m"
	exit 1
}

function setp_build_git()
{
	# su -s
	# yum install zlib-devel expat-devel libcurl-devel
	# make prefix=/usr/local
	# make prefix=/usr/local install
	echo 'skip build git now.'
}

function dlfile()
{
	echo -n "Downloading $1 ..."
	if [ ! -f "$4/$3" ]; then
		echo ""
		# curl --insecure https://www.python.org/ftp/python/3.7.0/${VER_PYTHON}.tgz -o "${PATH_PYTHON}/${VER_PYTHON}.tgz"
		echo wget $2$3 -O "$4/$3"
		wget --no-check-certificate $2$3 -O "$4/$3"

		if [ ! -f "$4/$3" ]; then
			on_error "Can not download $1: $3"
		fi
	else
		echo " already exists, skip."
	fi
}

function step_download_files()
{
	echo "download necessary source tarball ..."

	if [ ! -d "${PATH_DOWNLOAD}" ]; then
		mkdir -p "${PATH_DOWNLOAD}"
		if [ ! -d "${PATH_DOWNLOAD}" ]; then
			on_error "Can not create folder for download files."
		fi
	fi

	dlfile "python source tarball"  "https://www.python.org/ftp/python/${VER_PYTHON}/" "Python-${VER_PYTHON}.tgz" ${PATH_DOWNLOAD}
	dlfile "openssl source tarball" "https://www.openssl.org/source/" "openssl-${VER_OPENSSL}.tar.gz" ${PATH_DOWNLOAD}
	dlfile "sqlite source tarball"  "http://sqlite.org/2018/" "sqlite-autoconf-${VER_SQLITE}.tar.gz" ${PATH_DOWNLOAD}
	dlfile "zlib source tarball"    "https://www.zlib.net/" "zlib-${VER_ZLIB}.tar.gz" ${PATH_DOWNLOAD}
}


function step_prepare_source()
{
	echo "prepare source ..."

	if [ ! -d "${PATH_TMP}" ]; then
		mkdir -p "${PATH_TMP}"
		if [ ! -d "${PATH_TMP}" ]; then
			on_error "Can not create folder for tmp files."
		fi
	fi

	if [ ! -d "${PATH_TMP}/Python-${VER_PYTHON}" ]; then
		tar -zxvf "${PATH_DOWNLOAD}/Python-${VER_PYTHON}.tgz" -C "${PATH_TMP}"
	fi

	if [ ! -d "${PATH_TMP}/openssl-${VER_OPENSSL}" ]; then
		tar -zxvf "${PATH_DOWNLOAD}/openssl-${VER_OPENSSL}.tar.gz" -C "${PATH_TMP}"
	fi

	if [ ! -d "${PATH_TMP}/Python-${VER_PYTHON}/Modules/_sqlite/sqlite3" ]; then
		tar -zxvf "${PATH_DOWNLOAD}/sqlite-autoconf-${VER_SQLITE}.tar.gz" -C "${PATH_TMP}"
		mv "${PATH_TMP}/sqlite-autoconf-${VER_SQLITE}" "${PATH_TMP}/Python-${VER_PYTHON}/Modules/_sqlite/sqlite3"
	fi

	if [ ! -d "${PATH_TMP}/Python-${VER_PYTHON}/Modules/zlib" ]; then
		tar -zxvf "${PATH_DOWNLOAD}/zlib-${VER_ZLIB}.tar.gz" -C "${PATH_TMP}"
		mv "${PATH_TMP}/zlib-${VER_ZLIB}" "${PATH_TMP}/Python-${VER_PYTHON}/Modules/zlib"
	fi

	if [ ! -d "${PATH_TMP}/Python-${VER_PYTHON}" ]; then
		on_error "Can not prepare source code for build Python."
	fi
	if [ ! -d "${PATH_TMP}/openssl-${VER_OPENSSL}" ]; then
		on_error "Can not prepare source code for build OpenSSL."
	fi
	if [ ! -d "${PATH_TMP}/Python-${VER_PYTHON}/Modules/_sqlite/sqlite3" ]; then
		on_error "Can not prepare source code for build sqlite3 module for Python."
	fi

	cp "${PATH_FIX}/Python-${VER_PYTHON}/Modules/Setup.dist" "${PY_PATH_SRC}/Modules/Setup.dist"
	cp "${PATH_FIX}/Python-${VER_PYTHON}/Modules/Setup.dist" "${PY_PATH_SRC}/Modules/Setup"
	cp "${PATH_FIX}/Python-${VER_PYTHON}/Modules/_sqlite/cache.h" "${PY_PATH_SRC}/Modules/_sqlite/cache.h"
	cp "${PATH_FIX}/Python-${VER_PYTHON}/Modules/_sqlite/prepare_protocol.h" "${PY_PATH_SRC}/Modules/_sqlite/prepare_protocol.h"

	echo "prepare source done"
}

function step_build_openssl()
{
	echo -n "build openssl static library ..."

	if [ ! -f "${PATH_RELEASE}/lib/libssl.a" ] || [ ! -f "${PATH_RELEASE}/lib/libcrypto.a" ]; then
		echo ""
		cd "${OSSL_PATH_SRC}"
		./config -fPIC --prefix=${PATH_RELEASE} --openssldir=${PATH_RELEASE}/openssl no-zlib no-shared
		make
		make install
		cd "${PATH_ROOT}"

		if [ ! -f "${PATH_RELEASE}/lib/libssl.a" ] || [ ! -f "${PATH_RELEASE}/lib/libcrypto.a" ]; then
			on_error "Build openssl failed."
		fi

	else
		echo " already exists, skip."
	fi
}

function step_build_python()
{
	echo -n "build python static library ..."

	if [ ! -f "${PATH_RELEASE}/lib/${FILE_PYTHON_STATIC_LIB}" ]; then
	    echo ""

        echo " ... configure zlib..."
		cd "${PY_PATH_SRC}/Modules/zlib"
		./configure --prefix=${PATH_RELEASE}

		cd "${PY_PATH_SRC}"
        echo " ... configure python..."
		LDFLAGS=-lrt ./configure --prefix=${PATH_RELEASE} --disable-shared --enable-optimizations --with-openssl=${PATH_RELEASE}

        echo " ... build python..."
		make

        echo " ... install python..."
		make altinstall
		cd "${PATH_ROOT}"

		if [ ! -f "${PATH_RELEASE}/lib/${FILE_PYTHON_STATIC_LIB}" ]; then
			on_error "Build python failed."
		fi

	else
		echo " already exists, skip."
	fi
}

function step_finalize()
{
	echo "finalize ..."

	if [ ! -d "${PATH_RELEASE}/lib/python${VER_PYTHON_SHORT}/site-packages" ]; then
		on_error "something goes wrong."
	fi
}


step_download_files
step_prepare_source
step_build_openssl
step_build_python
step_finalize