#!/usr/bin/env bash

#
# Configuration script to build the 2D_Engine for different platforms.
#
# Creates makefile configuration to build for target host.
#

#
# Project settings
#

CONFIG_FILE="config.mk"

#
# Main
#

set -e

exit_error_message()
{
    echo -e "\033[31merror\033[m: $1"
    exit 0
}

## Parse args
HOST="guess"
TARGET_HOST="guess"

for i in "$@"; do
    case $i in
      --target-host=*)
        TARGET_HOST="${i#*=}"
        shift
        ;;

      --current-host=*)
        HOST="${i#*=}"
        shift
        ;;

      --clean)
        CLEAN=1
        EXIT_AFTER_CLEAN=1
        shift
        ;;

      --reconfigure)
        CLEAN=1
        shift
        ;;

      -h|--help)
        echo "Usage : ./configure [OPTION]..."
        echo "Add submodules depending on target host platform and"
        echo "create makefile configuration to build for target host"
        echo
        echo -e "\033[1m  --target-host=\033[mHOST"
        echo -e "\tselect target host platform, default is \"guess\" and"
        echo -e "\twill try to configure for your current OS"
        echo -e "\033[1m  --current-host=\033[mHOST"
        echo -e "\tselect current host platform, default is \"guess\" and"
        echo -e "\twill try to detect your current OS"
        echo -e "\033[1m  --clean\033[m"
        echo -e "\tclean build, config, cache, etc, and exit"
        echo -e "\033[1m  --reconfigure\033[m"
        echo -e "\tcall clean, and configure"
        echo -e "\033[1m  -h, --help\033[m"
        echo -e "\tshow help and exit"
        exit 0
        ;;

      -*)
        exit_error_message "Unknown option $i"
        ;;

      *)
        ;;
    esac
done

## Clean
if [ -n "${CLEAN}" ]; then
    make clean-all
    rm -rf ${CONFIG_FILE}
fi

if [ -n "${EXIT_AFTER_CLEAN}" ]; then
    exit 0
fi

## Deduce current and target hosts
if [ "${HOST}" = "guess" ]; then
    case "${OSTYPE}" in
      linux*)
        HOST="linux"
        ;;
      msys*|cygwin*)
        HOST="windows"
        ;;
#      darwin*)
#        HOST="macos"
#        ;;
    *)
        exit_error_message "Current detected os is unsuppoted to build from: ${OSTYPE}\nUse --help for more informations."
        ;;
    esac
fi

echo "Configuring for host: ${HOST}"

# If target host is guess then configure for host
if [ "${TARGET_HOST}" = "guess" ]; then
    TARGET_HOST=${HOST}
fi

# Set host compiler and asset builder flags
case "${HOST}" in
  linux)
    HOST_CC=gcc
    HOST_PKG_CONFIG=pkg-config
    ASSET_BUILDER_CFLAGS=(
        "--std=c17"
        "-O2"
    )
    ASSET_BUILDER_LDFLAGS=()
    ASSET_BUILDER_LIBS=(
        "libpng|1.6.34"
        "json-c|0.11"
        )
    ;;

  windows)
    HOST_CC=x86_64-w64-mingw32-gcc
    HOST_PKG_CONFIG=x86_64-w64-mingw32-pkg-config
    ASSET_BUILDER_CFLAGS=(
        "--std=c17" "-O2"
    )
    ASSET_BUILDER_LDFLAGS=()
    ASSET_BUILDER_LIBS=(
        "libpng|1.6.34"
        "json-c|0.11"
    )
    ;;
  *)
    exit_error_message "Compiling from ${HOST} is not supported yet."
    ;;
esac

# Set target host compiler, outputs extensions and flags
case "${TARGET_HOST}" in
  linux)
    echo "Configuring for target: ${TARGET_HOST}"

    case "${HOST}" in
      linux)
        TARGET_HOST_CC=gcc
        TARGET_HOST_AR=ar
        TARGET_HOST_PKG_CONFIG=pkg-config
        TARGET_HOST_CFLAGS=(
            "--std=c17" "-Os"
            "-DASSET_FILE_NAME=\\\"\$(notdir \$(ASSET_OUTPUT))\\\""
        )
        TARGET_HOST_LDFLAGS=(
            "-lm"
        )
        OUTPUT_EXT=""
        DYNAMIC_LIB_OUTPUT_EXT=".so"
        STATIC_LIB_OUTPUT_EXT=".a"
        ;;

      *)
        exit_error_message "Cross compiling from ${HOST} for ${TARGET_HOST} is not supported yet."
        ;;
    esac

    TARGET_HOST_LIBS=(
        "sdl3|3.2.10"
    )
    ;;

  windows)
    echo "Configuring for target: ${TARGET_HOST}"

    case "${HOST}" in
      windows|linux)
        TARGET_HOST_CC=x86_64-w64-mingw32-gcc
        TARGET_HOST_AR=x86_64-w64-mingw32-gcc-ar
        TARGET_HOST_PKG_CONFIG=x86_64-w64-mingw32-pkg-config
        TARGET_HOST_CFLAGS=(
            "--std=c17" "-Os"
            "-DASSET_FILE_NAME=\\\"\$(notdir \$(ASSET_OUTPUT))\\\"" "-D_GNU_SOURCE=1"
        )
        TARGET_HOST_LDFLAGS=()
        OUTPUT_EXT=".exe"
        DYNAMIC_LIB_OUTPUT_EXT=".dll"
        STATIC_LIB_OUTPUT_EXT=".dll.a"
        ;;

      *)
        exit_error_message "Cross compiling from ${HOST} for ${TARGET_HOST} is not supported yet."
        ;;
    esac

    TARGET_HOST_LIBS=(
        "sdl3|3.3.4"
    )
    ;;

  fxcg50)
    echo "Configuring for target: ${TARGET_HOST}"

    case "${HOST}" in
      linux)
        TARGET_HOST_CC=sh-elf-gcc
        TARGET_HOST_AR=sh-elf-ar
        TARGET_HOST_CFLAGS=(
            "--std=c17" "-Os"
            "-DASSET_FILE_NAME=\\\"\$(notdir \$(ASSET_OUTPUT))\\\"" "-DFXCG50" "-DTARGET_FXCG50"
            "-mb" "-m4-nofpu"
            "-ffreestanding" "-nostdlib" "-fstrict-volatile-bitfields"
        )
        TARGET_HOST_LDFLAGS="-T fxcg50.ld"
        OUTPUT_EXT=""
        DYNAMIC_LIB_OUTPUT_EXT=".so"
        STATIC_LIB_OUTPUT_EXT=".a"
        ;;
      *)
        exit_error_message "Cross compiling from ${HOST} for ${TARGET_HOST} is not supported yet."
        ;;
    esac
    ;;

  *)
    exit_error_message "Unsupported target host: ${TARGET_HOST}"
esac

#
# Checks
#

echo

echo "Checking host compiler \"${HOST_CC}\"."
if ${HOST_CC} --version &> /dev/null; then
    echo "  ${HOST_CC} OK."
else
    exit_error_message "Compiler not working."
fi

echo "Checking asset builder libs."
for LIB in ${ASSET_BUILDER_LIBS[@]}; do
    LIB_NAME="$(echo ${LIB} | cut -d "|" -f 1)"
    LIB_MIN_VERSION="$(echo ${LIB} | cut -d "|" -f 2)"

    if ${HOST_PKG_CONFIG} --atleast-version "${LIB_MIN_VERSION}" "${LIB_NAME}"; then
        echo "  ${LIB_NAME} OK."
    else
        exit_error_message "Library ${LIB_NAME} version >= ${LIB_MIN_VERSION} not found."
    fi
done

echo "Checking target host compiler \"${TARGET_HOST_CC}\"."
if ${TARGET_HOST_CC} --version &> /dev/null; then
    echo "  ${TARGET_HOST_CC} OK."
else
    exit_error_message "Compiler not working."
fi

echo "Checking target host archiver \"${TARGET_HOST_AR}\"."
if ${TARGET_HOST_AR} --version &> /dev/null; then
    echo "  ${TARGET_HOST_AR} OK."
else
    exit_error_message "Compiler not working."
fi

echo "Checking target host libs."
for LIB in ${TARGET_HOST_LIBS[@]}; do
    LIB_NAME="$(echo ${LIB} | cut -d "|" -f 1)"
    LIB_MIN_VERSION="$(echo ${LIB} | cut -d "|" -f 2)"

    if ${TARGET_HOST_PKG_CONFIG} --atleast-version "${LIB_MIN_VERSION}" "${LIB_NAME}"; then
        echo "  ${LIB_NAME} OK."
    else
        exit_error_message "Library ${LIB_NAME} version >= ${LIB_MIN_VERSION} not found."
    fi
done

#
# Config file
#

echo

echo "Writing config file."
echo "${CONFIG_FILE}:"
echo "\`\`\`"

tee "${CONFIG_FILE}" <<EOF
# This file was generated by the configure script.

TARGET_HOST = ${TARGET_HOST}

OUTPUT_EXT = ${OUTPUT_EXT}
DYNAMIC_LIB_OUTPUT_EXT = ${DYNAMIC_LIB_OUTPUT_EXT}
STATIC_LIB_OUTPUT_EXT = ${STATIC_LIB_OUTPUT_EXT}

TARGET_HOST_CC = ${TARGET_HOST_CC}
TARGET_HOST_AR = ${TARGET_HOST_AR}

TARGET_HOST_CFLAGS = ${TARGET_HOST_CFLAGS[@]} $(${TARGET_HOST_PKG_CONFIG} --cflags $(echo ${TARGET_HOST_LIBS[@]} | tr " " "\n" | cut -d "|" -f 1))
TARGET_HOST_LDFLAGS = ${TARGET_HOST_LDFLAGS[@]} $(${TARGET_HOST_PKG_CONFIG} --libs $(echo ${TARGET_HOST_LIBS[@]} | tr " " "\n" | cut -d "|" -f 1))

HOST_CC = ${HOST_CC}

ASSET_BUILDER_CFLAGS = ${ASSET_BUILDER_CFLAGS[@]} $(${HOST_PKG_CONFIG} --cflags $(echo ${ASSET_BUILDER_LIBS[@]} | tr " " "\n" | cut -d "|" -f 1))
ASSET_BUILDER_LDFLAGS = ${ASSET_BUILDER_LDFLAGS[@]} $(${HOST_PKG_CONFIG} --libs $(echo ${ASSET_BUILDER_LIBS[@]} | tr " " "\n" | cut -d "|" -f 1))
EOF

if [ "${HOST}" = "windows" ]; then
tee -a "${CONFIG_FILE}" <<EOF

# OS specific options
ECHO_OPTION = -e
EOF
fi

echo "\`\`\`"