#!/bin/bash

set -euo pipefail

SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"

#----------------------------------------------------------------------------------------------------------
# Headers on Host (Native)
#----------------------------------------------------------------------------------------------------------

function install_headers() {
    sudo apt install -y nlohmann-json3-dev wget curl cmake ninja-build mold

    # put libassert headers on the host.
    if [ ! -f /usr/local/lib/libassert.a ]; then
        git clone https://github.com/jeremy-rifkin/libassert.git
        git checkout v2.1.5
        mkdir libassert/build
        cd "libassert/build" || exit 1
        cmake .. -DCMAKE_BUILD_TYPE=Release
        make -j
        sudo make install
        cd ../..
        rm -rf libassert
    fi
}


#----------------------------------------------------------------------------------------------------------
# OpenSSL for musl cross toolchains
#----------------------------------------------------------------------------------------------------------

function install_openssl_musl() {
    OPENSSL_VERSION=3.5.0

    SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
    BUILD_DIR="${SCRIPT_DIR}/build"
    MUSL_CROSS_DIR="$HOME/.musl-cross"
    mkdir -p "$BUILD_DIR"

    # Helper: compare versions (returns 0 if $1 >= $2)
    version_ge() {
        [ "$1" = "$2" ] && return 0
        [ "$(printf '%s\n' "$1" "$2" | sort -V | head -n1)" = "$2" ]
    }

    # Find all installed musl cross toolchains
    TOOLCHAINS=()
    for tc in "$MUSL_CROSS_DIR"/*-linux-musl-cross; do
        [ -d "$tc" ] || continue
        arch=$(basename "$tc" | sed 's/-linux-musl-cross//')
        TOOLCHAINS+=("$arch")
    done

    if [ ${#TOOLCHAINS[@]} -eq 0 ]; then
        echo "No musl cross toolchains found in $MUSL_CROSS_DIR. Exiting."
        exit 1
    fi

    echo "Found musl cross toolchains: ${TOOLCHAINS[*]}"

    for ARCH in "${TOOLCHAINS[@]}"; do
        echo "==============================="
        echo "Checking OpenSSL for $ARCH..."
        echo "==============================="
        if [ "$ARCH" = "x86_64" ]; then
            MUSL_PREFIX="$MUSL_CROSS_DIR/x86_64-linux-musl-cross"
            OPENSSL_TARGET=linux-x86_64
        elif [ "$ARCH" = "aarch64" ]; then
            MUSL_PREFIX="$MUSL_CROSS_DIR/aarch64-linux-musl-cross"
            OPENSSL_TARGET=linux-aarch64
        else
            # Try to guess OpenSSL target for other musl toolchains
            OPENSSL_TARGET="linux-$ARCH"
            MUSL_PREFIX="$MUSL_CROSS_DIR/${ARCH}-linux-musl-cross"
        fi
        SYSROOT="$MUSL_PREFIX/${ARCH}-linux-musl/sysroot"
        CC="$MUSL_PREFIX/bin/${ARCH}-linux-musl-gcc"
        AR="$MUSL_PREFIX/bin/${ARCH}-linux-musl-ar"
        RANLIB="$MUSL_PREFIX/bin/${ARCH}-linux-musl-ranlib"

        SKIP_BUILD=0
        if [ -f "$SYSROOT/usr/lib/libssl.a" ]; then
            # Try to extract version from opensslv.h
            OPENSSLV_H="$SYSROOT/usr/include/openssl/opensslv.h"
            if [ -f "$OPENSSLV_H" ]; then
                INSTALLED_VERSION=$(grep '# *define *OPENSSL_VERSION_TEXT' "$OPENSSLV_H" | sed -E 's/.*OpenSSL ([0-9.]+)[^ ]*.*/\1/')
                if [ -n "$INSTALLED_VERSION" ]; then
                    echo "Found installed OpenSSL version: $INSTALLED_VERSION"
                    if version_ge "$INSTALLED_VERSION" "$OPENSSL_VERSION"; then
                        echo "OpenSSL $INSTALLED_VERSION is up-to-date (>= $OPENSSL_VERSION), skipping build for $ARCH."
                        SKIP_BUILD=1
                    else
                        echo "OpenSSL $INSTALLED_VERSION is older than $OPENSSL_VERSION, will rebuild."
                    fi
                else
                    echo "Could not determine installed OpenSSL version, will rebuild."
                fi
            else
                echo "No opensslv.h found, will rebuild."
            fi
        fi

        if [ "$SKIP_BUILD" -eq 1 ]; then
            echo
            continue
        fi

        cd "$BUILD_DIR"
        if [ ! -d "openssl-${OPENSSL_VERSION}" ]; then
            if [ ! -f "openssl-${OPENSSL_VERSION}.tar.gz" ]; then
                wget "https://www.openssl.org/source/openssl-${OPENSSL_VERSION}.tar.gz"
            fi
            tar xf "openssl-${OPENSSL_VERSION}.tar.gz"
        fi
        cd "openssl-${OPENSSL_VERSION}"

        # Clean previous build for this arch
        make clean || true

        echo "Configuring for $ARCH with sysroot $SYSROOT..."
        CC="$CC" AR="$AR" RANLIB="$RANLIB" ./Configure "$OPENSSL_TARGET" no-shared --prefix="$SYSROOT/usr"
        echo "Building..."
        make -j"$(nproc)"
        echo "Installing to $SYSROOT/usr ..."
        make install_sw
        cd "$BUILD_DIR"
        echo "Done for $ARCH."
        echo
        # Remove build dir for next arch to avoid cross contamination
        rm -rf "openssl-${OPENSSL_VERSION}"
        tar xf "openssl-${OPENSSL_VERSION}.tar.gz"
    done

    echo "OpenSSL built and installed for all detected musl toolchains."
}



# ----------------------------------------------------------------------------------------------------------
# MUSL CROSS COMPILERS
# ----------------------------------------------------------------------------------------------------------

function installmusl() {
    echo "Installing musl toolchain"

    # Set install directory
    if [ -n "$SUDO_USER" ] && [ "$SUDO_USER" != "root" ]; then
        USER_HOME=$(eval echo "~${SUDO_USER}")
    else
        USER_HOME="$HOME"
    fi
    INSTALL_DIR="$USER_HOME/.musl-cross"
    mkdir -p "$INSTALL_DIR"

    TMPDIR=$(mktemp -d)
    trap 'rm -rf "$TMPDIR"' EXIT

    function install_musl_cross() {
        local TOOLCHAIN="$1"
        local MUSL_CC_URL="https://musl.cc"
        if [ ! -d "$INSTALL_DIR/$TOOLCHAIN" ]; then
            echo "Downloading $TOOLCHAIN musl cross toolchain..."
            wget -nc -O "$TMPDIR/$TOOLCHAIN.tgz" "$MUSL_CC_URL/$TOOLCHAIN.tgz"
            tar -C "$INSTALL_DIR" -xvf "$TMPDIR/$TOOLCHAIN.tgz"
        fi
    }

    function check_path() {
        if [ -n "$SUDO_USER" ] && [ "$SUDO_USER" != "root" ]; then
            local BASHRC="$USER_HOME/.bashrc"
            local TOOLCHAIN="$1"
            local MUSL_PATH="$INSTALL_DIR/$TOOLCHAIN/bin"
            if ! echo "$PATH" | grep -q "$MUSL_PATH"; then
                echo "Adding $MUSL_PATH to PATH in $BASHRC"
                PATH_LINE="export PATH=\"$MUSL_PATH:\$PATH\""
                if ! grep -Fxq "$PATH_LINE" "$BASHRC"; then
                    echo "" >> "$BASHRC"
                    echo "# Add musl cross compilers to PATH for dropshell" >> "$BASHRC"
                    echo "$PATH_LINE" >> "$BASHRC"
                    
                    echo "Added musl cross compilers to $BASHRC"
                    echo "You should run 'source ~/.bashrc' to update your PATH"
                else
                    echo "You should run 'source ~/.bashrc' to update your PATH"
                fi
            fi
        fi
    }

    TOOLCHAIN_LIST=(
        "aarch64-linux-musl-cross"
        "x86_64-linux-musl-cross"
    )

    for TOOLCHAIN in "${TOOLCHAIN_LIST[@]}"; do
        install_musl_cross "$TOOLCHAIN"
        check_path "$TOOLCHAIN"
    done

    # Clean up
    rm -rf "$TMPDIR"
}



#----------------------------------------------------------------------------------------------------------
# Main
#----------------------------------------------------------------------------------------------------------

function main() {
    install_headers

    installmusl

    install_openssl_musl
}

main