#!/usr/bin/env bash
# ── scripts/fetch-libsodium.sh ──────────────────────────────────────────────
# Download and build libsodium from source for the target platform.
# Called automatically by CMake when the pre-built library is not found,
# or manually before building:
#
#   ./scripts/fetch-libsodium.sh              # native (Linux/macOS)
#   ./scripts/fetch-libsodium.sh --mac        # macOS cross-compile via osxcross
#   ./scripts/fetch-libsodium.sh --win        # Windows cross-compile via MinGW
#
# Output:  libs/libsodium/  (include/ + lib/libsodium.a)
# ─────────────────────────────────────────────────────────────────────────────
set -euo pipefail

SODIUM_VERSION="1.0.18"
SODIUM_SHA256="6f504490b342a4f8a4c4a02fc9b866cbef8622d5df4e5452b46be121e46636c1"
SODIUM_URL="https://github.com/jedisct1/libsodium/releases/download/1.0.18-RELEASE/libsodium-${SODIUM_VERSION}.tar.gz"

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PROJECT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"

TARGET="native"
while [[ $# -gt 0 ]]; do
    case $1 in
        --mac)  TARGET="mac";  shift ;;
        --win)  TARGET="win";  shift ;;
        *)      echo "Unknown option: $1"; exit 1 ;;
    esac
done

# ── Output directories ──────────────────────────────────────────────────────
case "$TARGET" in
    mac) INSTALL_DIR="$PROJECT_DIR/libs/libsodium-mac" ;;
    win) INSTALL_DIR="$PROJECT_DIR/libs/libsodium-win" ;;
    *)   INSTALL_DIR="$PROJECT_DIR/libs/libsodium"     ;;
esac

# Skip if already built
if [[ -f "$INSTALL_DIR/lib/libsodium.a" ]]; then
    echo "[fetch-libsodium] Already present: $INSTALL_DIR/lib/libsodium.a"
    exit 0
fi

# ── Download ────────────────────────────────────────────────────────────────
TARBALL="$PROJECT_DIR/libs/libsodium-${SODIUM_VERSION}.tar.gz"
SRC_DIR="$PROJECT_DIR/libs/libsodium-${SODIUM_VERSION}"

if [[ ! -f "$TARBALL" ]]; then
    echo "[fetch-libsodium] Downloading libsodium ${SODIUM_VERSION}..."
    curl -fSL -o "$TARBALL" "$SODIUM_URL"
fi

# Verify checksum
echo "$SODIUM_SHA256  $TARBALL" | sha256sum -c - || {
    echo "[fetch-libsodium] ERROR: SHA256 mismatch! Removing corrupted download."
    rm -f "$TARBALL"
    exit 1
}

# ── Extract ─────────────────────────────────────────────────────────────────
if [[ ! -d "$SRC_DIR" ]]; then
    echo "[fetch-libsodium] Extracting..."
    tar -xzf "$TARBALL" -C "$PROJECT_DIR/libs/"
fi

# ── Configure & build ───────────────────────────────────────────────────────
cd "$SRC_DIR"

CONFIGURE_ARGS=(
    --prefix="$INSTALL_DIR"
    --disable-shared
    --enable-static
    --with-pic
)

case "$TARGET" in
    mac)
        # Cross-compile for macOS via osxcross
        if [[ -z "${OSXCROSS:-}" ]]; then
            for try in "$HOME/osxcross" "/opt/osxcross" "$PROJECT_DIR/osxcross"; do
                [[ -d "$try/target" ]] && OSXCROSS="$try" && break
            done
        fi
        if [[ -z "${OSXCROSS:-}" ]]; then
            echo "[fetch-libsodium] ERROR: osxcross not found. Set OSXCROSS=/path/to/osxcross"
            exit 1
        fi
        export PATH="$OSXCROSS/target/bin:$PATH"

        # Detect osxcross triple
        TRIPLE=$(ls "$OSXCROSS/target/bin/" | grep -o 'x86_64-apple-darwin[0-9]*' | head -1)
        [[ -z "$TRIPLE" ]] && TRIPLE="x86_64-apple-darwin22"

        CONFIGURE_ARGS+=(--host="$TRIPLE")
        export CC="${TRIPLE}-cc"
        export CXX="${TRIPLE}-c++"
        export AR="${TRIPLE}-ar"
        export RANLIB="${TRIPLE}-ranlib"
        ;;
    win)
        # Cross-compile for Windows via MinGW
        CONFIGURE_ARGS+=(--host=x86_64-w64-mingw32)
        # Prefer the posix-thread variant if available
        if command -v x86_64-w64-mingw32-gcc-posix &>/dev/null; then
            export CC=x86_64-w64-mingw32-gcc-posix
            export CXX=x86_64-w64-mingw32-g++-posix
        else
            export CC=x86_64-w64-mingw32-gcc
            export CXX=x86_64-w64-mingw32-g++
        fi
        export AR=x86_64-w64-mingw32-ar
        export RANLIB=x86_64-w64-mingw32-ranlib
        # Disable _FORTIFY_SOURCE — MinGW doesn't provide __memcpy_chk etc.
        export CFLAGS="${CFLAGS:-} -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0"
        ;;
esac

echo "[fetch-libsodium] Configuring for target: $TARGET ..."
./configure "${CONFIGURE_ARGS[@]}" > /dev/null

echo "[fetch-libsodium] Building..."
make -j"$(nproc)" > /dev/null 2>&1

echo "[fetch-libsodium] Installing to $INSTALL_DIR ..."
make install > /dev/null

# ── Cleanup ─────────────────────────────────────────────────────────────────
cd "$PROJECT_DIR"
rm -rf "$SRC_DIR"
rm -f "$TARBALL"

echo "[fetch-libsodium] Done: $INSTALL_DIR/lib/libsodium.a"