#!/bin/bash
# Rumpk Build Script
# Builds Zig L0 + Nim L1 into a single ELF

set -e

RUMPK_DIR="$(cd "$(dirname "$0")" && pwd)"
BUILD_DIR="$RUMPK_DIR/build"

echo "╔═══════════════════════════════════════╗"
echo "║       RUMPK BUILD SYSTEM v0.1         ║"
echo "╚═══════════════════════════════════════╝"
echo ""

# Create build directory
mkdir -p "$BUILD_DIR"
mkdir -p "$BUILD_DIR/nimcache"

# =========================================================
# Step 1: Compile Zig L0 (HAL)
# =========================================================
echo "[1/3] Compiling Zig L0 (HAL)..."

zig build-obj \
    "$RUMPK_DIR/hal/main.zig" \
    -target aarch64-freestanding-none \
    -O ReleaseSmall \
    -femit-bin="$BUILD_DIR/hal.o"

echo "      → $BUILD_DIR/hal.o"

# =========================================================
# Step 2: Compile Nim L1 (Kernel)
# =========================================================
echo "[2/3] Compiling Nim L1 (Kernel)..."

# Note: This requires careful Nim configuration for freestanding
# For now, we'll try direct compilation with clang

nim c \
    --cpu:arm64 \
    --os:any \
    --mm:arc \
    --noMain:on \
    --cc:clang \
    --passC:"-target aarch64-unknown-none -ffreestanding -fno-stack-protector -fno-builtin" \
    --passL:"-target aarch64-unknown-none -nostdlib -ffreestanding" \
    --define:useMalloc \
    --define:StandaloneHeapSize=65536 \
    -d:release \
    -d:danger \
    --nimcache:"$BUILD_DIR/nimcache" \
    --path:"$RUMPK_DIR/core" \
    -c \
    "$RUMPK_DIR/core/kernel.nim"

echo "      → $BUILD_DIR/nimcache/*.c"

# =========================================================
# Step 3: Compile Nim C files to objects
# =========================================================
echo "[3/4] Compiling Nim C files..."

# First compile cstubs.c
echo "      Compiling cstubs.c..."
zig cc \
    -target aarch64-freestanding-none \
    -ffreestanding \
    -fno-builtin \
    -I"$RUMPK_DIR/core/include" \
    -c "$RUMPK_DIR/core/cstubs.c" \
    -o "$BUILD_DIR/cstubs.o"

# Now compile Nim C files
for cfile in "$BUILD_DIR/nimcache"/*.c; do
    ofile="${cfile%.c}.o"
    zig cc \
        -target aarch64-freestanding-none \
        -ffreestanding \
        -fno-stack-protector \
        -fno-builtin \
        -I"$RUMPK_DIR/core/include" \
        -I/usr/lib/nim \
        -I"$RUMPK_DIR/core" \
        -c "$cfile" \
        -o "$ofile" 2>&1 || true
done

echo "      → $BUILD_DIR/nimcache/*.o"

# =========================================================
# Step 4: Link Everything
# =========================================================
echo "[4/4] Linking..."

# Collect all Nim object files
NIM_OBJS=$(find "$BUILD_DIR/nimcache" -name "*.o" 2>/dev/null | tr '\n' ' ')

if [ -z "$NIM_OBJS" ]; then
    echo "ERROR: No Nim object files found!"
    exit 1
fi

zig cc \
    -target aarch64-freestanding-none \
    -nostdlib \
    -T "$RUMPK_DIR/boot/linker.ld" \
    "$BUILD_DIR/hal.o" \
    "$BUILD_DIR/cstubs.o" \
    $NIM_OBJS \
    -o "$BUILD_DIR/rumpk.elf"

echo "      → $BUILD_DIR/rumpk.elf"

# =========================================================
# Done
# =========================================================
echo ""
echo "✅ Build complete!"
echo ""
echo "Run with:"
echo "  qemu-system-aarch64 -M virt -cpu cortex-a57 -nographic -kernel $BUILD_DIR/rumpk.elf"