#!/bin/bash
# MARKUS MAIWALD (ARCHITECT) | VOXIS FORGE (AI)
# Rumpk Build Script - Multi-Architecture
# Supports: aarch64, x86_64, riscv64

set -e

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

# Default architecture
ARCH="${1:-aarch64}"

# Validate architecture
case "$ARCH" in
    aarch64|arm64)
        ARCH="aarch64"
        ZIG_TARGET="aarch64-freestanding-none"
        NIM_CPU="arm64"
        NIM_DEFINE="arm64"
        QEMU_CMD="qemu-system-aarch64 -M virt -cpu cortex-a57"
        UART_ADDR="0x09000000"
        ;;
    x86_64|amd64)
        ARCH="x86_64"
        ZIG_TARGET="x86_64-freestanding-none"
        NIM_CPU="amd64"
        NIM_DEFINE="amd64"
        QEMU_CMD="qemu-system-x86_64 -M q35"
        UART_ADDR="0x3F8"  # COM1
        ;;
    riscv64)
        ARCH="riscv64"
        ZIG_TARGET="riscv64-freestanding-none"
        NIM_CPU="riscv64"
        NIM_DEFINE="riscv64"
        QEMU_CMD="qemu-system-riscv64 -M virt"
        UART_ADDR="0x10000000"
        ;;
    *)
        echo "Usage: $0 [aarch64|x86_64|riscv64]"
        echo "Default: aarch64"
        exit 1
        ;;
esac

echo "╔═══════════════════════════════════════╗"
echo "║    RUMPK MULTI-ARCH BUILD v0.3        ║"
echo "║    Architecture: $ARCH                 "
echo "╚═══════════════════════════════════════╝"
echo ""

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

# =========================================================
# Step 1: Compile Zig L0 (HAL + Stubs)
# =========================================================
echo "[1/5] Compiling Zig L0 (HAL + libc stubs)..."

# Compile main.zig
zig build-obj \
    "$RUMPK_DIR/hal/main.zig" \
    -target $ZIG_TARGET \
    -O ReleaseSmall \
    -femit-bin="$BUILD_DIR/hal.o"

# Compile stubs.zig
zig build-obj \
    "$RUMPK_DIR/hal/stubs.zig" \
    -target $ZIG_TARGET \
    -O ReleaseSmall \
    -femit-bin="$BUILD_DIR/stubs.o"

echo "      → $BUILD_DIR/hal.o"
echo "      → $BUILD_DIR/stubs.o"

# =========================================================
# Step 2: Compile Context Switch Assembly
# =========================================================
echo "[2/5] Compiling context switch ($ARCH)..."

zig cc \
    -target $ZIG_TARGET \
    -c "$RUMPK_DIR/hal/arch/$ARCH/switch.S" \
    -o "$BUILD_DIR/switch.o"

echo "      → $BUILD_DIR/switch.o"

# =========================================================
# Step 3: Compile Nim L1 (Kernel + Fibers)
# =========================================================
echo "[3/5] Compiling Nim L1 (Kernel + Fibers)..."

nim c \
    --cpu:$NIM_CPU \
    --os:any \
    --mm:arc \
    --noMain:on \
    --cc:clang \
    --passC:"-target ${ZIG_TARGET/-freestanding-none/-unknown-none} -ffreestanding -fno-stack-protector -fno-builtin" \
    --passL:"-target ${ZIG_TARGET/-freestanding-none/-unknown-none} -nostdlib -ffreestanding" \
    --define:useMalloc \
    --define:StandaloneHeapSize=65536 \
    --define:$NIM_DEFINE \
    -d:release \
    -d:danger \
    --checks:off \
    --assertions:off \
    --boundChecks:off \
    --overflowChecks:off \
    --nimcache:"$BUILD_DIR/nimcache" \
    --path:"$RUMPK_DIR/core" \
    -c \
    "$RUMPK_DIR/core/kernel.nim"

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

# =========================================================
# Step 4: Compile Nim C files to objects
# =========================================================
echo "[4/5] Compiling Nim C files..."

for cfile in "$BUILD_DIR/nimcache"/*.c; do
    ofile="${cfile%.c}.o"
    zig cc \
        -target $ZIG_TARGET \
        -ffreestanding \
        -fno-stack-protector \
        -fno-builtin \
        -fno-sanitize=all \
        -I"$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 5: Link Everything
# =========================================================
echo "[5/5] Linking (freestanding, no libc)..."

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

# Select linker script based on architecture
LINKER_SCRIPT="$RUMPK_DIR/boot/linker.ld"
if [ -f "$RUMPK_DIR/boot/linker-$ARCH.ld" ]; then
    LINKER_SCRIPT="$RUMPK_DIR/boot/linker-$ARCH.ld"
fi

zig cc \
    -target $ZIG_TARGET \
    -nostdlib \
    -T "$LINKER_SCRIPT" \
    "$BUILD_DIR/hal.o" \
    "$BUILD_DIR/stubs.o" \
    "$BUILD_DIR/switch.o" \
    $NIM_OBJS \
    -o "$BUILD_DIR/rumpk-$ARCH.elf"

echo "      → $BUILD_DIR/rumpk-$ARCH.elf"

# =========================================================
# Done
# =========================================================
echo ""
echo "✅ Build complete for $ARCH!"
echo ""
echo "Run with:"
echo "  $QEMU_CMD -nographic -kernel $BUILD_DIR/rumpk-$ARCH.elf"