#!/bin/bash

# BBeOS Minimal Root Filesystem Build Script
# Creates a BusyBox-based initramfs for BlackBerry Classic Q20

set -e

echo "Building minimal root filesystem for BBeOS..."

# Configuration
ROOTFS_DIR="rootfs"
BUSYBOX_VERSION="1.36.1"
BUSYBOX_URL="https://busybox.net/downloads/busybox-${BUSYBOX_VERSION}.tar.bz2"
BUSYBOX_DIR="busybox-${BUSYBOX_VERSION}"

# Set up environment
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabihf-

# Create directories
echo "Creating directories..."
rm -rf ${ROOTFS_DIR}
mkdir -p ${ROOTFS_DIR}/{bin,dev,etc,lib,proc,sys,tmp,usr/bin,usr/sbin}

# Download and build BusyBox
echo "Downloading BusyBox ${BUSYBOX_VERSION}..."
if [ ! -f "${BUSYBOX_DIR}.tar.bz2" ]; then
    wget ${BUSYBOX_URL}
fi

if [ ! -d "${BUSYBOX_DIR}" ]; then
    tar xf ${BUSYBOX_DIR}.tar.bz2
fi

echo "Building BusyBox..."
cd ${BUSYBOX_DIR}

# Configure BusyBox
make defconfig
sed -i 's/# CONFIG_STATIC is not set/CONFIG_STATIC=y/' .config
sed -i 's/# CONFIG_FEATURE_PREFER_APPLETS is not set/CONFIG_FEATURE_PREFER_APPLETS=y/' .config
sed -i 's/# CONFIG_FEATURE_SH_STANDALONE is not set/CONFIG_FEATURE_SH_STANDALONE=y/' .config

# Build BusyBox
make -j$(nproc)
make install

# Copy BusyBox to rootfs
echo "Installing BusyBox to rootfs..."
cp busybox ../${ROOTFS_DIR}/bin/
cd ..

# Create init script
echo "Creating init script..."
cat > ${ROOTFS_DIR}/init << 'EOF'
#!/bin/sh

# BBeOS Init Script
echo "BBeOS starting..."

# Mount essential filesystems
mount -t proc none /proc
mount -t sysfs none /sys
mount -t tmpfs none /tmp

# Create device nodes
mknod /dev/console c 5 1
mknod /dev/null c 1 3
mknod /dev/zero c 1 5
mknod /dev/tty c 5 0
mknod /dev/tty0 c 4 0
mknod /dev/ttyMSM0 c 251 0

# Set up console
exec 0</dev/console
exec 1>/dev/console
exec 2>/dev/console

echo "BBeOS root filesystem loaded"
echo "Welcome to BBeOS on BlackBerry Classic Q20!"

# Start shell
exec /bin/sh
EOF

chmod +x ${ROOTFS_DIR}/init

# Create basic configuration files
echo "Creating configuration files..."

# /etc/passwd
cat > ${ROOTFS_DIR}/etc/passwd << 'EOF'
root:x:0:0:root:/root:/bin/sh
EOF

# /etc/group
cat > ${ROOTFS_DIR}/etc/group << 'EOF'
root:x:0:
EOF

# /etc/hostname
echo "bbeos-q20" > ${ROOTFS_DIR}/etc/hostname

# /etc/hosts
cat > ${ROOTFS_DIR}/etc/hosts << 'EOF'
127.0.0.1 localhost
127.0.1.1 bbeos-q20
EOF

# Create symlinks for BusyBox
echo "Creating BusyBox symlinks..."
cd ${ROOTFS_DIR}/bin
for cmd in sh ls cat echo mount umount mknod chmod chown; do
    ln -sf busybox $cmd
done
cd ../..

# Create initramfs
echo "Creating initramfs..."
cd ${ROOTFS_DIR}
find . | cpio -o -H newc | gzip > ../initramfs.img
cd ..

echo "Root filesystem build complete!"
echo "Files created:"
echo "  - rootfs/ (root filesystem directory)"
echo "  - initramfs.img (compressed initramfs)"
echo "  - busybox-${BUSYBOX_VERSION}/ (BusyBox source and build)"