#!/bin/sh
# /sbin/init — KubeSolo OS init system
# POSIX sh compatible (BusyBox ash)
#
# Boot stages are sourced from /usr/lib/kubesolo-os/init.d/ in numeric order.
# Each stage file must be a valid POSIX sh script.
# If any mandatory stage fails, the system drops to an emergency shell.
#
# Boot parameters (from kernel command line):
#   kubesolo.data=<device>    Persistent data partition (required)
#   kubesolo.debug            Enable verbose logging
#   kubesolo.shell            Drop to emergency shell immediately
#   kubesolo.nopersist        Run without persistent storage (RAM only)
#   kubesolo.cloudinit=<path> Path to cloud-init config
#   kubesolo.flags=<flags>    Extra flags for KubeSolo binary

set -e

# --- Switch root: escape initramfs so runc pivot_root works ---
# The kernel boots into an initramfs (rootfs), which is a special mount that
# doesn't support pivot_root. Container runtimes (runc) need pivot_root to
# set up container root filesystems. To fix this, we copy the rootfs to a
# tmpfs and switch_root to it. The sentinel file prevents infinite loops.
if [ ! -f /etc/.switched_root ]; then
    mount -t proc proc /proc 2>/dev/null || true
    mount -t sysfs sysfs /sys 2>/dev/null || true
    mount -t devtmpfs devtmpfs /dev 2>/dev/null || true
    mkdir -p /mnt/newroot
    mount -t tmpfs -o size=400M,mode=755 tmpfs /mnt/newroot
    echo "[init] Copying rootfs to tmpfs..." >&2
    # Copy each top-level directory explicitly (BusyBox cp -ax on rootfs is broken)
    for d in bin sbin usr lib lib64 etc var opt; do
        [ -d "/$d" ] && cp -a "/$d" /mnt/newroot/ 2>/dev/null || true
    done
    # Recreate mount point and special directories
    mkdir -p /mnt/newroot/proc /mnt/newroot/sys /mnt/newroot/dev
    mkdir -p /mnt/newroot/run /mnt/newroot/tmp /mnt/newroot/mnt
    touch /mnt/newroot/etc/.switched_root
    mount --move /proc /mnt/newroot/proc
    mount --move /sys /mnt/newroot/sys
    mount --move /dev /mnt/newroot/dev
    echo "[init] Switching root..." >&2
    exec switch_root /mnt/newroot /sbin/init
fi

# --- PATH setup ---
# Ensure /usr/local paths are in PATH (iptables, KubeSolo, etc.)
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
# iptables shared libraries live in /usr/local/lib
export LD_LIBRARY_PATH="/usr/local/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"

# --- Constants ---
INIT_LIB="/usr/lib/kubesolo-os"
INIT_STAGES="/usr/lib/kubesolo-os/init.d"
LOG_PREFIX="[kubesolo-init]"
DATA_MOUNT="/mnt/data"

# --- Parsed boot parameters (populated by 10-parse-cmdline.sh) ---
export KUBESOLO_DATA_DEV=""
export KUBESOLO_DEBUG=""
export KUBESOLO_SHELL=""
export KUBESOLO_NOPERSIST=""
export KUBESOLO_CLOUDINIT=""
export KUBESOLO_EXTRA_FLAGS=""
export KUBESOLO_PORTAINER_EDGE_ID=""
export KUBESOLO_PORTAINER_EDGE_KEY=""
export KUBESOLO_NOAPPARMOR=""

# --- Logging ---
log() {
    echo "$LOG_PREFIX $*" >&2
}

log_ok() {
    echo "$LOG_PREFIX [OK] $*" >&2
}

log_err() {
    echo "$LOG_PREFIX [ERROR] $*" >&2
}

log_warn() {
    echo "$LOG_PREFIX [WARN] $*" >&2
}

# --- Emergency shell ---
emergency_shell() {
    log_err "Boot failed: $*"
    log_err "Dropping to emergency shell. Type 'exit' to retry boot."
    exec /bin/sh
}

# --- Main boot sequence ---
log "KubeSolo OS v$(cat /etc/kubesolo-os-version 2>/dev/null || echo 'dev') starting..."

# Source shared functions
if [ -f "$INIT_LIB/functions.sh" ]; then
    . "$INIT_LIB/functions.sh"
fi

# Run init stages in order
for stage in "$INIT_STAGES"/*.sh; do
    [ -f "$stage" ] || continue
    stage_name="$(basename "$stage")"

    log "Running stage: $stage_name"

    if ! . "$stage"; then
        emergency_shell "Stage $stage_name failed"
    fi

    # Check for early shell request (parsed in 10-parse-cmdline.sh)
    if [ "$KUBESOLO_SHELL" = "1" ] && [ "$stage_name" = "10-parse-cmdline.sh" ]; then
        log "Emergency shell requested via boot parameter"
        exec /bin/sh
    fi

    log_ok "Stage $stage_name complete"
done

# If we get here, all stages ran but KubeSolo should have exec'd.
# This means 90-kubesolo.sh didn't exec (shouldn't happen).
emergency_shell "Init completed without exec'ing KubeSolo — this is a bug"