#!/bin/bash
set -euo pipefail

# Path to the variables log file
VARIABLES_LOG="/rescue/variables.log"

# Auto-elevate script if not running as root
if [ "$EUID" -ne 0 ]; then
    echo "🔒 Root privileges required. Re-running with sudo..."
    exec sudo "$0" "$@"
fi

# Check if variables log file exists and ask if user wants to reload them
if [ -f "$VARIABLES_LOG" ]; then
    read -p "Found saved variables. Do you want to reload them? (y/n): " reload_choice
    if [[ "$reload_choice" == "y" || "$reload_choice" == "Y" ]]; then
        echo "Reloading saved variables from $VARIABLES_LOG..."

        # Reload the variables from the file
        source "$VARIABLES_LOG"

        # Check if any variable is missing after loading
        if [ -z "${partition:-}" ] || [ -z "${efi:-}" ] || [ -z "${home:-}" ]; then
            echo "❌ One or more required variables are missing from the log file. Please re-enter them."
            exit 1
        fi
        echo "Successfully reloaded variables:"
        echo "  OS Partition: $partition"
        echo "  EFI Partition: $efi"
        echo "  Home Partition: $home"
    else
        echo "Proceeding with fresh input..."
    fi
fi

# Show block devices to assist user if variables aren't loaded
lsblk

# Prompt for partitions if variables weren't reloaded
if [ -z "${partition:-}" ]; then
    read -p "Enter the defective OS partition (e.g., sda2): " partition
fi
if [ -z "${efi:-}" ]; then
    read -p "Enter the EFI partition (e.g., sda1): " efi
fi
if [ -z "${home:-}" ]; then
    read -p "Enter the Home partition (e.g., sda3): " home
fi

# Save the variables to a file for later use (in key=value format)
echo "partition=\"$partition\"" > "$VARIABLES_LOG"
echo "efi=\"$efi\"" >> "$VARIABLES_LOG"
echo "home=\"$home\"" >> "$VARIABLES_LOG"
echo "Variables saved to $VARIABLES_LOG."

# Check and create /rescue directory if not exists
if [ -d /rescue ]; then
    echo "/rescue exists already, continuing..."
else
    echo "Creating /rescue directory..."
    mkdir -p /rescue
fi

# Ensure necessary mount points are available before mounting
mkdir -p /rescue/boot
mkdir -p /rescue/home
mkdir -p /rescue/proc
mkdir -p /rescue/sys
mkdir -p /rescue/dev/pts
mkdir -p /rescue/run

# Mount the partitions
echo "Mounting OS partition..."
mount "/dev/$partition" /rescue
echo "Mounting EFI partition..."
mount "/dev/$efi" /rescue/boot
echo "Mounting Home partition..."
mount "/dev/$home" /rescue/home

# Mount virtual filesystems for chroot
echo "Mounting /proc..."
mount -t proc proc /rescue/proc
echo "Mounting /sys..."
mount -t sysfs sys /rescue/sys
echo "Mounting /dev..."
mount -o bind /dev /rescue/dev
echo "Mounting /dev/pts..."
mount -t devpts pts /rescue/dev/pts
echo "Mounting /run..."
mount -o bind /run /rescue/run

# Ensure /etc exists and link resolv.conf for DNS inside chroot
mkdir -p /rescue/etc
ln -sf /etc/resolv.conf /rescue/etc/resolv.conf

# Final instructions
echo
echo "✅ The chroot environment is ready."
echo "➡️  To start chroot, run: chroot /rescue"
echo "❌ When you're done, unmount everything with: umount -R /rescue"