#!/bin/bash

# Requires ideviceinfo (libimobiledevice), pzb, jtool2, jq

build_kernel_string () {
	# $1 = product type ie. iPhone12,1
	# $2 = product version ie. 13.2.2

	short_product_type=$(echo "$1" | sed 's/iPhone//g; s/iPad//g; s/,//g')

	short_product_version=$(echo "$2" | sed 's/\.//g')

	echo "$short_product_type-$short_product_version"
}

find_kernel_file() {
	# $1 = URL string
	# $2 = HardwareModel

	pzb -g BuildManifest.plist "$1" 1>/dev/null

	found_kernel_file=""

	ctr=0
	while true; do
		plist_parse=$(plutil -extract BuildIdentities.$ctr.Info.DeviceClass xml1 -o - BuildManifest.plist)

		if [[ ! "$?" -eq "0" ]]; then
			break
		fi

		curr_id=$(echo $plist_parse | sed -n "s/.*<string>\(.*\)<\/string>.*/\1/p" | tr [a-z] [A-Z])

		kernel_file=$(plutil -extract BuildIdentities.$ctr.Manifest.KernelCache.Info.Path xml1 -o - BuildManifest.plist | sed -n "s/.*<string>\(.*\)<\/string>.*/\1/p")

		if [[ "$2" == "$curr_id" ]]; then
			found_kernel_file=$kernel_file
			break
		fi

		((ctr++))
	done

	rm BuildManifest.plist

	if [[ "$found_kernel_file" == "" ]]; then
		echo "Failed to find kernel file from BuildManifest for model: $2"
		exit 1
	fi

	echo "$found_kernel_file"
}

if [[ "$#" == "0" ]]; then
	echo "Usage: pullkernel [uuid] {version}"
	exit 0
fi

target_uuid=$1
echo "Pulling kernel for $target_uuid..."

device_info=$(ideviceinfo -u $target_uuid)

if [[ "$device_info" == ERROR* ]]; then
	echo "Failed to find device with UUID $target_uuid!"
	exit 0
fi

product_type=$(echo "$device_info" | grep ProductType | sed 's/ProductType: //g')
device_name=$(echo "$device_info" | grep DeviceName | sed 's/DeviceName: //g')
product_version=$(echo "$device_info" | grep ProductVersion | sed 's/ProductVersion: //g')
build_version=$(echo "$device_info" | grep BuildVersion | sed 's/BuildVersion: //g')
hardware_model=$(echo "$device_info" | grep HardwareModel | sed 's/HardwareModel: //g')

if [[ "$#" == "2" ]]; then
	requested_version="$2"
	echo "Finding Build ID for requested version $requested_version..."

	all_ipsw_info=$(curl https://api.ipsw.me/v4/device/$product_type?type=ipsw 2>/dev/null)
	build_id=$(echo "$all_ipsw_info" | jq -r '.firmwares[] | select (.version == "'$requested_version'") | .buildid')

	echo "Found Build ID: $build_id"

	product_version="$requested_version"
	build_version="$build_id"		
fi

kernel_string=$(build_kernel_string $product_type $product_version)

echo "Device name:     $device_name"
echo "Product type:    $product_type"
echo "Product version: $product_version"
echo "Build version:   $build_version"
echo "Kernel string:   $kernel_string"

final_kernel_path="/Users/ben/Desktop/kernels/$kernel_string"

if [[ -e $final_kernel_path ]]; then
	echo "Kernel already found, exiting..."
	exit 0
fi

# Download the kernel

cd /tmp 

url_string="https://api.ipsw.me/v4/ipsw/download/$product_type/$build_version"

echo "URL: $url_string"
echo "Fetching files..."

pzb_kernel_string=$(find_kernel_file $url_string $hardware_model)

# pzb_kernel_string=$(pzb -l "$url_string" | grep kernelcache | tail -1 | cut -d' ' -f5)

if [[ $(echo $pzb_kernel_string | wc -c) -lt 3 ]]; then
	echo "Failed to find kernel string."
	exit 0
fi

echo "Pulling kernel file $pzb_kernel_string..."

pzb -g $pzb_kernel_string $url_string 

if [[ ! -e $pzb_kernel_string ]]; then
	echo "Failed to download kernel file."
	exit 0
fi

echo "Decompressing with jtool2..."

jtool2 -dec $pzb_kernel_string

if [[ ! -e kernel ]]; then
	echo "Failed to decompress kernel file."
	exit 0
fi

mv kernel $final_kernel_path

echo
listdevices
echo

echo "Complete!"