#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-or-later

set -eu

script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
source_dir=$(CDPATH= cd -- "$script_dir/.." && pwd)
build_root=${A6_RECOVERY_BUILD_DIR:-"$source_dir/build/macos-recovery"}
prefix=${A6_RECOVERY_PREFIX:-"$source_dir/build/limd-prefix"}
downloads="$build_root/downloads"

libirecovery_commit=95dec3aa25b1e30654ca107eb971971f6a216520
libirecovery_sha256=fcd91f2d5c6c3d70bba5b6f790ae37e
libirecovery_sha256=${libirecovery_sha256}dcc2ff9419ac56de67770bb5f1cc2eca9
idevicerestore_commit=540c352c4c44896f7415abef87a166e8bbaea9b0
idevicerestore_sha256=d971449c0838fe6733e6cd18268ffa2e5
idevicerestore_sha256=${idevicerestore_sha256}499b8d9034e10cf2984c2c5835913b3

libirecovery_archive="$downloads/libirecovery-$libirecovery_commit.tar.gz"
idevicerestore_archive="$downloads/idevicerestore-$idevicerestore_commit.tar.gz"
github_base=https://github.com/libimobiledevice
libirecovery_url="$github_base/libirecovery/archive/$libirecovery_commit.tar.gz"
idevicerestore_path="idevicerestore/archive/$idevicerestore_commit.tar.gz"
idevicerestore_url="$github_base/$idevicerestore_path"

fail()
{
    echo "error: $*" >&2
    exit 1
}

for command_name in curl shasum tar patch autoreconf pkg-config make; do
    command -v "$command_name" >/dev/null 2>&1 ||
        fail "required command not found: $command_name"
done

if command -v brew >/dev/null 2>&1; then
    brew_prefix=$(brew --prefix)
else
    brew_prefix=/usr/local
fi

pkg_config_path="$prefix/lib/pkgconfig:$brew_prefix/lib/pkgconfig"
pkg_config_path="$pkg_config_path:$brew_prefix/opt/libusb/lib/pkgconfig"
if [ -n "${PKG_CONFIG_PATH:-}" ]; then
    pkg_config_path="$pkg_config_path:$PKG_CONFIG_PATH"
fi
export PKG_CONFIG_PATH=$pkg_config_path

for package in \
    libimobiledevice-glue-1.0 \
    libimobiledevice-1.0 \
    libusbmuxd-2.0 \
    libplist-2.0 \
    libtatsu-1.0 \
    libzip \
    libcurl \
    zlib; do
    pkg-config --exists "$package" || fail \
        "missing $package dependency; run: brew install libimobiledevice libusb libzip"
done

mkdir -p "$downloads" "$prefix"

fetch_verified()
{
    archive=$1
    url=$2
    expected=$3
    temporary="$archive.tmp"

    if [ -f "$archive" ]; then
        actual=$(shasum -a 256 "$archive" | awk '{print $1}')
        if [ "$actual" = "$expected" ]; then
            return
        fi
    fi

    echo "Downloading: $url"
    curl -fsSL "$url" -o "$temporary"
    actual=$(shasum -a 256 "$temporary" | awk '{print $1}')
    [ "$actual" = "$expected" ] ||
        fail "unexpected SHA-256 for $url: $actual"
    mv "$temporary" "$archive"
}

fetch_verified "$libirecovery_archive" "$libirecovery_url" \
    "$libirecovery_sha256"
fetch_verified "$idevicerestore_archive" "$idevicerestore_url" \
    "$idevicerestore_sha256"

work_dir=$(mktemp -d "$build_root/source.XXXXXX")
case $work_dir in
    "$build_root"/source.*) ;;
    *) fail "unexpected temporary directory: $work_dir" ;;
esac
trap 'rm -rf "$work_dir"' EXIT HUP INT TERM

tar -xzf "$libirecovery_archive" -C "$work_dir"
tar -xzf "$idevicerestore_archive" -C "$work_dir"

libirecovery_source="$work_dir/libirecovery-$libirecovery_commit"
idevicerestore_source="$work_dir/idevicerestore-$idevicerestore_commit"

echo "Applying the QEMU backend to libirecovery"
patch -d "$libirecovery_source" -p1 \
    -i "$script_dir/patches/libirecovery-qemu.patch"
printf '%s\n' '1.3.1-qemu-a6' > "$libirecovery_source/.tarball-version"
(
    cd "$libirecovery_source"
    autoreconf -fiv
    ./configure --prefix="$prefix"
    make -j4
    make install
)

printf '%s\n' '1.0.0-qemu-a6' > "$idevicerestore_source/.tarball-version"
echo "Applying boot-only mode without filesystem extraction"
patch -d "$idevicerestore_source" -p1 \
    -i "$script_dir/patches/idevicerestore-no-restore-fs.patch"
echo "Applying QEMU boot support for a local lab identity"
patch -d "$idevicerestore_source" -p1 \
    -i "$script_dir/patches/idevicerestore-qemu-lab-boot.patch"
(
    cd "$idevicerestore_source"
    autoreconf -fiv
    ./configure --prefix="$prefix"
    make -j4
    make install
)

echo
echo "Tools installed in $prefix/bin"
echo "Start QEMU with ./Run-iPhone5-macOS.sh, then run:"
echo "  scripts/irecovery-qemu -q"
echo "  scripts/idevicerestore-qemu -d -y /path/to/Restore.ipsw"