From b5124bd82621701172ce17db245e57d053892557 Mon Sep 17 00:00:00 2001
From: Caoimhe <caoimhebyrne06@gmail.com>
Date: Fri, 2 Jun 2023 17:31:20 +0100
Subject: [PATCH] LibArchive: Add helper functions for adding members to a
 ZipOutputStream

---
 Userland/Libraries/LibArchive/CMakeLists.txt |  2 +-
 Userland/Libraries/LibArchive/Zip.cpp        | 58 ++++++++++++++++++++
 Userland/Libraries/LibArchive/Zip.h          | 12 ++++
 3 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/Userland/Libraries/LibArchive/CMakeLists.txt b/Userland/Libraries/LibArchive/CMakeLists.txt
index 4bc0335c89..710e4b5733 100644
--- a/Userland/Libraries/LibArchive/CMakeLists.txt
+++ b/Userland/Libraries/LibArchive/CMakeLists.txt
@@ -5,4 +5,4 @@ set(SOURCES
         )
 
 serenity_lib(LibArchive archive)
-target_link_libraries(LibArchive PRIVATE LibCore)
+target_link_libraries(LibArchive PRIVATE LibCompress LibCore LibCrypto)
diff --git a/Userland/Libraries/LibArchive/Zip.cpp b/Userland/Libraries/LibArchive/Zip.cpp
index 8b71b5ee5f..a9904f4178 100644
--- a/Userland/Libraries/LibArchive/Zip.cpp
+++ b/Userland/Libraries/LibArchive/Zip.cpp
@@ -6,6 +6,8 @@
  */
 
 #include <LibArchive/Zip.h>
+#include <LibCompress/Deflate.h>
+#include <LibCrypto/Checksum/CRC32.h>
 
 namespace Archive {
 
@@ -138,6 +140,62 @@ ErrorOr<void> ZipOutputStream::add_member(ZipMember const& member)
     return local_file_header.write(*m_stream);
 }
 
+ErrorOr<ZipOutputStream::MemberInformation> ZipOutputStream::add_member_from_stream(StringView path, Stream& stream, Optional<Core::DateTime> const& modification_time)
+{
+    auto buffer = TRY(stream.read_until_eof());
+
+    Archive::ZipMember member {};
+    member.name = TRY(String::from_utf8(path));
+
+    if (modification_time.has_value()) {
+        member.modification_date = to_packed_dos_date(modification_time->year(), modification_time->month(), modification_time->day());
+        member.modification_time = to_packed_dos_time(modification_time->hour(), modification_time->minute(), modification_time->second());
+    }
+
+    auto deflate_buffer = Compress::DeflateCompressor::compress_all(buffer);
+    auto compression_ratio = 1.f;
+    auto compressed_size = buffer.size();
+
+    if (!deflate_buffer.is_error() && deflate_buffer.value().size() < buffer.size()) {
+        member.compressed_data = deflate_buffer.value().bytes();
+        member.compression_method = Archive::ZipCompressionMethod::Deflate;
+
+        compression_ratio = static_cast<float>(deflate_buffer.value().size()) / static_cast<float>(buffer.size());
+        compressed_size = member.compressed_data.size();
+    } else {
+        member.compressed_data = buffer.bytes();
+        member.compression_method = Archive::ZipCompressionMethod::Store;
+    }
+
+    member.uncompressed_size = buffer.size();
+
+    Crypto::Checksum::CRC32 checksum { buffer.bytes() };
+    member.crc32 = checksum.digest();
+    member.is_directory = false;
+
+    TRY(add_member(member));
+
+    return MemberInformation { compression_ratio, compressed_size };
+}
+
+ErrorOr<void> ZipOutputStream::add_directory(StringView name, Optional<Core::DateTime> const& modification_time)
+{
+    Archive::ZipMember member {};
+    member.name = TRY(String::from_utf8(name));
+    member.compressed_data = {};
+    member.compression_method = Archive::ZipCompressionMethod::Store;
+    member.uncompressed_size = 0;
+    member.crc32 = 0;
+    member.is_directory = true;
+
+    if (modification_time.has_value()) {
+        member.modification_date = to_packed_dos_date(modification_time->year(), modification_time->month(), modification_time->day());
+        member.modification_time = to_packed_dos_time(modification_time->hour(), modification_time->minute(), modification_time->second());
+    }
+
+    return add_member(member);
+}
+
 ErrorOr<void> ZipOutputStream::finish()
 {
     VERIFY(!m_finished);
diff --git a/Userland/Libraries/LibArchive/Zip.h b/Userland/Libraries/LibArchive/Zip.h
index f87c6dca8f..9a1e940369 100644
--- a/Userland/Libraries/LibArchive/Zip.h
+++ b/Userland/Libraries/LibArchive/Zip.h
@@ -15,6 +15,7 @@
 #include <AK/Stream.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
+#include <LibCore/DateTime.h>
 #include <string.h>
 
 namespace Archive {
@@ -271,9 +272,20 @@ private:
 
 class ZipOutputStream {
 public:
+    struct MemberInformation {
+        float compression_ratio;
+        size_t compressed_size;
+    };
+
     ZipOutputStream(NonnullOwnPtr<Stream>);
 
     ErrorOr<void> add_member(ZipMember const&);
+    ErrorOr<MemberInformation> add_member_from_stream(StringView, Stream&, Optional<Core::DateTime> const& = {});
+
+    // NOTE: This does not add any of the files within the directory,
+    //       it just adds an entry for it.
+    ErrorOr<void> add_directory(StringView, Optional<Core::DateTime> const& = {});
+
     ErrorOr<void> finish();
 
 private: