refactor: refactor cli parser, print license on startup

CMakeLists.txt

@@ -14,6 +14,7 @@ add_executable(kgg-dec
         src/qmc2/qmc2_factory.cpp
         src/qmc2/qmc2_map.cpp
         src/qmc2/qmc2_rc4.cpp
+        src/utils/cli.cpp
 )
 
 target_include_directories(kgg-dec

src/jobs.hpp

@@ -27,7 +27,7 @@ class KggTask {
     void info(const wchar_t* msg) const { fwprintf(stderr, L"[INFO] %s (%s)\n", msg, kgg_path_.filename().c_str()); }
     void info(const std::wstring& msg) const { info(msg.c_str()); }
 
-    void Execute(const Infra::kgm_ekey_db_t& ekey_db) {
+    void Execute(const Infra::kgm_ekey_db_t& ekey_db) const {
         constexpr static std::array<uint8_t, 16> kMagicHeader{0x7C, 0xD5, 0x32, 0xEB, 0x86, 0x02, 0x7F, 0x4B,
                                                               0xA8, 0xAF, 0xA6, 0x8E, 0x0F, 0xFF, 0x99, 0x14};
 
@@ -38,8 +38,8 @@ class KggTask {
             warning(L"invalid kgg header");
             return;
         }
-        uint32_t offset_to_audio = *reinterpret_cast<uint32_t*>(&header[0x10]);
+        const uint32_t offset_to_audio = *reinterpret_cast<uint32_t*>(&header[0x10]);
-        uint32_t encrypt_mode = *reinterpret_cast<uint32_t*>(&header[0x14]);
+        const uint32_t encrypt_mode = *reinterpret_cast<uint32_t*>(&header[0x14]);
         if (encrypt_mode != 5) {
             warning(std::format(L"unsupported enc_version (expect=0x05, got 0x{:02x})", encrypt_mode));
             return;
@@ -104,7 +104,7 @@ class KggTask {
     std::filesystem::path kgg_path_;
     std::filesystem::path out_dir_;
 
-    static const wchar_t* DetectRealExt(std::string_view magic) {
+    static const wchar_t* DetectRealExt(const std::string_view magic) {
         if (magic == "fLaC") {
             return L"flac";
         }

src/main.cpp

@@ -1,22 +1,7 @@
 #include "infra/infra.h"
 #include "infra/sqlite_error.h"
 #include "jobs.hpp"
-#include "qmc2/qmc2.h"
+#include "utils/cli.h"
-
-// clang-format off
-#include <windows.h>
-#include <shlobj.h>
-#include <initguid.h>
-#include <knownfolders.h>
-// clang-format on
-
-#include <algorithm>
-#include <cstdint>
-#include <cstdio>
-#include <filesystem>
-#include <fstream>
-#include <span>
-#include <utility>
 
 using Infra::kgm_ekey_db_t;
 
@@ -48,83 +33,54 @@ void WalkFileOrDir(KggTaskQueue& queue, const std::filesystem::path& input_path,
     }
 }
 
-std::pair<std::vector<std::wstring>, std::unordered_map<std::wstring, std::wstring>> ParseCommandLine() {
+void print_license() {
-    int argc;
+    fputs("  This software is free and open source, licensed under the MIT license.\n", stderr);
-    wchar_t** argv = CommandLineToArgvW(GetCommandLineW(), &argc);
+    fputs("  For more details, check out: https://git.unlock-music.dev/um/kgg-dec\n", stderr);
-
-    std::vector<std::wstring> positional_args{};
-    std::unordered_map<std::wstring, std::wstring> named_args{};
-
-    bool positional_only{false};
-    for (int i = 1; i < argc; i++) {
-        std::wstring arg{argv[i]};
-        if (arg == L"--") {
-            positional_only = true;
-            continue;
-        }
-
-        if (!positional_only && arg.starts_with(L"--")) {
-            auto pos = arg.find(L'=');
-            if (pos != std::wstring::npos) {
-                named_args[arg.substr(2, pos - 2)] = arg.substr(pos + 1);
-            } else if (++i < argc) {
-                named_args[arg.substr(2)] = argv[i];
-            } else {
-                named_args[arg.substr(2)] = L"";
-            }
-        } else {
-            positional_args.push_back(arg);
-        }
-    }
-
-    return std::make_pair(positional_args, named_args);
 }
 
-int main() {
+void print_usage() {
-    SetConsoleOutputCP(CP_UTF8);
-    setlocale(LC_ALL, ".UTF8");
-
-    fprintf(stderr, "kgg-dec v" KGGDEC_PROJECT_VERSION " by LSR\n");
     fputs(
         "Usage: kgg-dec "
         "[--infra-dll infra.dll] "
         "[--scan-all-file-ext 0] "
         "[--db /path/to/KGMusicV3.db] "
-        "[--] [kgg-dir... = '.']\n\n",
+        "[--suffix _kgg-dec] "
+        "[--] "
+        "[FILE]...\n\n\n",
         stderr);
+}
 
-    auto [positional_args, named_args] = ParseCommandLine();
+void print_banner() {
-    if (positional_args.empty()) {
+    fprintf(stderr, "kgg-dec v" KGGDEC_PROJECT_VERSION " by LSR\n");
-        positional_args.emplace_back(L".");
+    print_license();
-    }
+    print_usage();
+}
 
-    std::filesystem::path kgm_db_path{};
+int main() {
-    std::filesystem::path infra_dll_path{L"infra.dll"};
+    CliParser cli_args;
-    if (auto it = named_args.find(L"infra-dll"); it != named_args.end()) {
+    print_banner();
-        infra_dll_path = std::filesystem::path{it->second};
-    }
-    infra_dll_path = absolute(infra_dll_path);
-    if (!exists(infra_dll_path)) {
-        fputs("[ERR ] infra.dll not found\n", stderr);
-        return 1;
-    }
 
-    bool scan_all_exts{false};
+    cli_args.parse_from_cli();
-    if (auto it = named_args.find(L"scan-all-file-ext"); it != named_args.end()) {
-        scan_all_exts = it->second == L"1";
-    }
 
-    if (auto it = named_args.find(L"db"); it != named_args.end()) {
+    bool scan_all_exts = cli_args.get_scan_all_file_ext();
-        kgm_db_path = std::filesystem::path{it->second};
+
-    } else {
+    auto infra_dll_path = cli_args.get_infra_dll();
-        PWSTR pAppDirPath{};
+    auto kgm_db_path = cli_args.get_db_path();
-        SHGetKnownFolderPath(FOLDERID_RoamingAppData, 0, nullptr, &pAppDirPath);
+    auto file_suffix = cli_args.get_file_suffix();
-        kgm_db_path = std::filesystem::path{pAppDirPath} / L"Kugou8" / L"KGMusicV3.db";
+    {
-        CoTaskMemFree(pAppDirPath);
+        bool cli_arg_error{false};
-    }
+        if (!exists(infra_dll_path)) {
-    if (!exists(kgm_db_path)) {
+            fputs("[ERR ] infra.dll not found\n", stderr);
-        fputs("[ERR ] KGMusicV3.db not found\n", stderr);
+            cli_arg_error = true;
-        return 1;
+        }
+
+        if (!exists(kgm_db_path)) {
+            fputs("[ERR ] KGMusicV3.db not found\n", stderr);
+            cli_arg_error = true;
+        }
+        if (cli_arg_error) {
+            return 1;
+        }
     }
 
     int error{-1};
@@ -159,7 +115,11 @@ int main() {
         queue.AddWorkerThread();
     }
 
-    for (auto& positional_arg : positional_args) {
+    auto input_files = cli_args.get_input_files();
+    if (input_files.empty()) {
+        input_files.emplace_back(L".");
+    }
+    for (auto& positional_arg : input_files) {
         WalkFileOrDir(queue, positional_arg, scan_all_exts);
     }
     queue.Join();

src/utils/cli.cpp

@@ -0,0 +1,67 @@
+#include "cli.h"
+
+#include <Windows.h>
+#include <clocale>
+
+// clang-format off
+#include <shlobj.h>
+#include <knownfolders.h>
+// clang-format on
+
+CliParser::CliParser() {
+    SetConsoleOutputCP(CP_UTF8);
+    setlocale(LC_ALL, ".UTF8");
+}
+
+void CliParser::parse_from_cli() {
+    int argc;
+    wchar_t** argv = CommandLineToArgvW(GetCommandLineW(), &argc);
+
+    std::vector<std::wstring> positional_args{};
+    std::unordered_map<std::wstring, std::wstring> named_args{};
+
+    bool positional_only{false};
+    for (int i = 1; i < argc; i++) {
+        std::wstring arg{argv[i]};
+        if (arg == L"--") {
+            positional_only = true;
+            continue;
+        }
+
+        if (!positional_only && arg.starts_with(L"--")) {
+            auto pos = arg.find(L'=');
+            if (pos != std::wstring::npos) {
+                named_args[arg.substr(2, pos - 2)] = arg.substr(pos + 1);
+            } else if (++i < argc) {
+                named_args[arg.substr(2)] = argv[i];
+            } else {
+                named_args[arg.substr(2)] = L"";
+            }
+        } else {
+            positional_args.push_back(arg);
+        }
+    }
+    LocalFree(argv);
+
+    positional_args_ = positional_args;
+    named_args_ = named_args;
+}
+
+std::filesystem::path CliParser::get_infra_dll() const {
+    std::filesystem::path infra_dll_path{get_with_default(L"infra-dll", L"infra.dll")};
+    return absolute(infra_dll_path);
+}
+
+std::filesystem::path CliParser::get_db_path() const {
+    std::filesystem::path kugou_db{};
+    if (const auto& it = named_args_.find(L"db"); it != named_args_.end()) {
+        kugou_db = std::filesystem::path{it->second};
+    } else {
+        PWSTR pAppDirPath{};
+        SHGetKnownFolderPath(FOLDERID_RoamingAppData, 0, nullptr, &pAppDirPath);
+        kugou_db = std::filesystem::path{pAppDirPath} / L"Kugou8" / L"KGMusicV3.db";
+        CoTaskMemFree(pAppDirPath);
+    }
+
+    return absolute(kugou_db);
+}

src/utils/cli.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <filesystem>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+typedef std::pair<std::vector<std::wstring>, std::unordered_map<std::wstring, std::wstring>> parsed_raw_args_t;
+
+class CliParser {
+   public:
+    CliParser();
+    void parse_from_cli();
+
+    [[nodiscard]] std::filesystem::path get_infra_dll() const;
+    [[nodiscard]] std::filesystem::path get_db_path() const;
+    [[nodiscard]] std::wstring get_file_suffix() const { return get_with_default(L"suffix", L"_kgg-dec"); }
+    [[nodiscard]] bool get_scan_all_file_ext() const { return get_with_default(L"scan-all-file-ext", L"0") == L"1"; };
+    [[nodiscard]] std::vector<std::wstring> get_input_files() const { return positional_args_; }
+
+   private:
+    std::vector<std::wstring> positional_args_{};
+    std::unordered_map<std::wstring, std::wstring> named_args_{};
+
+    static parsed_raw_args_t parse();
+    [[nodiscard]] std::wstring get_with_default(const std::wstring& key, const std::wstring& default_value) const {
+        if (const auto& it = named_args_.find(key); it != named_args_.end()) {
+            return it->second;
+        }
+        return default_value;
+    }
+};