CLI command parser impl.

src/app/cli_cmd.cpp

+//
+// This file is a part of UERANSIM open source project.
+// Copyright (c) 2021 ALİ GÜNGÖR.
+//
+// The software and all associated files are licensed under GPL-3.0
+// and subject to the terms and conditions defined in LICENSE file.
+//
+
+#include "cli_cmd.hpp"
+#include <map>
+#include <optional>
+#include <sstream>
+#include <utils/common.hpp>
+#include <utils/constants.hpp>
+#include <utils/options.hpp>
+
+#define CMD_ERR(x)                                                                                                     \
+    {                                                                                                                  \
+        error = x;                                                                                                     \
+        return nullptr;                                                                                                \
+    }
+
+static opt::OptionsDescription Desc(const std::string &subCommand, const std::string &desc, const std::string &usage,
+                                    bool helpIfEmpty)
+{
+    return {subCommand, cons::Tag, desc, {}, subCommand, {usage}, helpIfEmpty};
+}
+
+class OptionsHandler : public opt::IOptionsHandler
+{
+  public:
+    std::stringstream m_output{};
+    std::stringstream m_err{};
+
+  public:
+    std::ostream &ostream(bool isError) override
+    {
+        return isError ? m_err : m_output;
+    }
+
+    void status(int code) override
+    {
+        // nothing to do
+    }
+};
+
+static std::string DumpCommands(const std::map<std::string, std::string> &descTable)
+{
+    std::stringstream ss{};
+    for (auto &item : descTable)
+        ss << item.first << " | " << item.second << "\n";
+    std::string output = ss.str();
+    utils::Trim(output);
+    return output;
+}
+
+namespace app
+{
+
+static std::map<std::string, std::string> g_gnbCmdToDescription = {
+    {"status", "Show some status information about the gNB"},
+    {"amf-list", "List all AMFs associated with the gNB"},
+    {"amf-status", "Show some status information about the given AMF"},
+    {"info", "Show some information about the gNB"},
+};
+
+static std::map<std::string, std::string> g_gnbCmdToUsage = {
+    {"status", "[option...]"},
+    {"amf-list", "[option...]"},
+    {"amf-status", "<amf-id> [option...]"},
+    {"info", "[option...]"},
+};
+
+static std::map<std::string, bool> g_gnbCmdToHelpIfEmpty = {
+    {"status", false},
+    {"amf-list", false},
+    {"amf-status", true},
+    {"info", false},
+};
+
+std::unique_ptr<GnbCliCommand> ParseGnbCliCommand(std::vector<std::string> &&tokens, std::string &error,
+                                                  std::string &output)
+{
+    if (tokens.empty())
+    {
+        error = "Empty command";
+        return nullptr;
+    }
+
+    std::string &subCmd = tokens[0];
+
+    if (subCmd == "commands")
+    {
+        output = DumpCommands(g_gnbCmdToDescription);
+        return nullptr;
+    }
+
+    if (g_gnbCmdToDescription.count(subCmd) == 0 || g_gnbCmdToUsage.count(subCmd) == 0 ||
+        g_gnbCmdToHelpIfEmpty.count(subCmd) == 0)
+    {
+        error = "Command not recognized: " + subCmd;
+        return nullptr;
+    }
+
+    opt::OptionsDescription desc =
+        Desc(subCmd, g_gnbCmdToDescription[subCmd], g_gnbCmdToUsage[subCmd], g_gnbCmdToHelpIfEmpty[subCmd]);
+
+    OptionsHandler handler{};
+
+    opt::OptionsResult options{tokens, desc, &handler};
+
+    error = handler.m_err.str();
+    output = handler.m_output.str();
+    utils::Trim(error);
+    utils::Trim(output);
+
+    if (!error.empty() || !output.empty())
+        return nullptr;
+
+    if (subCmd == "info")
+    {
+        return std::make_unique<GnbCliCommand>(GnbCliCommand::INFO);
+    }
+    if (subCmd == "status")
+    {
+        return std::make_unique<GnbCliCommand>(GnbCliCommand::STATUS);
+    }
+    else if (subCmd == "amf-list")
+    {
+        return std::make_unique<GnbCliCommand>(GnbCliCommand::AMF_LIST);
+    }
+    else if (subCmd == "amf-status")
+    {
+        auto cmd = std::make_unique<GnbCliCommand>(GnbCliCommand::AMF_STATUS);
+        if (options.positionalCount() == 0)
+            CMD_ERR("AMF ID is expected")
+        if (options.positionalCount() > 1)
+            CMD_ERR("Only one AMF ID is expected")
+        cmd->amfId = utils::ParseInt(options.getPositional(0));
+        if (cmd->amfId <= 0)
+            CMD_ERR("Invalid AMF ID")
+        return cmd;
+    }
+
+    return nullptr;
+}
+
+} // namespace app

src/app/cli_cmd.hpp

+//
+// This file is a part of UERANSIM open source project.
+// Copyright (c) 2021 ALİ GÜNGÖR.
+//
+// The software and all associated files are licensed under GPL-3.0
+// and subject to the terms and conditions defined in LICENSE file.
+//
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace app
+{
+
+struct GnbCliCommand
+{
+    enum PR
+    {
+        STATUS,
+        INFO,
+        AMF_LIST,
+        AMF_STATUS
+    } present;
+
+    // AMF_STATUS
+    int amfId{};
+
+    explicit GnbCliCommand(PR present) : present(present)
+    {
+    }
+};
+
+std::unique_ptr<GnbCliCommand> ParseGnbCliCommand(std::vector<std::string> &&tokens, std::string &error,
+                                                  std::string &output);
+
+} // namespace app
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