Command done

src/CMakeLists.txt

@@ -7,6 +7,10 @@ add_executable(${PROJECT_NAME}
         Page.cpp
         stringutil.hpp
         stringutil.cpp
+        Tui.cpp
+        Tui.h
+        Command.h
+        Command.cpp
 )
 
 target_link_libraries(${PROJECT_NAME} PRIVATE LibXml2::LibXml2 cpr::cpr)

src/Command.cpp

@@ -0,0 +1,51 @@
+#include "Command.h"
+
+#include <iostream>
+
+
+namespace Command {
+    Command readCommand() {
+        if (!std::cin)
+            return {Exit{}};
+        std::string line;
+        if (!std::getline(std::cin, line))
+            return {Exit{}};
+
+        // Trim leading and trailing whitespaces
+        constexpr std::string_view TO_TRIM = " \t\n\r";
+        const size_t start = line.find_first_not_of(TO_TRIM);
+        const size_t end = line.find_last_not_of(TO_TRIM);
+        if (start == std::string::npos) return None{};
+        const std::string_view line_trimmed(line.data() + start, end - start + 1);
+
+        using namespace std::string_view_literals;
+        if (line_trimmed == "r"sv || line_trimmed == "refresh"sv)
+            return Refresh{};
+        if (line_trimmed == "n"sv || line_trimmed == ">"sv || line_trimmed == "next"sv)
+            return Next{};
+        if (line_trimmed == "p"sv || line_trimmed == "<"sv || line_trimmed == "previous"sv)
+            return Previous{};
+        if (line_trimmed == "x"sv || line_trimmed == "exit"sv || line_trimmed == "q"sv || line_trimmed == "quit"sv)
+            return Exit{};
+        if (line_trimmed == "help"sv || line_trimmed == "?"sv || line_trimmed == "?"sv)
+            return Help{};
+
+        if (line_trimmed.starts_with("seek") || line.starts_with("s ")) {
+            const size_t space = line_trimmed.find(' ');
+            if (space == std::string::npos)
+                throw NoNumberException();
+            int number = 0;
+            const size_t size = line.size();
+            for (size_t i = space + 1; i < size; ++i) {
+                const char c = line_trimmed[i];
+                if (!std::isdigit(c))
+                    throw NoNumberException();
+                number = number * 10 + (c - '0');
+            }
+
+            return {Seek{number}};
+        }
+
+        return {None{}};
+    }
+}

src/Command.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <string>
+#include <variant>
+
+
+namespace Command {
+    class NoNumberException final : public std::exception {
+    public:
+        [[nodiscard]] const char *what() const noexcept override {
+            return "Seek option was used without a number";
+        }
+    };
+
+
+    struct Help {
+    };
+
+    struct None {
+    };
+
+    struct Next {
+    };
+
+    struct Previous {
+    };
+
+    struct Refresh {
+    };
+
+    struct Exit {
+    };
+
+    struct Seek {
+        int number;
+    };
+
+    using Command = std::variant<None, Help, Next, Previous, Refresh, Exit, Seek>;
+
+    Command readCommand();
+}

src/Page.cpp

@@ -74,7 +74,7 @@ Page &Page::operator-=(int) {
     return *this;
 }
 
-std::string Page::str() const {
+std::string Page::str_pretty() const {
     std::string ret;
 
     std::istringstream stream(m_subpage);

src/Page.hpp

@@ -32,7 +32,7 @@ public:
 
     Page &operator-=(int);
 
-    [[nodiscard]] std::string str() const;
+    [[nodiscard]] std::string str_pretty() const;
 
     bool refresh();
 

src/Tui.cpp

@@ -0,0 +1,81 @@
+#include "Tui.h"
+
+#include <iostream>
+#include <optional>
+#include <ostream>
+#include <utility>
+
+#include "Command.h"
+
+Tui::Tui(Page page) : m_page(std::move(page)) {
+}
+
+
+std::optional<int> get_page_number(const std::string_view line) {
+    const size_t space = line.find_first_of(' ');
+    if (space == std::string::npos)
+        return std::nullopt;
+
+    int number = 0;
+    const size_t size = line.size();
+    for (size_t i = space; i < size; i++) {
+        const char c = line[i];
+        if (!std::isdigit(c))
+            return std::nullopt;
+
+        number = number * 10 + (c - '0');
+    }
+
+    return number;
+}
+
+void printHelp() {
+    std::cout
+            << "Available Commands:\n"
+            << "  r, refresh                : Refresh the current view.\n"
+            << "  n, >, next                : Move to the next item.\n"
+            << "  p, <, previous            : Move to the previous item.\n"
+            << "  x, exit, q, quit          : Exit the application.\n"
+            << "  seek <number>, s <number> : Seek to the specified number.\n"
+            << "  help, h, ?                : Display this help message."
+            << std::endl;
+}
+
+void Tui::run() {
+    std::cout << m_page.str_pretty() << std::endl;
+    for (;;) {
+        std::cout << "Enter a command: ";
+        std::flush(std::cout);
+        const Command::Command command = Command::readCommand();
+
+        bool should_exit = false;
+        auto visitor = [this, &should_exit]<typename T0>(T0 &&arg) {
+            using T = std::decay_t<T0>;
+
+            if constexpr (std::is_same_v<T, Command::None>) {
+                std::cout << "Invalid command!" << std::endl;
+            } else if constexpr (std::is_same_v<T, Command::Next>) {
+                m_page += 1;
+                std::cout << m_page.str_pretty() << std::endl;
+            } else if constexpr (std::is_same_v<T, Command::Previous>) {
+                m_page -= 1;
+                std::cout << m_page.str_pretty() << std::endl;
+            } else if constexpr (std::is_same_v<T, Command::Refresh>) {
+                m_page.refresh();
+                std::cout << m_page.str_pretty() << std::endl;
+            } else if constexpr (std::is_same_v<T, Command::Exit>) {
+                should_exit = true;
+            } else if constexpr (std::is_same_v<T, Command::Help>) {
+                printHelp();
+            } else if constexpr (std::is_same_v<T, Command::Seek>) {
+                const Command::Seek &seek = arg;
+                const int number = seek.number;
+                m_page = Page(number);
+                std::cout << m_page.str_pretty() << std::endl;
+            }
+        };
+        std::visit(visitor, command);
+        if (should_exit)
+            return;
+    }
+}

src/Tui.h

@@ -0,0 +1,13 @@
+#pragma once
+#include "Page.hpp"
+
+
+class Tui {
+public:
+    Tui(Page page);
+
+    void run();
+
+private:
+    Page m_page;
+};

src/main.cpp

@@ -1,8 +1,7 @@
-#include <iostream>
-
 #include "Page.hpp"
+#include "Tui.h"
 
 int main(int argc, char *argv[]) {
-    const auto page = Page();
-    std::cout << page.str() << std::endl;
+    Tui tui = Page();
+    tui.run();
 }