#pragma once

#include <cstddef>
#include <ctime>
#include <optional>
#include <string>
#include <vector>

#include "CommandSpec.h"
#include "Completer.h"
#include "Config.h"
#include "Database.h"
#include "Display.h"
#include "LineEditor.h"
#include "Tracker.h"
#include "Status.h"

// Interactive prompt: commands are typed live, one per line.
class Repl {
public:
    Repl(Database& db, Display& display, Config& config);

    int run();

private:
    using Args = std::vector<std::string>;
    using Handler = bool (Repl::*)(const Args&);  // returns true if the panels should be redrawn

    struct Command {
        CommandSpec spec;
        Handler handler;
    };

    void registerCommands();
    void add(const std::string& key, const std::string& usage, const std::string& help,
             std::size_t minArgs, std::size_t maxArgs, const std::vector<ArgKind>& argKinds,
             Handler handler);
    const Command* find(const Args& tokens, std::size_t& consumed) const;

    void execute(const std::string& line);
    void refresh() const;
    void say(const std::string& message);
    void flushMessages();
    bool endOfInput();  // true if the program should exit

    enum class Answer { Yes, No, Cancel };
    // Asks until the reply is valid (y / n, and c when allowed). nullopt if input closed.
    std::optional<Answer> ask(const std::string& question, bool allowCancel) const;

    // Account commands
    bool cmdAccAdd(const Args& args);
    bool cmdAccDel(const Args& args);
    bool cmdAccRename(const Args& args);
    bool cmdAccWait(const Args& args);
    bool cmdAccUnwait(const Args& args);
    bool cmdAccLs(const Args& args);

    // Task commands
    bool cmdTskAdd(const Args& args);
    bool cmdTskDel(const Args& args);
    bool cmdTskLs(const Args& args);
    bool cmdTskRename(const Args& args);
    bool cmdTskReacc(const Args& args);
    bool cmdTskRestat(const Args& args);
    bool cmdTskNotes(const Args& args);

    // Display commands
    bool cmdDisp(const Args& args);
    bool cmdDispTsk(const Args& args);
    bool cmdDispTskLevel(const Args& args);
    bool cmdDispAcc(const Args& args);
    bool cmdDispAccLevel(const Args& args);

    // Database commands
    bool cmdDbSave(const Args& args);
    bool cmdDbBackup(const Args& args);
    bool cmdDbRestore(const Args& args);

    // Misc
    bool cmdEditor(const Args& args);
    bool cmdHelp(const Args& args);
    bool cmdQuit(const Args& args);

    Database& db_;
    Display& display_;
    Config& config_;
    Tracker tracker_;
    std::vector<Command> commands_;
    std::vector<CommandSpec> specs_;
    Completer completer_;
    LineEditor lineEditor_;
    std::vector<std::string> messages_;
    bool quit_;
};