#pragma once

#include <filesystem>
#include <optional>
#include <ostream>
#include <string>
#include <vector>

namespace ota {

    enum class Phase {
        AConfirmed,
        PreparingB,
        BPrepared,
        TrialPending,
        TrialRunning,
        BConfirmed,
        RecoveryPending,
        RecoveryRunning,
        RecoveryChecked,
        SeparateRecoveryRequired
    };

    enum class Slot { A,
                      B };

    const char *name(Phase phase);
    const char *name(Slot slot);

    struct State {
        Phase phase = Phase::AConfirmed;
        Slot normal = Slot::A;
        std::optional<Slot> trial;
        int attempts_left = 0;
        bool a_ready = true;
        bool b_ready = false;
        std::string outcome;
    };

    class Device {
    public:
        explicit Device(const std::filesystem::path &directory);
        const State &state() const { return state_; }
        std::optional<Slot> running() const { return running_; }
        void prepare(bool complete = true);
        void request_trial(int attempts = 2);
        Slot boot();
        void check(bool healthy);

    private:
        void save() const;
        State state_;
        std::filesystem::path path_;
        // Volatile: reconstructing a Device requires another boot before checks.
        std::optional<Slot> running_;
    };

    // Own only a freshly created directory and clean it up at scope exit.
    class TemporaryDirectory {
    public:
        TemporaryDirectory();
        ~TemporaryDirectory();
        TemporaryDirectory(const TemporaryDirectory &) = delete;
        TemporaryDirectory &operator=(const TemporaryDirectory &) = delete;
        const std::filesystem::path &path() const { return path_; }

    private:
        std::filesystem::path path_;
    };

    const std::vector<std::string> &scenarios();
    Device run_scenario(const std::string &scenario,
                        const std::filesystem::path &directory,
                        std::ostream *output = nullptr);

}// namespace ota