#pragma once

#include <chrono>
#include <initializer_list>
#include <memory>
#include <string>
#include <string_view>

#include "alvin/error.hpp"
#include "alvin/keys.hpp"
#include "alvin/types.hpp"

namespace alvin {

enum class InputBackend {
    Auto,
    WlrVirtual,  // Wayland zwlr_virtual_pointer_v1 + zwp_virtual_keyboard_v1 (Hyprland, sway, other wlroots)
    LibEi,       // libei via xdg-desktop-portal RemoteDesktop (GNOME, KDE)
    UInput,      // /dev/uinput kernel virtual devices (any Linux session; needs write access)
    SendInput,   // Win32
};

std::string_view toString(InputBackend backend) noexcept;

struct InputOptions {
    InputBackend backend = InputBackend::Auto;

    // LibEi only: token from a previous session (Input::restoreToken()) that
    // lets the portal skip its permission dialog.
    std::string restoreToken;

    // How long to wait for the user to answer a portal permission dialog.
    std::chrono::milliseconds permissionTimeout = std::chrono::minutes(2);
};

// Synthesises mouse and keyboard events.
//
// Coordinates passed to moveTo() are global desktop coordinates in logical
// pixels, matching Monitor::bounds and WindowInfo::bounds.
class Input {
public:
    // Picks a backend (or uses options.backend). With Auto, the environment
    // variable ALVIN_INPUT_BACKEND=wlr|libei|uinput|sendinput overrides the choice.
    static Result<std::unique_ptr<Input>> create(const InputOptions& options = {});

    virtual ~Input() = default;
    Input(const Input&) = delete;
    Input& operator=(const Input&) = delete;

    virtual InputBackend backend() const = 0;

    virtual Status moveTo(Point p) = 0;
    virtual Status moveBy(int dx, int dy) = 0;
    virtual Status buttonDown(MouseButton button) = 0;
    virtual Status buttonUp(MouseButton button) = 0;
    // Wheel notches; positive dy scrolls down, positive dx scrolls right.
    virtual Status scroll(int dx, int dy) = 0;

    virtual Status keyDown(Key key) = 0;
    virtual Status keyUp(Key key) = 0;
    // Types UTF-8 text using the active keyboard layout (or a synthesized one).
    virtual Status typeText(std::string_view utf8) = 0;

    // Portal-backed sessions can hand out a token to skip the dialog next time.
    virtual std::string restoreToken() const { return {}; }

    // ---- Convenience helpers built on the primitives above ----

    Status click(MouseButton button = MouseButton::Left, int count = 1);
    Status clickAt(Point p, MouseButton button = MouseButton::Left, int count = 1);
    Status drag(Point from, Point to, MouseButton button = MouseButton::Left);
    Status keyPress(Key key);
    // Presses keys in order, releases in reverse: chord({Key::LeftCtrl, Key::C}).
    Status chord(std::initializer_list<Key> keys);
    // Same, from a string such as "ctrl+shift+esc".
    Status chord(std::string_view chord);

    // Delay inserted between the down/up halves of clicks and key presses.
    // Some applications drop events that arrive with zero spacing.
    void setEventDelay(std::chrono::milliseconds delay) { eventDelay_ = delay; }
    std::chrono::milliseconds eventDelay() const { return eventDelay_; }

protected:
    Input() = default;
    void pause() const;

private:
    std::chrono::milliseconds eventDelay_{8};
};

}  // namespace alvin