#pragma once

#include <cstdint>
#include <mutex>
#include <string>
#include <vector>

#include "core/effect.hpp"

namespace effector {

// Writes a line (or several) over its input: a title, a caption, a watermark.
// The family and the weight are chosen freely, and the text can sit on a box
// filled with a colour or with a picture from disk. Like the blur and the
// overlay it needs no source images of its own, so it can lead a chain; given
// sources it fills the canvas from a randomly chosen one first.
//
// The glyphs come from Pango, so the exact pixels depend on the fonts the
// machine has installed: a seed reproduces everything this effect draws, but a
// machine without the chosen family renders the substitute its fontconfig
// picks.
class TextEffect : public Effect {
public:
    std::string name() const override { return "text"; }
    std::string title() const override { return "Text"; }
    std::string description() const override {
        return "Writes text over its input in a chosen family, weight and size, optionally on a "
               "box filled with a colour or with a picture.";
    }
    const std::vector<ParamSpec>& params() const override;
    bool needsSources() const override { return false; }

    Image render(const std::vector<Image>& sources, int width, int height, Rng& rng,
                 const ParamValues& values) const override;

private:
    // The box picture is re-read on every param change otherwise, and a render
    // is a keystroke away in the interface. Renders can overlap, so it is
    // guarded.
    void loadBoxImage(const std::string& path, Image& image,
                      std::vector<std::uint8_t>& alpha) const;

    mutable std::mutex cacheMutex_;
    mutable std::string cachedPath_;
    mutable Image cached_;
    mutable std::vector<std::uint8_t> cachedAlpha_;
};

}  // namespace effector