#pragma once
#include "hd2d/GL.h"

#include <glm/glm.hpp>

namespace hd2d {

class Terrain;

// Planar water body: reflective, refractive, depth-absorbing surface with
// procedural waves, sun glints and shoreline foam. Rendered at full
// resolution (not pixelated) on purpose, like HD-2D's water.
class Water {
public:
    ~Water();
    // Builds a tessellated grid covering [minXZ, maxXZ] at height `level`.
    void build(glm::vec2 minXZ, glm::vec2 maxXZ, float level, float cellSize = 0.25f);
    // Distance-to-shore field (world units) over the water bounds, from every
    // terrain tile whose top is above the water. Drives foam and ripples.
    void buildShoreField(const Terrain& terrain, int texelsPerUnit = 8);
    void draw() const;
    float level() const { return level_; }
    GLuint shoreTexture() const { return shoreTex_; }
    // (minX, minZ, 1/sizeX, 1/sizeZ): maps world xz to shore texture uv.
    glm::vec4 shoreRect() const { return {min_.x, min_.y, 1.0f / (max_.x - min_.x), 1.0f / (max_.y - min_.y)}; }

    // Look parameters (tweakable at runtime).
    glm::vec3 shallowColor{0.03f, 0.40f, 0.62f};
    glm::vec3 deepColor{0.005f, 0.10f, 0.30f};
    glm::vec3 absorption{1.6f, 0.5f, 0.22f};    // per unit of light path, per channel
    float clarity = 0.5f;             // how much of the bottom stays visible
    float waveScale = 0.9f;
    float waveStrength = 1.2f;
    float waveSpeed = 0.35f;
    float refraction = 0.035f;
    float reflectionDistort = 0.05f;
    float specular = 6.0f;
    float glitter = 1.0f;             // twinkling point sparkles
    float foamWidth = 0.45f;          // world units from the shore
    float foamIntensity = 0.85f;
    float causticsIntensity = 1.4f;

private:
    GLuint vao_ = 0, vbo_ = 0, ibo_ = 0, shoreTex_ = 0;
    GLsizei indexCount_ = 0;
    float level_ = 0.0f;
    glm::vec2 min_{0.0f}, max_{1.0f};
};

}  // namespace hd2d