#import "ExampleCustomDrawableStyleLayer.h"
#import "MLNStyleLayer.h"

#import "MLNCustomDrawableStyleLayer_Private.h"
#import "MLNStyle_Private.h"
#import "MLNStyleLayer_Private.h"
#import "MLNGeometry_Private.h"

#include <mbgl/layermanager/layer_factory.hpp>
#include <mbgl/style/layer.hpp>
#include <mbgl/style/layers/custom_drawable_layer.hpp>
#include <mbgl/util/constants.hpp>

#include <memory>
#include <cmath>

class ExampleCustomDrawableStyleLayerHost;

@implementation ExampleCustomDrawableStyleLayer

- (instancetype)initWithIdentifier:(NSString *)identifier {
    auto layer = std::make_unique<mbgl::style::CustomDrawableLayer>(identifier.UTF8String,
                                                            std::make_unique<ExampleCustomDrawableStyleLayerHost>(self));
    return self = [super initWithPendingLayer:std::move(layer)];
}


@end

class ExampleCustomDrawableStyleLayerHost : public mbgl::style::CustomDrawableLayerHost {
public:
    ExampleCustomDrawableStyleLayerHost(ExampleCustomDrawableStyleLayer *styleLayer) {
        layerRef = styleLayer;
        layer = nil;
    }
    
    void initialize() override {
        if (layerRef == nil) return;
        else if (layer == nil) layer = layerRef;
    }
    
    void update(Interface& interface) override {
        
        // if we have built our drawable(s) already, either update or skip
        if (interface.getDrawableCount())
            return;
        
        // set tile
        interface.setTileID({11, 327, 791});

        // add polylines
        using namespace mbgl;
        
        constexpr auto numLines = 6;
        Interface::LineOptions options[numLines] {
            {/*color=*/Color::red(),                /*blur=*/0.0f,  /*opacity=*/1.0f, /*gapWidth=*/0.0f, /*offset=*/0.0f,   /*width=*/8.0f,     {} },
            {/*color=*/Color::blue(),               /*blur=*/4.0f,  /*opacity=*/1.0f, /*gapWidth=*/2.0f, /*offset=*/-1.0f,  /*width=*/4.0f,     {} },
            {/*color=*/Color(1.f, 0.5f, 0, 0.5f),   /*blur=*/16.0f, /*opacity=*/1.0f, /*gapWidth=*/1.0f, /*offset=*/2.0f,   /*width=*/16.0f,    {} },
            {/*color=*/Color(1.f, 1.f, 0, 0.3f),    /*blur=*/2.0f,  /*opacity=*/1.0f, /*gapWidth=*/1.0f, /*offset=*/-2.0f,  /*width=*/2.0f,     {} },
            {/*color=*/Color::black(),              /*blur=*/0.5f,  /*opacity=*/0.5f, /*gapWidth=*/1.0f, /*offset=*/0.5f,   /*width=*/0.5f,     {} },
            {/*color=*/Color(1.f, 0, 1.f, 0.2f),    /*blur=*/24.0f, /*opacity=*/0.5f, /*gapWidth=*/1.0f, /*offset=*/-5.0f,  /*width=*/24.0f,    {} },
        };
        for(auto& opt: options) {
            opt.geometry.beginCap = style::LineCapType::Round;
            opt.geometry.endCap = style::LineCapType::Round;
            opt.geometry.joinType = style::LineJoinType::Round;
        }

        constexpr auto numPoints = 100;
        GeometryCoordinates polyline;
        for (auto ipoint{0}; ipoint < numPoints; ++ipoint) {
            polyline.emplace_back(ipoint * util::EXTENT / numPoints, std::sin(ipoint * 2 * M_PI / numPoints) * util::EXTENT / numLines / 2.f);
        }
                
        for (auto index {0}; index <  numLines; ++index) {
            for(auto &p : polyline) {
                p.y += util::EXTENT / numLines;
            }
            
            // set property values
            interface.setLineOptions(options[index]);
            
            // add polyline
            interface.addPolyline(polyline);
        }
        
        // finish
        interface.finish();
    }
    
    void deinitialize() override {
        if (layer == nil) return;
        
        layerRef = layer;
        layer = nil;
    }
private:
    __weak ExampleCustomDrawableStyleLayer * layerRef;
    ExampleCustomDrawableStyleLayer * layer = nil;
};