#include <catch2/catch_all.hpp>

#include <numeric>
#include <sstream>

#include "test_data.hpp" // get access to init_print, etc

#include "libslic3r/Config.hpp"
#include "libslic3r/Model.hpp"
#include "libslic3r/Config.hpp"
#include "libslic3r/GCodeReader.hpp"
#include "libslic3r/Flow.hpp"
#include "libslic3r/libslic3r.h"

using namespace Slic3r::Test;
using namespace Slic3r;

/// Test the expected behavior for auto-width,
/// spacing, etc
SCENARIO("Flow: Flow math for non-bridges", "[Flow]") {
    GIVEN("Nozzle Diameter of 0.4, a desired width of 1mm and layer height of 0.5") {
        ConfigOptionFloatOrPercent	width(1.0, false);
        float nozzle_diameter	= 0.4f;
        float layer_height		= 0.4f;

        // Spacing for non-bridges is has some overlap
        THEN("External perimeter flow has spacing fixed to 1.125 * nozzle_diameter") {
            auto flow = Flow::new_from_config_width(frExternalPerimeter, ConfigOptionFloatOrPercent(0, false), nozzle_diameter, layer_height);
            REQUIRE(flow.spacing() == Catch::Approx(1.125 * nozzle_diameter - layer_height * (1.0 - PI / 4.0)));
        }

        THEN("Internal perimeter flow has spacing fixed to 1.125 * nozzle_diameter") {
            auto flow = Flow::new_from_config_width(frPerimeter, ConfigOptionFloatOrPercent(0, false), nozzle_diameter, layer_height);
            REQUIRE(flow.spacing() == Catch::Approx(1.125 *nozzle_diameter - layer_height * (1.0 - PI / 4.0)));
        }
        THEN("Spacing for supplied width is 0.8927f") {
            auto flow = Flow::new_from_config_width(frExternalPerimeter, width, nozzle_diameter, layer_height);
            REQUIRE(flow.spacing() == Catch::Approx(width.value - layer_height * (1.0 - PI / 4.0)));
            flow = Flow::new_from_config_width(frPerimeter, width, nozzle_diameter, layer_height);
            REQUIRE(flow.spacing() == Catch::Approx(width.value - layer_height * (1.0 - PI / 4.0)));
        }
    }
    /// Check the min/max
    GIVEN("Nozzle Diameter of 0.25") {
        float nozzle_diameter	= 0.25f;
        float layer_height		= 0.5f;
        WHEN("layer height is set to 0.2") {
            layer_height = 0.15f;
            THEN("Max width is set.") {
                auto flow = Flow::new_from_config_width(frPerimeter, ConfigOptionFloatOrPercent(0, false), nozzle_diameter, layer_height);
                REQUIRE(flow.width() == Catch::Approx(1.125 * nozzle_diameter));
            }
        }
        WHEN("Layer height is set to 0.25") {
            layer_height = 0.25f;
            THEN("Min width is set.") {
                auto flow = Flow::new_from_config_width(frPerimeter, ConfigOptionFloatOrPercent(0, false), nozzle_diameter, layer_height);
                REQUIRE(flow.width() == Catch::Approx(1.125 * nozzle_diameter));
            }
        }
    }

#if 0
    /// Check for an edge case in the maths where the spacing could be 0; original
    /// math is 0.99. Slic3r issue #4654
    GIVEN("Input spacing of 0.414159 and a total width of 2") {
        double in_spacing = 0.414159;
        double total_width = 2.0;
        auto flow = Flow::new_from_spacing(1.0, 0.4, 0.3);
        WHEN("solid_spacing() is called") {
            double result = flow.solid_spacing(total_width, in_spacing);
            THEN("Yielded spacing is greater than 0") {
                REQUIRE(result > 0);
            }
        }
    }
#endif    

}

/// Spacing, width calculation for bridge extrusions
SCENARIO("Flow: Flow math for bridges", "[Flow]") {
    GIVEN("Nozzle Diameter of 0.4, a desired width of 1mm and layer height of 0.5") {
		float nozzle_diameter	= 0.4f;
		float bridge_flow		= 1.0f;
        WHEN("Flow role is frExternalPerimeter") {
            auto flow = Flow::bridging_flow(nozzle_diameter * sqrt(bridge_flow), nozzle_diameter);
            THEN("Bridge width is same as nozzle diameter") {
                REQUIRE(flow.width() == Catch::Approx(nozzle_diameter));
            }
            THEN("Bridge spacing is same as nozzle diameter + BRIDGE_EXTRA_SPACING") {
                REQUIRE(flow.spacing() == Catch::Approx(nozzle_diameter + BRIDGE_EXTRA_SPACING));
            }
        }
    }
}