#include <gtest/gtest.h>

#include <cmath>

#include "ground/TileMath.hpp"

using geopro::render::lonLatToTile;
using geopro::render::tileBounds;

// z=1 把世界分 2x2：原点(0°,0°)在东/南象限交界 → 标准 slippy 取 (1,1)。
TEST(TileMath, OriginZoom1) {
    auto t = lonLatToTile(0.0, 0.0, 1);
    EXPECT_EQ(t.z, 1);
    EXPECT_EQ(t.x, 1);
    EXPECT_EQ(t.y, 1);
}

// z=1 西北瓦片 (0,0) 覆盖西半球北部：west=-180, east=0, north≈85.0511(墨卡托上限), south=0。
TEST(TileMath, BoundsZoom1NW) {
    auto b = tileBounds(1, 0, 0);
    EXPECT_NEAR(b.west, -180.0, 1e-6);
    EXPECT_NEAR(b.east, 0.0, 1e-6);
    EXPECT_NEAR(b.north, 85.0511287798, 1e-4);
    EXPECT_NEAR(b.south, 0.0, 1e-6);
}

// 往返一致：任一经纬点所属瓦片的边界必须包含该点（经度严格、纬度含墨卡托方向）。
TEST(TileMath, RoundTripContains) {
    const double lon = 116.391, lat = 39.907;  // 北京附近
    const int z = 12;
    auto t = lonLatToTile(lon, lat, z);
    EXPECT_EQ(t.z, z);
    auto b = tileBounds(t.z, t.x, t.y);
    EXPECT_GE(lon, b.west);
    EXPECT_LE(lon, b.east);
    EXPECT_LE(lat, b.north);  // north 是瓦片上边界(纬度大)
    EXPECT_GE(lat, b.south);
}

// 夹紧：超界经纬不应产生越界瓦片索引。
TEST(TileMath, ClampInRange) {
    auto t = lonLatToTile(500.0, 95.0, 3);  // 非法输入
    const int hi = (1 << 3) - 1;
    EXPECT_GE(t.x, 0);
    EXPECT_LE(t.x, hi);
    EXPECT_GE(t.y, 0);
    EXPECT_LE(t.y, hi);
}