#include "data/store/ChunkedVolumeStore.hpp"
#include "core/algo/GprVolumeBuilder.hpp"
#include <gtest/gtest.h>
#include <filesystem>
#include <cstdint>
using namespace geopro::data;
namespace {
geopro::core::BuiltI16 makeRamp(int n) {
  geopro::core::BuiltI16 b;
  b.vol = geopro::core::ScalarVolumeI16(n, n, n);
  for (int k = 0; k < n; k++)
    for (int j = 0; j < n; j++)
      for (int i = 0; i < n; i++) b.vol.at(i, j, k) = (short)(i);  // 沿 x 斜坡
  b.quant = {1.0, 0.0};
  b.origin = {{0, 0, 0}};
  b.spacing = {{1, 1, 1}};
  b.vminPhys = 0;
  b.vmaxPhys = n;
  return b;
}
}  // namespace

TEST(Pyramid, BuildsHalfResLevelsAndRanges) {
  auto dir = (std::filesystem::temp_directory_path() / "gpr_pyr").string();
  std::filesystem::remove_all(dir);
  ChunkedVolumeStore::write(dir, makeRamp(64), 32);
  ChunkedVolumeStore s(dir);
  s.buildPyramid(2);  // level 0(64³),1(32³),2(16³)
  EXPECT_GE(s.levels(), 3);
  int nx, ny, nz;
  s.dims(1, nx, ny, nz);
  EXPECT_EQ(nx, 32);
  EXPECT_EQ(ny, 32);
  EXPECT_EQ(nz, 32);
  // level0 块0 的 range:x 斜坡 0..31(brick32) → min=0,max=31
  auto r0 = s.brickRange(0, 0, 0, 0);
  EXPECT_EQ(r0.first, 0);
  EXPECT_EQ(r0.second, 31);
  auto blk1 = s.readBrick(1, 0, 0, 0);  // level1 块,降采样后非空
  EXPECT_FALSE(blk1.empty());
  std::filesystem::remove_all(dir);
}

TEST(Pyramid, Level0ReadCompatUnchanged) {
  auto dir = (std::filesystem::temp_directory_path() / "gpr_pyr_compat").string();
  std::filesystem::remove_all(dir);
  ChunkedVolumeStore::write(dir, makeRamp(64), 32);
  ChunkedVolumeStore s(dir);
  s.buildPyramid(1);
  EXPECT_EQ(s.readBrick(0, 0, 0), s.readBrick(0, 0, 0, 0));  // 兼容重载等价
  std::filesystem::remove_all(dir);
}

// 降采样语义:level1(0,0,0) 由 level0 每 2×2×2 平均得到。
// x 斜坡:level1 体素 i 来自 level0 的 (2i, 2i+1) 平均 = round((2i + 2i+1)/2) = 2i(取整向偶或截断,
// 这里两值差 1,平均 2i+0.5,round→2i+1 或 2i 取决实现;仅校验单调与范围)。
TEST(Pyramid, DownsampledRangeWithinSource) {
  auto dir = (std::filesystem::temp_directory_path() / "gpr_pyr_ds").string();
  std::filesystem::remove_all(dir);
  ChunkedVolumeStore::write(dir, makeRamp(64), 32);
  ChunkedVolumeStore s(dir);
  s.buildPyramid(2);
  // level1 维度 32³;以 brick32 仍是 1 块(覆盖 i=0..31 → 源 i=0..63)。
  int nx, ny, nz;
  s.dims(1, nx, ny, nz);
  EXPECT_EQ(nx, 32);
  auto r1 = s.brickRange(1, 0, 0, 0);
  // 降采样值落在源范围 [0,63] 内,且块覆盖全 x → min≈0, max≈63 附近(round 后)。
  EXPECT_GE(r1.first, 0);
  EXPECT_LE(r1.second, 63);
  EXPECT_LT(r1.first, r1.second);  // 斜坡降采样后仍有跨度
  // level1 块尺寸 = 32³。
  auto blk1 = s.readBrick(1, 0, 0, 0);
  EXPECT_EQ(blk1.size(), 32u * 32 * 32);
  std::filesystem::remove_all(dir);
}

// 全 blank 块 → range 记 (kBlank,kBlank),降采样后该区域仍 blank。
TEST(Pyramid, AllBlankBrickRange) {
  auto dir = (std::filesystem::temp_directory_path() / "gpr_pyr_blank").string();
  std::filesystem::remove_all(dir);
  geopro::core::BuiltI16 b;
  b.vol = geopro::core::ScalarVolumeI16(64, 64, 64);
  for (auto& v : b.vol.data()) v = geopro::core::ScalarVolumeI16::kBlank;
  b.quant = {1.0, 0.0};
  b.origin = {{0, 0, 0}};
  b.spacing = {{1, 1, 1}};
  b.vminPhys = 0;
  b.vmaxPhys = 0;
  ChunkedVolumeStore::write(dir, b, 32);
  ChunkedVolumeStore s(dir);
  s.buildPyramid(2);
  auto r0 = s.brickRange(0, 0, 0, 0);
  EXPECT_EQ(r0.first, geopro::core::ScalarVolumeI16::kBlank);
  EXPECT_EQ(r0.second, geopro::core::ScalarVolumeI16::kBlank);
  auto r1 = s.brickRange(1, 0, 0, 0);
  EXPECT_EQ(r1.first, geopro::core::ScalarVolumeI16::kBlank);
  std::filesystem::remove_all(dir);
}

// 真实全零块(非 blank):brickRange 返回 (0,0) 且不退化为惰性。
// (0,0) 是合法值域,旧实现用 (vmin==0&&vmax==0) 当「未计算」哨兵会误判;
// hasRange 标志修正后:buildPyramid 算出的全零块 hasRange=true,返回 (0,0)。
TEST(Pyramid, RealAllZeroBrickRangeIsZeroZeroNotDegenerate) {
  auto dir =
      (std::filesystem::temp_directory_path() / "gpr_pyr_zero").string();
  std::filesystem::remove_all(dir);
  geopro::core::BuiltI16 b;
  b.vol = geopro::core::ScalarVolumeI16(64, 64, 64);
  for (auto& v : b.vol.data()) v = 0;  // 真实 0(非 kBlank)
  b.quant = {1.0, 0.0};
  b.origin = {{0, 0, 0}};
  b.spacing = {{1, 1, 1}};
  b.vminPhys = 0;
  b.vmaxPhys = 0;
  ChunkedVolumeStore::write(dir, b, 32);
  ChunkedVolumeStore s(dir);
  s.buildPyramid(1);
  auto r0 = s.brickRange(0, 0, 0, 0);
  EXPECT_EQ(r0.first, 0);
  EXPECT_EQ(r0.second, 0);  // 合法 (0,0),不退化、不是 kBlank
  EXPECT_NE(r0.first, geopro::core::ScalarVolumeI16::kBlank);
  std::filesystem::remove_all(dir);
}

// 老 store 全零块(无金字塔):首次 brickRange 惰性算出 (0,0),不无限退化。
TEST(Pyramid, LegacyRealAllZeroBrickRangeIsZeroZero) {
  auto dir =
      (std::filesystem::temp_directory_path() / "gpr_pyr_zero_legacy").string();
  std::filesystem::remove_all(dir);
  geopro::core::BuiltI16 b;
  b.vol = geopro::core::ScalarVolumeI16(64, 64, 64);
  for (auto& v : b.vol.data()) v = 0;
  b.quant = {1.0, 0.0};
  b.origin = {{0, 0, 0}};
  b.spacing = {{1, 1, 1}};
  b.vminPhys = 0;
  b.vmaxPhys = 0;
  ChunkedVolumeStore::write(dir, b, 32);
  ChunkedVolumeStore s(dir);  // 未 buildPyramid:老 store,块无 hasRange
  auto r0 = s.brickRange(0, 0, 0, 0);  // 惰性算 → (0,0)
  EXPECT_EQ(r0.first, 0);
  EXPECT_EQ(r0.second, 0);
  std::filesystem::remove_all(dir);
}

// 老 store(未 buildPyramid):levels()==1;brickRange(0,...) 仍可惰性算。
TEST(Pyramid, LegacyStoreNoPyramidLevelsIsOne) {
  auto dir = (std::filesystem::temp_directory_path() / "gpr_pyr_legacy").string();
  std::filesystem::remove_all(dir);
  ChunkedVolumeStore::write(dir, makeRamp(64), 32);
  ChunkedVolumeStore s(dir);  // 未调用 buildPyramid
  EXPECT_EQ(s.levels(), 1);
  EXPECT_EQ(s.bricksX(), s.bricksX(0));
  auto r0 = s.brickRange(0, 0, 0, 0);  // 惰性算
  EXPECT_EQ(r0.first, 0);
  EXPECT_EQ(r0.second, 31);
  std::filesystem::remove_all(dir);
}