#include "data/store/ChunkedVolumeStore.hpp"
#include "core/algo/GprVolumeBuilder.hpp"
#include <gtest/gtest.h>
#include <filesystem>
#include <cstdint>
#include <vector>
using namespace geopro::data;

namespace {
// 非常量体：体素随 (i,j,k) 变化，确保逐块对拍真正区分块内容（非全相同）。
geopro::core::BuiltI16 makeBuilt(int nx, int ny, int nz) {
  geopro::core::BuiltI16 b;
  b.vol = geopro::core::ScalarVolumeI16(nx, ny, nz);
  for (int k = 0; k < nz; ++k)
    for (int j = 0; j < ny; ++j)
      for (int i = 0; i < nx; ++i)
        b.vol.at(i, j, k) =
            static_cast<std::int16_t>((i * 131 + j * 17 + k * 7) % 251);
  b.quant = {0.5, -3.0};
  b.origin = {{10.0, 20.0, 30.0}};
  b.spacing = {{2.0, 3.0, 4.0}};
  b.vminPhys = -3.0;
  b.vmaxPhys = 122.0;
  return b;
}

int ceilDiv(int n, int brick) { return (n + brick - 1) / brick; }
int extent(int n, int b, int brick) {
  const int got = n - b * brick;
  return got < brick ? got : brick;
}

// 从整卷切出 (bx,by,bz) 块体素（块内 i 最快、k 最慢，与 write 同布局）。
std::vector<std::int16_t> sliceBrickFrom(const geopro::core::BuiltI16& b, int bx,
                                         int by, int bz, int brick) {
  const auto& vol = b.vol;
  const int bw = extent(vol.nx(), bx, brick);
  const int bh = extent(vol.ny(), by, brick);
  const int bd = extent(vol.nz(), bz, brick);
  std::vector<std::int16_t> out(static_cast<std::size_t>(bw) * bh * bd);
  const int i0 = bx * brick, j0 = by * brick, k0 = bz * brick;
  std::size_t w = 0;
  for (int kk = 0; kk < bd; ++kk)
    for (int jj = 0; jj < bh; ++jj)
      for (int ii = 0; ii < bw; ++ii)
        out[w++] = vol.at(i0 + ii, j0 + jj, k0 + kk);
  return out;
}

std::string tmp(const char* name) {
  return (std::filesystem::temp_directory_path() / name).string();
}
}  // namespace

// 核心验收：流式逐块写 vs 非流式整卷 write，逐块 readBrick + meta 完全一致。
TEST(StreamingVolumeWriter, MatchesNonStreamingWrite) {
  auto b = makeBuilt(100, 40, 30);  // 100/40/30 均非整除 64 → 含边缘块
  const int brick = 64;
  auto dirA = tmp("swA"), dirB = tmp("swB");
  std::filesystem::remove_all(dirA);
  std::filesystem::remove_all(dirB);

  ChunkedVolumeStore::write(dirA, b, brick);            // 金标准
  StoreMeta m = ChunkedVolumeStore::readMeta(dirA);     // 复用同一 meta 元信息

  const int bX = ceilDiv(m.nx, brick);
  const int bY = ceilDiv(m.ny, brick);
  const int bZ = ceilDiv(m.nz, brick);

  {
    StreamingVolumeWriter w(dirB, m);
    // 故意打乱写入顺序（与 write 的固定遍历顺序不同），验证顺序无关。
    for (int bx = 0; bx < bX; ++bx)
      for (int by = 0; by < bY; ++by)
        for (int bz = 0; bz < bZ; ++bz)
          w.writeBrick(bx, by, bz, sliceBrickFrom(b, bx, by, bz, brick));
    w.finalize();
  }

  ChunkedVolumeStore A(dirA), B(dirB);
  for (int bz = 0; bz < bZ; ++bz)
    for (int by = 0; by < bY; ++by)
      for (int bx = 0; bx < bX; ++bx)
        EXPECT_EQ(A.readBrick(bx, by, bz), B.readBrick(bx, by, bz))
            << "brick mismatch at " << bx << "," << by << "," << bz;

  EXPECT_EQ(B.meta().nx, A.meta().nx);
  EXPECT_EQ(B.meta().ny, A.meta().ny);
  EXPECT_EQ(B.meta().nz, A.meta().nz);
  EXPECT_EQ(B.meta().brick, A.meta().brick);
  EXPECT_EQ(B.meta().origin, A.meta().origin);
  EXPECT_EQ(B.meta().spacing, A.meta().spacing);
  EXPECT_EQ(B.meta().quant.scale, A.meta().quant.scale);
  EXPECT_EQ(B.meta().quant.offset, A.meta().quant.offset);
  EXPECT_EQ(B.meta().vminPhys, A.meta().vminPhys);
  EXPECT_EQ(B.meta().vmaxPhys, A.meta().vmaxPhys);

  std::filesystem::remove_all(dirA);
  std::filesystem::remove_all(dirB);
}

// 同一块重复写 → 抛异常（约定：每块只写一次）。
TEST(StreamingVolumeWriter, DuplicateBrickThrows) {
  auto b = makeBuilt(70, 30, 20);
  auto dirA = tmp("swDup");
  std::filesystem::remove_all(dirA);
  ChunkedVolumeStore::write(dirA, b, 64);
  StoreMeta m = ChunkedVolumeStore::readMeta(dirA);

  auto dirB = tmp("swDupB");
  std::filesystem::remove_all(dirB);
  StreamingVolumeWriter w(dirB, m);
  w.writeBrick(0, 0, 0, sliceBrickFrom(b, 0, 0, 0, 64));
  EXPECT_THROW(w.writeBrick(0, 0, 0, sliceBrickFrom(b, 0, 0, 0, 64)),
               std::runtime_error);
  std::filesystem::remove_all(dirA);
  std::filesystem::remove_all(dirB);
}

// 缺块 finalize → 抛异常（约定：所有块必须写齐）。
TEST(StreamingVolumeWriter, MissingBrickFinalizeThrows) {
  auto b = makeBuilt(70, 30, 20);  // bX=2,bY=1,bZ=1 → 共 2 块
  auto dirA = tmp("swMiss");
  std::filesystem::remove_all(dirA);
  ChunkedVolumeStore::write(dirA, b, 64);
  StoreMeta m = ChunkedVolumeStore::readMeta(dirA);

  auto dirB = tmp("swMissB");
  std::filesystem::remove_all(dirB);
  StreamingVolumeWriter w(dirB, m);
  w.writeBrick(0, 0, 0, sliceBrickFrom(b, 0, 0, 0, 64));  // 只写 1 块，缺 (1,0,0)
  EXPECT_THROW(w.finalize(), std::runtime_error);
  std::filesystem::remove_all(dirA);
  std::filesystem::remove_all(dirB);
}

// 块体素大小不符（bw*bh*bd 不匹配）→ 抛异常。
TEST(StreamingVolumeWriter, WrongVoxelCountThrows) {
  auto b = makeBuilt(70, 30, 20);
  auto dirA = tmp("swSize");
  std::filesystem::remove_all(dirA);
  ChunkedVolumeStore::write(dirA, b, 64);
  StoreMeta m = ChunkedVolumeStore::readMeta(dirA);

  auto dirB = tmp("swSizeB");
  std::filesystem::remove_all(dirB);
  StreamingVolumeWriter w(dirB, m);
  std::vector<std::int16_t> bad(10);  // 远小于 64*30*20
  EXPECT_THROW(w.writeBrick(0, 0, 0, bad), std::runtime_error);
  std::filesystem::remove_all(dirA);
  std::filesystem::remove_all(dirB);
}