#include "io/gpr/IprbReader.hpp"
#include "io/gpr/IprHeader.hpp"
#include <gtest/gtest.h>
#include <fstream>
#include <cstdio>
namespace {
std::string writeTmp(const std::vector<int16_t>& v) {
  std::string p = std::tmpnam(nullptr);
  std::ofstream f(p, std::ios::binary);
  f.write(reinterpret_cast<const char*>(v.data()),
          static_cast<std::streamsize>(v.size()*sizeof(int16_t)));
  return p;
}
}
using namespace geopro::io::gpr;
TEST(IprbReader, ReadsInt16AndLayout) {
  std::vector<int16_t> raw{0,1,2, 10,11,12, 20,21,22, 30,31,32}; // 4 道×3 采样
  auto path = writeTmp(raw);
  IprHeader h{}; h.samples = 3; h.lastTrace = 3; // traces = 4
  auto b = readIprb(path, h);
  EXPECT_EQ(b.samples, 3);
  EXPECT_EQ(b.traces, 4);
  EXPECT_EQ(b.data.size(), 12u);
  EXPECT_EQ(b.data[1*3 + 2], 12); // 第1道第2采样
  std::remove(path.c_str());
}
TEST(IprbReader, ThrowsOnSizeMismatch) {
  std::vector<int16_t> raw{0,1,2,3,4}; // 5 个,非 samples 整数倍 → 抛
  auto path = writeTmp(raw);
  IprHeader h{}; h.samples = 3; h.lastTrace = 3; // 5*2=10, 10%6!=0
  EXPECT_THROW(readIprb(path, h), std::runtime_error);
  std::remove(path.c_str());
}
// 真实数据规律：LAST TRACE=N 但文件恰含 N 道(非 N+1)。
// 文件大小为权威 → traces 应等于文件实含道数 N，而非 N+1。
TEST(IprbReader, FileSizeIsAuthoritativeNotLastTracePlusOne) {
  // 4 道×3 采样 = 12 个 int16，文件恰含 4 道。
  std::vector<int16_t> raw{0,1,2, 10,11,12, 20,21,22, 30,31,32};
  auto path = writeTmp(raw);
  IprHeader h{}; h.samples = 3; h.lastTrace = 4; // 假设 +1 会得 5 道(错)
  auto b = readIprb(path, h);
  EXPECT_EQ(b.traces, 4); // 以文件大小为准 → 4，复刻真实数据 traces==lastTrace 规律
  EXPECT_EQ(b.data.size(), 12u);
  std::remove(path.c_str());
}
TEST(IprbReader, ThrowsOnMissingFile) {
  IprHeader h{}; h.samples = 3; h.lastTrace = 3;
  EXPECT_THROW(readIprb("____no_such_file____.iprb", h), std::runtime_error);
}
TEST(IprbReader, RangeReadMatchesFullSlice) {
  // 造 samples=3, traces=5 的文件(15 个 int16,值=trace*10+s)
  std::vector<int16_t> raw; for(int t=0;t<5;t++)for(int s=0;s<3;s++) raw.push_back((int16_t)(t*10+s));
  auto path = writeTmp(raw);
  IprHeader h{}; h.samples=3; h.lastTrace=4; // 总道数=5(由文件大小推)
  auto full = readIprb(path, h);
  auto seg = readIprbRange(path, h, 1, 4);   // 读道 [1,4)=3 道
  EXPECT_EQ(seg.traces, 3); EXPECT_EQ(seg.samples, 3);
  ASSERT_EQ(seg.data.size(), 9u);
  for (int t=0;t<3;t++) for(int s=0;s<3;s++)
    EXPECT_EQ(seg.data[t*3+s], full.data[(t+1)*3+s]); // 段==全读对应段
  std::remove(path.c_str());
}
TEST(IprbReader, RangeOutOfBoundsThrows) {
  std::vector<int16_t> raw(15,0); auto path=writeTmp(raw);
  IprHeader h{}; h.samples=3; h.lastTrace=4;
  EXPECT_THROW(readIprbRange(path,h,3,99), std::runtime_error); // t1>5
  EXPECT_THROW(readIprbRange(path,h,4,2),  std::runtime_error); // t0>t1
  std::remove(path.c_str());
}