#include <gtest/gtest.h>

#include <filesystem>
#include <string>
#include <system_error>

#include <stdlib.h>

#include "libreichwein/file.h"

#include "diff.h"

namespace fs = std::filesystem;
using namespace Reichwein;

class DiffTest: public ::testing::Test
{
protected:
 DiffTest(){
 }

 ~DiffTest(){
 }
};

TEST_F(DiffTest, constructor)
{
 // empty constructor
 {
  Diff d{};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data/></diff>");
 }

 // constructor via xml diff
 {
  EXPECT_THROW(Diff d{""}, std::exception);
 }
 {
  EXPECT_THROW(Diff d{"<diff><begin></begin></diff>"}, std::exception);
  EXPECT_THROW(Diff d{"<diff><end>0</end><data>abc</data></diff>"}, std::exception);
  EXPECT_THROW(Diff d{"<diff><start>0</start><data>abc</data></diff>"}, std::exception);
  EXPECT_THROW(Diff d{"<diff><start>0</start><end>0</end></diff>"}, std::exception);
  EXPECT_THROW(Diff d{"<diff><start>5</start><end>0</end><data>abc</data></diff>"}, std::exception);
  EXPECT_THROW(Diff d{"<diff><start></start><end>0</end><data>abc</data></diff>"}, std::exception);
 }

 {
  Diff d{"<diff><start>0</start><end>0</end><data>abc</data></diff>"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data>abc</data></diff>");
 }

 {
  Diff d{"<diff><start>5</start><end>5</end><data>abc</data></diff>"};
  EXPECT_EQ(d.get_xml(), "<diff><start>5</start><end>5</end><data>abc</data></diff>");
 }

 {
  Diff d{"<diff><start>5</start><end>50</end><data>abc</data></diff>"};
  EXPECT_EQ(d.get_xml(), "<diff><start>5</start><end>50</end><data>abc</data></diff>");
 }

 // constructor via versions
 {
  Diff d{"", ""};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data/></diff>");
 }
 {
  Diff d{"a", "a"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data/></diff>");
 }
 {
  Diff d{"a", "b"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>1</end><data>b</data></diff>");
 }
 {
  Diff d{"0a1", "0b1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>1</start><end>2</end><data>b</data></diff>");
 }
 {
  Diff d{"0abc1", "00b01"};
  EXPECT_EQ(d.get_xml(), "<diff><start>1</start><end>4</end><data>0b0</data></diff>");
 }
 {
  Diff d{"0ab1", "00b01"};
  EXPECT_EQ(d.get_xml(), "<diff><start>1</start><end>3</end><data>0b0</data></diff>");
 }
 {
  Diff d{"0abc1", "00b1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>1</start><end>4</end><data>0b</data></diff>");
 }
 {
  Diff d{"0abc1", ""};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>5</end><data/></diff>");
 }
 {
  Diff d{"bc1", "0abc1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data>0a</data></diff>");
 }
 {
  Diff d{"0abc1", "0ab"};
  EXPECT_EQ(d.get_xml(), "<diff><start>3</start><end>5</end><data/></diff>");
 }
 {
  Diff d{"0abc1", "0abc123"};
  EXPECT_EQ(d.get_xml(), "<diff><start>5</start><end>5</end><data>23</data></diff>");
 }
 {
  Diff d{"0abc1", "010abc1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>0</end><data>01</data></diff>");
 }
 {
  Diff d{"0abc1", "0ac1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>2</start><end>3</end><data/></diff>");
 }
 {
  Diff d{"0abc1", "0abxc1"};
  EXPECT_EQ(d.get_xml(), "<diff><start>3</start><end>3</end><data>x</data></diff>");
 }
 {
  Diff d{"abc", "c"};
  EXPECT_EQ(d.get_xml(), "<diff><start>0</start><end>2</end><data/></diff>");
 }
}

TEST_F(DiffTest, diff_create)
{
 const char* result {diff_create("0abc1", "0ab")};

 EXPECT_EQ(std::string(result), "<diff><start>3</start><end>5</end><data/></diff>");
 free((void*)result); // this will be done by javascript side in real scenario
}

TEST_F(DiffTest, diff_apply)
{
 const char* result {diff_apply("0abc1", "<diff><start>3</start><end>5</end><data/></diff>")};

 EXPECT_EQ(std::string(result), "0ab");
 free((void*)result); // this will be done by javascript side in real scenario
}