// IACore-OSS; The Core Library for All IA Open Source Projects
// Copyright (C) 2026 IAS (ias@iasoft.dev)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <IACore/IATest.hpp>
#include <IACore/ProcessOps.hpp>

using namespace IACore;

// -----------------------------------------------------------------------------
// Platform Abstraction for Test Commands
// -----------------------------------------------------------------------------
#if IA_PLATFORM_WINDOWS
#define CMD_ECHO_EXE "cmd.exe"
#define CMD_ARG_PREFIX "/c echo"
#define NULL_DEVICE "NUL"
#else
#define CMD_ECHO_EXE "/bin/echo"
#define CMD_ARG_PREFIX ""
#define NULL_DEVICE "/dev/null"
#endif

IAT_BEGIN_BLOCK(Core, ProcessOps)

// -------------------------------------------------------------------------
// 1. Basic Execution (Exit Code 0)
// -------------------------------------------------------------------------
auto test_basic_run() -> bool {
  // Simple "echo hello"
  String captured;

  const auto result =
      ProcessOps::spawn_process_sync(CMD_ECHO_EXE, CMD_ARG_PREFIX " HelloIA",
                                     [&](StringView line) { captured = line; });

  IAT_CHECK(result.has_value());
  IAT_CHECK_EQ(*result, 0); // Exit code 0

  // We check if "HelloIA" is contained or equal.
  IAT_CHECK(captured.find("HelloIA") != String::npos);

  return true;
}

// -------------------------------------------------------------------------
// 2. Argument Parsing
// -------------------------------------------------------------------------
auto test_arguments() -> bool {
  Vec<String> lines;

  // Echo two distinct words.
  // Windows: cmd.exe /c echo one two
  // Linux: /bin/echo one two
  String args = String(CMD_ARG_PREFIX) + " one two";
  if (!args.empty() && args[0] == ' ') {
    args.erase(0, 1); // cleanup space if prefix empty
  }

  const auto result =
      ProcessOps::spawn_process_sync(CMD_ECHO_EXE, args, [&](StringView line) {
        lines.push_back(String(line));
      });

  IAT_CHECK_EQ(*result, 0);
  IAT_CHECK(lines.size() > 0);

  // Output should contain "one two"
  IAT_CHECK(lines[0].find("one two") != String::npos);

  return true;
}

// -------------------------------------------------------------------------
// 3. Error / Non-Zero Exit Codes
// -------------------------------------------------------------------------
auto test_exit_codes() -> bool {
  // We need a command that returns non-zero.
  // Windows: cmd /c exit 1
  // Linux: /bin/sh -c "exit 1"

  String cmd;
  String arg;

#if IA_PLATFORM_WINDOWS
  cmd = "cmd.exe";
  arg = "/c exit 42";
#else
  cmd = "/bin/sh";
  arg = "-c \"exit 42\""; // quotes needed for sh -c
#endif

  const auto result =
      ProcessOps::spawn_process_sync(cmd, arg, [](StringView) {});

  IAT_CHECK(result.has_value());
  IAT_CHECK_EQ(*result, 42);

  return true;
}

// -------------------------------------------------------------------------
// 4. Missing Executable Handling
// -------------------------------------------------------------------------
auto test_missing_exe() -> bool {
  // Try to run a random string
  const auto result =
      ProcessOps::spawn_process_sync("sdflkjghsdflkjg", "", [](StringView) {});

  // Windows: CreateProcess usually fails -> returns unexpected
  // Linux: execvp fails inside child, returns 127 via waitpid

#if IA_PLATFORM_WINDOWS
  IAT_CHECK_NOT(result.has_value()); // Should be an error string
#else
  // Linux fork succeeds, but execvp fails, returning 127
  IAT_CHECK(result.has_value());
  IAT_CHECK_EQ(*result, 127);
#endif

  return true;
}

// -------------------------------------------------------------------------
// 5. Line Buffer Logic (The 4096 split test)
// -------------------------------------------------------------------------
auto test_large_output() -> bool {
  // Need to generate output larger than the internal 4096 buffer
  // to ensure the "partial line" logic works when a line crosses a buffer
  // boundary.

  String massive_string;
  massive_string.reserve(5000);
  for (i32 i = 0; i < 500; ++i) {
    massive_string += "1234567890"; // 5000 chars
  }

  String cmd;
  String arg;

#if IA_PLATFORM_WINDOWS
  cmd = "cmd.exe";
  // Windows has command line length limits (~8k), 5k is safe.
  arg = "/c echo " + massive_string;
#else
  cmd = "/bin/echo";
  arg = massive_string;
#endif

  String captured;
  const auto result = ProcessOps::spawn_process_sync(
      cmd, arg, [&](StringView line) { captured += line; });

  IAT_CHECK(result.has_value());
  IAT_CHECK_EQ(*result, 0);

  // If the LineBuffer failed to stitch chunks, the length wouldn't match
  // or we would get multiple callbacks if we expected 1 line.
  IAT_CHECK_EQ(captured.length(), massive_string.length());

  return true;
}

// -------------------------------------------------------------------------
// 6. Multi-Line Handling
// -------------------------------------------------------------------------
auto test_multi_line() -> bool {
  // Windows: cmd /c "echo A && echo B"
  // Linux: /bin/sh -c "echo A; echo B"

  String cmd;
  String arg;
#if IA_PLATFORM_WINDOWS
  cmd = "cmd.exe";
  arg = "/c \"echo LineA && echo LineB\"";
#else
  cmd = "/bin/sh";
  arg = "-c \"echo LineA; echo LineB\"";
#endif

  i32 line_count = 0;
  bool found_a = false;
  bool found_b = false;

  IA_UNUSED const auto res =
      ProcessOps::spawn_process_sync(cmd, arg, [&](StringView line) {
        line_count++;
        if (line.find("LineA") != String::npos) {
          found_a = true;
        }
        if (line.find("LineB") != String::npos) {
          found_b = true;
        }
      });

  IAT_CHECK(found_a);
  IAT_CHECK(found_b);
  // We expect at least 2 lines.
  // (Windows sometimes echoes the command itself depending on echo settings,
  // but we check contents)
  IAT_CHECK(line_count >= 2);

  return true;
}

// -------------------------------------------------------------------------
// 6. Complex Command Line Arguments Handling
// -------------------------------------------------------------------------
auto test_complex_arguments() -> bool {
  // Should parse as 3 arguments:
  // 1. -DDEFINED_MSG="Hello World"
  // 2. -v
  // 3. path/to/file
  const String complex_args =
      "-DDEFINED_MSG=\\\"Hello World\\\" -v path/to/file";

  const String cmd = CMD_ECHO_EXE;

  String final_args;
#if IA_PLATFORM_WINDOWS
  final_args = "/c echo " + complex_args;
#else
  final_args = complex_args;
#endif

  String captured;
  const auto result = ProcessOps::spawn_process_sync(
      cmd, final_args, [&](StringView line) { captured += line; });

  IAT_CHECK(result.has_value());
  IAT_CHECK_EQ(*result, 0);

  // Verify the quotes were preserved in the output
  IAT_CHECK(captured.find("Hello World") != String::npos);
  return true;
}

// -------------------------------------------------------------------------
// Registration
// -------------------------------------------------------------------------
IAT_BEGIN_TEST_LIST()
IAT_ADD_TEST(test_basic_run);
IAT_ADD_TEST(test_arguments);
IAT_ADD_TEST(test_exit_codes);
IAT_ADD_TEST(test_missing_exe);
IAT_ADD_TEST(test_large_output);
IAT_ADD_TEST(test_multi_line);
IAT_ADD_TEST(test_complex_arguments);
IAT_END_TEST_LIST()

IAT_END_BLOCK()

IAT_REGISTER_ENTRY(Core, ProcessOps)