// Copyright 2026 The GN Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gn/edit_command.h"

#include <string>
#include <string_view>
#include <vector>

#include "base/files/file_util.h"
#include "base/files/scoped_temp_dir.h"
#include "gn/err.h"
#include "gn/filesystem_utils.h"
#include "gn/setup.h"
#include "gn/test_with_scheduler.h"
#include "util/test/test.h"

namespace commands {
namespace {
struct Edited;
std::string Pretty(const Edited& edited);

struct Edited {
  Edited(std::string_view contents, EditState edit_state = EditState())
      : contents_(contents.starts_with('\n') ? contents.substr(1) : contents),
        edit_state_(std::move(edit_state)) {}

  bool operator==(const Edited& other) const {
    return Pretty(*this) == Pretty(other);
  }

  std::string contents_;
  EditState edit_state_;
};

std::string Pretty(const Edited& edited) {
  std::string res = edited.contents_;
  if (!edited.edit_state_.needs_manual_review.empty()) {
    res += "\nNeeds manual review: " +
           testing::Pretty(edited.edit_state_.needs_manual_review);
  }
  if (!edited.edit_state_.warnings.empty()) {
    res += "\nWarnings: " + testing::Pretty(edited.edit_state_.warnings);
  }
  return res;
}

// Runs an edit command on matching the given target
// patterns, and returns the formatted output file contents.
Result<Edited> DoEdit(std::string command,
                      std::vector<std::string> patterns,
                      const std::string& before) {
  base::ScopedTempDir temp_dir;
  if (!temp_dir.CreateUniqueTempDir()) {
    return Err(Location(), "Failed to create temp dir");
  }
  base::FilePath root_path = base::MakeAbsoluteFilePath(temp_dir.GetPath());

  base::FilePath build_gn_path = root_path.AppendASCII("BUILD.gn");
  if (!WriteFile(build_gn_path, before, nullptr)) {
    return Err(Location(), "Failed to write BUILD.gn");
  }
  base::FilePath dot_gn_path = root_path.AppendASCII(".gn");
  if (!WriteFile(dot_gn_path, "", nullptr)) {
    return Err(Location(), "Failed to write .gn");
  }

  Setup setup;
  setup.build_settings().SetRootPath(root_path);

  std::vector<std::string> args;
  args.push_back(std::move(command));
  for (auto& p : patterns) {
    args.push_back(std::move(p));
  }

  auto result = RunEditImpl(args, setup);
  if (result.has_error()) {
    return result.error();
  }

  std::string after;
  if (!base::ReadFileToString(build_gn_path, &after)) {
    return Err(Location(), "Failed to read BUILD.gn");
  }
  return Edited(after, std::move(result->second));
}

// Runs an edit command matching all targets in the root BUILD.gn ("//:*").
Result<Edited> DoEdit(std::string command, const std::string& before) {
  return DoEdit(std::move(command), {"//:*"}, before);
}

}  // namespace

using EditCommandTest = TestWithScheduler;

TEST_F(EditCommandTest, MultipleTargetsSubset) {
  EXPECT_SUCCESS(DoEdit("set testonly true", {"//:foo"},
                        R"(
executable("foo") {
  testonly = false
}
executable("bar") {
  testonly = false
}
)"),
                 Edited(R"(
executable("foo") {
  testonly = true
}
executable("bar") {
  testonly = false
}
)"));
}

TEST_F(EditCommandTest, PatternNeverMatched) {
  EXPECT_FAILURE(DoEdit("set testonly true", {"//:nonexistent"},
                        R"(
executable("foo") {
}
)"),
                 "Target(s) not found: //:nonexistent");
}

TEST_F(EditCommandTest, DeleteSubcommand) {
  EXPECT_SUCCESS(DoEdit("delete", {"//:bar"},
                        R"(
executable("foo") {
  sources = [ "foo.cc" ]
}
executable("bar") {
  sources = [ "bar.cc" ]
}
)"),
                 Edited(R"(
executable("foo") {
  sources = [ "foo.cc" ]
}
)"));

  EXPECT_SUCCESS(DoEdit("delete", {"//:bar"},
                        R"(
if (is_win) {
  executable("bar") {
    sources = [ "bar.cc" ]
  }
} else {
  executable("bar") {
    sources = [ "bar.cc" ]
  }
}
)"),
                 Edited(R"(
if (is_win) {
  # TODO(gn edit: delete):
  # This would normally be deleted but is conditional.
  # Manual intervention is required to decide whether it should actually be deleted.
  executable("bar") {
    sources = [ "bar.cc" ]
  }
} else {
  # TODO(gn edit: delete):
  # This would normally be deleted but is conditional.
  # Manual intervention is required to decide whether it should actually be deleted.
  executable("bar") {
    sources = [ "bar.cc" ]
  }
}
)",
                        EditState({Label(SourceDir("//"), "bar")})));
}

TEST_F(EditCommandTest, RemoveAttributeSubcommand) {
  EXPECT_SUCCESS(DoEdit("remove testonly",
                        R"(
executable("foo") {
  sources = [ "foo.cc" ]
  testonly = true
}
)"),
                 Edited(R"(
executable("foo") {
  sources = [ "foo.cc" ]
}
)"));

  EXPECT_SUCCESS(
      DoEdit("remove nonexistent_attribute", {"//:foo"},
             R"(
executable("foo") {
}
)"),
      Edited(R"(
executable("foo") {
}
)",
             EditState{{},
                       {Err(Location(),
                            "Target \"//:foo\" does not contain the "
                            "attribute \"nonexistent_attribute\".")}}));
}

TEST_F(EditCommandTest, SetSubcommand) {
  // New bool attribute
  EXPECT_SUCCESS(DoEdit("set testonly true",
                        R"(
executable("foo") {
}
)"),
                 Edited(R"(
executable("foo") {
  testonly = true
}
)"));

  // Replacing existing attribute
  EXPECT_SUCCESS(DoEdit("set testonly false",
                        R"(
executable("foo") {
  testonly = true
}
)"),
                 Edited(R"(
executable("foo") {
  testonly = false
}
)"));

  // String attribute
  EXPECT_SUCCESS(DoEdit("set label \"//foo:bar\"",
                        R"(
executable("foo") {
}
)"),
                 Edited(R"(
executable("foo") {
  label = "//foo:bar"
}
)"));

  // Int attribute
  EXPECT_SUCCESS(DoEdit("set assert_no_deps 42",
                        R"(
executable("foo") {
}
)"),
                 Edited(R"(
executable("foo") {
  assert_no_deps = 42
}
)"));

  // Multiple values setting a list (replaces first, deletes modification,
  // adds review for conditional)
  EXPECT_SUCCESS(DoEdit("set deps //foo //bar",
                        R"(
executable("foo") {
  deps = [ "//bar" ]
  deps += [ "//baz" ]
  if (is_linux) {
    deps += [ "//linux" ]
  }
}
)"),
                 Edited(
                     R"(
executable("foo") {
  deps = [
    "//bar",
    "//foo",
  ]

  if (is_linux) {
    # TODO(gn edit: set deps //foo //bar):
    # This would normally be deleted but is conditional.
    # Manual intervention is required to decide whether it should actually be deleted.
    deps += [ "//linux" ]
  }
}
)",
                     EditState({Label(SourceDir("//"), "foo")})));

  // Forced list attribute (appends new list, adds review for conditional)
  EXPECT_SUCCESS(DoEdit("set deps:list //foo",
                        R"(
executable("foo") {
  if (is_linux) {
    deps = [ "//linux" ]
    public_deps = [ "//linux" ]
  }
}
)"),
                 Edited(
                     R"(
executable("foo") {
  if (is_linux) {
    # TODO(gn edit: set deps:list //foo):
    # This would normally be deleted but is conditional.
    # Manual intervention is required to decide whether it should actually be deleted.
    deps = [ "//linux" ]
    public_deps = [ "//linux" ]
  }
  deps = [ "//foo" ]
}
)",
                     EditState({Label(SourceDir("//"), "foo")})));
}

}  // namespace commands