// Copyright 2026 Google LLC
//
// 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
//
//    https://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 "formats/bmff/box_matcher.h"

#include <string>
#include <vector>

#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "constants/labels.h"
#include "formats/bmff/box_header.h"
#include "formats/bmff/test_utils.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "proto/bmff_based_hash_assertion.pb.h"
#include "riegeli/bytes/string_reader.h"

namespace credentio {
namespace {

using ::credentio_testing::BigBox;
using ::credentio_testing::Box;
using ::credentio_testing::BoxFlags;
using ::credentio_testing::BoxVersion;
using ::credentio_testing::UuidBoxPayload;
using ::testing::ElementsAre;
using ::testing::IsEmpty;

constexpr absl::string_view kFlagsForZero("\x00\x00\x00", 3);
constexpr absl::string_view kFlagsForOne("\x00\x00\x01", 3);
constexpr absl::string_view kFlagsForTwo("\x00\x00\x02", 3);

std::vector<std::string> MatchBmffBoxes(
    std::vector<credentio::BmffBoxHeader> boxes,
    const credentio::BMFFBoxMatcher* matcher) {
  std::vector<std::string> matched;
  for (const auto& box : boxes) {
    if (matcher->Matches(box)) {
      matched.push_back(box.xpath);
    }
  }
  return matched;
}

std::vector<credentio::BMFFBoxMatcher::Range> MatchBmffBoxRanges(
    std::vector<credentio::BmffBoxHeader> boxes,
    const credentio::BMFFBoxMatcher* matcher) {
  std::vector<credentio::BMFFBoxMatcher::Range> matched;
  for (const auto& box : boxes) {
    if (!matcher->Matches(box)) {
      continue;
    }
    auto ranges = matcher->MatchedRanges(box);
    matched.insert(matched.end(), ranges.begin(), ranges.end());
  }
  return matched;
}

TEST(BoxMatcher, MatchXPath) {
  std::string uuid = Box(
      "uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), BoxFlags(0), ""));
  std::string moov = Box("moov", "moov");
  std::string trak_trak1_trak1 = Box("trak", "abcd");
  std::string trak_trak1 = Box("trak", trak_trak1_trak1);
  std::string trak_trak2 = BigBox("trak", "efgh");
  std::string trak1 =
      BigBox("trak", absl::StrCat(trak_trak1, moov, trak_trak2));
  std::string trak2 = Box("trak", "ijkl");
  std::string contents = absl::StrCat(uuid, trak1, trak2);
  riegeli::StringReader<> input(contents);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]/trak[1]/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]/trak[1]/trak[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]/trak/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]/trak[1]/trak[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak/trak/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]/trak[1]/trak[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak/trak/trak[1]");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]/trak[1]/trak[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak/trak/abcd");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]", "/trak[2]"));
  }
}

TEST(BoxMatcher, MatchLength) {
  std::string uuid = Box(
      "uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), BoxFlags(0), ""));
  std::string moov = Box("moov", "moov");
  std::string trak_trak1_trak1 = Box("trak", "abcd");
  std::string trak_trak1 = Box("trak", trak_trak1_trak1);
  std::string trak_trak2 = BigBox("trak", "efgh");
  std::string trak1 =
      BigBox("trak", absl::StrCat(trak_trak1, moov, trak_trak2));
  std::string trak2 = Box("trak", "ijkl");
  std::string contents = absl::StrCat(uuid, trak1, trak2);
  riegeli::StringReader<> input(contents);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  {
    credentio::BmffRange range;
    range.set_xpath("/trak");
    range.set_length(68);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/trak[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak");
    range.set_length(12);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/trak[2]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher),
                ElementsAre("/trak[1]", "/trak[2]"));
  }
}

TEST(BoxMatcher, MatchVersion) {
  std::string uuid = Box(
      "uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(2), BoxFlags(0), ""));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    range.set_version(2);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    range.set_version(1);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
}

TEST(BoxMatcher, MatchFlagsDefaultExactMatch) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                                kFlagsForOne, ""));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  credentio::BmffRange range;
  range.set_xpath("/uuid");
  range.set_flags(kFlagsForOne);
  credentio::BMFFBoxMatcher matcher(range, &input);
  EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
};

TEST(BoxMatcher, MatchFlagsExplicitlyExactMatch) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                                kFlagsForOne, ""));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  credentio::BmffRange range;
  range.set_xpath("/uuid");
  range.set_flags(kFlagsForOne);
  range.set_exact(true);
  credentio::BMFFBoxMatcher matcher(range, &input);
  EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
};

TEST(BoxMatcher, MatchFlagsNotMatched) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                                kFlagsForOne, ""));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  credentio::BmffRange range;
  range.set_xpath("/uuid");
  range.set_flags(kFlagsForZero);
  credentio::BMFFBoxMatcher matcher(range, &input);
  EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
}

TEST(BoxMatcher, MatchFlagsNotExactButMatched) {
  credentio::BmffRange range;
  range.set_xpath("/uuid");
  range.set_flags(kFlagsForZero);
  range.set_exact(false);
  {
    std::string uuid =
        Box("uuid",
            UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), kFlagsForOne, ""));
    riegeli::StringReader<> input(uuid);
    auto boxes_or = ReadBmffBoxHeaders(input);
    ASSERT_TRUE(boxes_or.ok());
    auto boxes = *boxes_or;
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
  {
    std::string uuid =
        Box("uuid",
            UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), kFlagsForTwo, ""));
    riegeli::StringReader<> input(uuid);
    auto boxes_or = ReadBmffBoxHeaders(input);
    ASSERT_TRUE(boxes_or.ok());
    auto boxes = *boxes_or;
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
};

TEST(BoxMatcher, MatchFlagsNotExactNotMatched) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                                kFlagsForOne, ""));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  credentio::BmffRange range;
  range.set_xpath("/uuid");
  range.set_flags(kFlagsForTwo);
  range.set_exact(false);
  credentio::BMFFBoxMatcher matcher(range, &input);
  EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
};

TEST(BoxMatcher, MatchFlagsNotFullBoxNotMatched) {
  std::string some_box = Box("some", "abcd");
  riegeli::StringReader<> input(some_box);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  credentio::BmffRange range;
  range.set_xpath("/some");
  range.set_flags(kFlagsForZero);
  range.set_exact(false);
  credentio::BMFFBoxMatcher matcher(range, &input);
  EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
};

TEST(BoxMatcher, NoFlagsMatched) {
  {
    std::string uuid =
        Box("uuid",
            UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), kFlagsForOne, ""));
    riegeli::StringReader<> input(uuid);
    auto boxes_or = ReadBmffBoxHeaders(input);
    ASSERT_TRUE(boxes_or.ok());
    auto boxes = *boxes_or;
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  };
}

TEST(BoxMatcher, MatchData) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0),
                                                BoxFlags(0), "abcd"));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    auto data1 = range.add_data();
    data1->set_offset(4);
    data1->set_value("uuid");
    auto data2 = range.add_data();
    data2->set_offset(28);
    data2->set_value("abcd");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    auto data1 = range.add_data();
    data1->set_offset(4);
    data1->set_value("aaaa");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range;
    range.set_xpath("/uuid");
    auto data1 = range.add_data();
    data1->set_offset(10000);
    data1->set_value("uuid");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
}

TEST(BoxMatcher, MismatchOneField) {
  std::string uuid = Box("uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(1),
                                                kFlagsForOne, "abcd"));
  riegeli::StringReader<> input(uuid);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;

  credentio::BmffRange matched_range;
  matched_range.set_xpath("/uuid");
  matched_range.set_length(32);
  matched_range.set_version(1);
  matched_range.set_flags(kFlagsForOne);
  auto data1 = matched_range.add_data();
  data1->set_offset(4);
  data1->set_value("uuid");
  auto data2 = matched_range.add_data();
  data2->set_offset(28);
  data2->set_value("abcd");

  credentio::BMFFBoxMatcher matcher(matched_range, &input);
  ASSERT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));

  {
    credentio::BmffRange range = matched_range;
    range.set_xpath("/uuid[1]");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), ElementsAre("/uuid[1]"));
  }
  {
    credentio::BmffRange range = matched_range;
    range.set_length(31);  // length not matched.
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range = matched_range;
    range.set_version(2);  // version not matched.
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range = matched_range;
    range.set_length(1);  // length not matched.
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range = matched_range;
    range.set_flags(kFlagsForTwo);  // flags not matched.
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
  {
    credentio::BmffRange range = matched_range;
    range.mutable_data(1)->set_value("abce");  // data not matched.
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxes(boxes, &matcher), IsEmpty());
  }
}

TEST(BoxMatcher, MatchedRanges) {
  std::string uuid = Box(
      "uuid", UuidBoxPayload(kC2paBmffBoxUuid, BoxVersion(0), BoxFlags(0), ""));
  std::string moov = Box("moov", "moov");      // box_size = 12
  std::string trak1 = Box("trak", moov);       // box_size = 20
  std::string trak2 = BigBox("trak", "ijkl");  // box_size = 20
  std::string contents = absl::StrCat(uuid, trak1, trak2);
  riegeli::StringReader<> input(contents);
  auto boxes_or = ReadBmffBoxHeaders(input);
  ASSERT_TRUE(boxes_or.ok());
  auto boxes = *boxes_or;
  // Single box matched.
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxRanges(boxes, &matcher),
                ElementsAre(credentio::BMFFBoxMatcher::Range{.offset = 28,
                                                             .length = 20}));
  }
  // Multiple boxes matched.
  {
    credentio::BmffRange range;
    range.set_xpath("/trak");
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(
        MatchBmffBoxRanges(boxes, &matcher),
        ElementsAre(
            credentio::BMFFBoxMatcher::Range{.offset = 28, .length = 20},
            credentio::BMFFBoxMatcher::Range{.offset = 48, .length = 20}));
  }
  // Return subsets of the box.
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]");
    auto subset = range.add_subsets();
    subset->set_offset(12);
    subset->set_length(1);
    subset = range.add_subsets();
    subset->set_offset(16);
    subset->set_length(2);
    subset = range.add_subsets();
    subset->set_offset(18);
    subset->set_length(0);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(
        MatchBmffBoxRanges(boxes, &matcher),
        ElementsAre(
            credentio::BMFFBoxMatcher::Range{.offset = 40, .length = 1},
            credentio::BMFFBoxMatcher::Range{.offset = 44, .length = 2},
            credentio::BMFFBoxMatcher::Range{.offset = 46, .length = 2}));
  }
  // The last entry may have a length of zero; this indicates that the remainder
  // of the box from that relative byte offset onward is excluded.
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]");
    auto subset = range.add_subsets();
    subset->set_offset(18);
    subset->set_length(0);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxRanges(boxes, &matcher),
                ElementsAre(credentio::BMFFBoxMatcher::Range{.offset = 46,
                                                             .length = 2}));
  }
  //  Relative byte offset plus length that exceeds the length of the box is
  //  allowed; bytes beyond the end of the box are never hashed.
  {
    credentio::BmffRange range;
    range.set_xpath("/trak[1]");
    auto subset = range.add_subsets();
    subset->set_offset(18);
    subset->set_length(100);
    credentio::BMFFBoxMatcher matcher(range, &input);
    EXPECT_THAT(MatchBmffBoxRanges(boxes, &matcher),
                ElementsAre(credentio::BMFFBoxMatcher::Range{.offset = 46,
                                                             .length = 2}));
  }
}

}  // namespace
}  // namespace credentio