//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2025, the clio developers.

    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#include "data/LedgerCache.hpp"
#include "etl/Models.hpp"
#include "util/MockPrometheus.hpp"
#include "util/TmpFile.hpp"
#include "util/prometheus/Bool.hpp"

#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <xrpl/basics/base_uint.h>

#include <cstdint>
#include <string>
#include <vector>

using namespace data;

struct LedgerCacheTest : util::prometheus::WithPrometheus {
    LedgerCache cache;
};

TEST_F(LedgerCacheTest, defaultState)
{
    EXPECT_FALSE(cache.isDisabled());
    EXPECT_FALSE(cache.isFull());
    EXPECT_EQ(cache.size(), 0u);
    EXPECT_EQ(cache.latestLedgerSequence(), 0u);
}

struct LedgerCachePrometheusMetricTest : util::prometheus::WithMockPrometheus {
    LedgerCache cache;
};

TEST_F(LedgerCachePrometheusMetricTest, setDisabled)
{
    auto& disabledMock = makeMock<util::prometheus::Bool>("ledger_cache_disabled", {});

    EXPECT_CALL(disabledMock, set(1));
    cache.setDisabled();

    EXPECT_CALL(disabledMock, value()).WillOnce(testing::Return(1));
    EXPECT_TRUE(cache.isDisabled());
}

TEST_F(LedgerCachePrometheusMetricTest, setFull)
{
    auto& fullMock = makeMock<util::prometheus::Bool>("ledger_cache_full", {});
    auto& disabledMock = makeMock<util::prometheus::Bool>("ledger_cache_disabled", {});

    EXPECT_CALL(disabledMock, value()).WillOnce(testing::Return(0));
    EXPECT_CALL(fullMock, set(1));
    cache.setFull();

    EXPECT_CALL(fullMock, value()).WillOnce(testing::Return(1));
    EXPECT_TRUE(cache.isFull());
}

struct LedgerCacheSaveLoadTest : LedgerCacheTest {
    ripple::uint256 const key1{1};
    ripple::uint256 const key2{2};
    std::vector<etl::model::Object> const objs{
        etl::model::Object{
            .key = key1,
            .keyRaw = {},
            .data = {1, 2, 3, 4, 5},
            .dataRaw = {},
            .successor = {},
            .predecessor = {},
            .type = {}
        },
        etl::model::Object{
            .key = key2,
            .keyRaw = {},
            .data = {6, 7, 8, 9, 10},
            .dataRaw = {},
            .successor = {},
            .predecessor = {},
            .type = {}
        }
    };
    uint32_t const kLEDGER_SEQ = 100;
};

TEST_F(LedgerCacheSaveLoadTest, saveToFileFailsWhenCacheNotFull)
{
    auto const tmpFile = TmpFile::empty();
    ASSERT_FALSE(cache.isFull());
    auto const result = cache.saveToFile(tmpFile.path);
    ASSERT_FALSE(result.has_value());
    EXPECT_EQ(result.error(), "Ledger cache is not full");
}

TEST_F(LedgerCacheSaveLoadTest, saveAndLoadFromFile)
{
    cache.update(objs, kLEDGER_SEQ);
    cache.setFull();

    ASSERT_TRUE(cache.isFull());
    EXPECT_EQ(cache.size(), 2u);
    EXPECT_EQ(cache.latestLedgerSequence(), kLEDGER_SEQ);

    auto const blob1 = cache.get(key1, kLEDGER_SEQ);
    ASSERT_TRUE(blob1.has_value());
    EXPECT_EQ(blob1.value(), objs.front().data);

    auto const blob2 = cache.get(key2, kLEDGER_SEQ);
    ASSERT_TRUE(blob2.has_value());
    EXPECT_EQ(blob2.value(), objs.back().data);

    auto const tmpFile = TmpFile::empty();
    auto const saveResult = cache.saveToFile(tmpFile.path);
    ASSERT_TRUE(saveResult.has_value()) << "Save failed: " << saveResult.error();

    LedgerCache newCache;
    auto const loadResult = newCache.loadFromFile(tmpFile.path, 0);
    ASSERT_TRUE(loadResult.has_value()) << "Load failed: " << loadResult.error();

    EXPECT_TRUE(newCache.isFull());
    EXPECT_EQ(newCache.size(), 2u);
    EXPECT_EQ(newCache.latestLedgerSequence(), kLEDGER_SEQ);

    auto const loadedBlob1 = newCache.get(key1, kLEDGER_SEQ);
    ASSERT_TRUE(loadedBlob1.has_value());
    EXPECT_EQ(loadedBlob1.value(), blob1);

    auto const loadedBlob2 = newCache.get(key2, kLEDGER_SEQ);
    ASSERT_TRUE(loadedBlob2.has_value());
    EXPECT_EQ(loadedBlob2.value(), blob2);

    EXPECT_EQ(newCache.latestLedgerSequence(), cache.latestLedgerSequence());
}

TEST_F(LedgerCacheSaveLoadTest, saveAndLoadFromFileWithDeletedObjects)
{
    cache.update(objs, kLEDGER_SEQ - 1);

    auto objsCopy = objs;
    objsCopy.front().data = {};

    cache.update(objsCopy, kLEDGER_SEQ);
    cache.setFull();

    // Verify deleted object is accessible via getDeleted
    auto const blob1 = cache.get(key1, kLEDGER_SEQ);
    ASSERT_FALSE(blob1.has_value());

    auto const blob2 = cache.get(key2, kLEDGER_SEQ);
    ASSERT_TRUE(blob2.has_value());
    EXPECT_EQ(blob2.value(), objs.back().data);

    auto const deletedBlob = cache.getDeleted(key1, kLEDGER_SEQ - 1);
    ASSERT_TRUE(deletedBlob.has_value());
    EXPECT_EQ(deletedBlob.value(), objs.front().data);

    // Save and load
    auto const tmpFile = TmpFile::empty();
    auto saveResult = cache.saveToFile(tmpFile.path);
    ASSERT_TRUE(saveResult.has_value()) << "Save failed: " << saveResult.error();

    LedgerCache newCache;
    auto loadResult = newCache.loadFromFile(tmpFile.path, 0);
    ASSERT_TRUE(loadResult.has_value()) << "Load failed: " << loadResult.error();

    // Verify deleted object is preserved
    auto const loadedDeletedBlob = newCache.getDeleted(key1, kLEDGER_SEQ - 1);
    ASSERT_TRUE(loadedDeletedBlob.has_value());
    EXPECT_EQ(loadedDeletedBlob.value(), deletedBlob);

    // Verify active object
    auto const loadedBlob1 = newCache.get(key1, kLEDGER_SEQ);
    ASSERT_FALSE(loadedBlob1.has_value());

    auto const loadedBlob2 = newCache.get(key2, kLEDGER_SEQ);
    ASSERT_TRUE(loadedBlob2.has_value());
    EXPECT_EQ(loadedBlob2.value(), blob2);

    EXPECT_TRUE(newCache.isFull());
    EXPECT_EQ(newCache.latestLedgerSequence(), cache.latestLedgerSequence());
}

TEST_F(LedgerCacheTest, SaveFailedDueToFilePermissions)
{
    cache.setFull();
    auto const result = cache.saveToFile("/");
    ASSERT_FALSE(result.has_value());
    EXPECT_FALSE(result.error().empty());
}

TEST_F(LedgerCacheTest, loadFromNonExistentFileReturnsError)
{
    auto const result = cache.loadFromFile("/nonexistent/path/cache.dat", 0);
    ASSERT_FALSE(result.has_value());
    EXPECT_FALSE(result.error().empty());
}

TEST_F(LedgerCacheSaveLoadTest, RejectOldCacheFile)
{
    uint32_t const cacheSeq = 100;
    cache.update(objs, cacheSeq);
    cache.setFull();

    auto const tmpFile = TmpFile::empty();
    auto const saveResult = cache.saveToFile(tmpFile.path);
    ASSERT_TRUE(saveResult.has_value());

    LedgerCache newCache;
    auto const loadResult = newCache.loadFromFile(tmpFile.path, cacheSeq + 1);
    EXPECT_FALSE(loadResult.has_value());
    EXPECT_THAT(loadResult.error(), ::testing::HasSubstr("too low"));
}

TEST_F(LedgerCacheSaveLoadTest, AcceptRecentCacheFile)
{
    uint32_t const cacheSeq = 100;
    cache.update(objs, cacheSeq);
    cache.setFull();

    auto const tmpFile = TmpFile::empty();
    auto const saveResult = cache.saveToFile(tmpFile.path);
    ASSERT_TRUE(saveResult.has_value());

    LedgerCache newCache;
    auto const loadResult = newCache.loadFromFile(tmpFile.path, cacheSeq - 1);
    ASSERT_TRUE(loadResult.has_value());
    EXPECT_EQ(newCache.latestLedgerSequence(), cacheSeq);
}