// Copyright 2022 Nick Brassel (@tzarc)
// SPDX-License-Identifier: GPL-2.0-or-later
#include <numeric>
#include "gtest/gtest.h"
#include "gmock/gmock.h"
#include "backing_mocks.hpp"

class WearLevelingGeneral : public ::testing::Test {
   protected:
    void SetUp() override {
        MockBackingStore::Instance().reset_instance();
        wear_leveling_init();
    }
};

/**
 * This test verifies that even if there is consolidated data present, if the checksum doesn't match then the cache is zero'd after reading the consolidated area, but before write log is played back.
 */
TEST_F(WearLevelingGeneral, InvalidChecksum_ConsolidatedDataIgnored) {
    auto& inst     = MockBackingStore::Instance();
    auto  logstart = inst.storage_begin() + (WEAR_LEVELING_LOGICAL_SIZE / sizeof(backing_store_int_t));

    // Generate a test block of data
    std::array<std::uint8_t, WEAR_LEVELING_LOGICAL_SIZE> testvalue;
    std::iota(testvalue.begin(), testvalue.end(), 0x20);

    // Write the data
    EXPECT_EQ(wear_leveling_write(0, testvalue.data(), testvalue.size()), WEAR_LEVELING_CONSOLIDATED) << "Write returned incorrect status";

    // Invalidate the checksum
    (logstart + 0)->erase();
    (logstart + 1)->erase();
    (logstart + 2)->erase();
    (logstart + 3)->erase();

    // Set up a 1-byte logical write of [0x11] at logical offset 0x01
    auto entry0 = LOG_ENTRY_MAKE_OPTIMIZED_64(0x01, 0x11);
    (logstart + 4)->set(~entry0.raw16[0]);

    // Re-init
    EXPECT_EQ(wear_leveling_init(), WEAR_LEVELING_SUCCESS) << "Init returned incorrect status";
    EXPECT_EQ(wear_leveling_read(0, testvalue.data(), testvalue.size()), WEAR_LEVELING_SUCCESS) << "Failed to read";
    for (int i = 0; i < WEAR_LEVELING_LOGICAL_SIZE; ++i) {
        EXPECT_EQ(testvalue[i], i == 0x01 ? 0x11 : 0x00) << "Invalid readback";
    }
}

/**
 * This test verifies that writing the same data multiple times does not result in subsequent writes to the backing store.
 */
TEST_F(WearLevelingGeneral, SameValue_SingleBackingWrite) {
    auto& inst = MockBackingStore::Instance();

    uint8_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(0x02, &test_val, sizeof(test_val)), WEAR_LEVELING_SUCCESS) << "First overall write operation should have succeeded";

    uint64_t invoke_count = inst.unlock_invoke_count();
    uint64_t erase_count  = inst.erase_invoke_count();
    uint64_t write_count  = inst.write_invoke_count();
    uint64_t lock_count   = inst.lock_invoke_count();

    for (int i = 0; i < 10; ++i) {
        EXPECT_EQ(wear_leveling_write(0x02, &test_val, sizeof(test_val)), WEAR_LEVELING_SUCCESS) << "Subsequent overall write operation should have succeeded";

        EXPECT_EQ(inst.unlock_invoke_count(), invoke_count) << "Unlock count should match";
        EXPECT_EQ(inst.erase_invoke_count(), erase_count) << "Erase count should match";
        EXPECT_EQ(inst.write_invoke_count(), write_count) << "Write count should match";
        EXPECT_EQ(inst.lock_invoke_count(), lock_count) << "Lock count should match";
    }
}

/**
 * This test verifies that no other invocations occur if `backing_store_init()` fails.
 */
TEST_F(WearLevelingGeneral, InitFailure) {
    auto& inst = MockBackingStore::Instance();
    inst.reset_instance(); // make sure the counters are all zero
    inst.set_init_callback([](std::uint64_t count) { return false; });

    EXPECT_EQ(inst.erasure_count(), 0) << "Invalid initial erase count";
    EXPECT_EQ(wear_leveling_init(), WEAR_LEVELING_FAILED) << "Init should have failed";
    EXPECT_EQ(inst.erasure_count(), 0) << "Invalid final erase count";

    EXPECT_EQ(inst.init_invoke_count(), 1) << "Init should have been invoked once";
    EXPECT_EQ(inst.unlock_invoke_count(), 0) << "Unlock should not have been invoked";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";
}

/**
 * This test verifies that no invocations occur if the supplied address is out of range while writing.
 */
TEST_F(WearLevelingGeneral, WriteFailure_OOB) {
    auto& inst = MockBackingStore::Instance();

    uint8_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(0x21349830, &test_val, sizeof(test_val)), WEAR_LEVELING_FAILED) << "Overall write operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 0) << "Unlock should not have been invoked";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";
}

/**
 * This test verifies that a single write occurs if the supplied address and data length hits the edge of the logical area.
 */
TEST_F(WearLevelingGeneral, WriteSuccess_BoundaryOK) {
    auto& inst = MockBackingStore::Instance();

    uint16_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(WEAR_LEVELING_LOGICAL_SIZE - sizeof(test_val), &test_val, sizeof(test_val)), WEAR_LEVELING_SUCCESS) << "Overall write operation should have succeeded";

    EXPECT_EQ(inst.unlock_invoke_count(), 1) << "Unlock should have been invoked once";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 2) << "Write should have been invoked twice";
    EXPECT_EQ(inst.lock_invoke_count(), 1) << "Lock should have been invoked once";
}

/**
 * This test verifies that no invocations occur if the supplied address and length would generate writes outside the logical range.
 */
TEST_F(WearLevelingGeneral, WriteFailure_BoundaryOverflow) {
    auto& inst = MockBackingStore::Instance();

    uint16_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(WEAR_LEVELING_LOGICAL_SIZE - sizeof(test_val) + 1, &test_val, sizeof(test_val)), WEAR_LEVELING_FAILED) << "Overall write operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 0) << "Unlock should not have been invoked";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";
}

/**
 * This test verifies that no invocations occur if the supplied address is out of range while reading.
 */
TEST_F(WearLevelingGeneral, ReadFailure_OOB) {
    auto& inst = MockBackingStore::Instance();

    uint8_t test_val = 0;
    EXPECT_EQ(wear_leveling_read(0x21349830, &test_val, sizeof(test_val)), WEAR_LEVELING_FAILED) << "Overall read operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 0) << "Unlock should not have been invoked";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";
}

/**
 * This test verifies that no write invocations occur if `backing_store_unlock()` fails.
 */
TEST_F(WearLevelingGeneral, UnlockFailure_NoWrite) {
    auto& inst = MockBackingStore::Instance();
    inst.set_unlock_callback([](std::uint64_t count) { return false; });

    uint8_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(0x04, &test_val, sizeof(test_val)), WEAR_LEVELING_FAILED) << "Overall write operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 1) << "Unlock should have been invoked once";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";

    test_val = 0;
    wear_leveling_read(0x04, &test_val, sizeof(test_val));
    EXPECT_EQ(test_val, 0x14) << "Readback should come from cache regardless of unlock failure";
}

/**
 * This test verifies that no erase invocations occur if `backing_store_unlock()` fails.
 */
TEST_F(WearLevelingGeneral, UnlockFailure_NoErase) {
    auto& inst = MockBackingStore::Instance();
    inst.set_unlock_callback([](std::uint64_t count) { return false; });

    EXPECT_EQ(wear_leveling_erase(), WEAR_LEVELING_FAILED) << "Overall erase operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 1) << "Unlock should have been invoked once";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 0) << "Write should not have been invoked";
    EXPECT_EQ(inst.lock_invoke_count(), 0) << "Lock should not have been invoked";
}

/**
 * This test verifies that only one write invocation occurs if `backing_store_write()` fails.
 */
TEST_F(WearLevelingGeneral, WriteFailure_NoSubsequentWrites) {
    auto& inst = MockBackingStore::Instance();
    inst.set_write_callback([](std::uint64_t count, std::uint32_t address) { return false; });

    uint8_t test_val = 0x14;
    EXPECT_EQ(wear_leveling_write(0x04, &test_val, sizeof(test_val)), WEAR_LEVELING_FAILED) << "Overall write operation should have failed";

    EXPECT_EQ(inst.unlock_invoke_count(), 1) << "Unlock should have been invoked once";
    EXPECT_EQ(inst.erase_invoke_count(), 0) << "Erase should not have been invoked";
    EXPECT_EQ(inst.write_invoke_count(), 1) << "Write should have been invoked once";
    EXPECT_EQ(inst.lock_invoke_count(), 1) << "Lock should have been invoked once";

    test_val = 0;
    wear_leveling_read(0x04, &test_val, sizeof(test_val));
    EXPECT_EQ(test_val, 0x14) << "Readback should come from cache regardless of unlock failure";
}