/*
 * Copyright (c) 2018-2019 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <map>
#include <switch.h>
#include "dmnt_cheat_manager.hpp"
#include "dmnt_cheat_vm.hpp"
#include "dmnt_config.hpp"
#include "dmnt_cheat_debug_events_manager.hpp"
#include "pm_shim.h"

static HosMutex g_cheat_lock;
static HosThread g_detect_thread, g_vm_thread, g_debug_events_thread;

static IEvent *g_cheat_process_event;
static DmntCheatVm *g_cheat_vm;

static CheatProcessMetadata g_cheat_process_metadata = {0};
static Handle g_cheat_process_debug_hnd = 0;

/* Should we enable cheats by default? */
static bool g_enable_cheats_by_default = true;
static bool g_always_save_cheat_toggles = false;
static bool g_should_save_cheat_toggles = false;

/* For debug event thread management. */
static HosMutex g_debug_event_thread_lock, g_attach_lock;
static bool g_has_debug_events_thread = false;

/* To save some copying. */
static bool g_needs_reload_vm_program = false;

/* Global cheat entry storage. */
static CheatEntry g_cheat_entries[DmntCheatManager::MaxCheatCount];

/* Global frozen address storage. */
static std::map<u64, FrozenAddressValue> g_frozen_addresses_map;

void DmntCheatManager::StartDebugEventsThread() {
    std::scoped_lock<HosMutex> lk(g_debug_event_thread_lock);

    /* Spawn the debug events thread. */
    if (!g_has_debug_events_thread) {
        R_ASSERT(g_debug_events_thread.Initialize(&DmntCheatManager::DebugEventsThread, nullptr, 0x4000, 48));
        R_ASSERT(g_debug_events_thread.Start());

        g_has_debug_events_thread = true;
    }
}

void DmntCheatManager::WaitDebugEventsThread() {
    std::scoped_lock<HosMutex> lk(g_debug_event_thread_lock);

    /* Wait for the thread to exit. */
    if (g_has_debug_events_thread) {
        g_debug_events_thread.CancelSynchronization();
        g_debug_events_thread.Join();

        g_has_debug_events_thread = false;
    }
}

void DmntCheatManager::CloseActiveCheatProcess() {
    if (g_cheat_process_debug_hnd != 0) {
        /* Close process resources. */
        svcCloseHandle(g_cheat_process_debug_hnd);
        g_cheat_process_debug_hnd = 0;

        /* Save cheat toggles. */
        if (g_always_save_cheat_toggles || g_should_save_cheat_toggles) {
            SaveCheatToggles(g_cheat_process_metadata.title_id);
            g_should_save_cheat_toggles = false;
        }

        /* Clear metadata. */
        g_cheat_process_metadata = (CheatProcessMetadata){0};

        /* Clear cheat list. */
        ResetAllCheatEntries();

        /* Clear frozen addresses. */
        ResetFrozenAddresses();

        /* Signal to our fans. */
        g_cheat_process_event->Signal();
    }
}

bool DmntCheatManager::HasActiveCheatProcess() {
    u64 tmp;
    bool has_cheat_process = g_cheat_process_debug_hnd != 0;

    if (has_cheat_process) {
        has_cheat_process &= R_SUCCEEDED(svcGetProcessId(&tmp, g_cheat_process_debug_hnd));
    }

    if (has_cheat_process) {
        has_cheat_process &= R_SUCCEEDED(pmdmntGetApplicationPid(&tmp));
    }

    if (has_cheat_process) {
        has_cheat_process &= tmp == g_cheat_process_metadata.process_id;
    }

    if (!has_cheat_process) {
        CloseActiveCheatProcess();
    }

    return has_cheat_process;
}

Result DmntCheatManager::ReadCheatProcessMemoryForVm(u64 proc_addr, void *out_data, size_t size) {
    if (HasActiveCheatProcess()) {
        return svcReadDebugProcessMemory(out_data, g_cheat_process_debug_hnd, proc_addr, size);
    }

    return ResultDmntCheatNotAttached;
}

Result DmntCheatManager::WriteCheatProcessMemoryForVm(u64 proc_addr, const void *data, size_t size) {
    if (HasActiveCheatProcess()) {
        R_TRY(svcWriteDebugProcessMemory(g_cheat_process_debug_hnd, data, proc_addr, size));

        /* We might have a frozen address. Update it if we do! */
        for (auto & [address, value] : g_frozen_addresses_map) {
            /* Map is in order, so break here. */
            if (address >= proc_addr + size) {
                break;
            }

            /* Check if we need to write. */
            if (proc_addr <= address) {
                const size_t offset = (address - proc_addr);
                const size_t size_to_copy = size - offset;
                memcpy(&value.value, (void *)((uintptr_t)data + offset), size_to_copy < sizeof(value.value) ? size_to_copy : sizeof(value.value));
            }
        }

        return ResultSuccess;
    }

    return ResultDmntCheatNotAttached;
}


Result DmntCheatManager::GetCheatProcessMappingCount(u64 *out_count) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    MemoryInfo mem_info;

    u64 address = 0;
    *out_count = 0;
    do {
        mem_info.perm = 0;
        u32 tmp;
        if (R_FAILED(svcQueryDebugProcessMemory(&mem_info, &tmp, g_cheat_process_debug_hnd, address))) {
            break;
        }

        if (mem_info.perm != 0) {
            *out_count += 1;
        }

        address = mem_info.addr + mem_info.size;
    } while (address != 0);

    return ResultSuccess;
}

Result DmntCheatManager::GetCheatProcessMappings(MemoryInfo *mappings, size_t max_count, u64 *out_count, u64 offset) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    MemoryInfo mem_info;
    u64 address = 0;
    u64 count = 0;
    *out_count = 0;
    do {
        mem_info.perm = 0;
        u32 tmp;
        if (R_FAILED(svcQueryDebugProcessMemory(&mem_info, &tmp, g_cheat_process_debug_hnd, address))) {
            break;
        }

        if (mem_info.perm != 0) {
            count++;
            if (count > offset) {
                mappings[(*out_count)++] = mem_info;
            }
        }

        address = mem_info.addr + mem_info.size;
    } while (address != 0 && *out_count < max_count);

    return ResultSuccess;
}

Result DmntCheatManager::ReadCheatProcessMemory(u64 proc_addr, void *out_data, size_t size) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    return ReadCheatProcessMemoryForVm(proc_addr, out_data, size);
}

Result DmntCheatManager::WriteCheatProcessMemory(u64 proc_addr, const void *data, size_t size) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    return WriteCheatProcessMemoryForVm(proc_addr, data, size);
}

Result DmntCheatManager::QueryCheatProcessMemory(MemoryInfo *mapping, u64 address) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (HasActiveCheatProcess()) {
        u32 tmp;
        return svcQueryDebugProcessMemory(mapping, &tmp, g_cheat_process_debug_hnd, address);
    }

    return ResultDmntCheatNotAttached;
}

void DmntCheatManager::ResetFrozenAddresses() {
    /* Just clear the map. */
    g_frozen_addresses_map.clear();
}

void DmntCheatManager::ResetCheatEntry(size_t i) {
    if (i < DmntCheatManager::MaxCheatCount) {
        g_cheat_entries[i].enabled = false;
        g_cheat_entries[i].cheat_id = i;
        g_cheat_entries[i].definition = {0};

        /* Trigger a VM reload. */
        g_needs_reload_vm_program = true;
    }
}

void DmntCheatManager::ResetAllCheatEntries() {
    for (size_t i = 0; i < DmntCheatManager::MaxCheatCount; i++) {
        ResetCheatEntry(i);
    }
}

CheatEntry *DmntCheatManager::GetFreeCheatEntry() {
    /* Check all non-master cheats for availability. */
    for (size_t i = 1; i < DmntCheatManager::MaxCheatCount; i++) {
        if (g_cheat_entries[i].definition.num_opcodes == 0) {
            return &g_cheat_entries[i];
        }
    }

    return nullptr;
}

CheatEntry *DmntCheatManager::GetCheatEntryById(size_t i) {
    if (i < DmntCheatManager::MaxCheatCount) {
        return &g_cheat_entries[i];
    }

    return nullptr;
}

CheatEntry *DmntCheatManager::GetCheatEntryByReadableName(const char *readable_name) {
    /* Check all non-master cheats for match. */
    for (size_t i = 1; i < DmntCheatManager::MaxCheatCount; i++) {
        if (strcmp(g_cheat_entries[i].definition.readable_name, readable_name) == 0) {
            return &g_cheat_entries[i];
        }
    }

    return nullptr;
}

bool DmntCheatManager::ParseCheats(const char *s, size_t len) {
    size_t i = 0;
    CheatEntry *cur_entry = NULL;

    /* Trigger a VM reload. */
    g_needs_reload_vm_program = true;

    while (i < len) {
        if (isspace((unsigned char)s[i])) {
            /* Just ignore space. */
            i++;
        } else if (s[i] == '[') {
            /* Parse a readable cheat name. */
            cur_entry = GetFreeCheatEntry();
            if (cur_entry == NULL) {
                return false;
            }

            /* Extract name bounds. */
            size_t j = i + 1;
            while (s[j] != ']') {
                j++;
                if (j >= len || (j - i - 1) >= sizeof(cur_entry->definition.readable_name)) {
                    return false;
                }
            }

            /* s[i+1:j] is cheat name. */
            const size_t cheat_name_len = (j - i - 1);
            memcpy(cur_entry->definition.readable_name, &s[i+1], cheat_name_len);
            cur_entry->definition.readable_name[cheat_name_len] = 0;

            /* Skip onwards. */
            i = j + 1;
        } else if (s[i] == '{') {
            /* We're parsing a master cheat. */
            cur_entry = &g_cheat_entries[0];

            /* There can only be one master cheat. */
            if (cur_entry->definition.num_opcodes > 0) {
                return false;
            }

            /* Extract name bounds */
            size_t j = i + 1;
            while (s[j] != '}') {
                j++;
                if (j >= len || (j - i - 1) >= sizeof(cur_entry->definition.readable_name)) {
                    return false;
                }
            }

            /* s[i+1:j] is cheat name. */
            const size_t cheat_name_len = (j - i - 1);
            memcpy(cur_entry->definition.readable_name, &s[i+1], cheat_name_len);
            cur_entry->definition.readable_name[cheat_name_len] = 0;

            /* Skip onwards. */
            i = j + 1;
        } else if (isxdigit((unsigned char)s[i])) {
            /* Make sure that we have a cheat open. */
            if (cur_entry == NULL) {
                return false;
            }

            /* Bounds check the opcode count. */
            if (cur_entry->definition.num_opcodes >= sts::util::size(cur_entry->definition.opcodes)) {
                return false;
            }

            /* We're parsing an instruction, so validate it's 8 hex digits. */
            for (size_t j = 1; j < 8; j++) {
                /* Validate 8 hex chars. */
                if (i + j >= len || !isxdigit((unsigned char)s[i+j])) {
                    return false;
                }
            }

            /* Parse the new opcode. */
            char hex_str[9] = {0};
            memcpy(hex_str, &s[i], 8);
            cur_entry->definition.opcodes[cur_entry->definition.num_opcodes++] = strtoul(hex_str, NULL, 16);


            /* Skip onwards. */
            i += 8;
        } else {
            /* Unexpected character encountered. */
            return false;
        }
    }

    /* Master cheat can't be disabled. */
    if (g_cheat_entries[0].definition.num_opcodes > 0) {
        g_cheat_entries[0].enabled = true;
    }

    /* Enable all entries we parsed. */
    for (size_t i = 1; i < DmntCheatManager::MaxCheatCount; i++) {
        if (g_cheat_entries[i].definition.num_opcodes > 0) {
            g_cheat_entries[i].enabled = g_enable_cheats_by_default;
        }
    }

    return true;
}

bool DmntCheatManager::LoadCheats(u64 title_id, const u8 *build_id) {
    /* Reset existing entries. */
    ResetAllCheatEntries();

    FILE *f_cht = NULL;
    /* Open the file for title/build_id. */
    {
        char path[FS_MAX_PATH+1] = {0};
        snprintf(path, FS_MAX_PATH, "sdmc:/atmosphere/titles/%016lx/cheats/%02x%02x%02x%02x%02x%02x%02x%02x.txt", title_id,
                build_id[0], build_id[1], build_id[2], build_id[3], build_id[4], build_id[5], build_id[6], build_id[7]);

        f_cht = fopen(path, "rb");
    }

    /* Check for NULL */
    if (f_cht == NULL) {
        return false;
    }
    ON_SCOPE_EXIT { fclose(f_cht); };

    /* Get file size. */
    fseek(f_cht, 0L, SEEK_END);
    const size_t cht_sz = ftell(f_cht);
    fseek(f_cht, 0L, SEEK_SET);

    /* Allocate cheat txt buffer. */
    char *cht_txt = (char *)malloc(cht_sz + 1);
    if (cht_txt == NULL) {
        return false;
    }
    ON_SCOPE_EXIT { free(cht_txt); };

    /* Read cheats into buffer. */
    if (fread(cht_txt, 1, cht_sz, f_cht) != cht_sz) {
        return false;
    }
    cht_txt[cht_sz] = 0;

    /* Parse cheat buffer. */
    return ParseCheats(cht_txt, strlen(cht_txt));
}

bool DmntCheatManager::ParseCheatToggles(const char *s, size_t len) {
    size_t i = 0;
    char cur_cheat_name[sizeof(CheatEntry::definition.readable_name)];
    char toggle[8];

    while (i < len) {
        if (isspace((unsigned char)s[i])) {
            /* Just ignore space. */
            i++;
        } else if (s[i] == '[') {

            /* Extract name bounds. */
            size_t j = i + 1;
            while (s[j] != ']') {
                j++;
                if (j >= len || (j - i - 1) >= sizeof(cur_cheat_name)) {
                    return false;
                }
            }

            /* s[i+1:j] is cheat name. */
            const size_t cheat_name_len = (j - i - 1);
            memcpy(cur_cheat_name, &s[i+1], cheat_name_len);
            cur_cheat_name[cheat_name_len] = 0;

            /* Skip onwards. */
            i = j + 1;

            /* Skip whitespace. */
            while (isspace((unsigned char)s[i])) {
                i++;
            }

            /* Parse whether to toggle. */
            j = i + 1;
            while (!isspace((unsigned char)s[j])) {
                j++;
                if (j >= len || (j - i) >= sizeof(toggle)) {
                    return false;
                }
            }

            /* s[i:j] is toggle. */
            const size_t toggle_len = (j - i);
            memcpy(toggle, &s[i], toggle_len);
            toggle[toggle_len] = 0;

            /* Allow specifying toggle for not present cheat. */
            CheatEntry *entry = GetCheatEntryByReadableName(cur_cheat_name);
            if (entry != nullptr) {
                if (strcasecmp(toggle, "1") == 0 || strcasecmp(toggle, "true") == 0 || strcasecmp(toggle, "on") == 0) {
                    entry->enabled = true;
                } else if (strcasecmp(toggle, "0") == 0 || strcasecmp(toggle, "false") == 0 || strcasecmp(toggle, "off") == 0) {
                    entry->enabled = false;
                }
            }

            /* Skip onwards. */
            i = j + 1;
        } else {
            /* Unexpected character encountered. */
            return false;
        }
    }

    return true;
}

bool DmntCheatManager::LoadCheatToggles(u64 title_id) {
    FILE *f_tg = NULL;
    /* Open the file for title id. */
    {
        char path[FS_MAX_PATH+1] = {0};
        snprintf(path, FS_MAX_PATH, "sdmc:/atmosphere/titles/%016lx/cheats/toggles.txt", title_id);

        f_tg = fopen(path, "rb");
    }

    /* Unless we successfully parse, don't save toggles on close. */
    g_should_save_cheat_toggles = false;

    /* Check for NULL, which is allowed. */
    if (f_tg == NULL) {
        return true;
    }
    ON_SCOPE_EXIT { fclose(f_tg); };

    /* Get file size. */
    fseek(f_tg, 0L, SEEK_END);
    const size_t tg_sz = ftell(f_tg);
    fseek(f_tg, 0L, SEEK_SET);

    /* Allocate toggle txt buffer. */
    char *tg_txt = (char *)malloc(tg_sz + 1);
    if (tg_txt == NULL) {
        return false;
    }
    ON_SCOPE_EXIT { free(tg_txt); };

    /* Read toggles into buffer. */
    if (fread(tg_txt, 1, tg_sz, f_tg) != tg_sz) {
        return false;
    }
    tg_txt[tg_sz] = 0;

    /* Parse toggle buffer. */
    g_should_save_cheat_toggles = ParseCheatToggles(tg_txt, strlen(tg_txt));
    return g_should_save_cheat_toggles;
}

void DmntCheatManager::SaveCheatToggles(u64 title_id) {
    FILE *f_tg = NULL;
    /* Open the file for title id. */
    {
        char path[FS_MAX_PATH+1] = {0};
        snprintf(path, FS_MAX_PATH, "sdmc:/atmosphere/titles/%016lx/cheats/toggles.txt", title_id);

        f_tg = fopen(path, "wb");
    }

    if (f_tg == NULL) {
        return;
    }

    ON_SCOPE_EXIT { fclose(f_tg); };

    /* Save all non-master cheats. */
    for (size_t i = 1; i < DmntCheatManager::MaxCheatCount; i++) {
        if (g_cheat_entries[i].definition.num_opcodes != 0) {
            fprintf(f_tg, "[%s]\n", g_cheat_entries[i].definition.readable_name);
            if (g_cheat_entries[i].enabled) {
                fprintf(f_tg, "true\n");
            } else {
                fprintf(f_tg, "false\n");
            }
        }
    }
}

Result DmntCheatManager::GetCheatCount(u64 *out_count) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    *out_count = 0;
    for (size_t i = 0; i < DmntCheatManager::MaxCheatCount; i++) {
        if (g_cheat_entries[i].definition.num_opcodes > 0) {
            *out_count += 1;
        }
    }

    return ResultSuccess;
}

Result DmntCheatManager::GetCheats(CheatEntry *cheats, size_t max_count, u64 *out_count, u64 offset) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    u64 count = 0;
    *out_count = 0;
    for (size_t i = 0; i < DmntCheatManager::MaxCheatCount && (*out_count) < max_count; i++) {
        if (g_cheat_entries[i].definition.num_opcodes > 0) {
            count++;
            if (count > offset) {
                cheats[(*out_count)++] = g_cheat_entries[i];
            }
        }
    }

    return ResultSuccess;
}

Result DmntCheatManager::GetCheatById(CheatEntry *out_cheat, u32 cheat_id) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    const CheatEntry *entry = GetCheatEntryById(cheat_id);
    if (entry == nullptr || entry->definition.num_opcodes == 0) {
        return ResultDmntCheatUnknownChtId;
    }

    *out_cheat = *entry;
    return ResultSuccess;
}

Result DmntCheatManager::ToggleCheat(u32 cheat_id) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    CheatEntry *entry = GetCheatEntryById(cheat_id);
    if (entry == nullptr || entry->definition.num_opcodes == 0) {
        return ResultDmntCheatUnknownChtId;
    }

    if (cheat_id == 0) {
        return ResultDmntCheatCannotDisableMasterCheat;
    }

    entry->enabled = !entry->enabled;

    /* Trigger a VM reload. */
    g_needs_reload_vm_program = true;
    return ResultSuccess;
}

Result DmntCheatManager::AddCheat(u32 *out_id, CheatDefinition *def, bool enabled) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    if (def->num_opcodes == 0 || def->num_opcodes > sts::util::size(def->opcodes)) {
        return ResultDmntCheatInvalidCheat;
    }

    CheatEntry *new_entry = GetFreeCheatEntry();
    if (new_entry == nullptr) {
        return ResultDmntCheatOutOfCheats;
    }

    new_entry->enabled = enabled;
    new_entry->definition = *def;

    /* Trigger a VM reload. */
    g_needs_reload_vm_program = true;
    return ResultSuccess;
}

Result DmntCheatManager::RemoveCheat(u32 cheat_id) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    if (cheat_id >= DmntCheatManager::MaxCheatCount) {
        return ResultDmntCheatUnknownChtId;
    }

    ResetCheatEntry(cheat_id);

    /* Trigger a VM reload. */
    g_needs_reload_vm_program = true;
    return ResultSuccess;
}

Result DmntCheatManager::GetFrozenAddressCount(u64 *out_count) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    *out_count = g_frozen_addresses_map.size();
    return ResultSuccess;
}

Result DmntCheatManager::GetFrozenAddresses(FrozenAddressEntry *frz_addrs, size_t max_count, u64 *out_count, u64 offset) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    u64 count = 0;
    *out_count = 0;
    for (auto const& [address, value] : g_frozen_addresses_map) {
        if ((*out_count) >= max_count) {
            break;
        }

        count++;
        if (count > offset) {
            const u64 cur_ind = (*out_count)++;
            frz_addrs[cur_ind].address = address;
            frz_addrs[cur_ind].value = value;
        }
    }

    return ResultSuccess;
}

Result  DmntCheatManager::GetFrozenAddress(FrozenAddressEntry *frz_addr, u64 address) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    const auto it = g_frozen_addresses_map.find(address);
    if (it == g_frozen_addresses_map.end()) {
        return ResultDmntCheatAddressNotFrozen;
    }

    frz_addr->address = it->first;
    frz_addr->value = it->second;
    return ResultSuccess;
}

Result DmntCheatManager::EnableFrozenAddress(u64 *out_value, u64 address, u64 width) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    if (g_frozen_addresses_map.size() >= DmntCheatManager::MaxFrozenAddressCount) {
        return ResultDmntCheatTooManyFrozenAddresses;
    }

    const auto it = g_frozen_addresses_map.find(address);
    if (it != g_frozen_addresses_map.end()) {
        return ResultDmntCheatAddressAlreadyFrozen;
    }

    FrozenAddressValue value = {0};
    value.width = width;
    R_TRY(ReadCheatProcessMemoryForVm(address, &value.value, width));

    g_frozen_addresses_map[address] = value;
    *out_value = value.value;
    return ResultSuccess;
}

Result DmntCheatManager::DisableFrozenAddress(u64 address) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (!HasActiveCheatProcess()) {
        return ResultDmntCheatNotAttached;
    }

    const auto it = g_frozen_addresses_map.find(address);
    if (it == g_frozen_addresses_map.end()) {
        return ResultDmntCheatAddressNotFrozen;
    }

    g_frozen_addresses_map.erase(address);
    return ResultSuccess;
}

Handle DmntCheatManager::PrepareDebugNextApplication() {
    Handle event_h;
    R_ASSERT(pmdmntEnableDebugForApplication(&event_h));

    return event_h;
}

static void PopulateMemoryExtents(MemoryRegionExtents *extents, Handle p_h, u64 id_base, u64 id_size) {
    /* Get base extent. */
    R_ASSERT(svcGetInfo(&extents->base, id_base, p_h, 0));

    /* Get size extent. */
    R_ASSERT(svcGetInfo(&extents->size, id_size, p_h, 0));
}

static void StartDebugProcess(u64 pid) {
    R_ASSERT(pmdmntStartProcess(pid));
}

Result DmntCheatManager::ForceOpenCheatProcess() {
    std::scoped_lock<HosMutex> attach_lk(g_attach_lock);

    /* Acquire the cheat lock for long enough to close the process if needed. */
    {
        std::scoped_lock<HosMutex> lk(g_cheat_lock);

        if (HasActiveCheatProcess()) {
            return ResultSuccess;
        }

        /* Close the current application, if it's open. */
        CloseActiveCheatProcess();
    }

    /* Intentionally yield the cheat lock to the debug events thread. */
    /* Wait to not have debug events thread. */
    WaitDebugEventsThread();

    /* At this point, we can re-acquire the lock for the rest of the function. */
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    /* Get the current application process ID. */
    R_TRY(pmdmntGetApplicationPid(&g_cheat_process_metadata.process_id));
    auto proc_guard = SCOPE_GUARD {
        g_cheat_process_metadata.process_id = 0;
    };

    /* Get process handle, use it to learn memory extents. */
    {
        Handle proc_h = 0;
        ON_SCOPE_EXIT { if (proc_h != 0) { svcCloseHandle(proc_h); } };

        R_TRY(pmdmntAtmosphereGetProcessInfo(&proc_h, &g_cheat_process_metadata.title_id, nullptr, g_cheat_process_metadata.process_id));

        /* Get memory extents. */
        PopulateMemoryExtents(&g_cheat_process_metadata.heap_extents, proc_h, 4, 5);
        PopulateMemoryExtents(&g_cheat_process_metadata.alias_extents, proc_h, 2, 3);
        if ((GetRuntimeFirmwareVersion() >= FirmwareVersion_200)) {
            PopulateMemoryExtents(&g_cheat_process_metadata.address_space_extents, proc_h, 12, 13);
        } else {
            g_cheat_process_metadata.address_space_extents.base = 0x08000000UL;
            g_cheat_process_metadata.address_space_extents.size = 0x78000000UL;
        }
    }

    /* Get module information from Loader. */
    {
        LoaderModuleInfo proc_modules[2];
        u32 num_modules;
        R_TRY(ldrDmntGetModuleInfos(g_cheat_process_metadata.process_id, proc_modules, sts::util::size(proc_modules), &num_modules));

        /* All applications must have two modules. */
        /* However, this is a force-open, so we will accept one module. */
        /* Poor HBL, I guess... */
        LoaderModuleInfo *proc_module;
        if (num_modules == 2) {
            proc_module = &proc_modules[1];
        } else if (num_modules == 1) {
            proc_module = &proc_modules[0];
        } else {
            return ResultDmntCheatNotAttached;
        }

        g_cheat_process_metadata.main_nso_extents.base = proc_module->base_address;
        g_cheat_process_metadata.main_nso_extents.size = proc_module->size;
        memcpy(g_cheat_process_metadata.main_nso_build_id, proc_module->build_id, sizeof(g_cheat_process_metadata.main_nso_build_id));
    }

    /* Read cheats off the SD. */
    /* This is allowed to fail. We may not have any cheats. */
    LoadCheats(g_cheat_process_metadata.title_id, g_cheat_process_metadata.main_nso_build_id);

    /* Load saved toggles, if present. */
    LoadCheatToggles(g_cheat_process_metadata.title_id);

    /* Open a debug handle. */
    R_TRY(svcDebugActiveProcess(&g_cheat_process_debug_hnd, g_cheat_process_metadata.process_id));

    /* Cancel process guard. */
    proc_guard.Cancel();

    /* Start debug events thread. */
    StartDebugEventsThread();

    /* Signal to our fans. */
    g_cheat_process_event->Signal();

    return ResultSuccess;
}

void DmntCheatManager::OnNewApplicationLaunch() {
    std::scoped_lock<HosMutex> attach_lk(g_attach_lock);

    {
        std::scoped_lock<HosMutex> lk(g_cheat_lock);
        /* Close the current application, if it's open. */
        CloseActiveCheatProcess();
    }

    /* Intentionally yield the cheat lock to the debug events thread. */
    /* Wait to not have debug events thread. */
    WaitDebugEventsThread();

    /* At this point, we can re-acquire the lock for the rest of the function. */
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    /* Get the new application's process ID. */
    R_ASSERT(pmdmntGetApplicationPid(&g_cheat_process_metadata.process_id));

    /* Get process handle, use it to learn memory extents. */
    {
        Handle proc_h = 0;
        ON_SCOPE_EXIT { if (proc_h != 0) { svcCloseHandle(proc_h); } };

        R_ASSERT(pmdmntAtmosphereGetProcessInfo(&proc_h, &g_cheat_process_metadata.title_id, nullptr, g_cheat_process_metadata.process_id));

        /* Get memory extents. */
        PopulateMemoryExtents(&g_cheat_process_metadata.heap_extents, proc_h, 4, 5);
        PopulateMemoryExtents(&g_cheat_process_metadata.alias_extents, proc_h, 2, 3);
        if ((GetRuntimeFirmwareVersion() >= FirmwareVersion_200)) {
            PopulateMemoryExtents(&g_cheat_process_metadata.address_space_extents, proc_h, 12, 13);
        } else {
            g_cheat_process_metadata.address_space_extents.base = 0x08000000UL;
            g_cheat_process_metadata.address_space_extents.size = 0x78000000UL;
        }
    }

    /* Check if we should skip based on keys down. */
    if (!DmntConfigManager::HasCheatEnableButton(g_cheat_process_metadata.title_id)) {
        StartDebugProcess(g_cheat_process_metadata.process_id);
        g_cheat_process_metadata.process_id = 0;
        return;
    }

    /* Get module information from Loader. */
    {
        LoaderModuleInfo proc_modules[2];
        u32 num_modules;
        R_ASSERT(ldrDmntGetModuleInfos(g_cheat_process_metadata.process_id, proc_modules, sts::util::size(proc_modules), &num_modules));

        /* All applications must have two modules. */
        /* If we only have one, we must be e.g. mitming HBL. */
        /* We don't want to fuck with HBL. */
        if (num_modules != 2) {
            StartDebugProcess(g_cheat_process_metadata.process_id);
            g_cheat_process_metadata.process_id = 0;
            return;
        }

        g_cheat_process_metadata.main_nso_extents.base = proc_modules[1].base_address;
        g_cheat_process_metadata.main_nso_extents.size = proc_modules[1].size;
        memcpy(g_cheat_process_metadata.main_nso_build_id, proc_modules[1].build_id, sizeof(g_cheat_process_metadata.main_nso_build_id));
    }

    /* Read cheats off the SD. */
    if (!LoadCheats(g_cheat_process_metadata.title_id, g_cheat_process_metadata.main_nso_build_id) || !LoadCheatToggles(g_cheat_process_metadata.title_id)) {
        /* If we don't have cheats, or cheats are malformed, don't attach. */
        StartDebugProcess(g_cheat_process_metadata.process_id);
        g_cheat_process_metadata.process_id = 0;
        return;
    }

    /* Open a debug handle. */
    R_ASSERT(svcDebugActiveProcess(&g_cheat_process_debug_hnd, g_cheat_process_metadata.process_id));

    /* Start the process. */
    StartDebugProcess(g_cheat_process_metadata.process_id);

    /* Start debug events thread. */
    StartDebugEventsThread();

    /* Signal to our fans. */
    g_cheat_process_event->Signal();
}

void DmntCheatManager::DetectThread(void *arg) {
    static auto s_waiter = WaitableManager(1);
    s_waiter.AddWaitable(LoadReadOnlySystemEvent(PrepareDebugNextApplication(), [](u64 timeout) {
        /* Process stuff for new application. */
        DmntCheatManager::OnNewApplicationLaunch();

        /* Setup detection for the next application, and close the duplicate handle. */
        svcCloseHandle(PrepareDebugNextApplication());

        return ResultSuccess;
    }, true));

    s_waiter.Process();
}

void DmntCheatManager::VmThread(void *arg) {
    while (true) {
        /* Execute Cheat VM. */
        {
            /* Acquire lock. */
            std::scoped_lock<HosMutex> lk(g_cheat_lock);

            if (HasActiveCheatProcess()) {
                /* Execute VM. */
                if (!g_needs_reload_vm_program || (g_cheat_vm->LoadProgram(g_cheat_entries, DmntCheatManager::MaxCheatCount))) {
                    /* Program: reloaded. */
                    g_needs_reload_vm_program = false;

                    /* Execute program if it's present. */
                    if (g_cheat_vm->GetProgramSize() != 0) {
                        g_cheat_vm->Execute(&g_cheat_process_metadata);
                    }
                }

                /* Apply frozen addresses. */
                for (auto const& [address, value] : g_frozen_addresses_map) {
                    WriteCheatProcessMemoryForVm(address, &value.value, value.width);
                }
            }
        }

        constexpr u64 ONE_SECOND = 1000000000ul;
        constexpr u64 NUM_TIMES = 12;
        constexpr u64 DELAY = ONE_SECOND / NUM_TIMES;
        svcSleepThread(DELAY);
    }
}

void DmntCheatManager::DebugEventsThread(void *arg) {

    while (R_SUCCEEDED(svcWaitSynchronizationSingle(g_cheat_process_debug_hnd, U64_MAX))) {
        std::scoped_lock<HosMutex> lk(g_cheat_lock);

        /* Handle any pending debug events. */
        if (HasActiveCheatProcess()) {
            DmntCheatDebugEventsManager::ContinueCheatProcess(g_cheat_process_debug_hnd);
        }

    }
}

bool DmntCheatManager::GetHasActiveCheatProcess() {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    return HasActiveCheatProcess();
}

Handle DmntCheatManager::GetCheatProcessEventHandle() {
    return g_cheat_process_event->GetHandle();
}

Result DmntCheatManager::GetCheatProcessMetadata(CheatProcessMetadata *out) {
    std::scoped_lock<HosMutex> lk(g_cheat_lock);

    if (HasActiveCheatProcess()) {
        *out = g_cheat_process_metadata;
        return ResultSuccess;
    }

    return ResultDmntCheatNotAttached;
}

void DmntCheatManager::InitializeCheatManager() {
    /* Create cheat process detection event. */
    g_cheat_process_event = CreateWriteOnlySystemEvent();

    /* Create cheat vm. */
    g_cheat_vm = new DmntCheatVm();

    /* Learn whether we should enable cheats by default. */
    {
        u8 en;
        if (R_SUCCEEDED(setsysGetSettingsItemValue("atmosphere", "dmnt_cheats_enabled_by_default", &en, sizeof(en)))) {
            g_enable_cheats_by_default = (en != 0);
        }

        if (R_SUCCEEDED(setsysGetSettingsItemValue("atmosphere", "dmnt_always_save_cheat_toggles", &en, sizeof(en)))) {
            g_always_save_cheat_toggles = (en != 0);
        }
    }

    /* Initialize debug events manager. */
    DmntCheatDebugEventsManager::Initialize();

    /* Spawn application detection thread, spawn cheat vm thread. */
    R_ASSERT(g_detect_thread.Initialize(&DmntCheatManager::DetectThread, nullptr, 0x4000, 39));
    R_ASSERT(g_vm_thread.Initialize(&DmntCheatManager::VmThread, nullptr, 0x4000, 48));

    /* Start threads. */
    R_ASSERT(g_detect_thread.Start());
    R_ASSERT(g_vm_thread.Start());
}