// Copyright (c) 2026 Bitflash developers
// Distributed under the MIT/X11 software license.
//
// Integration self-tests that need the real wallet/database code linked into
// the node. These are intentionally run behind an explicit command-line flag
// and against a temporary data directory.

#include "headers_core.h"
#include "selftest.h"

// Test results go to the terminal, not to debug.log.
//
// printf in this tree is OutputDebugStringF, which writes into the data
// directory's debug.log and binds that path, once, on its first call. For a
// self-test that produced two bad outcomes at the same time. On Windows the
// binary is linked -mwindows and has no console, so `make tests` printed the
// bip32 results, echoed the self-test command, and then showed nothing at all --
// a failure was still caught, because a non-zero return stops make, but it
// arrived with no way to tell which check failed. And because the first line
// printed before strSetDataDir was pointed at the temporary directory, every
// line landed in the developer's real debug.log: the same file users are asked
// to paste into issues.
//
// Undefining the macro here gives this file the real printf, so results reach
// stdout. Nothing else in the tree is affected.
#undef printf

#include <mutex>
#include <stdexcept>
#include <thread>

#ifdef _WIN32
#include <direct.h>
#else
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#endif

static std::string HexStrLocal(const std::vector<unsigned char>& v)
{
    static const char* hex = "0123456789abcdef";
    std::string out;
    out.reserve(v.size() * 2);
    for (unsigned char c : v)
    {
        out.push_back(hex[c >> 4]);
        out.push_back(hex[c & 0x0f]);
    }
    return out;
}

static bool MakeTempDir(std::string& out)
{
#ifdef _WIN32
    char base[MAX_PATH + 1] = {0};
    if (!GetTempPathA(MAX_PATH, base))
        return false;
    for (int i = 0; i < 100; i++)
    {
        std::string path = strprintf("%sbitflash-selftest-%lu-%lld-%d",
            base, (unsigned long)GetCurrentProcessId(), (long long)GetTime(), i);
        if (CreateDirectoryA(path.c_str(), NULL))
        {
            out = path;
            return true;
        }
    }
    return false;
#else
    char tmpl[256];
    snprintf(tmpl, sizeof(tmpl), "/tmp/bitflash-selftest-%ld-XXXXXX", (long)getpid());
    char* p = mkdtemp(tmpl);
    if (!p)
        return false;
    out = p;
    return true;
#endif
}

static bool GetCurrentDir(std::string& out)
{
#ifdef _WIN32
    char buf[MAX_PATH + 1] = {0};
    DWORD n = GetCurrentDirectoryA(MAX_PATH, buf);
    if (n == 0 || n > MAX_PATH)
        return false;
    out = buf;
    return true;
#else
    char buf[4096];
    if (!getcwd(buf, sizeof(buf)))
        return false;
    out = buf;
    return true;
#endif
}

static bool SetCurrentDir(const std::string& path)
{
#ifdef _WIN32
    return SetCurrentDirectoryA(path.c_str()) != 0;
#else
    return chdir(path.c_str()) == 0;
#endif
}

static void RemoveTree(const std::string& path)
{
#ifdef _WIN32
    DWORD attr = GetFileAttributesA(path.c_str());
    if (attr == INVALID_FILE_ATTRIBUTES)
        return;
    if (!(attr & FILE_ATTRIBUTE_DIRECTORY))
    {
        DeleteFileA(path.c_str());
        return;
    }

    WIN32_FIND_DATAA findData;
    std::string pattern = path + "\\*";
    HANDLE hFind = FindFirstFileA(pattern.c_str(), &findData);
    if (hFind != INVALID_HANDLE_VALUE)
    {
        do
        {
            std::string name = findData.cFileName;
            if (name == "." || name == "..")
                continue;
            RemoveTree(path + "\\" + name);
        }
        while (FindNextFileA(hFind, &findData));
        FindClose(hFind);
    }
    RemoveDirectoryA(path.c_str());
#else
    struct stat st;
    if (lstat(path.c_str(), &st) != 0)
        return;
    if (!S_ISDIR(st.st_mode))
    {
        unlink(path.c_str());
        return;
    }

    DIR* dir = opendir(path.c_str());
    if (dir)
    {
        struct dirent* ent;
        while ((ent = readdir(dir)) != NULL)
        {
            std::string name = ent->d_name;
            if (name == "." || name == "..")
                continue;
            RemoveTree(path + "/" + name);
        }
        closedir(dir);
    }
    rmdir(path.c_str());
#endif
}

static bool WalletHasPrivateKey(const std::vector<unsigned char>& vchPubKey)
{
    CPrivKey priv;
    return CWalletDB("r").ReadKey(vchPubKey, priv) && !priv.empty();
}

static bool Check(bool condition, const char* message)
{
    if (condition)
    {
        printf("  ok   %s\n", message);
        return true;
    }
    printf("  FAIL %s\n", message);
    return false;
}

static int RunWalletKeyPoolSelfTest()
{
    fflush(stdout);
    printf("wallet-keypool self-test\n");

    std::string tmp;
    std::string cwd;
    if (!MakeTempDir(tmp))
    {
        printf("  FAIL could not create a temporary data directory\n");
        return 1;
    }
    if (!GetCurrentDir(cwd) || !SetCurrentDir(tmp))
    {
        printf("  FAIL could not move into the temporary data directory\n");
        RemoveTree(tmp);
        return 1;
    }

    int nFail = 0;
    // Before anything can open the database or resolve the log path: what the
    // node itself prints during the test belongs in the temporary directory,
    // and dies with it. The test's own results are on stdout, above.
    strSetDataDir = tmp;
    printf("  temp datadir: %s\n", tmp.c_str());

    try
    {
        if (!LoadWallet())
            throw std::runtime_error("LoadWallet failed");

        TopUpKeyPool();
        int nInitialPoolSize = 0;
        CRITICAL_BLOCK(cs_keyPool)
            nInitialPoolSize = (int)mapKeyPool.size();
        nFail += Check(nInitialPoolSize == KEYPOOL_SIZE, "TopUpKeyPool fills the pool") ? 0 : 1;

        bool fPooledKeysStored = true;
        CRITICAL_BLOCK(cs_keyPool)
        {
            for (map<int64, vector<unsigned char> >::const_iterator mi = mapKeyPool.begin();
                 mi != mapKeyPool.end(); ++mi)
                if (!WalletHasPrivateKey(mi->second))
                    fPooledKeysStored = false;
        }
        nFail += Check(fPooledKeysStored, "every pooled public key has a stored private key") ? 0 : 1;

        std::vector<std::vector<unsigned char> > drawn;
        std::mutex drawnMutex;
        const int nThreads = 8;
        const int nDrawsPerThread = 32;
        std::vector<std::thread> threads;

        for (int t = 0; t < nThreads; t++)
        {
            threads.emplace_back([&drawn, &drawnMutex, nDrawsPerThread]() {
                for (int i = 0; i < nDrawsPerThread; i++)
                {
                    std::vector<unsigned char> key = GetKeyFromPool();
                    std::lock_guard<std::mutex> lock(drawnMutex);
                    drawn.push_back(key);
                }
            });
        }
        for (std::thread& t : threads)
            t.join();

        nFail += Check((int)drawn.size() == nThreads * nDrawsPerThread,
                       "all concurrent draws returned a key") ? 0 : 1;

        std::set<std::string> seen;
        bool fUnique = true;
        bool fAllStored = true;
        for (const std::vector<unsigned char>& key : drawn)
        {
            if (!seen.insert(HexStrLocal(key)).second)
                fUnique = false;
            if (!WalletHasPrivateKey(key))
                fAllStored = false;
        }

        nFail += Check(fUnique, "concurrent draws never return the same key") ? 0 : 1;
        nFail += Check(fAllStored, "each drawn key was already stored in wallet.dat") ? 0 : 1;
        int nPoolSize = 0;
        CRITICAL_BLOCK(cs_keyPool)
            nPoolSize = (int)mapKeyPool.size();
        nFail += Check(nPoolSize == KEYPOOL_SIZE, "drawing leaves the key pool topped up") ? 0 : 1;
    }
    catch (const std::exception& e)
    {
        printf("  FAIL exception: %s\n", e.what());
        nFail++;
    }
    catch (...)
    {
        printf("  FAIL unknown exception\n");
        nFail++;
    }

    DBFlush(true);
    SetCurrentDir(cwd);
    RemoveTree(tmp);
    printf("%s (%d failure%s)\n", nFail == 0 ? "ALL TESTS PASSED" : "TESTS FAILED",
           nFail, nFail == 1 ? "" : "s");
    fflush(stdout);
    return nFail == 0 ? 0 : 1;
}

// A -mwindows binary starts with no console attached, so stdout goes nowhere
// even when it was launched from a terminal. Borrow the caller's console for
// the duration of the self-test. Nothing to do on Linux, where stdout is
// already connected.
static void AttachTerminal()
{
#ifdef _WIN32
    // Only when there is nowhere for stdout to go. If the caller redirected it
    // to a file or a pipe -- which is what `make tests > log` and any CI does --
    // that handle is inherited and already works, and reopening it on CONOUT$
    // would take the output away from the file and put it on the screen. That
    // was the first version of this fix, and it broke the one case that
    // mattered.
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hOut != NULL && hOut != INVALID_HANDLE_VALUE)
        return;

    if (AttachConsole(ATTACH_PARENT_PROCESS))
    {
        // Return values ignored on purpose: if the reopen fails there is
        // nowhere left to report it, and the exit status still carries the
        // result.
        freopen("CONOUT$", "w", stdout);
        freopen("CONOUT$", "w", stderr);
    }
#endif
}

int RunSelfTest(const std::string& name)
{
    AttachTerminal();

    if (name == "wallet-keypool")
        return RunWalletKeyPoolSelfTest();

    printf("Unknown self-test '%s'\n", name.c_str());
    printf("Known self-tests: wallet-keypool\n");
    return 1;
}