#define GC_LINUX_THREADS 1
#include <gc/gc_allocator.h>

#include "json.hh"

#include "attr-path.hh"
#include "derivations.hh"

#include <sys/resource.h>

using namespace nix;

#include <nlohmann/json.hpp>

using namespace nix;

static size_t maxMemorySize;

struct MyArgs : MixEvalArgs, MixCommonArgs
{
    Path releaseExpr;
    bool dryRun = false;

static void findJobs(EvalState & state, JSONObject & top,
    Bindings & autoArgs, Value & v, const string & attrPath);

    MyArgs() : MixCommonArgs("hydra-eval-jobs")
    {
        mkFlag()
            .longName("help")
            .description("show usage information")
            .handler([&]() {
                printHelp(programName, std::cout);
                throw Exit();
            });

        mkFlag()
            .longName("gc-roots-dir")
            .description("garbage collector roots directory")
            .labels({"path"})
            .dest(&gcRootsDir);

static string queryMetaStrings(EvalState & state, DrvInfo & drv, const string & name, const string & subAttribute)

        mkFlag()
            .longName("dry-run")
            .description("don't create store derivations")
            .set(&dryRun, true);
        expectArg("expr", &releaseExpr);
    }
};
static MyArgs myArgs;
static std::string queryMetaStrings(EvalState & state, DrvInfo & drv, const string & name, const string & subAttribute)

static std::string lastAttrPath;
static bool comma = false;
static size_t maxHeapSize;

struct BailOut { };

static void worker(
    EvalState & state,
    Bindings & autoArgs,
    AutoCloseFD & to,
    AutoCloseFD & from)
{
    Value vTop;
    state.evalFile(lookupFileArg(state, myArgs.releaseExpr), vTop);

    auto vRoot = state.allocValue();
    state.autoCallFunction(autoArgs, vTop, *vRoot);

bool lte(const std::string & s1, const std::string & s2)
{
    size_t p1 = 0, p2 = 0;

        if (p1 == s1.size()) return p2 == s2.size();
        if (p2 == s2.size()) return true;

        /* Wait for the master to send us a job name. */
        writeLine(to.get(), "next");

        auto d1 = s1.find('.', p1);
        auto d2 = s2.find('.', p2);

        auto s = readLine(from.get());
        if (s == "exit") break;
        if (!hasPrefix(s, "do ")) abort();
        std::string attrPath(s, 3);

        auto c = s1.compare(p1, d1 - p1, s2, p2, d2 - p2);

        debug("worker process %d at '%s'", getpid(), attrPath);

        if (c < 0) return true;
        if (c > 0) return false;

        /* Evaluate it and send info back to the master. */
        nlohmann::json reply;

        p1 = d1 == std::string::npos ? s1.size() : d1 + 1;
        p2 = d2 == std::string::npos ? s2.size() : d2 + 1;
    }
}

        try {
            auto v = findAlongAttrPath(state, attrPath, autoArgs, *vRoot).first;

            state.forceValue(*v);

static void findJobsWrapped(EvalState & state, JSONObject & top,
    Bindings & autoArgs, Value & vIn, const string & attrPath)
{
    if (lastAttrPath != "" && lte(attrPath, lastAttrPath)) return;

            if (auto drv = getDerivation(state, *v, false)) {

    debug(format("at path `%1%'") % attrPath);

                DrvInfo::Outputs outputs = drv->queryOutputs();

    checkInterrupt();

                if (drv->querySystem() == "unknown")
                    throw EvalError("derivation must have a 'system' attribute");

    Value v;
    state.autoCallFunction(autoArgs, vIn, v);

                auto drvPath = drv->queryDrvPath();

    if (v.type == tAttrs) {

                nlohmann::json job;

        auto drv = getDerivation(state, v, false);

                job["nixName"] = drv->queryName();
                job["system"] =drv->querySystem();
                job["drvPath"] = drvPath;
                job["description"] = drv->queryMetaString("description");
                job["license"] = queryMetaStrings(state, *drv, "license", "shortName");
                job["homepage"] = drv->queryMetaString("homepage");
                job["maintainers"] = queryMetaStrings(state, *drv, "maintainers", "email");
                job["schedulingPriority"] = drv->queryMetaInt("schedulingPriority", 100);
                job["timeout"] = drv->queryMetaInt("timeout", 36000);
                job["maxSilent"] = drv->queryMetaInt("maxSilent", 7200);
                job["isChannel"] = drv->queryMetaBool("isHydraChannel", false);

        if (drv) {
            Path drvPath;

                /* If this is an aggregate, then get its constituents. */
                auto a = v->attrs->get(state.symbols.create("_hydraAggregate"));
                if (a && state.forceBool(*a->value, *a->pos)) {
                    auto a = v->attrs->get(state.symbols.create("constituents"));
                    if (!a)
                        throw EvalError("derivation must have a ‘constituents’ attribute");

            DrvInfo::Outputs outputs = drv->queryOutputs();

            if (drv->querySystem() == "unknown")
                throw EvalError("derivation must have a ‘system’ attribute");
            if (comma) { std::cout << ","; comma = false; }
            {
            auto res = top.object(attrPath);
            res.attr("nixName", drv->queryName());
            res.attr("system", drv->querySystem());
            res.attr("drvPath", drvPath = drv->queryDrvPath());
            res.attr("description", drv->queryMetaString("description"));
            res.attr("license", queryMetaStrings(state, *drv, "license", "shortName"));
            res.attr("homepage", drv->queryMetaString("homepage"));
            res.attr("maintainers", queryMetaStrings(state, *drv, "maintainers", "email"));
            res.attr("schedulingPriority", drv->queryMetaInt("schedulingPriority", 100));
            res.attr("timeout", drv->queryMetaInt("timeout", 36000));
            res.attr("maxSilent", drv->queryMetaInt("maxSilent", 7200));
            res.attr("isChannel", drv->queryMetaBool("isHydraChannel", false));

                    PathSet context;
                    state.coerceToString(*a->pos, *a->value, context, true, false);
                    for (auto & i : context)
                        if (i.at(0) == '!') {
                            size_t index = i.find("!", 1);
                            job["constituents"].push_back(string(i, index + 1));
                        }

            /* If this is an aggregate, then get its constituents. */
            Bindings::iterator a = v.attrs->find(state.symbols.create("_hydraAggregate"));
            if (a != v.attrs->end() && state.forceBool(*a->value, *a->pos)) {
                Bindings::iterator a = v.attrs->find(state.symbols.create("constituents"));
                if (a == v.attrs->end())
                    throw EvalError("derivation must have a ‘constituents’ attribute");
                PathSet context;
                state.coerceToString(*a->pos, *a->value, context, true, false);
                PathSet drvs;
                for (auto & i : context)
                    if (i.at(0) == '!') {
                        size_t index = i.find("!", 1);
                        drvs.insert(string(i, index + 1));

                    state.forceList(*a->value, *a->pos);
                    for (unsigned int n = 0; n < a->value->listSize(); ++n) {
                        auto v = a->value->listElems()[n];
                        state.forceValue(*v);
                        if (v->type == tString)
                            job["namedConstituents"].push_back(state.forceStringNoCtx(*v));

                res.attr("constituents", concatStringsSep(" ", drvs));
            }

                }

            /* Register the derivation as a GC root.  !!! This
               registers roots for jobs that we may have already
               done. */
            auto localStore = state.store.dynamic_pointer_cast<LocalFSStore>();
            if (gcRootsDir != "" && localStore) {
                Path root = gcRootsDir + "/" + std::string(baseNameOf(drvPath));
                if (!pathExists(root))
                    localStore->addPermRoot(localStore->parseStorePath(drvPath), root, false);
            }
            auto res2 = res.object("outputs");
            for (auto & j : outputs)
                res2.attr(j.first, j.second);
            }

                /* Register the derivation as a GC root.  !!! This
                   registers roots for jobs that we may have already
                   done. */
                auto localStore = state.store.dynamic_pointer_cast<LocalFSStore>();
                if (gcRootsDir != "" && localStore) {
                    Path root = gcRootsDir + "/" + std::string(baseNameOf(drvPath));
                    if (!pathExists(root))
                        localStore->addPermRoot(localStore->parseStorePath(drvPath), root, false);
                }

            GC_prof_stats_s gc;
            GC_get_prof_stats(&gc, sizeof(gc));

                nlohmann::json out;
                for (auto & j : outputs)
                    out[j.first] = j.second;
                job["outputs"] = std::move(out);

            if (gc.heapsize_full > maxHeapSize) {
                printInfo("restarting hydra-eval-jobs after job '%s' because heap size is at %d bytes", attrPath, gc.heapsize_full);
                lastAttrPath = attrPath;
                throw BailOut();

                reply["job"] = std::move(job);

        }

        else {
            if (!state.isDerivation(v)) {
                for (auto & i : v.attrs->lexicographicOrder()) {

            else if (v->type == tAttrs) {
                auto attrs = nlohmann::json::array();
                StringSet ss;
                for (auto & i : v->attrs->lexicographicOrder()) {

                    /* Skip jobs with dots in the name. */
                    if (name.find('.') != std::string::npos) {

                    if (name.find('.') != std::string::npos || name.find(' ') != std::string::npos) {

                    findJobs(state, top, autoArgs, *i->value,
                        (attrPath.empty() ? "" : attrPath + ".") + name);

                    attrs.push_back(name);

                reply["attrs"] = std::move(attrs);

        } catch (EvalError & e) {
            reply["error"] = filterANSIEscapes(e.msg(), true);

    }

    else if (v.type == tNull) {
        // allow null values, meaning 'do nothing'

        writeLine(to.get(), reply.dump());
        /* If our RSS exceeds the maximum, exit. The master will
           start a new process. */
        struct rusage r;
        getrusage(RUSAGE_SELF, &r);
        if ((size_t) r.ru_maxrss > maxMemorySize * 1024) break;

    else
        throw TypeError(format("unsupported value: %1%") % v);

    writeLine(to.get(), "restart");

static void findJobs(EvalState & state, JSONObject & top,
    Bindings & autoArgs, Value & v, const string & attrPath)
{
    try {
        findJobsWrapped(state, top, autoArgs, v, attrPath);
    } catch (EvalError & e) {
        if (comma) { std::cout << ","; comma = false; }
        auto res = top.object(attrPath);
        res.attr("error", filterANSIEscapes(e.msg(), true));
    }
}

    assert(lte("abc", "def"));
    assert(lte("abc", "def.foo"));
    assert(!lte("def", "abc"));
    assert(lte("nixpkgs.hello", "nixpkgs"));
    assert(lte("nixpkgs.hello", "nixpkgs.hellooo"));
    assert(lte("gitAndTools.git-annex.x86_64-darwin", "gitAndTools.git-annex.x86_64-linux"));
    assert(lte("gitAndTools.git-annex.x86_64-linux", "gitAndTools.git-annex-remote-b2.aarch64-linux"));

        auto initialHeapSize = config->getStrOption("evaluator_initial_heap_size", "");
        if (initialHeapSize != "")
            setenv("GC_INITIAL_HEAP_SIZE", initialHeapSize.c_str(), 1);

        maxHeapSize = config->getIntOption("evaluator_max_heap_size", 1UL << 30);

        auto nrWorkers = config->getIntOption("evaluator_workers", 1);
        maxMemorySize = config->getIntOption("evaluator_max_memory_size", 4096);

        /* Read the current heap size, which is the initial heap size. */
        GC_prof_stats_s gc;
        GC_get_prof_stats(&gc, sizeof(gc));
        auto initialHeapSizeInt = gc.heapsize_full;

        myArgs.parseCmdline(argvToStrings(argc, argv));

        /* Then make sure the maximum heap size will be bigger than the initial heap size. */
        if (initialHeapSizeInt > maxHeapSize) {
            printInfo("warning: evaluator_initial_heap_size (%d) bigger than evaluator_max_heap_size (%d).", initialHeapSizeInt, maxHeapSize);
            maxHeapSize = initialHeapSizeInt * 1.1;
            printInfo("         evaluator_max_heap_size now set to %d.", maxHeapSize);
        }

        /* FIXME: The build hook in conjunction with import-from-derivation is causing "unexpected EOF" during eval */
        settings.builders = "";

        Path releaseExpr;

        /* Prevent access to paths outside of the Nix search path and
           to the environment. */
        evalSettings.restrictEval = true;

        struct MyArgs : LegacyArgs, MixEvalArgs

        if (myArgs.dryRun) settings.readOnlyMode = true;
        if (myArgs.releaseExpr == "") throw UsageError("no expression specified");
        if (gcRootsDir == "") printMsg(lvlError, "warning: `--gc-roots-dir' not specified");
        struct State

            using LegacyArgs::LegacyArgs;

            std::set<std::string> todo{""};
            std::set<std::string> active;
            nlohmann::json jobs;
            std::exception_ptr exc;

        MyArgs myArgs(baseNameOf(argv[0]), [&](Strings::iterator & arg, const Strings::iterator & end) {
            if (*arg == "--gc-roots-dir")
                gcRootsDir = getArg(*arg, arg, end);
            else if (*arg == "--dry-run")
                settings.readOnlyMode = true;
            else if (*arg != "" && arg->at(0) == '-')
                return false;
            else
                releaseExpr = *arg;
            return true;
        });

        std::condition_variable wakeup;
        Sync<State> state_;
        /* Start a handler thread per worker process. */
        auto handler = [&]()
        {
            try {
                pid_t pid = -1;
                AutoCloseFD from, to;
                while (true) {

        myArgs.parseCmdline(argvToStrings(argc, argv));

                    /* Start a new worker process if necessary. */
                    if (pid == -1) {
                        Pipe toPipe, fromPipe;
                        toPipe.create();
                        fromPipe.create();
                        pid = startProcess(
                            [&,
                             to{std::make_shared<AutoCloseFD>(std::move(fromPipe.writeSide))},
                             from{std::make_shared<AutoCloseFD>(std::move(toPipe.readSide))}
                            ]()
                            {
                                try {
                                    EvalState state(myArgs.searchPath, openStore());
                                    Bindings & autoArgs = *myArgs.getAutoArgs(state);
                                    worker(state, autoArgs, *to, *from);
                                } catch (std::exception & e) {
                                    nlohmann::json err;
                                    err["error"] = e.what();
                                    writeLine(to->get(), err.dump());
                                }
                            },
                            ProcessOptions { .allowVfork = false });
                        from = std::move(fromPipe.readSide);
                        to = std::move(toPipe.writeSide);
                        debug("created worker process %d", pid);
                    }

        JSONObject json(std::cout, true);
        std::cout.flush();

                    /* Check whether the existing worker process is still there. */
                    auto s = readLine(from.get());
                    if (s == "restart") {
                        pid = -1;
                        continue;
                    } else if (s != "next") {
                        auto json = nlohmann::json::parse(s);
                        throw Error("worker error: %s", (std::string) json["error"]);
                    }

        do {

                    /* Wait for a job name to become available. */
                    std::string attrPath;

            Pipe pipe;
            pipe.create();

                    while (true) {
                        checkInterrupt();
                        auto state(state_.lock());
                        if ((state->todo.empty() && state->active.empty()) || state->exc) {
                            writeLine(to.get(), "exit");
                            return;
                        }
                        if (!state->todo.empty()) {
                            attrPath = *state->todo.begin();
                            state->todo.erase(state->todo.begin());
                            state->active.insert(attrPath);
                            break;
                        } else
                            state.wait(wakeup);
                    }

            ProcessOptions options;
            options.allowVfork = false;

                    /* Tell the worker to evaluate it. */
                    writeLine(to.get(), "do " + attrPath);

            GC_atfork_prepare();

                    /* Wait for the response. */
                    auto response = nlohmann::json::parse(readLine(from.get()));

            auto pid = startProcess([&]() {
                pipe.readSide = -1;

                    /* Handle the response. */
                    StringSet newAttrs;

                GC_atfork_child();
                GC_start_mark_threads();

                    if (response.find("job") != response.end()) {
                        auto state(state_.lock());
                        state->jobs[attrPath] = response["job"];
                    }

                if (lastAttrPath != "") debug("resuming from '%s'", lastAttrPath);

                    if (response.find("attrs") != response.end()) {
                        for (auto & i : response["attrs"]) {
                            auto s = (attrPath.empty() ? "" : attrPath + ".") + (std::string) i;
                            newAttrs.insert(s);
                        }
                    }

                /* FIXME: The build hook in conjunction with import-from-derivation is causing "unexpected EOF" during eval */
                settings.builders = "";

                    if (response.find("error") != response.end()) {
                        auto state(state_.lock());
                        state->jobs[attrPath]["error"] = response["error"];
                    }

                /* Prevent access to paths outside of the Nix search path and
                   to the environment. */
                evalSettings.restrictEval = true;

                    /* Add newly discovered job names to the queue. */
                    {
                        auto state(state_.lock());
                        state->active.erase(attrPath);
                        for (auto & s : newAttrs)
                            state->todo.insert(s);
                        wakeup.notify_all();
                    }
                }
            } catch (...) {
                auto state(state_.lock());
                state->exc = std::current_exception();
                wakeup.notify_all();
            }
        };

                if (releaseExpr == "") throw UsageError("no expression specified");

        std::vector<std::thread> threads;
        for (size_t i = 0; i < nrWorkers; i++)
            threads.emplace_back(std::thread(handler));

                if (gcRootsDir == "") printMsg(lvlError, "warning: `--gc-roots-dir' not specified");

        for (auto & thread : threads)
            thread.join();

                EvalState state(myArgs.searchPath, openStore());

        auto state(state_.lock());

                Bindings & autoArgs = *myArgs.getAutoArgs(state);

        if (state->exc)
            std::rethrow_exception(state->exc);

                Value v;
                state.evalFile(lookupFileArg(state, releaseExpr), v);

        /* For aggregate jobs that have named consistuents
           (i.e. constituents that are a job name rather than a
           derivation), look up the referenced job and add it to the
           dependencies of the aggregate derivation. */
        auto store = openStore();

                comma = lastAttrPath != "";

        for (auto i = state->jobs.begin(); i != state->jobs.end(); ++i) {
            auto jobName = i.key();
            auto & job = i.value();

                try {
                    findJobs(state, json, autoArgs, v, "");
                    lastAttrPath = "";
                } catch (BailOut &) { }

            auto named = job.find("namedConstituents");
            if (named == job.end()) continue;

                writeFull(pipe.writeSide.get(), lastAttrPath);

            if (myArgs.dryRun) {
                for (std::string jobName2 : *named) {
                    auto job2 = state->jobs.find(jobName2);
                    if (job2 == state->jobs.end())
                        throw Error("aggregate job '%s' references non-existent job '%s'", jobName, jobName2);
                    std::string drvPath2 = (*job2)["drvPath"];
                    job["constituents"].push_back(drvPath2);
                }
            } else {
                std::string drvPath = job["drvPath"];
                auto drv = readDerivation(*store, drvPath);

                exit(0);
            }, options);

                for (std::string jobName2 : *named) {
                    auto job2 = state->jobs.find(jobName2);
                    if (job2 == state->jobs.end())
                        throw Error("aggregate job '%s' references non-existent job '%s'", jobName, jobName2);
                    std::string drvPath2 = (*job2)["drvPath"];
                    auto drv2 = readDerivation(*store, drvPath2);
                    job["constituents"].push_back(drvPath2);
                    drv.inputDrvs[store->parseStorePath(drvPath2)] = {drv2.outputs.begin()->first};
                }

            GC_atfork_parent();

                std::string drvName(store->parseStorePath(drvPath).name());
                assert(hasSuffix(drvName, drvExtension));
                drvName.resize(drvName.size() - drvExtension.size());
                auto h = hashDerivationModulo(*store, drv, true);
                auto outPath = store->makeOutputPath("out", h, drvName);
                drv.env["out"] = store->printStorePath(outPath);
                drv.outputs.insert_or_assign("out", DerivationOutput(outPath.clone(), "", ""));
                auto newDrvPath = store->printStorePath(writeDerivation(store, drv, drvName));

            pipe.writeSide = -1;

                debug("rewrote aggregate derivation %s -> %s", drvPath, newDrvPath);

            int status;
            while (true) {
                checkInterrupt();
                if (waitpid(pid, &status, 0) == pid) break;
                if (errno != EINTR) continue;

                job["drvPath"] = newDrvPath;
                job["outputs"]["out"] = store->printStorePath(outPath);

            if (status != 0)
                throw Exit(WIFEXITED(status) ? WEXITSTATUS(status) : 99);

            job.erase("namedConstituents");
        }

            maxHeapSize += 64 * 1024 * 1024;
            lastAttrPath = drainFD(pipe.readSide.get());
        } while (lastAttrPath != "");

        std::cout << state->jobs.dump(2) << "\n";