// SPDX-License-Identifier: LGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

// The crafter-debug client end to end against a real Session in the same
// process, through a Connection that hands each request to Session::Handle
// while a thread plays the app's frame loop (Advance, Pump). Covers what an
// agent sees: typed key=value calls and the usage error for a bad value,
// suggestions for typos, get/set, pause/step/resume, waits, the log, traces,
// screenshots written where asked, --json, instance selection, the protocol
// and source checks against the discovery record, a server-side timeout,
// and a client-side one that diagnoses an app no longer calling Pump.
#include <stdio.h>
import std;
import Crafter.Debug;
import Crafter.Debug.Cli;
using namespace Crafter::Debug;
namespace fs = std::filesystem;
using namespace std::chrono_literals;

namespace {
    std::int32_t failures = 0;

    void Check(bool ok, std::string_view what) {
        std::println("{} {}", ok ? "PASS" : "FAIL", what);
        if (!ok) ++failures;
    }

    struct AimArgs {
        Required<std::int32_t> slot;
        float yaw = 10;
    };

    struct Aimed {
        std::int32_t slot = 0;
        float yaw = 0;
    };

    Session* session = nullptr;

    class Collect : public Detail::Exchange {
    public:
        explicit Collect(std::function<bool(const Value&)> onLine) : onLine(std::move(onLine)) {}
        void Reply(const Value& reply) override {
            std::lock_guard lock(mutex);
            if (final) return;
            final = reply;
            ready.notify_all();
        }
        bool Stream(const Value& line) override { return onLine ? onLine(line) : true; }
        std::optional<Value> Wait(std::chrono::milliseconds timeout) {
            std::unique_lock lock(mutex);
            ready.wait_for(lock, timeout, [&] { return final.has_value(); });
            return final;
        }

    private:
        std::function<bool(const Value&)> onLine;
        std::mutex mutex;
        std::condition_variable ready;
        std::optional<Value> final;
    };

    class InProcess : public Cli::Connection {
    public:
        std::expected<Value, Cli::CallError> Call(const Value& request, std::chrono::milliseconds timeout, const std::function<bool(const Value&)>& onLine) override {
            auto exchange = std::make_shared<Collect>(onLine);
            session->Handle(request, exchange);
            if (auto reply = exchange->Wait(timeout)) return *reply;
            return std::unexpected(Cli::CallError{ Cli::CallError::Kind::TimedOut, "no reply" });
        }
    };

    struct Ran {
        std::int32_t code = 0;
        std::string out;
        std::string err;
    };

    Ran Run(std::vector<std::string_view> args, const std::vector<Instance>& instances) {
        std::ostringstream out;
        std::ostringstream err;
        Cli::Environment environment;
        environment.connect = [](const InstanceRecord&) -> std::unique_ptr<Cli::Connection> { return std::make_unique<InProcess>(); };
        environment.list = [instances] { return instances; };
        environment.out = &out;
        environment.err = &err;
        environment.cwd = fs::temp_directory_path() / "crafter-debug-ShouldRunClientCommands";
        environment.haveLldb = [] { return false; };
        const std::int32_t code = Cli::Run(args, environment);
        return { code, out.str(), err.str() };
    }

    bool Has(const std::string& text, std::string_view part) {
        return text.find(part) != std::string::npos;
    }
}

int main() {
    std::thread([] {
        std::this_thread::sleep_for(50s);
        std::println("FAIL the test hung");
        std::fflush(stdout);
        std::_Exit(1);
    }).detach();

    Command("Player_SetAim", "Aim the turret.", [](const AimArgs& args) { return Aimed{ *args.slot, args.yaw }; });
    std::int32_t hp = 100;
    Watch("hp", hp);
    std::int32_t score = 0;
    Watch("score", score);
    SetCapture([] {
        return Async<std::vector<std::byte>>([]() -> std::optional<std::vector<std::byte>> {
            return std::vector<std::byte>{ std::byte{ 0x89 }, std::byte{ 'P' }, std::byte{ 'N' }, std::byte{ 'G' } };
        });
    });

    Session owned({ .name = "game", .listen = false });
    session = &owned;
    const InstanceRecord record{ .name = "game", .instanceId = "abc123", .pid = 2, .token = owned.Token(), .protocol = protocolVersion, .sourceId = std::string(Detail::SourceId()) };
    const std::vector<Instance> instances = { { record, {} } };

    std::atomic<bool> pumping = true;
    std::thread app([&] {
        while (pumping) {
            if (Advance()) ++score;
            Pump();
            std::this_thread::sleep_for(2ms);
        }
    });

    Ran r = Run({ "status" }, instances);
    Check(r.code == 0 && Has(r.out, "game  frame"), "status");
    r = Run({ "cmds" }, instances);
    Check(r.code == 0 && Has(r.out, "Player_SetAim(slot: integer (required), yaw: number = 10.0) -> Aimed  -- Aim the turret."), std::format("cmds shows arguments and defaults: {}", r.out));
    r = Run({ "help", "Player_SetAim" }, instances);
    Check(r.code == 0 && Has(r.out, "required") && Has(r.out, "default 10.0"), "help shows each argument");

    r = Run({ "call", "Player_SetAim", "slot=2", "yaw=45" }, instances);
    Check(r.code == 0 && Has(r.out, R"({"slot":2,"yaw":45.0})"), std::format("call types key=value from the arguments ({})", r.out + r.err));
    r = Run({ "call", "Player_SetAim", "slot=two" }, instances);
    Check(r.code == 2 && Has(r.err, "slot: 'two' is not a number"), "a value that does not fit its field is a usage error");
    r = Run({ "call", "Player_SetAm" }, instances);
    Check(r.code == 6 && Has(r.err, "did you mean 'Player_SetAim'"), "a mistyped command gets a suggestion");

    r = Run({ "get", "hp" }, instances);
    Check(r.code == 0 && r.out == "hp = 100\n", "get");
    r = Run({ "set", "hp", "5" }, instances);
    Check(r.code == 0 && r.out == "hp = 5\n", "set");
    r = Run({ "get", "nope" }, instances);
    Check(r.code == 6 && Has(r.err, "no watch or sample 'nope'"), "get of an unknown path");

    r = Run({ "pause" }, instances);
    Check(r.code == 0 && Has(r.out, "paused at frame"), "pause");
    r = Run({ "step", "2" }, instances);
    Check(r.code == 0 && Has(r.out, "stepped 2 to frame"), "step");
    r = Run({ "resume" }, instances);
    Check(r.code == 0 && Has(r.out, "running from frame"), "resume");
    r = Run({ "wait", "--frames", "3" }, instances);
    Check(r.code == 0 && Has(r.out, "frame "), "wait --frames");
    r = Run({ "wait", "score >= 1" }, instances);
    Check(r.code == 0 && Has(r.out, "'score >= 1' held at frame"), "wait for a condition");
    r = Run({ "--timeout", "100ms", "wait", "score < 0" }, instances);
    Check(r.code == 5 && Has(r.err, "was not true within"), "a wait that times out exits 5 and says what the paths were");
    r = Run({ "wait", "score < 0", "--timeout", "100ms" }, instances);
    Check(r.code == 5 && Has(r.err, "was not true within"), std::format("global flags also go after the command's own ({})", r.err));
    r = Run({ "wait", "--frames", "1", "--timeout" }, instances);
    Check(r.code == 2 && Has(r.err, "--timeout needs a value"), "a global flag without its value is a usage error");

    r = Run({ "log", "--last", "5" }, instances);
    Check(r.code == 0 && Has(r.out, "AGENT"), "log shows the agent's actions");
    r = Run({ "trace", "hp", "--frames", "3" }, instances);
    Check(r.code == 0 && Has(r.out, "changes 0"), "trace");

    r = Run({ "screenshot", "-o", "shot.png" }, instances);
    const fs::path shot = fs::temp_directory_path() / "crafter-debug-ShouldRunClientCommands" / "shot.png";
    Check(r.code == 0 && fs::exists(shot) && fs::file_size(shot) == 4 && Has(r.out, "(4 bytes)"), "screenshot writes the PNG where asked");

    r = Run({ "--json", "status" }, instances);
    bool json = false;
    try {
        json = Value::Parse(r.out).Find("frame") != nullptr;
    } catch (const ParseError&) {
    }
    Check(r.code == 0 && json, "--json prints JSON");
    r = Run({ "status", "--json" }, instances);
    Check(r.code == 0 && r.out.starts_with("{"), "--json after the command too");
    r = Run({ "call", "Player_SetAim", "--json", R"({"slot": 4, "yaw": 5})" }, instances);
    Check(r.code == 0 && Has(r.out, R"({"slot":4,"yaw":5.0})"), std::format("call takes its arguments as JSON ({})", r.out + r.err));
    r = Run({ "call", "Player_SetAim", "--json", R"({"slot": 4})", "yaw=7", "--json" }, instances);
    Check(r.code == 0 && Has(r.out, R"({"slot":4,"yaw":7.0})"), std::format("JSON arguments with key=value on top, and --json after them ({})", r.out + r.err));

    r = Run({ "stauts" }, instances);
    Check(r.code == 2 && Has(r.err, "did you mean 'status'"), "a mistyped command name gets a suggestion");
    r = Run({ "-i", "other", "status" }, instances);
    Check(r.code == 3 && Has(r.err, "no running instance named 'other'"), "-i with no match exits 3");
    r = Run({ "status" }, {});
    Check(r.code == 3 && Has(r.err, "ls --wait"), "no instance exits 3 and says how to start one");

    InstanceRecord newer = record;
    newer.protocol = protocolVersion + 1;
    r = Run({ "status" }, { { newer, {} } });
    Check(r.code == 4 && Has(r.err, "the app is newer"), "a newer app's protocol exits 4");
    InstanceRecord otherSources = record;
    otherSources.sourceId = "0000000000000000";
    r = Run({ "status" }, { { otherSources, {} } });
    Check(r.code == 0 && Has(r.err, "built from other Crafter.Debug sources"), "other sources only warn");

    r = Run({ "ls" }, instances);
    Check(r.code == 0 && Has(r.out, "game  id abc123"), "ls");
    r = Run({ "debugger" }, instances);
    Check(r.code == 0 && Has(r.out, "gdb -p 2"), "debugger prints the attach command");
    r = Run({ "guide" }, instances);
    Check(r.code == 0 && Has(r.out, "# crafter-debug"), "guide");

    pumping = false;
    app.join();
    r = Run({ "--timeout", "100ms", "get", "hp" }, instances);
    Check(r.code == 5 && Has(r.err, "has not called Debug::Pump()"), std::format("a timeout explains an app that stopped pumping ({})", r.err));

    std::error_code ignored;
    fs::remove_all(fs::temp_directory_path() / "crafter-debug-ShouldRunClientCommands", ignored);
    return failures == 0 ? 0 : 1;
}