// SPDX-License-Identifier: GPL-3.0-or-later
// Copyright (c) 2025 Trevon Sides

#include <nlohmann/json.hpp>
#include <catch2/catch_test_macros.hpp>
#include <catch2/matchers/catch_matchers_string.hpp>
#include <yams/daemon/resource/external_plugin_host.h>

#include <chrono>
#include <filesystem>
#include <fstream>

namespace yams::daemon {
namespace fs = std::filesystem;

struct ExternalPluginHostFixture {
    ExternalPluginHostFixture() {
        tempDir_ = fs::temp_directory_path() / ("yams_eph_" + std::to_string(time(nullptr)));
        fs::create_directories(tempDir_);
        trustFile_ = tempDir_ / "external_plugins_trust.txt";
    }

    ~ExternalPluginHostFixture() {
        std::error_code ec;
        fs::remove_all(tempDir_, ec);
    }

    fs::path makeFile(std::string_view name, std::string_view content = "") {
        auto p = tempDir_ / name;
        std::ofstream{p, std::ios::binary} << content;
        return p;
    }

    fs::path tempDir_;
    fs::path trustFile_;
};

TEST_CASE("ExternalPluginHost - Static File Detection", "[external-plugin][host]") {
    SECTION("Python files are detected") {
        auto temp = fs::temp_directory_path() / "test_plugin.py";
        std::ofstream{temp} << "# test";
        CHECK(ExternalPluginHost::isExternalPluginFile(temp));
        fs::remove(temp);
    }

    SECTION("JavaScript files are detected") {
        auto temp = fs::temp_directory_path() / "test_plugin.js";
        std::ofstream{temp} << "// test";
        CHECK(ExternalPluginHost::isExternalPluginFile(temp));
        fs::remove(temp);
    }

    SECTION("C++ files are not detected") {
        auto temp = fs::temp_directory_path() / "test.cpp";
        std::ofstream{temp} << "// test";
        CHECK_FALSE(ExternalPluginHost::isExternalPluginFile(temp));
        fs::remove(temp);
    }

    SECTION("Non-existent files return false") {
        CHECK_FALSE(ExternalPluginHost::isExternalPluginFile("/nonexistent/path.py"));
    }
}

TEST_CASE("ExternalPluginHost - Supported Extensions", "[external-plugin][host]") {
    auto exts = ExternalPluginHost::supportedExtensions();
    REQUIRE(exts.size() >= 2);

    bool hasPython = false;
    bool hasJs = false;
    for (const auto& ext : exts) {
        if (ext == ".py")
            hasPython = true;
        if (ext == ".js")
            hasJs = true;
    }

    CHECK(hasPython);
    CHECK(hasJs);
}

TEST_CASE("ExternalPluginHost - Construction and Destruction", "[external-plugin][host]") {
    ExternalPluginHostFixture fixture;

    SECTION("Default construction") {
        ExternalPluginHostConfig config;
        ExternalPluginHost host(nullptr, fixture.trustFile_, config);

        // Host should be constructible with nullptr ServiceManager
        auto loaded = host.listLoaded();
        CHECK(loaded.empty());
    }

    SECTION("Construction with custom config") {
        ExternalPluginHostConfig config;
        config.maxPlugins = 5;
        config.defaultRpcTimeout = std::chrono::milliseconds{5000};
        config.pythonExecutable = "python";

        ExternalPluginHost host(nullptr, fixture.trustFile_, config);
        CHECK(host.listLoaded().empty());
    }
}

TEST_CASE("ExternalPluginHost - Trust Management", "[external-plugin][host][trust]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    SECTION("Initially empty trust list") {
        auto trustList = host.trustList();
        CHECK(trustList.empty());
    }

    SECTION("Add and remove from trust list") {
        auto pluginPath = fixture.makeFile("trusted_plugin.py", "# trusted");

        // Add to trust
        auto addResult = host.trustAdd(pluginPath);
        REQUIRE(addResult.has_value());

        auto trustList = host.trustList();
        REQUIRE(trustList.size() == 1);

        // Verify canonical path is stored
        auto canonical = fs::weakly_canonical(pluginPath);
        bool found = std::find(trustList.begin(), trustList.end(), canonical) != trustList.end();
        CHECK(found);

        // Remove from trust
        auto removeResult = host.trustRemove(pluginPath);
        REQUIRE(removeResult.has_value());
        CHECK(host.trustList().empty());
    }

    SECTION("Trust list persists") {
        auto pluginPath = fixture.makeFile("persistent_plugin.py", "# persist");

        {
            ExternalPluginHost host1(nullptr, fixture.trustFile_, config);
            host1.trustAdd(pluginPath);
        }

        // Check file was written
        REQUIRE(fs::exists(fixture.trustFile_));

        {
            ExternalPluginHost host2(nullptr, fixture.trustFile_, config);
            auto trustList = host2.trustList();
            CHECK(trustList.size() == 1);
        }
    }

#if !defined(_WIN32)
    SECTION("Trust file permissions are private") {
        auto pluginPath = fixture.makeFile("private_perms_plugin.py", "# perms");
        auto addResult = host.trustAdd(pluginPath);
        REQUIRE(addResult.has_value());
        REQUIRE(fs::exists(fixture.trustFile_));

        std::error_code ec;
        auto perms = fs::status(fixture.trustFile_, ec).permissions();
        REQUIRE_FALSE(ec);
        CHECK((perms & (fs::perms::group_all | fs::perms::others_all)) == fs::perms::none);
    }
#endif

    SECTION("Trust remove persists") {
        auto plugin1 = fixture.makeFile("persist_remove_a.py", "# a");
        auto plugin2 = fixture.makeFile("persist_remove_b.py", "# b");

        {
            ExternalPluginHost host1(nullptr, fixture.trustFile_, config);
            REQUIRE(host1.trustAdd(plugin1).has_value());
            REQUIRE(host1.trustAdd(plugin2).has_value());
            REQUIRE(host1.trustRemove(plugin1).has_value());
        }

        {
            ExternalPluginHost host2(nullptr, fixture.trustFile_, config);
            auto trustList = host2.trustList();
            auto c1 = fs::weakly_canonical(plugin1);
            auto c2 = fs::weakly_canonical(plugin2);
            bool has1 = std::find(trustList.begin(), trustList.end(), c1) != trustList.end();
            bool has2 = std::find(trustList.begin(), trustList.end(), c2) != trustList.end();
            CHECK_FALSE(has1);
            CHECK(has2);
        }
    }

    SECTION("Adding already-trusted path is idempotent") {
        auto pluginPath = fixture.makeFile("idempotent_plugin.py", "# test");

        // Add first time
        auto addResult1 = host.trustAdd(pluginPath);
        REQUIRE(addResult1.has_value());
        CHECK(host.trustList().size() == 1);

        // Add second time - should succeed without error and not duplicate
        auto addResult2 = host.trustAdd(pluginPath);
        REQUIRE(addResult2.has_value());
        CHECK(host.trustList().size() == 1);
    }

    SECTION("Trust paths with varying depth levels") {
        // Create 10 paths with varying depths
        std::vector<fs::path> paths;

        // Depth 0 - root level file
        paths.push_back(fixture.makeFile("plugin_root.py", "# root"));

        // Depth 1
        fs::create_directories(fixture.tempDir_ / "level1");
        paths.push_back(fixture.tempDir_ / "level1" / "plugin_d1.py");
        std::ofstream{paths.back()} << "# depth 1";

        // Depth 2
        fs::create_directories(fixture.tempDir_ / "level1" / "level2");
        paths.push_back(fixture.tempDir_ / "level1" / "level2" / "plugin_d2.py");
        std::ofstream{paths.back()} << "# depth 2";

        // Depth 3
        fs::create_directories(fixture.tempDir_ / "a" / "b" / "c");
        paths.push_back(fixture.tempDir_ / "a" / "b" / "c" / "plugin_d3.py");
        std::ofstream{paths.back()} << "# depth 3";

        // Depth 4
        fs::create_directories(fixture.tempDir_ / "deep" / "nested" / "path" / "here");
        paths.push_back(fixture.tempDir_ / "deep" / "nested" / "path" / "here" / "plugin_d4.py");
        std::ofstream{paths.back()} << "# depth 4";

        // Depth 5
        fs::create_directories(fixture.tempDir_ / "x" / "y" / "z" / "w" / "v");
        paths.push_back(fixture.tempDir_ / "x" / "y" / "z" / "w" / "v" / "plugin_d5.py");
        std::ofstream{paths.back()} << "# depth 5";

        // More depth 1 variations
        fs::create_directories(fixture.tempDir_ / "plugins");
        paths.push_back(fixture.tempDir_ / "plugins" / "my_plugin.py");
        std::ofstream{paths.back()} << "# plugins dir";

        // Path with special characters (spaces, dashes)
        fs::create_directories(fixture.tempDir_ / "my-plugins" / "sub dir");
        paths.push_back(fixture.tempDir_ / "my-plugins" / "sub dir" / "special_plugin.py");
        std::ofstream{paths.back()} << "# special chars";

        // Directory trust (not file)
        fs::create_directories(fixture.tempDir_ / "trusted_dir");
        paths.push_back(fixture.tempDir_ / "trusted_dir");

        // Another deep path
        fs::create_directories(fixture.tempDir_ / "org" / "company" / "project" / "plugins");
        paths.push_back(fixture.tempDir_ / "org" / "company" / "project" / "plugins" / "plugin.py");
        std::ofstream{paths.back()} << "# org path";

        REQUIRE(paths.size() == 10);

        // Add all paths to trust
        for (size_t i = 0; i < paths.size(); ++i) {
            INFO("Adding trust for path " << i << ": " << paths[i].string());
            auto result = host.trustAdd(paths[i]);
            REQUIRE(result.has_value());
        }

        // Verify all paths are trusted
        auto trustList = host.trustList();
        CHECK(trustList.size() == 10);

        // Re-add all paths (idempotency check)
        for (size_t i = 0; i < paths.size(); ++i) {
            INFO("Re-adding trust for path " << i << ": " << paths[i].string());
            auto result = host.trustAdd(paths[i]);
            REQUIRE(result.has_value());
        }

        // Count should still be 10 (no duplicates)
        trustList = host.trustList();
        CHECK(trustList.size() == 10);

        // Verify each canonical path is in the list
        for (const auto& path : paths) {
            auto canonical = fs::weakly_canonical(path);
            bool found =
                std::find(trustList.begin(), trustList.end(), canonical) != trustList.end();
            INFO("Checking path: " << canonical.string());
            CHECK(found);
        }

        // Remove paths one by one and verify count decreases
        for (size_t i = 0; i < paths.size(); ++i) {
            auto result = host.trustRemove(paths[i]);
            REQUIRE(result.has_value());
            CHECK(host.trustList().size() == (10 - i - 1));
        }

        CHECK(host.trustList().empty());
    }
}

TEST_CASE("ExternalPluginHost - Scan Invalid Files", "[external-plugin][host][scan]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    SECTION("Scan non-existent file returns error") {
        auto result = host.scanTarget("/nonexistent/plugin.py");
        REQUIRE_FALSE(result.has_value());
        CHECK(result.error().code == ErrorCode::InvalidArgument);
    }

    SECTION("Scan non-plugin file returns error") {
        auto textFile = fixture.makeFile("readme.txt", "Not a plugin");
        auto result = host.scanTarget(textFile);
        REQUIRE_FALSE(result.has_value());
        CHECK(result.error().code == ErrorCode::InvalidArgument);
    }
}

TEST_CASE("ExternalPluginHost - Load Non-Existent Plugin", "[external-plugin][host][load]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto result = host.load("/nonexistent/plugin.py", "{}");
    REQUIRE_FALSE(result.has_value());
    CHECK(result.error().code == ErrorCode::FileNotFound);
}

TEST_CASE("ExternalPluginHost - Unload Non-Existent Plugin", "[external-plugin][host][unload]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto result = host.unload("nonexistent-plugin");
    REQUIRE_FALSE(result.has_value());
    CHECK(result.error().code == ErrorCode::NotFound);
}

TEST_CASE("ExternalPluginHost - Health Check Non-Existent Plugin",
          "[external-plugin][host][health]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto result = host.health("nonexistent-plugin");
    REQUIRE_FALSE(result.has_value());
    CHECK(result.error().code == ErrorCode::NotFound);
}

TEST_CASE("ExternalPluginHost - RPC Call Non-Existent Plugin", "[external-plugin][host][rpc]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    nlohmann::json emptyParams = nlohmann::json::object();
    auto result = host.callRpc("nonexistent-plugin", "test.method", emptyParams);
    REQUIRE_FALSE(result.has_value());
    CHECK(result.error().code == ErrorCode::NotFound);
}

TEST_CASE("ExternalPluginHost - Scan Empty Directory", "[external-plugin][host][scan]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto emptyDir = fixture.tempDir_ / "empty";
    fs::create_directories(emptyDir);

    auto result = host.scanDirectory(emptyDir);
    REQUIRE(result.has_value());
    CHECK(result.value().empty());
}

TEST_CASE("ExternalPluginHost - Scan Non-Existent Directory", "[external-plugin][host][scan]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto result = host.scanDirectory("/nonexistent/directory");
    REQUIRE_FALSE(result.has_value());
    CHECK(result.error().code == ErrorCode::InvalidPath);
}

TEST_CASE("ExternalPluginHost - Get Stats Empty", "[external-plugin][host][stats]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    auto stats = host.getStats();
    REQUIRE(stats.contains("total_loaded"));
    CHECK(stats["total_loaded"].get<size_t>() == 0);
    REQUIRE(stats.contains("plugins"));
    CHECK(stats["plugins"].is_array());
    CHECK(stats["plugins"].empty());
}

TEST_CASE("ExternalPluginHost - State Callback", "[external-plugin][host][callback]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    std::vector<std::pair<std::string, std::string>> events;
    host.setStateCallback([&events](const std::string& name, const std::string& event) {
        events.emplace_back(name, event);
    });

    // Callback shouldn't be called for operations that fail
    host.unload("nonexistent");
    CHECK(events.empty());
}

TEST_CASE("ExternalPluginHost - Plugin Manifest Interfaces Parsing",
          "[external-plugin][host][manifest][interfaces]") {
    ExternalPluginHostFixture fixture;
    ExternalPluginHostConfig config;
    ExternalPluginHost host(nullptr, fixture.trustFile_, config);

    SECTION("String interfaces array is parsed correctly") {
        // Create plugin directory with manifest containing string interfaces
        auto pluginDir = fixture.tempDir_ / "test_plugin";
        fs::create_directories(pluginDir);

        // Write yams-plugin.json with string interfaces
        nlohmann::json manifest;
        manifest["name"] = "test_interfaces_plugin";
        manifest["version"] = "1.0.0";
        manifest["interfaces"] =
            nlohmann::json::array({"content_extractor_v1", "kg_entity_provider_v1"});
        manifest["entry"] = {{"fallback_cmd", nlohmann::json::array({"python", "plugin.py"})}};

        std::ofstream manifestFile(pluginDir / "yams-plugin.json");
        manifestFile << manifest.dump(2);
        manifestFile.close();

        // Create a dummy plugin.py
        std::ofstream pluginFile(pluginDir / "plugin.py");
        pluginFile << "# Dummy plugin";
        pluginFile.close();

        // Scan the plugin directory
        auto result = host.scanTarget(pluginDir);
        REQUIRE(result.has_value());

        const auto& desc = result.value();
        CHECK(desc.name == "test_interfaces_plugin");
        CHECK(desc.version == "1.0.0");

        // Verify interfaces were parsed
        REQUIRE(desc.interfaces.size() == 2);
        CHECK(desc.interfaces[0] == "content_extractor_v1");
        CHECK(desc.interfaces[1] == "kg_entity_provider_v1");
    }

    SECTION("Empty interfaces array results in empty interfaces") {
        auto pluginDir = fixture.tempDir_ / "empty_interfaces_plugin";
        fs::create_directories(pluginDir);

        nlohmann::json manifest;
        manifest["name"] = "empty_interfaces_plugin";
        manifest["version"] = "1.0.0";
        manifest["interfaces"] = nlohmann::json::array();
        manifest["entry"] = {{"fallback_cmd", nlohmann::json::array({"python", "plugin.py"})}};

        std::ofstream manifestFile(pluginDir / "yams-plugin.json");
        manifestFile << manifest.dump(2);
        manifestFile.close();

        std::ofstream pluginFile(pluginDir / "plugin.py");
        pluginFile << "# Dummy plugin";
        pluginFile.close();

        auto result = host.scanTarget(pluginDir);
        REQUIRE(result.has_value());
        CHECK(result.value().interfaces.empty());
    }

    SECTION("Interfaces inferred from capabilities when interfaces not present") {
        auto pluginDir = fixture.tempDir_ / "capabilities_plugin";
        fs::create_directories(pluginDir);

        nlohmann::json manifest;
        manifest["name"] = "capabilities_plugin";
        manifest["version"] = "1.0.0";
        manifest["capabilities"] = {
            {"content_extraction", {{"formats", nlohmann::json::array({"text/plain"})}}},
            {"symbol_extraction", {{"languages", nlohmann::json::array({"python"})}}}};
        manifest["entry"] = {{"fallback_cmd", nlohmann::json::array({"python", "plugin.py"})}};

        std::ofstream manifestFile(pluginDir / "yams-plugin.json");
        manifestFile << manifest.dump(2);
        manifestFile.close();

        std::ofstream pluginFile(pluginDir / "plugin.py");
        pluginFile << "# Dummy plugin";
        pluginFile.close();

        auto result = host.scanTarget(pluginDir);
        REQUIRE(result.has_value());

        const auto& desc = result.value();
        // Should have inferred interfaces from capabilities
        REQUIRE(desc.interfaces.size() == 2);
        CHECK(std::find(desc.interfaces.begin(), desc.interfaces.end(), "content_extractor_v1") !=
              desc.interfaces.end());
        CHECK(std::find(desc.interfaces.begin(), desc.interfaces.end(), "symbol_extractor_v1") !=
              desc.interfaces.end());
    }
}

} // namespace yams::daemon