#include "webserver_service.hpp"
#include "api/auth_controller.hpp"
#include "api/user_controller.hpp"
#include "api/workflow_controller.hpp"
#include "api/workflow_group_controller.hpp"
#include "api/execution_controller.hpp"
#include "api/node_controller.hpp"
#include "api/runner_controller.hpp"
#include "api/webhook_controller.hpp"
#include "api/database_controller.hpp"
#include "api/file_controller.hpp"
#include "api/proxy_controller.hpp"
#include "api/credential_controller.hpp"
#include "nodes/node_store.hpp"
#include "grpc/node_sync_service.hpp"
#include "grpc/credential_service.hpp"
#include "credentials/credential_store.hpp"
#include "scheduler/workflow_scheduler.hpp"
#include "common/time_utils.hpp"
#include "common/config_defaults.hpp"
#include "logging/logger.hpp"
#include <grpcpp/grpcpp.h>
#include "proto/runner.grpc.pb.h"

namespace smartbotic::webserver {

WebServerService::WebServerService(const WebServerServiceConfig& config)
    : config_(config) {

    // Initialize storage client
    storage::StorageClientConfig storage_config;
    storage_config.address = config_.database_address;
    storage_config.project = config_.database_project;
    storage_ = std::make_unique<storage::StorageClient>(storage_config);

    // Initialize JWT
    jwt_ = std::make_unique<auth::JwtUtils>(config_.jwt_config);

    // Initialize auth store
    auth_store_ = std::make_unique<auth::AuthStore>(*storage_, *jwt_);

    // Initialize auth middleware
    auth_middleware_ = std::make_unique<auth::AuthMiddleware>(*jwt_, *auth_store_);

    // Initialize runner registry
    runner_registry_ = std::make_unique<runners::RunnerRegistry>(*storage_, config_.runner_config);

    // Initialize load balancer
    load_balancer_ = std::make_unique<runners::LoadBalancer>(*runner_registry_,
                                                              config_.load_balancer_config);

    // Initialize node store
    node_store_ = std::make_unique<nodes::NodeStore>(*storage_);

    // Migrate/sync nodes from disk - updates existing nodes if code has changed
    auto migrate_result = node_store_->migrateFromFiles("./nodes");
    if (migrate_result.ok()) {
        LOG_INFO("Node migration: {} new nodes imported", migrate_result.value().size());
    } else {
        LOG_WARN("Node migration failed: {}", migrate_result.error().message());
    }

    // Initialize credential store
    credentials::CredentialStoreConfig cred_config;
    cred_config.master_key = config_.credentials_config.master_key;
    cred_config.pbkdf2_iterations = config_.credentials_config.pbkdf2_iterations;
    credential_store_ = std::make_unique<credentials::CredentialStore>(*storage_, cred_config);
    credential_store_->initialize();

    // Initialize workflow scheduler
    scheduler_ = std::make_unique<WorkflowScheduler>();
    scheduler_->setExecuteCallback([this](const std::string& workflow_id,
                                          const std::string& trigger_node_id,
                                          const std::string& trigger_type) {
        executeScheduledWorkflow(workflow_id, trigger_node_id, trigger_type);
    });

    // Initialize HTTP server
    HttpServerConfig http_config;
    http_config.port = config_.http_port;
    http_config.static_files_path = config_.static_files_path;
    http_server_ = std::make_unique<HttpServer>(http_config);

    // Initialize WebSocket server on separate port
    WebSocketServerConfig ws_config;
    ws_config.port = config_.http_port + 1;  // WebSocket on next port (8091)
    ws_server_ = std::make_unique<WebSocketServer>(ws_config, *jwt_);

    // Initialize NodeSync gRPC server for runners
    node_sync_server_ = std::make_unique<grpc::NodeSyncServer>(*node_store_, config_.node_sync_port);

    // Initialize Credential gRPC server for runners
    credential_server_ = std::make_unique<grpc::CredentialServer>(*credential_store_, config_.credential_service_port);
}

WebServerService::~WebServerService() {
    stop();
}

WebServerServiceConfig WebServerService::loadConfig(const std::filesystem::path& path) {
    WebServerServiceConfig config;

    auto result = config::Config::fromFile(path);
    if (result.ok()) {
        auto& cfg = result.value();

        config.http_port = cfg.getOr<int>("http_port", 8080);
        config.node_sync_port = cfg.getOr<int>("node_sync_port", 9002);
        config.credential_service_port = cfg.getOr<int>("credential_service_port", 9003);
        config.static_files_path = cfg.getOr<std::string>("static_files_path", "./webui/dist");
        config.database_address = cfg.getOr<std::string>("database_address", "localhost:9004");
        config.database_project = cfg.getOr<std::string>("database_project", "smartbotic-automation");

        // Runner config
        config.runner_config.heartbeat_timeout_sec =
            cfg.getOr<int>("runners.heartbeat_timeout_sec", 30);
        config.runner_config.offline_removal_sec =
            cfg.getOr<int>("runners.offline_removal_sec", 60);

        // Load balancer config
        auto strategy_str = cfg.getOr<std::string>("runners.load_balancing", "least-connections");
        config.load_balancer_config.strategy =
            runners::loadBalancingStrategyFromString(strategy_str);

        // JWT config
        config.jwt_config.secret = cfg.getOr<std::string>("auth.jwt_secret",
                                                           "dev-secret-change-in-production");
        config.jwt_config.access_token_lifetime_sec =
            cfg.getOr<int>("auth.access_token_lifetime_sec", 900);

        // Credentials config
        config.credentials_config.master_key = cfg.getOr<std::string>("credentials.master_key",
                                                           "dev-key-change-in-production");
        config.credentials_config.pbkdf2_iterations =
            cfg.getOr<int>("credentials.pbkdf2_iterations", 100000);
    }

    return config;
}

void WebServerService::start() {
    LOG_INFO("Starting WebServer service...");

    // Ensure admin user exists
    auth_store_->ensureAdminUser();

    // Setup API routes
    setupRoutes();

    // Start runner registry cleanup
    runner_registry_->start();

    // Start workflow scheduler
    scheduler_->start();

    // Ensure the executions summary view exists before serving requests
    ensureExecutionsSummaryView();

    // Load active workflows from database and register with scheduler
    loadScheduledWorkflows();

    // Start NodeSync gRPC server for runners
    node_sync_server_->start();

    // Start Credential gRPC server for runners
    credential_server_->start();

    // Start WebSocket server
    ws_server_->start();

    // Start HTTP server (blocking in background thread)
    http_server_->start();

    LOG_INFO("WebServer service started on port {}", config_.http_port);
}

void WebServerService::stop() {
    LOG_INFO("Stopping WebServer service...");

    http_server_->stop();
    ws_server_->stop();
    credential_server_->stop();
    node_sync_server_->stop();
    scheduler_->stop();
    runner_registry_->stop();

    LOG_INFO("WebServer service stopped");
}

void WebServerService::setupRoutes() {
    auto& server = http_server_->server();

    // Health check
    server.Get("/health", [](const httplib::Request& req, httplib::Response& res) {
        res.set_content(R"({"status":"ok"})", "application/json");
    });

    // API version
    server.Get("/api/v1", [](const httplib::Request& req, httplib::Response& res) {
        res.set_content(R"({"name":"SmartBotic API","version":"1.0.0"})", "application/json");
    });

    // Register controllers - stored as members to ensure they outlive httplib callbacks
    auth_ctrl_ = std::make_unique<api::AuthController>(*auth_store_, *auth_middleware_);
    auth_ctrl_->registerRoutes(server);

    user_ctrl_ = std::make_unique<api::UserController>(*auth_store_, *auth_middleware_);
    user_ctrl_->registerRoutes(server);

    workflow_ctrl_ = std::make_unique<api::WorkflowController>(
        *storage_, *auth_middleware_, *runner_registry_, *load_balancer_, *ws_server_,
        *scheduler_, *node_store_);
    workflow_ctrl_->registerRoutes(server);

    workflow_group_ctrl_ = std::make_unique<api::WorkflowGroupController>(
        *storage_, *auth_middleware_, *ws_server_);
    workflow_group_ctrl_->registerRoutes(server);

    execution_ctrl_ = std::make_unique<api::ExecutionController>(
        *storage_, *auth_middleware_, *ws_server_, *scheduler_, *load_balancer_,
        [this](const std::string& workflow_id, const std::string& execution_id,
               const std::string& error) {
            runErrorWorkflow(workflow_id, execution_id, error);
        });
    file_ctrl_ = std::make_unique<api::FileController>(*storage_, *auth_middleware_);
    execution_ctrl_->registerRoutes(server);
    file_ctrl_->registerRoutes(server);

    proxy_ctrl_ = std::make_unique<api::ProxyController>(*auth_middleware_);
    proxy_ctrl_->registerRoutes(server);

    node_ctrl_ = std::make_unique<api::NodeController>(
        *node_store_, *auth_middleware_, &node_sync_server_->service());
    node_ctrl_->registerRoutes(server);

    runner_ctrl_ = std::make_unique<api::RunnerController>(*runner_registry_, *auth_middleware_);
    runner_ctrl_->registerRoutes(server);

    webhook_ctrl_ = std::make_unique<api::WebhookController>(
        *storage_, *runner_registry_, *load_balancer_, *ws_server_, *node_store_);
    webhook_ctrl_->registerRoutes(server);

    database_ctrl_ = std::make_unique<api::DatabaseController>(*storage_, *auth_middleware_);
    database_ctrl_->registerRoutes(server);

    credential_ctrl_ = std::make_unique<api::CredentialController>(*credential_store_, *auth_middleware_);
    credential_ctrl_->registerRoutes(server);

    LOG_INFO("API routes registered");
}

void WebServerService::ensureExecutionsSummaryView() {
    // View names are namespaced per project from smartbotic-database 2.4.2, so a
    // view created by this client is also queryable by it. Earlier versions
    // registered the name unqualified while queries were project-prefixed, which
    // made the view unreachable.
    // Recreate rather than reuse. A view is metadata over a collection, so
    // rebuilding it costs nothing, and keeping an existing one means the view
    // silently outlives the field list below: after a database recovery the old
    // view served documents that were no longer in the collection at all.
    for (const auto& view : storage_->listViews()) {
        if (view.name == kExecutionsSummaryView) {
            LOG_INFO("Rebuilding the executions summary view");
            storage_->dropView(kExecutionsSummaryView);
            break;
        }
    }

    // stopReason belongs here for the same reason error does: it is the message
    // explaining how a run ended, and the listing is where someone looks for it.
    // A stopped run has status "completed" and an empty error, so without this
    // field the list cannot tell a run that finished its work from one that
    // deliberately ended early.
    auto result = storage_->createView(kExecutionsSummaryView, "executions",
                                       {"workflowId", "workflowName", "status", "triggerType",
                                        "startedAt", "finishedAt", "error", "runnerId",
                                        "stopped", "stopReason", "stoppedNodeId"});
    if (result.failed()) {
        LOG_ERROR("Could not create the executions summary view: {}. The executions "
                  "listing will fail until this is resolved.", result.error().message());
        return;
    }

    LOG_INFO("Created server-side view '{}' over executions", kExecutionsSummaryView);
}

void WebServerService::loadScheduledWorkflows() {
    LOG_INFO("Loading scheduled workflows from database...");

    // Query all active workflows
    storage::QueryOptions options;
    options.filters.push_back({"active", true});
    options.page_size = 1000;  // Load up to 1000 workflows

    auto result = storage_->query("workflows", options);
    if (result.failed()) {
        LOG_ERROR("Failed to load workflows: {}", result.error().message());
        return;
    }

    int registered_count = 0;
    for (const auto& workflow : result.value().documents) {
        std::string workflow_id = workflow.value("_id", "");
        std::string workflow_name = workflow.value("name", "");
        auto nodes = workflow.value("nodes", nlohmann::json::array());

        // Find scheduled trigger nodes
        for (const auto& node : nodes) {
            std::string node_id = node.value("id", "");
            std::string node_type = node.value("type", "");

            // Get node definition to check if it's a scheduled trigger
            auto node_result = node_store_->get(node_type);
            if (node_result.failed()) {
                continue;
            }

            const auto& node_def = node_result.value();
            if (!node_def.is_trigger || !node_def.is_scheduled) {
                continue;
            }

            // Get interval from node config, filling in any schema defaults
            // the stored config is missing (e.g. an untouched form field).
            auto config = smartbotic::common::applyConfigDefaults(
                node.value("config", nlohmann::json::object()), node_def.config_schema);
            int interval = config.value("pollInterval", 0);

            if (interval > 0) {
                auto policy = overlapPolicyFromString(
                    config.value("overlapPolicy", std::string("skip")));

                scheduler_->registerWorkflow(
                    workflow_id,
                    workflow_name,
                    node_id,
                    node_type,
                    interval,
                    policy,
                    config.value("maxConcurrent", 1),
                    config.value("maxRunMinutes", 0)
                );
                registered_count++;
                LOG_DEBUG("Registered workflow '{}' ({}) for scheduled execution every {} minutes",
                         workflow_name, workflow_id, interval);
            }
        }
    }

    LOG_INFO("Loaded {} scheduled workflows", registered_count);
}

void WebServerService::runErrorWorkflow(const std::string& failed_workflow_id,
                                        const std::string& failed_execution_id,
                                        const std::string& error_message) {
    {
        std::lock_guard<std::mutex> lock(handled_failures_mutex_);
        if (!handled_failures_.insert(failed_execution_id).second) {
            return;  // already handled this failure
        }
        if (handled_failures_.size() > 512) {
            handled_failures_.erase(handled_failures_.begin());
        }
    }

    auto failed = storage_->get("workflows", failed_workflow_id);
    if (failed.failed()) {
        return;
    }

    const auto settings = failed.value().value("settings", nlohmann::json::object());
    const std::string handler_id = settings.value("errorWorkflowId", std::string());
    if (handler_id.empty()) {
        return;
    }

    // A handler that fails must not summon itself, which would run forever.
    if (handler_id == failed_workflow_id) {
        LOG_WARN("Workflow {} names itself as its error workflow; not running it",
                 failed_workflow_id);
        return;
    }

    auto handler = storage_->get("workflows", handler_id);
    if (handler.failed()) {
        LOG_WARN("Workflow {} names error workflow {}, which no longer exists",
                 failed_workflow_id, handler_id);
        return;
    }

    auto runner = load_balancer_->selectRunner();
    if (!runner) {
        LOG_ERROR("No runners available to run error workflow {}", handler_id);
        return;
    }

    // The handler is told what failed rather than having to look it up, so it can
    // notify or record without needing read access to the executions collection.
    nlohmann::json trigger_data;
    trigger_data["errorWorkflow"] = true;
    trigger_data["failedWorkflowId"] = failed_workflow_id;
    trigger_data["failedWorkflowName"] = failed.value().value("name", std::string());
    trigger_data["failedExecutionId"] = failed_execution_id;
    trigger_data["error"] = error_message;
    trigger_data["failedAt"] = common::TimeUtils::nowMs();

    auto channel = ::grpc::CreateChannel(runner->address, ::grpc::InsecureChannelCredentials());
    auto stub = proto::RunnerService::NewStub(channel);

    proto::ExecuteWorkflowRequest request;
    request.set_workflow_id(handler_id);
    request.set_trigger_type("error-workflow");
    request.set_trigger_data(trigger_data.dump());
    request.set_wait_for_completion(false);

    proto::ExecuteWorkflowResponse response;
    ::grpc::ClientContext context;
    context.set_deadline(std::chrono::system_clock::now() + std::chrono::seconds(30));

    auto status = stub->ExecuteWorkflow(&context, request, &response);
    if (!status.ok()) {
        LOG_ERROR("Error workflow {} could not be started: {}", handler_id, status.error_message());
        return;
    }

    LOG_INFO("Error workflow {} started as {} after {} failed",
             handler_id, response.execution_id(), failed_workflow_id);

    scheduler_->notifyExecutionStarted(handler_id, response.execution_id());
}

void WebServerService::executeScheduledWorkflow(const std::string& workflow_id,
                                                 const std::string& trigger_node_id,
                                                 const std::string& trigger_type) {
    // Select a runner
    auto runner = load_balancer_->selectRunner();
    if (!runner) {
        LOG_ERROR("No runners available for scheduled workflow {}", workflow_id);
        return;
    }

    // Create gRPC channel and stub
    auto channel = ::grpc::CreateChannel(runner->address, ::grpc::InsecureChannelCredentials());
    auto stub = proto::RunnerService::NewStub(channel);

    // Prepare request
    proto::ExecuteWorkflowRequest request;
    request.set_workflow_id(workflow_id);
    request.set_trigger_type(trigger_type);

    nlohmann::json trigger_data;
    trigger_data["triggerNodeId"] = trigger_node_id;
    trigger_data["scheduledExecution"] = true;
    request.set_trigger_data(trigger_data.dump());
    request.set_wait_for_completion(false);

    // Execute
    proto::ExecuteWorkflowResponse response;
    ::grpc::ClientContext context;
    context.set_deadline(std::chrono::system_clock::now() + std::chrono::seconds(30));

    auto status = stub->ExecuteWorkflow(&context, request, &response);

    if (!status.ok()) {
        LOG_ERROR("Failed to execute scheduled workflow {}: {}", workflow_id, status.error_message());
        return;
    }

    LOG_INFO("Scheduled workflow {} execution started: {} on runner {}",
             workflow_id, response.execution_id(), runner->id);

    // Dispatch is fire-and-forget, so the scheduler only learns about the run here.
    scheduler_->notifyExecutionStarted(workflow_id, response.execution_id());

    // Broadcast execution started
    ws_server_->broadcast("executions." + response.execution_id() + ".started", {
        {"executionId", response.execution_id()},
        {"workflowId", workflow_id},
        {"runnerId", runner->id},
        {"triggeredBy", trigger_type},
        {"scheduled", true}
    });
}

} // namespace smartbotic::webserver