<?php
/**
 * CODING CONVENTION:
 * This file follows the coding convention where variable_names and function_names
 * use snake_case (underscore_wherever_possible).
 *
 * @ROUTE-EXISTS-01-EXCEPTION - This file contains documentation examples with fictional route names
 */

namespace App\RSpade\Core;

use RuntimeException;
use App\RSpade\Core\Debug\Rsx_Caller_Exception;
use App\RSpade\Core\Events\Event_Registry;
use App\RSpade\Core\Manifest\Manifest;

/**
 * Core RSX framework utility class
 *
 * Provides static utility methods for the RSX framework including
 * flash messages and other core functionality.
 */
class Rsx
{
    /**
     * Current controller being executed
     * @var string|null
     */
    protected static $current_controller = null;

    /**
     * Current action being executed
     * @var string|null
     */
    protected static $current_action = null;

    /**
     * Current request params
     * @var array|null
     */
    protected static $current_params = null;

    /**
     * Current route type ('spa' or 'standard')
     * @var string|null
     */
    protected static $current_route_type = null;

    /**
     * Set the current controller and action being executed
     *
     * @param string $controller_class The controller class name
     * @param string $action_method The action method name
     * @param array $params Optional request params to store
     * @param string|null $route_type Route type ('spa' or 'standard')
     */
    public static function _set_current_controller_action($controller_class, $action_method, array $params = [], $route_type = null)
    {
        // Extract just the class name without namespace
        $parts = explode('\\', $controller_class);
        $class_name = end($parts);

        static::$current_controller = $class_name;
        static::$current_action = $action_method;
        static::$current_params = $params;
        static::$current_route_type = $route_type;
    }

    /**
     * Get the current controller class name
     *
     * @return string|null The current controller class or null if not set
     */
    public static function get_current_controller()
    {
        return static::$current_controller;
    }

    /**
     * Get the current action method name
     *
     * @return string|null The current action method or null if not set
     */
    public static function get_current_action()
    {
        return static::$current_action;
    }

    /**
     * Get the current request params
     *
     * @return array|null The current request params or null if not set
     */
    public static function get_current_params()
    {
        return static::$current_params;
    }

    /**
     * Check if current route is a SPA route
     *
     * @return bool True if current route type is 'spa', false otherwise
     */
    public static function is_spa()
    {
        return static::$current_route_type === 'spa';
    }

    /**
     * Clear the current controller and action tracking
     */
    public static function _clear_current_controller_action()
    {
        static::$current_controller = null;
        static::$current_action = null;
        static::$current_params = null;
        static::$current_route_type = null;
    }

    // Flash alert methods have been removed - use Flash class instead:
    // Flash_Alert::success($message)
    // Flash_Alert::error($message)
    // Flash_Alert::info($message)
    // Flash_Alert::warning($message)
    //
    // See: /system/app/RSpade/Core/Flash/Flash.php
    // See: /system/app/RSpade/Core/Flash/CLAUDE.md

    /**
     * Generate URL for a controller route
     *
     * This method generates URLs for controller actions by looking up route patterns
     * and replacing parameters. It handles both regular routes and Ajax endpoints.
     *
     * Placeholder Routes:
     * When the action starts with '#' (e.g., '#index', '#show'), it indicates a placeholder/unimplemented
     * route for scaffolding purposes. These skip validation and return "#" to allow incremental
     * development without requiring all controllers to exist.
     *
     * Usage examples:
     * ```php
     * // Controller route (defaults to 'index' method)
     * $url = Rsx::Route('Frontend_Index_Controller');
     * // Returns: /dashboard
     *
     * // Controller route with explicit method
     * $url = Rsx::Route('Frontend_Client_View_Controller::view', 123);
     * // Returns: /clients/view/123
     *
     * // SPA action route
     * $url = Rsx::Route('Contacts_Index_Action');
     * // Returns: /contacts
     *
     * // Route with integer parameter (sets 'id')
     * $url = Rsx::Route('Contacts_View_Action', 123);
     * // Returns: /contacts/123
     *
     * // Route with named parameters (array)
     * $url = Rsx::Route('Contacts_View_Action', ['id' => 'C001']);
     * // Returns: /contacts/C001
     *
     * // Route with required and query parameters
     * $url = Rsx::Route('Contacts_View_Action', [
     *     'id' => 'C001',
     *     'tab' => 'history'
     * ]);
     * // Returns: /contacts/C001?tab=history
     *
     * // Placeholder route for scaffolding (doesn't need to exist)
     * $url = Rsx::Route('Future_Feature_Controller::#index');
     * // Returns: #
     * ```
     *
     * @param string $action Controller class, SPA action, or "Class::method". Defaults to 'index' method if not specified.
     * @param int|array|\stdClass|null $params Route parameters. Integer sets 'id', array/object provides named params.
     * @return string The generated URL
     * @throws RuntimeException If class doesn't exist, isn't a controller/action, method doesn't exist, or lacks Route attribute
     */
    public static function Route($action, $params = null)
    {
        // Parse action into class_name and action_name
        // Format: "Controller_Name" or "Controller_Name::method_name" or "Spa_Action_Name"
        if (str_contains($action, '::')) {
            [$class_name, $action_name] = explode('::', $action, 2);
        } else {
            $class_name = $action;
            $action_name = 'index';
        }

        // Normalize params to array
        $params_array = [];
        if (is_int($params)) {
            $params_array = ['id' => $params];
        } elseif (is_array($params)) {
            $params_array = $params;
        } elseif ($params instanceof \stdClass) {
            $params_array = (array) $params;
        } elseif ($params !== null) {
            throw new RuntimeException("Params must be integer, array, stdClass, or null");
        }

        // Placeholder route: action starts with # means unimplemented/scaffolding
        // Skip all validation and return placeholder
        if (str_starts_with($action_name, '#')) {
            return '#';
        }

        // Try to find the class in the manifest
        try {
            $metadata = Manifest::php_get_metadata_by_class($class_name);
        } catch (RuntimeException $e) {
            // Not found as PHP class - might be a SPA action, try that instead
            return static::_try_spa_action_route($class_name, $params_array);
        }

        // Verify it extends Rsx_Controller_Abstract
        $extends = $metadata['extends'] ?? '';
        $is_controller = false;

        if ($extends === 'Rsx_Controller_Abstract') {
            $is_controller = true;
        } else {
            // Check if it extends a class that extends Rsx_Controller_Abstract
            $current_class = $extends;
            $max_depth = 10;

            while ($current_class && $max_depth-- > 0) {
                try {
                    $parent_metadata = Manifest::php_get_metadata_by_class($current_class);
                    if (($parent_metadata['extends'] ?? '') === 'Rsx_Controller_Abstract') {
                        $is_controller = true;
                        break;
                    }
                    $current_class = $parent_metadata['extends'] ?? '';
                } catch (RuntimeException $e) {
                    // Check if parent is the abstract controller with FQCN
                    if ($current_class === 'Rsx_Controller_Abstract' ||
                        $current_class === 'App\\RSpade\\Core\\Controller\\Rsx_Controller_Abstract') {
                        $is_controller = true;
                    }
                    break;
                }
            }
        }

        if (!$is_controller) {
            throw new Rsx_Caller_Exception("Class {$class_name} must extend Rsx_Controller_Abstract");
        }

        // Check if method exists and has Route attribute
        if (!isset($metadata['public_static_methods'][$action_name])) {
            throw new Rsx_Caller_Exception("Method {$action_name} not found in class {$class_name}");
        }

        $method_info = $metadata['public_static_methods'][$action_name];

        // All methods in public_static_methods are guaranteed to be static
        // No need to check - but we assert for safety
        if (!isset($method_info['static']) || !$method_info['static']) {
            shouldnt_happen("Method {$class_name}::{$action_name} in public_static_methods is not static - extraction bug");
        }

        // Check for Route or Ajax_Endpoint attribute
        $has_route = false;
        $has_ajax_endpoint = false;
        $route_pattern = null;

        if (isset($method_info['attributes'])) {
            foreach ($method_info['attributes'] as $attr_name => $attr_instances) {
                if ($attr_name === 'Route' || str_ends_with($attr_name, '\\Route')) {
                    $has_route = true;
                    // Get the route pattern from the first instance
                    if (!empty($attr_instances)) {
                        $route_args = $attr_instances[0];
                        $route_pattern = $route_args[0] ?? ($route_args['pattern'] ?? null);
                    }
                    break;
                }
                if ($attr_name === 'Ajax_Endpoint' || str_ends_with($attr_name, '\\Ajax_Endpoint')) {
                    $has_ajax_endpoint = true;
                    break;
                }
            }
        }

        // If has Ajax_Endpoint, return AJAX route URL (no param substitution)
        if ($has_ajax_endpoint) {
            $ajax_url = '/_ajax/' . urlencode($class_name) . '/' . urlencode($action_name);
            // Add query params if provided
            if (!empty($params_array)) {
                $ajax_url .= '?' . http_build_query($params_array);
            }
            return $ajax_url;
        }

        if (!$has_route) {
            // Not a controller method with Route/Ajax - check if it's a SPA action class
            return static::_try_spa_action_route($class_name, $params_array);
        }

        if (!$route_pattern) {
            throw new Rsx_Caller_Exception("Route attribute on {$class_name}::{$action_name} must have a pattern");
        }

        // Generate URL from pattern
        return static::_generate_url_from_pattern($route_pattern, $params_array, $class_name, $action_name);
    }

    /**
     * Try to generate URL for a SPA action class
     * Called when class lookup fails for controller - checks if it's a JavaScript SPA action
     *
     * @param string $class_name The class name (might be a JS SPA action)
     * @param array $params_array Parameters for URL generation
     * @return string The generated URL
     * @throws Rsx_Caller_Exception If not a valid SPA action or route not found
     */
    protected static function _try_spa_action_route(string $class_name, array $params_array): string
    {
        // Check if this is a JavaScript class that extends Spa_Action
        try {
            $is_spa_action = Manifest::js_is_subclass_of($class_name, 'Spa_Action');
        } catch (\RuntimeException $e) {
            // Not a JS class or not found
            throw new Rsx_Caller_Exception("Class {$class_name} must extend Rsx_Controller_Abstract or Spa_Action");
        }

        if (!$is_spa_action) {
            throw new Rsx_Caller_Exception("JavaScript class {$class_name} must extend Spa_Action to generate routes");
        }

        // Get the file path for this JS class
        try {
            $file_path = Manifest::js_find_class($class_name);
        } catch (\RuntimeException $e) {
            throw new Rsx_Caller_Exception("SPA action class {$class_name} not found in manifest");
        }

        // Get file metadata which contains decorator information
        try {
            $file_data = Manifest::get_file($file_path);
        } catch (\RuntimeException $e) {
            throw new Rsx_Caller_Exception("File metadata not found for SPA action {$class_name}");
        }

        // Extract route pattern from decorators
        // JavaScript files have 'decorators' array in their metadata
        // Format: [[0 => 'route', 1 => ['/contacts']], ...]
        $route_pattern = null;
        if (isset($file_data['decorators']) && is_array($file_data['decorators'])) {
            foreach ($file_data['decorators'] as $decorator) {
                // Decorator format: [0 => 'decorator_name', 1 => [arguments]]
                if (isset($decorator[0]) && $decorator[0] === 'route') {
                    // First argument is the route pattern
                    if (isset($decorator[1][0])) {
                        $route_pattern = $decorator[1][0];
                        break;
                    }
                }
            }
        }

        if (!$route_pattern) {
            throw new Rsx_Caller_Exception("SPA action {$class_name} must have @route() decorator with pattern");
        }

        // Generate URL from pattern using same logic as regular routes
        return static::_generate_url_from_pattern($route_pattern, $params_array, $class_name, '(SPA action)');
    }

    /**
     * Generate URL from route pattern by replacing parameters
     *
     * @param string $pattern The route pattern (e.g., '/users/:id/view')
     * @param array $params Parameters to fill into the route
     * @param string $class_name Controller class name (for error messages)
     * @param string $action_name Action name (for error messages)
     * @return string The generated URL
     * @throws RuntimeException If required parameters are missing
     */
    protected static function _generate_url_from_pattern($pattern, $params, $class_name, $action_name)
    {
        // Extract required parameters from the pattern
        $required_params = [];
        if (preg_match_all('/:([a-zA-Z_][a-zA-Z0-9_]*)/', $pattern, $matches)) {
            $required_params = $matches[1];
        }

        // Check for required parameters
        $missing = [];
        foreach ($required_params as $required) {
            if (!array_key_exists($required, $params)) {
                $missing[] = $required;
            }
        }

        if (!empty($missing)) {
            throw new RuntimeException(
                "Required parameters [" . implode(', ', $missing) . "] are missing for route " .
                "{$pattern} on {$class_name}::{$action_name}"
            );
        }

        // Build the URL by replacing parameters
        $url = $pattern;
        $used_params = [];

        foreach ($required_params as $param_name) {
            $value = $params[$param_name];
            // URL encode the value
            $encoded_value = urlencode($value);
            $url = str_replace(':' . $param_name, $encoded_value, $url);
            $used_params[$param_name] = true;
        }

        // Collect any extra parameters for query string
        $query_params = [];
        foreach ($params as $key => $value) {
            if (!isset($used_params[$key])) {
                $query_params[$key] = $value;
            }
        }

        // Append query string if there are extra parameters
        if (!empty($query_params)) {
            $url .= '?' . http_build_query($query_params);
        }

        return $url;
    }

    /**
     * Trigger a filter event - data passes through chain of handlers
     *
     * Each handler receives the result of the previous handler and returns
     * the modified data. Use for transforming data through a pipeline.
     *
     * Example:
     * ```php
     * $params = Rsx::trigger_filter('file.upload.params', $params);
     * ```
     *
     * @param string $event Event name
     * @param mixed $data Data to pass through filter chain
     * @return mixed Transformed data
     */
    public static function trigger_filter(string $event, $data)
    {
        $handlers = Event_Registry::get_handlers($event);

        foreach ($handlers as $handler) {
            $data = $handler($data);
        }

        return $data;
    }

    /**
     * Trigger a gate event - first non-true return value halts execution
     *
     * Use for authorization, validation, and permission checks.
     * First handler that returns non-true halts the chain and returns that value.
     *
     * Example:
     * ```php
     * $result = Rsx::trigger_gate('file.upload.authorize', ['request' => $request]);
     * if ($result !== true) {
     *     return $result; // Handler returned error response
     * }
     * ```
     *
     * @param string $event Event name
     * @param mixed $data Data to pass to handlers
     * @return true|mixed Returns true if all handlers pass, or first non-true result
     */
    public static function trigger_gate(string $event, $data)
    {
        $handlers = Event_Registry::get_handlers($event);

        foreach ($handlers as $handler) {
            $result = $handler($data);
            if ($result !== true) {
                return $result; // First denial/error wins
            }
        }

        return true; // All handlers passed
    }

    /**
     * Trigger an action event - fire all handlers, ignore return values
     *
     * Use for logging, notifications, and other side effects.
     * All handlers are called regardless of their return values.
     *
     * Example:
     * ```php
     * Rsx::trigger_action('file.upload.complete', [
     *     'attachment' => $attachment,
     *     'request' => $request
     * ]);
     * ```
     *
     * @param string $event Event name
     * @param mixed $data Data to pass to handlers
     * @return void
     */
    public static function trigger_action(string $event, $data): void
    {
        $handlers = Event_Registry::get_handlers($event);

        foreach ($handlers as $handler) {
            $handler($data);
        }
    }
}