/**
 * JQHTML Integration - Component Hydration System
 *
 * This module bridges server-rendered HTML and client-side jqhtml components.
 *
 * == THE HYDRATION PROBLEM ==
 *
 * When PHP/Blade renders a page, jqhtml components appear as placeholder elements:
 *
 *   Blade source:      <User_Card $name="John" />
 *   Rendered HTML:     <div class="Component_Init"
 *                           data-component-init-name="User_Card"
 *                           data-component-args='{"name":"John"}'>
 *                      </div>
 *
 * These are just div tags - they have no behavior until JavaScript runs.
 * "Hydration" is the process of finding these placeholders and converting them
 * into live, interactive jqhtml components.
 *
 * == TWO-PHASE INITIALIZATION ==
 *
 * Phase 1: _on_framework_modules_define() - Component Registration
 *   - Runs early in framework boot, before DOM is processed
 *   - Registers all ES6 classes extending Component with jqhtml runtime
 *   - After this phase, jqhtml knows: "User_Card" → UserCardClass
 *
 * Phase 2: _on_framework_modules_init() - DOM Hydration
 *   - Runs after templates are loaded
 *   - Finds all .Component_Init elements in the DOM
 *   - Extracts component name and args from data attributes
 *   - Calls $element.component(name, args) to hydrate each one
 *   - Recursively processes nested components
 *   - Triggers 'jqhtml_ready' when all components are initialized
 *
 * == THE TRANSFORMATION ==
 *
 * Before hydration:
 *   <div class="Component_Init" data-component-init-name="User_Card" ...>
 *
 * After hydration:
 *   <div class="User_Card">          ← Component_Init removed, component class added
 *     [component template content]   ← Template rendered into element
 *   </div>
 *
 * The element is now a live component with event handlers, state, and lifecycle.
 *
 * == KEY PARTICIPANTS ==
 *
 * JqhtmlBladeCompiler.php  - Transforms <Component /> tags into .Component_Init divs
 * jqhtml runtime           - Maintains registry of component names → classes
 * This module              - Orchestrates registration and hydration
 * $().component()          - jQuery plugin that creates component instances
 */
class Jqhtml_Integration {
    /**
     * Phase 1: Register Component Classes
     *
     * Compiled .jqhtml templates self-register their render methods with jqhtml.
     * But the framework must separately register ES6 component classes (the ones
     * extending Component with lifecycle methods like on_create, on_load, etc).
     *
     * This runs during framework_modules_define, before any DOM processing.
     */
    static _on_framework_modules_define() {
        // ─────────────────────────────────────────────────────────────────────
        // Register Component Classes with jqhtml Runtime
        //
        // The Manifest knows all classes extending Component. We register each
        // with jqhtml so it can instantiate them by name during hydration.
        // ─────────────────────────────────────────────────────────────────────
        let jqhtml_components = Manifest.get_extending('Component');
        console_debug('JQHTML_INIT', 'Registering ' + jqhtml_components.length + ' Components');

        for (let component of jqhtml_components) {
            jqhtml.register_component(component.class_name, component.class_object);
        }

        // ─────────────────────────────────────────────────────────────────────
        // Tag Static Methods with Cache IDs
        //
        // jqhtml caches component output based on args. When a function is passed
        // as an arg (e.g., DataGrid's data_source), we need a stable string key.
        //
        // Without this: data_source: function() {...} → no cache (functions aren't serializable)
        // With this:    function._jqhtml_cache_id = "My_DataGrid.fetch_data" → cacheable
        // ─────────────────────────────────────────────────────────────────────
        const all_classes = Manifest.get_all_classes();
        let methods_tagged = 0;

        for (const class_info of all_classes) {
            const class_object = class_info.class_object;
            const class_name = class_info.class_name;
            const property_names = Object.getOwnPropertyNames(class_object);

            for (const property_name of property_names) {
                if (property_name === 'length' || property_name === 'name' || property_name === 'prototype') {
                    continue;
                }

                const property_value = class_object[property_name];
                if (typeof property_value === 'function') {
                    property_value._jqhtml_cache_id = `${class_name}.${property_name}`;
                    methods_tagged++;
                }
            }
        }

        console_debug('JQHTML_INIT', `Tagged ${methods_tagged} static methods with _jqhtml_cache_id`);

        // ─────────────────────────────────────────────────────────────────────
        // Configure jqhtml Caching
        //
        // scope_key() changes when: app code changes, user logs out, site changes.
        // This automatically invalidates cached component renders.
        // ─────────────────────────────────────────────────────────────────────
        jqhtml.set_cache_key(Rsx.scope_key());
        window.jqhtml.debug.verbose = false;
    }

    /**
     * Phase 2: DOM Hydration
     *
     * Finds all .Component_Init placeholders and converts them into live components.
     *
     * == HYDRATION PROCESS ==
     *
     * For each .Component_Init element:
     *
     *   1. EXTRACT: Read data-component-init-name and data-component-args
     *   2. CLEANUP: Remove data attributes (prevents re-hydration, hides implementation)
     *   3. CAPTURE: Save innerHTML for slot/content() processing
     *   4. INSTANTIATE: Call $element.component(name, args)
     *   5. RECURSE: After render, hydrate any nested .Component_Init elements
     *
     * == NESTED COMPONENT HANDLING ==
     *
     * Components can contain other components in their Blade output:
     *
     *   <User_Card>              ← Parent hydrates first
     *     <Avatar />             ← Child hydrates after parent renders
     *   </User_Card>
     *
     * We skip nested .Component_Init elements on first pass (they're inside a parent
     * that hasn't rendered yet). After each component renders, we recursively scan
     * its content for children to hydrate.
     *
     * == ASYNC COMPLETION ==
     *
     * Hydration is async because components may have on_load() methods that fetch data.
     * We track all component promises and trigger 'jqhtml_ready' only when every
     * component (including nested ones) has completed its full lifecycle.
     *
     * @param {jQuery} [$scope] Scope to search (defaults to body). Recursive calls pass component.$
     * @returns {Array<Promise>|undefined} Promises for recursive calls; undefined for top-level
     */
    static _on_framework_modules_init($scope) {
        const is_top_level = !$scope;
        const promises = [];
        const components_needing_init = ($scope || $('body')).find('.Component_Init');

        if (components_needing_init.length > 0) {
            console_debug('JQHTML_INIT', `Initializing ${components_needing_init.length} DOM components`);
        }

        components_needing_init.each(function () {
            const $element = $(this);

            // Guard: Element may have been removed by a parent component's render
            if (!document.contains($element[0])) {
                return;
            }

            // Guard: Skip nested components - they'll be processed after their parent renders
            let parent = $element[0].parentElement;
            while (parent) {
                if (parent.classList.contains('Component_Init')) {
                    return;
                }
                parent = parent.parentElement;
            }

            // ─────────────────────────────────────────────────────────────────
            // STEP 1: Extract hydration data from placeholder element
            // ─────────────────────────────────────────────────────────────────
            const component_name = $element.attr('data-component-init-name');
            const args_string = $element.attr('data-component-args');

            let component_args = {};
            if (args_string) {
                try {
                    component_args = JSON.parse(args_string);
                } catch (e) {
                    console.error(`[JQHTML Integration] Failed to parse component args for ${component_name}:`, e);
                    component_args = {};
                }
            }

            // ─────────────────────────────────────────────────────────────────
            // STEP 2: Remove hydration markers (cleanup)
            //
            // These attributes served their purpose. Removing them:
            // - Prevents accidental re-hydration
            // - Hides implementation details from DOM inspection
            // - Prevents other code from depending on this internal mechanism
            // ─────────────────────────────────────────────────────────────────
            $element.removeAttr('data-component-init-name');
            $element.removeAttr('data-component-args');
            $element.removeData('component-init-name');
            $element.removeData('component-args');

            if (component_name) {
                let component_args_filtered = {};
                for (const [key, value] of Object.entries(component_args)) {
                    if (key.startsWith('data-')) {
                        component_args_filtered[key.substring(5)] = value;
                    } else {
                        component_args_filtered[key] = value;
                    }
                }

                try {
                    // ─────────────────────────────────────────────────────────
                    // STEP 3: Capture innerHTML for slot/content() processing
                    //
                    // Blade content between <Component>...</Component> tags
                    // becomes available to the template via content() function
                    // ─────────────────────────────────────────────────────────
                    component_args_filtered._inner_html = $element.html();
                    $element.empty();

                    // ─────────────────────────────────────────────────────────
                    // STEP 4: Instantiate the component
                    //
                    // Remove .Component_Init first to prevent re-initialization
                    // if this element is somehow scanned again
                    // ─────────────────────────────────────────────────────────
                    $element.removeClass('Component_Init');

                    const component_promise = new Promise((resolve) => {
                        // $().component(name, args) creates the component instance,
                        // binds it to the element, and starts the lifecycle
                        let component = $element.component(component_name, component_args_filtered).component();

                        // ─────────────────────────────────────────────────────
                        // STEP 5: Recurse after render
                        //
                        // Component's template may contain nested .Component_Init
                        // elements. We must wait for render before we can find them.
                        //
                        // Note: If the template changed the tag (e.g., tag="button"),
                        // the original $element may have been replaced. Always use
                        // component.$ to get the current element.
                        // ─────────────────────────────────────────────────────
                        component.on('render', function () {
                            const nested_promises = Jqhtml_Integration._on_framework_modules_init(component.$);
                            promises.push(...nested_promises);
                            resolve();
                        }).$;
                    });

                    promises.push(component_promise);
                } catch (error) {
                    console.error(`[JQHTML Integration] Failed to initialize component ${component_name}:`, error);
                    console.error('Error details:', error.stack || error);
                }
            }
        });

        // ─────────────────────────────────────────────────────────────────────
        // COMPLETION: Top-level call waits for all components, then signals ready
        // ─────────────────────────────────────────────────────────────────────
        if (is_top_level) {
            (async () => {
                await Promise.all(promises);
                Rsx.trigger('jqhtml_ready');
            })();
            return;
        }

        // Recursive calls return promises for parent to collect
        return promises;
    }

    // ═══════════════════════════════════════════════════════════════════════
    // Utility Methods (pass-through to jqhtml runtime)
    // ═══════════════════════════════════════════════════════════════════════

    /** Get all registered component names. Useful for debugging/introspection. */
    static get_component_names() {
        return jqhtml.get_component_names();
    }

    /** Check if a component is registered by name. */
    static has_component(name) {
        return jqhtml.has_component(name);
    }
}

// Class is automatically made global by RSX manifest - no window assignment needed