<?php

declare(strict_types=1);

namespace LIT\MCP\Integrations\Divi\Pages;

use LIT\MCP\Integrations\Divi\Compose\AttrWriter;
use LIT\MCP\Integrations\Divi\Compose\Composer;
use LIT\MCP\Integrations\Divi\Compose\LinkTargets;
use LIT\MCP\Integrations\Divi\Compose\MediaResolver;
use LIT\MCP\Integrations\Divi\Compose\Placeholders;
use LIT\MCP\Integrations\Divi\Compose\ShortformWriter;
use LIT\MCP\Integrations\Divi\Compose\StoredNodeGuard;
use LIT\MCP\Integrations\Divi\Compose\StructureRules;
use LIT\MCP\Integrations\Divi\Compose\TreeEditor;
use LIT\MCP\Integrations\Divi\Compose\ValueCleaner;
use LIT\MCP\Integrations\Divi\Compose\ValueSanitizer;
use LIT\MCP\Integrations\Divi\Compose\VariableRef;
use LIT\MCP\Integrations\Divi\Compose\Warnings;
use LIT\MCP\Integrations\Divi\Design\DesignSystemReader;
use LIT\MCP\Integrations\Divi\Design\DesignSystemWriter;
use LIT\MCP\Integrations\Divi\Design\PresetAssignment;
use LIT\MCP\Integrations\Divi\Design\PresetBook;
use LIT\MCP\Integrations\Divi\Schema\DiviModules;

defined('ABSPATH') || exit;

/**
 * Wires the pure Compose classes with the live catalog, design system, Divi's dynamic content
 * registry and the WordPress sanitizer/media lookup – once per request and entry. Ruling S31:
 * ONE VariableRef (carrying the live dynamic content map of the entry, S22), ONE Placeholders
 * and ONE ValueCleaner instance are shared by AttrWriter, ShortformWriter and Composer, and the
 * same AttrWriter serves Composer and the abilities.
 *
 * Presets (D7) reach blocks through ONE PresetAssignment per composition: its book is Divi's stored preset
 * inventory (DesignSystemWriter::presets()), read lazily and at most once – only when a write names a preset or a
 * warning looks at a block that has one – and Divi's option groups come from DesignSystemWriter::groupsOf().
 * Without a preset source (null, unit tests) there are no presets.
 *
 * forPost() binds the composition to the entry being written (DiviWriter::composition() does it
 * for the abilities); unbound, VariableRef's default map applies. Not final so abilities can be
 * tested with a mock.
 */
class DiviComposition
{
    private ?int $postId = null;
    private ?string $themeBuilderArea = null;
    private ?VariableRef $references = null;
    private ?Placeholders $placeholders = null;
    private ?ValueCleaner $cleaner = null;
    private ?AttrWriter $attrWriter = null;
    private ?Composer $composer = null;
    private ?PresetAssignment $assignment = null;

    public function __construct(
        private DiviModules $modules,
        private DesignSystemReader $design,
        private ValueSanitizer $sanitizer = new WpValueSanitizer(),
        private MediaResolver $media = new WpMediaResolver(),
        private DynamicContentMap $dynamicContent = new DynamicContentMap(),
        private LinkTargets $links = new WpLinkTargets(),
        private ?DesignSystemWriter $presetSource = null
    ) {
    }

    /** A fresh composition for entry $postId (own VariableRef with its live map; TB area for StructureRules). */
    public function forPost(int $postId, ?string $themeBuilderArea = null): static
    {
        $bound = clone $this;
        $bound->postId = $postId;
        $bound->themeBuilderArea = $themeBuilderArea;
        $bound->references = null;
        $bound->placeholders = null;
        $bound->cleaner = null;
        $bound->attrWriter = null;
        $bound->composer = null;
        $bound->assignment = null;

        return $bound;
    }

    /**
     * The one checker of $variable(…)$ values of this composition, with the entry's live map (S22, S31).
     *
     * @internal Public for tests; code uses cleaner() / composer().
     */
    public function references(): VariableRef
    {
        return $this->references ??= new VariableRef(
            $this->design->read(),
            $this->postId === null ? null : $this->dynamicContent->forPost($this->postId)
        );
    }

    /**
     * The one Placeholders instance of this composition (ruling S31).
     *
     * @internal Public for tests; code uses attrWriter() / composer().
     */
    public function placeholders(): Placeholders
    {
        return $this->placeholders ??= new Placeholders($this->design->read(), $this->links);
    }

    /** The one choke point of this composition (ValueCleaner, rulings S1–S3, S7, S13, S28, S32). */
    public function cleaner(): ValueCleaner
    {
        return $this->cleaner ??= new ValueCleaner($this->modules->catalog(), $this->references(), $this->sanitizer);
    }

    public function attrWriter(): AttrWriter
    {
        return $this->attrWriter ??= new AttrWriter($this->modules->catalog(), $this->placeholders(), $this->cleaner());
    }

    /**
     * The one PresetAssignment of this composition (D7, rulings R2, R3): the book comes lazily from Divi's stored
     * presets, ids must pass the choke point unchanged.
     *
     * @internal Public for tests; code uses composer() / warnings().
     */
    public function presets(): PresetAssignment
    {
        return $this->assignment ??= new PresetAssignment(
            fn (): PresetBook => PresetBook::fromDivi($this->presetSource?->presets() ?? []),
            fn (string $module): array => $this->presetSource?->groupsOf($module) ?? [],
            $this->cleaner()->keepsId(...)
        );
    }

    public function composer(): Composer
    {
        return $this->composer ??= new Composer(
            $this->modules->catalog(),
            $this->rules(),
            new ShortformWriter($this->placeholders(), $this->media, $this->cleaner()),
            $this->attrWriter(),
            $this->cleaner(),
            $this->presets(),
            $this->modules->builderVersion()
        );
    }

    /** @internal Public for tests; code uses composer() / editor(). */
    public function rules(): StructureRules
    {
        return new StructureRules($this->modules->catalog(), $this->themeBuilderArea);
    }

    /** E6: the check for stored nodes that move into this composition's entry (same cleaner and references). */
    public function storedGuard(): StoredNodeGuard
    {
        return new StoredNodeGuard($this->cleaner(), $this->references(), $this->sanitizer);
    }

    public function editor(): TreeEditor
    {
        return new TreeEditor($this->rules());
    }

    public function warnings(): Warnings
    {
        return new Warnings($this->design->read());
    }
}