<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * One row per outbound link found on a captured page, pointing at a different
     * domain — the edges of a web graph, queryable from either end: "what does this
     * site link out to" (site_id) or "who links to this domain" (target_domain).
     */
    public function up(): void
    {
        Schema::create('backlinks', function (Blueprint $table) {
            $table->id();
            $table->foreignId('site_id')->constrained()->cascadeOnDelete();
            $table->foreignId('site_page_id')->constrained()->cascadeOnDelete();
            $table->text('target_url');
            // target_url is unbounded like site_pages.urlkey was — hash it for the
            // unique index rather than repeat that earlier mistake.
            $table->char('target_url_hash', 40);
            $table->string('target_domain')->nullable();
            $table->string('anchor_text')->nullable();
            $table->string('rel')->nullable();
            $table->timestamps();

            $table->unique(['site_page_id', 'target_url_hash']);
            $table->index('target_domain');
        });
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        Schema::dropIfExists('backlinks');
    }
};