<?php

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

return new class extends Migration {
    public function up(): void
    {
        Schema::create('service_calculation_profiles', function (Blueprint $t): void {
            $t->id(); $t->unsignedBigInteger('tenant_id'); $t->unsignedBigInteger('company_id'); $t->unsignedBigInteger('unit_id');
            $t->string('identifier'); $t->unsignedInteger('version'); $t->jsonb('definition'); $t->timestampTz('created_at');
            $t->unique(['unit_id','identifier','version']);
            $t->foreign(['tenant_id','company_id','unit_id'])->references(['tenant_id','company_id','id'])->on('units')->restrictOnDelete();
        });
        Schema::create('service_calculation_results', function (Blueprint $t): void {
            $t->id(); $t->unsignedBigInteger('tenant_id'); $t->unsignedBigInteger('company_id'); $t->unsignedBigInteger('unit_id');
            $t->foreignId('billing_draft_id')->constrained('a_billing_drafts')->restrictOnDelete();
            $t->foreignId('profile_id')->constrained('service_calculation_profiles')->restrictOnDelete();
            $t->foreignId('actor_id')->constrained('users')->restrictOnDelete();
            $t->string('fingerprint', 64); $t->jsonb('snapshot'); $t->timestampTz('created_at');
            $t->unique(['billing_draft_id','fingerprint']);
            $t->foreign(['tenant_id','company_id','unit_id'])->references(['tenant_id','company_id','id'])->on('units')->restrictOnDelete();
        });
        DB::unprepared(<<<'SQL'
            CREATE OR REPLACE FUNCTION sgf_calculation_insert_guard() RETURNS trigger LANGUAGE plpgsql AS $$
            BEGIN
                IF NOT EXISTS(SELECT 1 FROM a_billing_drafts b WHERE b.id=NEW.billing_draft_id AND b.tenant_id=NEW.tenant_id AND b.company_id=NEW.company_id AND b.unit_id=NEW.unit_id)
                OR NOT EXISTS(SELECT 1 FROM service_calculation_profiles p WHERE p.id=NEW.profile_id AND p.tenant_id=NEW.tenant_id AND p.company_id=NEW.company_id AND p.unit_id=NEW.unit_id)
                THEN RAISE EXCEPTION 'SGF_CALCULATION_SCOPE'; END IF;
                RETURN NEW;
            END; $$;
            CREATE TRIGGER calculation_scope BEFORE INSERT ON service_calculation_results FOR EACH ROW EXECUTE FUNCTION sgf_calculation_insert_guard();
            CREATE TRIGGER calculation_results_immutable BEFORE UPDATE OR DELETE ON service_calculation_results FOR EACH ROW EXECUTE FUNCTION sgf_append_only_audit();
            CREATE TRIGGER calculation_profiles_immutable BEFORE UPDATE OR DELETE ON service_calculation_profiles FOR EACH ROW EXECUTE FUNCTION sgf_append_only_audit();
            SQL);
    }
    public function down(): void { throw new RuntimeException('Calculation history requires a reviewed preservation procedure.'); }
};