<?php

declare(strict_types=1);

namespace Tests\Unit\Framework\Template\Expression;

use App\Framework\Template\Expression\ExpressionEvaluator;

describe('ExpressionEvaluator', function () {
    beforeEach(function () {
        $this->evaluator = new ExpressionEvaluator();
    });

    describe('nested array access', function () {
        it('supports single level array access', function () {
            $context = [
                'item' => ['name' => 'Test'],
            ];
            
            $result = $this->evaluator->evaluate("item['name']", $context);
            
            expect($result)->toBe('Test');
        });

        it('supports nested array access', function () {
            $context = [
                'item' => [
                    'user' => [
                        'name' => 'John',
                        'email' => 'john@example.com',
                    ],
                ],
            ];
            
            $result = $this->evaluator->evaluate("item['user']['name']", $context);
            
            expect($result)->toBe('John');
        });

        it('supports nested array access with $ prefix', function () {
            $context = [
                'item' => [
                    'user' => [
                        'name' => 'John',
                    ],
                ],
            ];
            
            $result = $this->evaluator->evaluate("\$item['user']['name']", $context);
            
            expect($result)->toBe('John');
        });

        it('returns null for missing nested keys', function () {
            $context = [
                'item' => ['name' => 'Test'],
            ];
            
            $result = $this->evaluator->evaluate("item['user']['name']", $context);
            
            expect($result)->toBeNull();
        });

        it('supports numeric indices in nested arrays', function () {
            $context = [
                'items' => [
                    [0 => ['name' => 'First']],
                    [0 => ['name' => 'Second']],
                ],
            ];
            
            $result = $this->evaluator->evaluate("items[0][0]['name']", $context);
            
            expect($result)->toBe('First');
        });
    });

    describe('fallback mechanism', function () {
        it('supports null coalescing operator', function () {
            $context = [
                'name' => null,
            ];
            
            // Note: This is handled by ForTransformer/PlaceholderTransformer, not ExpressionEvaluator
            // ExpressionEvaluator just evaluates the expression
            $result = $this->evaluator->evaluate("name", $context);
            
            expect($result)->toBeNull();
        });
    });

    describe('error handling', function () {
        it('returns null for missing variables', function () {
            $context = [];
            
            $result = $this->evaluator->evaluate('missingVar', $context);
            
            expect($result)->toBeNull();
        });

        it('returns null for missing array keys', function () {
            $context = [
                'item' => ['name' => 'Test'],
            ];
            
            $result = $this->evaluator->evaluate("item['missing']", $context);
            
            expect($result)->toBeNull();
        });

        it('handles invalid expressions gracefully', function () {
            $context = [];
            
            $result = $this->evaluator->evaluate('invalid[expression', $context);
            
            expect($result)->toBeNull();
        });
    });

    describe('dot notation', function () {
        it('supports dot notation for nested properties', function () {
            $context = [
                'user' => [
                    'profile' => [
                        'name' => 'John',
                    ],
                ],
            ];
            
            $result = $this->evaluator->evaluate('user.profile.name', $context);
            
            expect($result)->toBe('John');
        });

        it('supports dot notation with numeric indices', function () {
            $context = [
                'items' => [
                    ['name' => 'First'],
                    ['name' => 'Second'],
                ],
            ];
            
            $result = $this->evaluator->evaluate('items.0.name', $context);
            
            expect($result)->toBe('First');
        });

        it('supports dot notation with $ prefix for arrays', function () {
            $context = [
                'option' => [
                    'id' => 'landing_page',
                    'name' => 'Landing Page',
                ],
            ];
            
            $result = $this->evaluator->evaluate('$option.id', $context);
            
            expect($result)->toBe('landing_page');
        });

        it('supports dot notation with $ prefix for nested arrays', function () {
            $context = [
                'option' => [
                    'user' => [
                        'name' => 'John',
                    ],
                ],
            ];
            
            $result = $this->evaluator->evaluate('$option.user.name', $context);
            
            expect($result)->toBe('John');
        });

        it('supports both array notation and dot notation', function () {
            $context = [
                'option' => [
                    'id' => 'test',
                    'name' => 'Test',
                ],
            ];
            
            $arrayResult = $this->evaluator->evaluate("option['id']", $context);
            $dotResult = $this->evaluator->evaluate('option.id', $context);
            $dollarDotResult = $this->evaluator->evaluate('$option.id', $context);
            
            expect($arrayResult)->toBe('test');
            expect($dotResult)->toBe('test');
            expect($dollarDotResult)->toBe('test');
        });
    });
});