/**
 * @jest-environment jsdom
 */

/*
 * Runtime Web – Unified Serverless Framework for Full-Stack TypeScript Applications
 * Documentation: https://runtimeweb.com/docs/getting-started
 *
 * @template: ai-chat
 */

/**
 * Property-based tests for TypingIndicator component.
 *
 * **Property 3: Loading State Behavior**
 * **Validates: Requirements 3.1, 3.5, 3.6**
 *
 * Property: For any loading state where isLoading is true, the TypingIndicator
 * component SHALL be rendered with aria-live="polite" and aria-label attributes,
 * and WHEN streaming begins, the indicator SHALL transition to showing streaming content.
 *
 * @module components/chat/__tests__/TypingIndicator.property.test
 */

import * as React from 'react';
import * as fc from 'fast-check';
import { render, cleanup, screen } from '@testing-library/react';
import '@testing-library/jest-dom';
import { TypingIndicator } from '../TypingIndicator';

afterEach(() => {
    cleanup();
});

describe('TypingIndicator Property Tests', () => {
    /**
     * **Property 3: Loading State Behavior**
     * **Validates: Requirements 3.1, 3.5, 3.6**
     */
    describe('Property 3: Loading State Behavior', () => {
        /**
         * Validates: Requirement 3.6
         * The TypingIndicator SHALL render with aria-live="polite" attribute
         * for screen reader accessibility.
         */
        it('renders with aria-live="polite" attribute', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { unmount } = render(<TypingIndicator />);

                    const indicator = screen.getByTestId('typing-indicator');
                    expect(indicator).toBeInTheDocument();
                    expect(indicator).toHaveAttribute('aria-live', 'polite');

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.6
         * The TypingIndicator SHALL render with aria-label attribute
         * to provide accessible text for screen readers.
         */
        it('renders with aria-label attribute', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { unmount } = render(<TypingIndicator />);

                    const indicator = screen.getByTestId('typing-indicator');
                    expect(indicator).toBeInTheDocument();
                    expect(indicator).toHaveAttribute('aria-label');
                    expect(indicator.getAttribute('aria-label')).toBeTruthy();

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.6
         * The TypingIndicator SHALL have role="status" for accessibility,
         * indicating dynamic content that is not urgent enough for aria-live="assertive".
         */
        it('has role="status" for accessibility', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { unmount } = render(<TypingIndicator />);

                    const indicator = screen.getByTestId('typing-indicator');
                    expect(indicator).toBeInTheDocument();
                    expect(indicator).toHaveAttribute('role', 'status');

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.1, 3.2
         * The TypingIndicator SHALL contain animated dots for visual feedback.
         * Verifies the presence of exactly 3 dot elements for the pulsing animation.
         */
        it('contains animated dots', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { container, unmount } = render(<TypingIndicator />);

                    const dotsContainer = container.querySelector('.typing-indicator__dots');
                    expect(dotsContainer).not.toBeNull();

                    const dots = container.querySelectorAll('.typing-indicator__dot');
                    expect(dots.length).toBe(3);

                    // Dots should be hidden from screen readers
                    expect(dotsContainer).toHaveAttribute('aria-hidden', 'true');

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.3
         * The TypingIndicator SHALL have an avatar element matching assistant messages,
         * positioned where the AI response will appear.
         */
        it('has avatar element', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { unmount } = render(<TypingIndicator />);

                    const avatar = screen.getByTestId('typing-indicator-avatar');
                    expect(avatar).toBeInTheDocument();

                    // Avatar icon should be present and hidden from screen readers
                    const avatarIcon = avatar.querySelector('.typing-indicator__avatar-icon');
                    expect(avatarIcon).not.toBeNull();
                    expect(avatarIcon).toHaveAttribute('aria-hidden', 'true');

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirements 3.1, 3.6 combined
         * The TypingIndicator SHALL have all required accessibility attributes
         * and visual elements for a complete loading state indicator.
         */
        it('has complete accessibility and visual structure', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { container, unmount } = render(<TypingIndicator />);

                    const indicator = screen.getByTestId('typing-indicator');

                    // Accessibility attributes
                    expect(indicator).toHaveAttribute('role', 'status');
                    expect(indicator).toHaveAttribute('aria-live', 'polite');
                    expect(indicator).toHaveAttribute('aria-label');

                    // Visual structure
                    expect(container.querySelector('.typing-indicator__avatar')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__bubble')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__dots')).not.toBeNull();
                    expect(container.querySelectorAll('.typing-indicator__dot').length).toBe(3);

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.4
         * The TypingIndicator SHALL use CSS class naming that enables
         * performant CSS-only animations (no JavaScript timers).
         */
        it('uses CSS class structure for performant animations', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { container, unmount } = render(<TypingIndicator />);

                    // Verify BEM class naming structure for CSS animations
                    expect(container.querySelector('.typing-indicator')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__avatar')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__bubble')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__dots')).not.toBeNull();
                    expect(container.querySelector('.typing-indicator__dot')).not.toBeNull();

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Requirement 3.6
         * The aria-label SHALL provide meaningful text for screen readers
         * indicating that the AI is processing.
         */
        it('aria-label provides meaningful screen reader text', () => {
            fc.assert(
                fc.property(fc.constant(true), () => {
                    const { unmount } = render(<TypingIndicator />);

                    const indicator = screen.getByTestId('typing-indicator');
                    const ariaLabel = indicator.getAttribute('aria-label');

                    expect(ariaLabel).toBeTruthy();
                    // Label should indicate AI activity (thinking, processing, etc.)
                    expect(ariaLabel?.toLowerCase()).toMatch(/ai|thinking|processing|loading|generating/i);

                    unmount();
                }),
                { numRuns: 10 },
            );
        });

        /**
         * Validates: Consistent rendering across multiple renders
         * The TypingIndicator SHALL render consistently with the same structure
         * regardless of when it is rendered.
         */
        it('renders consistently across multiple renders', () => {
            fc.assert(
                fc.property(fc.integer({ min: 1, max: 10 }), (renderCount) => {
                    for (let i = 0; i < renderCount; i++) {
                        const { container, unmount } = render(<TypingIndicator />);

                        // Structure should be identical each time
                        expect(container.querySelector('.typing-indicator')).not.toBeNull();
                        expect(container.querySelectorAll('.typing-indicator__dot').length).toBe(3);

                        const indicator = screen.getByTestId('typing-indicator');
                        expect(indicator).toHaveAttribute('role', 'status');
                        expect(indicator).toHaveAttribute('aria-live', 'polite');

                        unmount();
                    }
                }),
                { numRuns: 20 },
            );
        });
    });
});
