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

/**
 * Chat Handler Property Tests
 *
 * Property-based tests for chat handler request/response validation and logging.
 */

import * as fc from 'fast-check';
import type { ChatRequest, ChatResponse } from '../../types/chat.types';

/**
 * Mock handler implementation for testing validation logic.
 */
const validateChatRequest = (
    body: Partial<ChatRequest>
): { valid: boolean; error?: string } => {
    if (!body.sessionId?.trim()) {
        return { valid: false, error: 'sessionId is required' };
    }
    if (!body.message?.trim()) {
        return { valid: false, error: 'message is required' };
    }
    return { valid: true };
};

/**
 * Mock response builder for testing.
 */
const buildChatResponse = (
    sessionId: string,
    response: string
): ChatResponse => ({
    sessionId,
    response,
    timestamp: new Date().toISOString(),
});

describe('Chat Handler Properties', () => {
    /**
     * Feature: ai-chat-template, Property 15: Chat Handler Request/Response Validation
     *
     * For any valid chat request with sessionId and message, the Chat Handler SHALL
     * return a 200 response with sessionId, response, and timestamp fields. For any
     * request missing sessionId or message, the handler SHALL return a 400 response
     * with an error field.
     *
     * **Validates: Requirements 9.2, 9.3, 9.4**
     */
    describe('Property 15: Chat Handler Request/Response Validation', () => {
        it('should reject requests with missing sessionId', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.oneof(
                        fc.constant(undefined),
                        fc.constant(null),
                        fc.constant(''),
                        fc.constant('   '),
                        fc.constant('\t\n')
                    ),
                    fc.string({ minLength: 1 }),
                    async (sessionId, message) => {
                        const body: Partial<ChatRequest> = {
                            sessionId: sessionId as string | undefined,
                            message,
                        };

                        const result = validateChatRequest(body);

                        expect(result.valid).toBe(false);
                        expect(result.error).toContain('sessionId');
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should reject requests with missing message', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1 }).filter((s) => s.trim().length > 0),
                    fc.oneof(
                        fc.constant(undefined),
                        fc.constant(null),
                        fc.constant(''),
                        fc.constant('   '),
                        fc.constant('\t\n')
                    ),
                    async (sessionId, message) => {
                        const body: Partial<ChatRequest> = {
                            sessionId,
                            message: message as string | undefined,
                        };

                        const result = validateChatRequest(body);

                        expect(result.valid).toBe(false);
                        expect(result.error).toContain('message');
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should accept valid requests with sessionId and message', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 100 }).filter((s) => s.trim().length > 0),
                    fc.string({ minLength: 1, maxLength: 1000 }).filter((s) => s.trim().length > 0),
                    async (sessionId, message) => {
                        const body: ChatRequest = {
                            sessionId,
                            message,
                        };

                        const result = validateChatRequest(body);

                        expect(result.valid).toBe(true);
                        expect(result.error).toBeUndefined();
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should return response with required fields for valid requests', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 100 }).filter((s) => s.trim().length > 0),
                    fc.string({ minLength: 1, maxLength: 1000 }).filter((s) => s.trim().length > 0),
                    async (sessionId, responseText) => {
                        const response = buildChatResponse(sessionId, responseText);

                        // Verify required fields exist
                        expect(response.sessionId).toBeDefined();
                        expect(response.response).toBeDefined();
                        expect(response.timestamp).toBeDefined();

                        // Verify field types
                        expect(typeof response.sessionId).toBe('string');
                        expect(typeof response.response).toBe('string');
                        expect(typeof response.timestamp).toBe('string');

                        // Verify sessionId matches input
                        expect(response.sessionId).toBe(sessionId);

                        // Verify timestamp is valid ISO format
                        expect(() => new Date(response.timestamp)).not.toThrow();
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should accept optional behavior parameter', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 100 }).filter((s) => s.trim().length > 0),
                    fc.string({ minLength: 1, maxLength: 1000 }).filter((s) => s.trim().length > 0),
                    fc.oneof(
                        fc.constant(undefined),
                        fc.constant('precise'),
                        fc.constant('balanced'),
                        fc.constant('creative')
                    ),
                    async (sessionId, message, behavior) => {
                        const body: ChatRequest = {
                            sessionId,
                            message,
                            behavior: behavior as ChatRequest['behavior'],
                        };

                        const result = validateChatRequest(body);

                        // Behavior is optional, should not affect validation
                        expect(result.valid).toBe(true);
                    }
                ),
                { numRuns: 100 }
            );
        });
    });

    /**
     * Feature: ai-chat-template, Property 18: Logging Includes Required Fields Without Sensitive Data
     *
     * For any chat request, the handler logs SHALL include requestId, sessionId, and
     * latency fields, and SHALL NOT include the raw message content or response content.
     *
     * **Validates: Requirements 11.1, 11.2, 11.3, 11.4, 11.6**
     */
    describe('Property 18: Logging Includes Required Fields Without Sensitive Data', () => {
        /**
         * Simulates log entry creation matching handler behavior.
         */
        const createRequestLog = (
            requestId: string,
            sessionId: string,
            behavior: string,
            messageLength: number
        ): Record<string, unknown> => ({
            requestId,
            sessionId,
            behavior,
            messageLength,
        });

        const createResponseLog = (
            requestId: string,
            sessionId: string,
            latency: number,
            responseLength: number
        ): Record<string, unknown> => ({
            requestId,
            sessionId,
            latency,
            responseLength,
        });

        it('should include required fields in request logs', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.constantFrom('precise', 'balanced', 'creative'),
                    fc.integer({ min: 1, max: 10000 }),
                    async (requestId, sessionId, behavior, messageLength) => {
                        const log = createRequestLog(requestId, sessionId, behavior, messageLength);

                        // Verify required fields exist
                        expect(log.requestId).toBeDefined();
                        expect(log.sessionId).toBeDefined();

                        // Verify field values match input
                        expect(log.requestId).toBe(requestId);
                        expect(log.sessionId).toBe(sessionId);
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should include latency in response logs', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.integer({ min: 0, max: 30000 }),
                    fc.integer({ min: 1, max: 10000 }),
                    async (requestId, sessionId, latency, responseLength) => {
                        const log = createResponseLog(requestId, sessionId, latency, responseLength);

                        // Verify latency field exists
                        expect(log.latency).toBeDefined();
                        expect(typeof log.latency).toBe('number');
                        expect(log.latency).toBe(latency);
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should NOT include message content in logs', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 10, maxLength: 500 }),
                    async (requestId, sessionId, messageContent) => {
                        const log = createRequestLog(
                            requestId,
                            sessionId,
                            'balanced',
                            messageContent.length
                        );

                        const logString = JSON.stringify(log);

                        // Log should NOT contain the actual message content
                        // (unless it happens to match requestId or sessionId)
                        if (
                            messageContent !== requestId &&
                            messageContent !== sessionId &&
                            messageContent !== 'balanced'
                        ) {
                            expect(logString).not.toContain(messageContent);
                        }

                        // Log should only contain length, not content
                        expect(log.messageLength).toBe(messageContent.length);
                        expect(log).not.toHaveProperty('message');
                        expect(log).not.toHaveProperty('content');
                    }
                ),
                { numRuns: 100 }
            );
        });

        it('should NOT include response content in logs', async () => {
            await fc.assert(
                fc.asyncProperty(
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 1, maxLength: 50 }),
                    fc.string({ minLength: 10, maxLength: 500 }),
                    async (requestId, sessionId, responseContent) => {
                        const log = createResponseLog(
                            requestId,
                            sessionId,
                            100,
                            responseContent.length
                        );

                        const logString = JSON.stringify(log);

                        // Log should NOT contain the actual response content
                        if (responseContent !== requestId && responseContent !== sessionId) {
                            expect(logString).not.toContain(responseContent);
                        }

                        // Log should only contain length, not content
                        expect(log.responseLength).toBe(responseContent.length);
                        expect(log).not.toHaveProperty('response');
                        expect(log).not.toHaveProperty('content');
                    }
                ),
                { numRuns: 100 }
            );
        });
    });
});
