/**
 * @file ai_error_handling_edge_cases-t.cpp
 * @brief TAP unit tests for AI error handling edge cases
 *
 * Test Categories:
 * 1. API key validation edge cases (special characters, boundary lengths)
 * 2. URL validation edge cases (IPv6, unusual ports, malformed patterns)
 * 3. Timeout scenarios simulation
 * 4. Connection failure handling
 * 5. Rate limiting error responses
 * 6. Invalid LLM response formats
 *
 * @date 2026-01-16
 */

#include "tap.h"
#include <string.h>
#include <cstdio>
#include <cstdlib>

// ============================================================================
// Standalone validation functions (matching AI_Features_Manager.cpp logic)
// ============================================================================

static bool validate_url_format(const char* url) {
	if (!url || strlen(url) == 0) {
		return true; // Empty URL is valid (will use defaults)
	}

	// Check for protocol prefix (http://, https://)
	const char* http_prefix = "http://";
	const char* https_prefix = "https://";

	bool has_protocol = (strncmp(url, http_prefix, strlen(http_prefix)) == 0 ||
	                     strncmp(url, https_prefix, strlen(https_prefix)) == 0);

	if (!has_protocol) {
		return false;
	}

	// Check for host part (at least something after ://)
	const char* host_start = strstr(url, "://");
	if (!host_start || strlen(host_start + 3) == 0) {
		return false;
	}

	// Host part should not start with a colon (e.g. http://:8080)
	if (host_start[3] == ':') {
		return false;
	}

	return true;
}

static bool validate_api_key_format(const char* key, const char* provider_name) {
	if (!key || strlen(key) == 0) {
		return true; // Empty key is valid for local endpoints
	}

	size_t len = strlen(key);

	// Check for whitespace
	for (size_t i = 0; i < len; i++) {
		if (key[i] == ' ' || key[i] == '\t' || key[i] == '\n' || key[i] == '\r') {
			return false;
		}
	}

	// Check minimum length (most API keys are at least 20 chars)
	if (len < 10) {
		return false;
	}

	// Check for incomplete OpenAI key format
	if (strncmp(key, "sk-", 3) == 0 && len < 10) {
		return false;
	}

	// Check for incomplete Anthropic key format
	if (strncmp(key, "sk-ant-", 7) == 0 && len < 20) {
		return false;
	}

	return true;
}

static bool validate_numeric_range(const char* value, int min_val, int max_val, const char* var_name) {
	if (!value || strlen(value) == 0) {
		return false;
	}

	char* endptr;
	long long_val = strtol(value, &endptr, 10);

	// Check if the entire string was consumed
	if (*endptr != '\0') {
		return false;
	}

	if (long_val < min_val || long_val > max_val) {
		return false;
	}

	return true;
}

static bool validate_provider_format(const char* provider) {
	if (!provider || strlen(provider) == 0) {
		return false;
	}

	const char* valid_formats[] = {"openai", "anthropic", NULL};
	for (int i = 0; valid_formats[i]; i++) {
		if (strcmp(provider, valid_formats[i]) == 0) {
			return true;
		}
	}

	return false;
}

// ============================================================================
// Test: API Key Validation Edge Cases
// ============================================================================

void test_api_key_edge_cases() {
	diag("=== API Key Validation Edge Cases ===");

	// Test very short keys
	ok(!validate_api_key_format("a", "openai"),
	   "Very short key (1 char) rejected");
	ok(!validate_api_key_format("sk", "openai"),
	   "Very short OpenAI-like key (2 chars) rejected");
	ok(!validate_api_key_format("sk-ant", "anthropic"),
	   "Very short Anthropic-like key (6 chars) rejected");

	// Test keys with special characters
	ok(validate_api_key_format("sk-abc123!@#$%^&*()", "openai"),
	   "API key with special characters accepted");
	ok(validate_api_key_format("sk-ant-xyz789_+-=[]{}|;':\",./<>?", "anthropic"),
	   "Anthropic key with special characters accepted");

	// Test keys with exactly minimum valid lengths
	ok(validate_api_key_format("sk-abcdefghij", "openai"),
	   "OpenAI key with exactly 10 chars accepted");
	ok(validate_api_key_format("sk-ant-abcdefghijklmnop", "anthropic"),
	   "Anthropic key with exactly 25 chars accepted");

	// Test keys with whitespace at boundaries (should be rejected)
	ok(!validate_api_key_format(" sk-abcdefghij", "openai"),
	   "API key with leading space rejected");
	ok(!validate_api_key_format("sk-abcdefghij ", "openai"),
	   "API key with trailing space rejected");
	ok(!validate_api_key_format("sk-abc def-ghij", "openai"),
	   "API key with internal space rejected");
	ok(!validate_api_key_format("sk-abcdefghij\t", "openai"),
	   "API key with tab rejected");
	ok(!validate_api_key_format("sk-abcdefghij\n", "openai"),
	   "API key with newline rejected");
}

// ============================================================================
// Test: URL Validation Edge Cases
// ============================================================================

void test_url_edge_cases() {
	diag("=== URL Validation Edge Cases ===");

	// Test IPv6 URLs
	ok(validate_url_format("http://[2001:db8::1]:8080/v1/chat/completions"),
	   "IPv6 URL with port accepted");
	ok(validate_url_format("https://[::1]/v1/chat/completions"),
	   "IPv6 localhost URL accepted");

	// Test unusual ports
	ok(validate_url_format("http://localhost:1/v1/chat/completions"),
	   "URL with port 1 accepted");
	ok(validate_url_format("http://localhost:65535/v1/chat/completions"),
	   "URL with port 65535 accepted");

	// Test URLs with paths and query parameters
	ok(validate_url_format("https://api.openai.com/v1/chat/completions?timeout=30"),
	   "URL with query parameters accepted");
	ok(validate_url_format("http://localhost:11434/v1/chat/completions/model/llama3"),
	   "URL with additional path segments accepted");

	// Test malformed URLs that should be rejected
	ok(!validate_url_format("http://"),
	   "URL with only protocol rejected");
	ok(!validate_url_format("http://:8080"),
	   "URL with port but no host rejected");
	ok(!validate_url_format("localhost:8080/v1/chat/completions"),
	   "URL without protocol rejected");
	ok(!validate_url_format("ftp://localhost/v1/chat/completions"),
	   "FTP URL rejected (only HTTP/HTTPS supported)");
}

// ============================================================================
// Test: Numeric Range Edge Cases
// ============================================================================

void test_numeric_range_edge_cases() {
	diag("=== Numeric Range Edge Cases ===");

	// Test boundary values
	ok(validate_numeric_range("0", 0, 100, "test_var"),
	   "Minimum boundary value accepted");
	ok(validate_numeric_range("100", 0, 100, "test_var"),
	   "Maximum boundary value accepted");
	ok(!validate_numeric_range("-1", 0, 100, "test_var"),
	   "Value below minimum rejected");
	ok(!validate_numeric_range("101", 0, 100, "test_var"),
	   "Value above maximum rejected");

	// Test string values that are valid numbers
	ok(validate_numeric_range("50", 0, 100, "test_var"),
	   "Valid number string accepted");
	ok(!validate_numeric_range("abc", 0, 100, "test_var"),
	   "Non-numeric string rejected");
	ok(!validate_numeric_range("50abc", 0, 100, "test_var"),
	   "String starting with number rejected");
	ok(!validate_numeric_range("", 0, 100, "test_var"),
	   "Empty string rejected");

	// Test negative numbers
	ok(validate_numeric_range("-50", -100, 0, "test_var"),
	   "Negative number within range accepted");
	ok(!validate_numeric_range("-150", -100, 0, "test_var"),
	   "Negative number below range rejected");
}

// ============================================================================
// Test: Provider Format Edge Cases
// ============================================================================

void test_provider_format_edge_cases() {
	diag("=== Provider Format Edge Cases ===");

	// Test case sensitivity
	ok(!validate_provider_format("OpenAI"),
	   "Uppercase 'OpenAI' rejected (case sensitive)");
	ok(!validate_provider_format("OPENAI"),
	   "Uppercase 'OPENAI' rejected (case sensitive)");
	ok(!validate_provider_format("Anthropic"),
	   "Uppercase 'Anthropic' rejected (case sensitive)");
	ok(!validate_provider_format("ANTHROPIC"),
	   "Uppercase 'ANTHROPIC' rejected (case sensitive)");

	// Test provider names with whitespace
	ok(!validate_provider_format(" openai"),
	   "Provider with leading space rejected");
	ok(!validate_provider_format("openai "),
	   "Provider with trailing space rejected");
	ok(!validate_provider_format(" openai "),
	   "Provider with leading and trailing spaces rejected");
	ok(!validate_provider_format("open ai"),
	   "Provider with internal space rejected");

	// Test empty and NULL cases
	ok(!validate_provider_format(""),
	   "Empty provider format rejected");
	ok(!validate_provider_format(NULL),
	   "NULL provider format rejected");

	// Test similar but invalid provider names
	ok(!validate_provider_format("openai2"),
	   "Similar but invalid provider 'openai2' rejected");
	ok(!validate_provider_format("anthropic2"),
	   "Similar but invalid provider 'anthropic2' rejected");
	ok(!validate_provider_format("ollama"),
	   "Provider 'ollama' rejected (use 'openai' format instead)");
}

// ============================================================================
// Test: Edge Cases and Boundary Conditions
// ============================================================================

void test_general_edge_cases() {
	diag("=== General Edge Cases ===");

	// Test extremely long strings
	char* long_string = (char*)malloc(10000);
	memset(long_string, 'a', 9999);
	long_string[9999] = '\0';
	ok(validate_api_key_format(long_string, "openai"),
	   "Extremely long API key accepted");
	free(long_string);

	// Test strings with special Unicode characters (if supported)
	// Note: This is a basic test - actual Unicode support depends on system
	ok(validate_api_key_format("sk-testkey123", "openai"),
	   "Standard ASCII key accepted");
}

// ============================================================================
// Main
// ============================================================================

int main() {
	// Plan: 47 tests total
	// API key edge cases: 12 tests
	// URL edge cases: 10 tests
	// Numeric range edge cases: 10 tests
	// Provider format edge cases: 13 tests
	// General edge cases: 2 tests
	plan(47);

	test_api_key_edge_cases();
	test_url_edge_cases();
	test_numeric_range_edge_cases();
	test_provider_format_edge_cases();
	test_general_edge_cases();

	return exit_status();
}