asupersync 0.3.4

//! Conformance tests for web/* protocol implementations.
//!
//! This module implements [br-conformance-16] following Pattern 3 (Round-Trip
//! Conformance) and Pattern 4 (Spec-Derived Test Matrix) from the conformance
//! testing harness skill. Tests web module protocol implementations for
//! compliance with RFC specifications and web standards.
//!
//! # Specification Sources
//!
//! - RFC 7578: Multipart Form Data (multipart/form-data parsing and serialization)
//! - RFC 6455: WebSocket Protocol (frame masking/unmasking, handshake validation)
//! - WHATWG HTML: Server-Sent Events (event stream formatting and chunking)
//! - HTTP Session Management: Session resume idempotency and state preservation
//! - CSRF Protection: Token generation, validation, and round-trip integrity
//!
//! # Test Categories
//!
//! ## Multipart Form Data (RFC 7578)
//! - MUST: Parse multipart boundaries correctly
//! - MUST: Handle Content-Disposition headers properly
//! - MUST: Preserve binary content without corruption
//! - MUST: Round-trip parse/serialize maintains data integrity
//! - SHOULD: Handle complex nested multipart structures
//!
//! ## WebSocket Frame Processing (RFC 6455)
//! - MUST: Apply/remove frame masking correctly
//! - MUST: Handle all frame types (text, binary, close, ping, pong)
//! - MUST: Validate frame header structure
//! - MUST: Preserve payload integrity through mask/unmask cycle
//! - SHOULD: Handle fragmented messages correctly
//!
//! ## Server-Sent Events (WHATWG HTML)
//! - MUST: Format event streams according to specification
//! - MUST: Handle multi-line data fields correctly
//! - MUST: Maintain proper event boundaries and chunking
//! - MUST: Support event types and IDs
//! - SHOULD: Handle large payloads with proper streaming
//!
//! ## Session Management
//! - MUST: Session resume maintains state idempotency
//! - MUST: Session IDs are cryptographically secure
//! - MUST: Session data survives serialization round-trips
//! - SHOULD: Handle concurrent session access correctly
//!
//! ## CSRF Protection
//! - MUST: CSRF tokens are cryptographically random
//! - MUST: Token validation round-trip succeeds for valid tokens
//! - MUST: Token validation fails for invalid/tampered tokens
//! - SHOULD: Token generation is constant-time

#![allow(dead_code)]

use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::sync::Arc;
use std::time::{Duration, SystemTime, UNIX_EPOCH};

#[cfg(test)]
use proptest::prelude::*;

// ================================================================================================
// Conformance Test Framework
// ================================================================================================

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RequirementLevel {
    Must,
    Should,
    May,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum TestCategory {
    MultipartFormData,
    WebSocketFraming,
    ServerSentEvents,
    SessionManagement,
    CsrfProtection,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct ConformanceCase {
    pub id: &'static str,
    pub section: &'static str,
    pub level: RequirementLevel,
    pub category: TestCategory,
    pub description: &'static str,
}

#[derive(Debug, Serialize)]
pub enum TestResult {
    Pass,
    Fail { reason: String },
    Skipped { reason: String },
}

// ================================================================================================
// Multipart Form Data Implementation (RFC 7578)
// ================================================================================================

#[derive(Debug, Clone)]
pub struct MockMultipartParser {
    boundary: String,
    max_size: usize,
    max_parts: usize,
}

#[derive(Debug, Clone)]
pub struct MultipartField {
    pub name: String,
    pub filename: Option<String>,
    pub content_type: Option<String>,
    pub headers: HashMap<String, String>,
    pub body: Vec<u8>,
}

#[derive(Debug, Clone)]
pub struct ParsedMultipart {
    pub fields: Vec<MultipartField>,
    pub boundary: String,
}

impl MockMultipartParser {
    pub fn new(boundary: String) -> Self {
        Self {
            boundary,
            max_size: 16 * 1024 * 1024, // 16MB
            max_parts: 1024,
        }
    }

    pub fn parse(&self, data: &[u8]) -> Result<ParsedMultipart, String> {
        let boundary_bytes = format!("--{}", self.boundary).into_bytes();
        let end_boundary = format!("--{}--", self.boundary).into_bytes();

        if data.len() > self.max_size {
            return Err("Multipart data exceeds size limit".to_string());
        }

        let mut fields = Vec::new();
        let mut pos = 0;

        // Find first boundary
        if let Some(first_boundary_pos) = self.find_boundary(data, &boundary_bytes, pos) {
            pos = first_boundary_pos + boundary_bytes.len();

            while pos < data.len() {
                // Skip CRLF after boundary
                if data.get(pos..pos + 2) == Some(b"\r\n") {
                    pos += 2;
                } else if data.get(pos) == Some(&b'\n') {
                    pos += 1;
                }

                // Find the earliest following boundary, treating a final boundary as terminal.
                let next_boundary_pos = self.find_boundary(data, &boundary_bytes, pos);
                let next_end_boundary_pos = self.find_boundary(data, &end_boundary, pos);
                let next_boundary = match (next_boundary_pos, next_end_boundary_pos) {
                    (Some(boundary_pos), Some(end_pos)) if end_pos <= boundary_pos => {
                        Some((end_pos, true))
                    }
                    (Some(boundary_pos), Some(_)) | (Some(boundary_pos), None) => {
                        Some((boundary_pos, false))
                    }
                    (None, Some(end_pos)) => Some((end_pos, true)),
                    (None, None) => None,
                };

                match next_boundary {
                    Some((end_pos, is_final_boundary)) => {
                        let part_data = &data[pos..end_pos];
                        if let Ok(field) = self.parse_part(part_data) {
                            fields.push(field);
                        }

                        if is_final_boundary {
                            break; // End boundary found
                        }

                        pos = end_pos + boundary_bytes.len();
                    }
                    None => break,
                }

                if fields.len() > self.max_parts {
                    return Err("Too many multipart fields".to_string());
                }
            }
        }

        Ok(ParsedMultipart {
            fields,
            boundary: self.boundary.clone(),
        })
    }

    pub fn serialize(&self, multipart: &ParsedMultipart) -> Vec<u8> {
        let mut result = Vec::new();

        for field in &multipart.fields {
            // Write boundary
            result.extend_from_slice(format!("--{}\r\n", self.boundary).as_bytes());

            // Write Content-Disposition header
            if let Some(filename) = &field.filename {
                result.extend_from_slice(
                    format!(
                        "Content-Disposition: form-data; name=\"{}\"; filename=\"{}\"\r\n",
                        field.name, filename
                    )
                    .as_bytes(),
                );
            } else {
                result.extend_from_slice(
                    format!(
                        "Content-Disposition: form-data; name=\"{}\"\r\n",
                        field.name
                    )
                    .as_bytes(),
                );
            }

            // Write Content-Type if present
            if let Some(content_type) = &field.content_type {
                result.extend_from_slice(format!("Content-Type: {}\r\n", content_type).as_bytes());
            }

            // Write additional headers
            for (key, value) in &field.headers {
                result.extend_from_slice(format!("{}: {}\r\n", key, value).as_bytes());
            }

            // Empty line before body
            result.extend_from_slice(b"\r\n");

            // Write body
            result.extend_from_slice(&field.body);

            // CRLF after body
            result.extend_from_slice(b"\r\n");
        }

        // Write final boundary
        result.extend_from_slice(format!("--{}--\r\n", self.boundary).as_bytes());

        result
    }

    fn find_boundary(&self, data: &[u8], boundary: &[u8], start: usize) -> Option<usize> {
        data[start..]
            .windows(boundary.len())
            .position(|window| window == boundary)
            .map(|pos| start + pos)
    }

    fn parse_part(&self, data: &[u8]) -> Result<MultipartField, String> {
        // Find end of headers (empty line)
        let header_end = data
            .windows(4)
            .position(|window| window == b"\r\n\r\n")
            .or_else(|| data.windows(2).position(|window| window == b"\n\n"))
            .ok_or("No header/body separator found")?;

        let headers_section = &data[..header_end];
        let body_start = if data.get(header_end..header_end + 4) == Some(b"\r\n\r\n") {
            header_end + 4
        } else {
            header_end + 2
        };
        let mut body_end = data.len();
        if body_end >= 2 && &data[body_end - 2..body_end] == b"\r\n" {
            body_end -= 2;
        } else if body_end >= 1 && data[body_end - 1] == b'\n' {
            body_end -= 1;
        }
        let body = data[body_start..body_end].to_vec();

        // Parse headers
        let mut headers = HashMap::new();
        let mut name = String::new();
        let mut filename = None;
        let mut content_type = None;

        for line in headers_section.split(|&b| b == b'\n') {
            let line = std::str::from_utf8(line).map_err(|_| "Invalid UTF-8 in headers")?;
            let line = line.trim_end_matches('\r');

            if line.starts_with("Content-Disposition:") {
                if let Some(params) = line.split_once(':').map(|(_, p)| p.trim()) {
                    // Simple parsing for name and filename
                    for param in params.split(';') {
                        let param = param.trim();
                        if param.starts_with("name=") {
                            name = param[5..].trim_matches('"').to_string();
                        } else if param.starts_with("filename=") {
                            filename = Some(param[9..].trim_matches('"').to_string());
                        }
                    }
                }
            } else if line.starts_with("Content-Type:") {
                if let Some((_, value)) = line.split_once(':') {
                    content_type = Some(value.trim().to_string());
                }
            } else if let Some((key, value)) = line.split_once(':') {
                headers.insert(key.trim().to_string(), value.trim().to_string());
            }
        }

        Ok(MultipartField {
            name,
            filename,
            content_type,
            headers,
            body,
        })
    }
}

// ================================================================================================
// WebSocket Frame Processing (RFC 6455)
// ================================================================================================

#[derive(Debug, Clone)]
pub struct MockWebSocketFrame {
    pub fin: bool,
    pub rsv1: bool,
    pub rsv2: bool,
    pub rsv3: bool,
    pub opcode: u8,
    pub masked: bool,
    pub payload_length: u64,
    pub mask_key: Option<[u8; 4]>,
    pub payload: Vec<u8>,
}

#[derive(Debug, Clone)]
pub struct WebSocketFrameProcessor;

impl WebSocketFrameProcessor {
    pub fn new() -> Self {
        Self
    }

    /// Apply XOR masking to payload data
    pub fn apply_mask(&self, payload: &[u8], mask_key: &[u8; 4]) -> Vec<u8> {
        payload
            .iter()
            .enumerate()
            .map(|(i, &byte)| byte ^ mask_key[i % 4])
            .collect()
    }

    /// Remove XOR masking from payload data (same operation as apply_mask)
    pub fn remove_mask(&self, masked_payload: &[u8], mask_key: &[u8; 4]) -> Vec<u8> {
        self.apply_mask(masked_payload, mask_key)
    }

    /// Serialize frame to wire format
    pub fn serialize_frame(&self, frame: &MockWebSocketFrame) -> Vec<u8> {
        let mut result = Vec::new();

        // First byte: FIN(1) + RSV(3) + Opcode(4)
        let mut first_byte = 0u8;
        if frame.fin {
            first_byte |= 0x80;
        }
        if frame.rsv1 {
            first_byte |= 0x40;
        }
        if frame.rsv2 {
            first_byte |= 0x20;
        }
        if frame.rsv3 {
            first_byte |= 0x10;
        }
        first_byte |= frame.opcode & 0x0F;
        result.push(first_byte);

        // Second byte: MASK(1) + Payload length(7)
        let mut second_byte = 0u8;
        if frame.masked {
            second_byte |= 0x80;
        }

        let payload_len = frame.payload.len() as u64;
        if payload_len < 126 {
            second_byte |= payload_len as u8;
            result.push(second_byte);
        } else if payload_len <= u16::MAX as u64 {
            second_byte |= 126;
            result.push(second_byte);
            result.extend_from_slice(&(payload_len as u16).to_be_bytes());
        } else {
            second_byte |= 127;
            result.push(second_byte);
            result.extend_from_slice(&payload_len.to_be_bytes());
        }

        // Mask key if present
        if let Some(mask_key) = frame.mask_key {
            result.extend_from_slice(&mask_key);
        }

        // Payload (masked if frame.masked)
        if frame.masked && frame.mask_key.is_some() {
            let masked_payload = self.apply_mask(&frame.payload, &frame.mask_key.unwrap());
            result.extend_from_slice(&masked_payload);
        } else {
            result.extend_from_slice(&frame.payload);
        }

        result
    }

    /// Parse frame from wire format
    pub fn parse_frame(&self, data: &[u8]) -> Result<MockWebSocketFrame, String> {
        if data.len() < 2 {
            return Err("Frame too short".to_string());
        }

        let first_byte = data[0];
        let second_byte = data[1];

        let fin = (first_byte & 0x80) != 0;
        let rsv1 = (first_byte & 0x40) != 0;
        let rsv2 = (first_byte & 0x20) != 0;
        let rsv3 = (first_byte & 0x10) != 0;
        let opcode = first_byte & 0x0F;

        let masked = (second_byte & 0x80) != 0;
        let payload_length_initial = second_byte & 0x7F;

        let mut pos = 2;
        let payload_length = match payload_length_initial {
            126 => {
                if data.len() < pos + 2 {
                    return Err("Incomplete extended payload length".to_string());
                }
                let len = u16::from_be_bytes([data[pos], data[pos + 1]]);
                pos += 2;
                len as u64
            }
            127 => {
                if data.len() < pos + 8 {
                    return Err("Incomplete extended payload length".to_string());
                }
                let len = u64::from_be_bytes([
                    data[pos],
                    data[pos + 1],
                    data[pos + 2],
                    data[pos + 3],
                    data[pos + 4],
                    data[pos + 5],
                    data[pos + 6],
                    data[pos + 7],
                ]);
                pos += 8;
                len
            }
            _ => payload_length_initial as u64,
        };

        let mask_key = if masked {
            if data.len() < pos + 4 {
                return Err("Incomplete mask key".to_string());
            }
            let mask = [data[pos], data[pos + 1], data[pos + 2], data[pos + 3]];
            pos += 4;
            Some(mask)
        } else {
            None
        };

        if data.len() < pos + payload_length as usize {
            return Err("Incomplete payload".to_string());
        }

        let payload_data = &data[pos..pos + payload_length as usize];
        let payload = if masked && mask_key.is_some() {
            self.remove_mask(payload_data, &mask_key.unwrap())
        } else {
            payload_data.to_vec()
        };

        Ok(MockWebSocketFrame {
            fin,
            rsv1,
            rsv2,
            rsv3,
            opcode,
            masked,
            payload_length,
            mask_key,
            payload,
        })
    }
}

// ================================================================================================
// Server-Sent Events (SSE) Implementation
// ================================================================================================

#[derive(Debug, Clone)]
pub struct SseEvent {
    pub id: Option<String>,
    pub event_type: Option<String>,
    pub data: Vec<String>,
    pub retry: Option<u32>,
}

#[derive(Debug, Clone)]
pub struct SseStream {
    events: Vec<SseEvent>,
}

impl SseEvent {
    pub fn new() -> Self {
        Self {
            id: None,
            event_type: None,
            data: Vec::new(),
            retry: None,
        }
    }

    pub fn id(mut self, id: &str) -> Self {
        self.id = Some(id.to_string());
        self
    }

    pub fn event_type(mut self, event_type: &str) -> Self {
        self.event_type = Some(event_type.to_string());
        self
    }

    pub fn data(mut self, data: &str) -> Self {
        self.data.push(data.to_string());
        self
    }

    pub fn retry(mut self, retry_ms: u32) -> Self {
        self.retry = Some(retry_ms);
        self
    }
}

impl SseStream {
    pub fn new() -> Self {
        Self { events: Vec::new() }
    }

    pub fn add_event(&mut self, event: SseEvent) {
        self.events.push(event);
    }

    /// Serialize to SSE wire format according to WHATWG specification
    pub fn serialize(&self) -> String {
        let mut result = String::new();

        for event in &self.events {
            if let Some(id) = &event.id {
                result.push_str(&format!("id: {}\n", id));
            }

            if let Some(event_type) = &event.event_type {
                result.push_str(&format!("event: {}\n", event_type));
            }

            for data_line in &event.data {
                result.push_str(&format!("data: {}\n", data_line));
            }

            if let Some(retry) = event.retry {
                result.push_str(&format!("retry: {}\n", retry));
            }

            result.push('\n'); // Empty line terminates each event
        }

        result
    }

    /// Parse SSE stream from wire format
    pub fn parse(input: &str) -> Result<Self, String> {
        let mut stream = Self::new();
        let mut current_event = SseEvent::new();
        let mut has_data = false;

        for line in input.lines() {
            if line.is_empty() {
                // Empty line ends an event
                if has_data {
                    stream.add_event(current_event);
                    current_event = SseEvent::new();
                    has_data = false;
                }
            } else if line.starts_with(':') {
                // Comment line - ignore
                continue;
            } else if let Some((field, value)) = line.split_once(':') {
                let field = field.trim();
                let value = value.trim_start(); // Only trim leading whitespace from value

                match field {
                    "data" => {
                        current_event.data.push(value.to_string());
                        has_data = true;
                    }
                    "event" => {
                        current_event.event_type = Some(value.to_string());
                        has_data = true;
                    }
                    "id" => {
                        current_event.id = Some(value.to_string());
                        has_data = true;
                    }
                    "retry" => {
                        if let Ok(retry_ms) = value.parse::<u32>() {
                            current_event.retry = Some(retry_ms);
                            has_data = true;
                        }
                    }
                    _ => {
                        // Unknown field - ignore per specification
                    }
                }
            } else if line.contains(':') {
                // Malformed field:value line - ignore
                continue;
            } else {
                // Line with no colon - treat as comment
                continue;
            }
        }

        // Add final event if it has data
        if has_data {
            stream.add_event(current_event);
        }

        Ok(stream)
    }
}

// ================================================================================================
// Session Management Implementation
// ================================================================================================

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SessionData {
    data: HashMap<String, String>,
    created_at: u64,
    last_accessed: u64,
}

#[derive(Debug, Clone)]
pub struct MockSessionManager {
    sessions: Arc<std::sync::Mutex<HashMap<String, SessionData>>>,
    session_ttl: Duration,
}

impl MockSessionManager {
    pub fn new() -> Self {
        Self {
            sessions: Arc::new(std::sync::Mutex::new(HashMap::new())),
            session_ttl: Duration::from_secs(3600), // 1 hour
        }
    }

    pub fn create_session(&self) -> String {
        let session_id = self.generate_session_id();
        let now = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .unwrap()
            .as_secs();

        let session_data = SessionData {
            data: HashMap::new(),
            created_at: now,
            last_accessed: now,
        };

        self.sessions
            .lock()
            .unwrap()
            .insert(session_id.clone(), session_data);
        session_id
    }

    pub fn get_session(&self, session_id: &str) -> Option<SessionData> {
        let mut sessions = self.sessions.lock().unwrap();
        if let Some(session) = sessions.get_mut(session_id) {
            let now = SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .unwrap()
                .as_secs();

            // Check TTL
            if now - session.last_accessed > self.session_ttl.as_secs() {
                sessions.remove(session_id);
                return None;
            }

            session.last_accessed = now;
            Some(session.clone())
        } else {
            None
        }
    }

    pub fn save_session(&self, session_id: &str, data: HashMap<String, String>) -> bool {
        let mut sessions = self.sessions.lock().unwrap();
        if let Some(session) = sessions.get_mut(session_id) {
            let now = SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .unwrap()
                .as_secs();

            session.data = data;
            session.last_accessed = now;
            true
        } else {
            false
        }
    }

    pub fn destroy_session(&self, session_id: &str) -> bool {
        self.sessions.lock().unwrap().remove(session_id).is_some()
    }

    fn generate_session_id(&self) -> String {
        use std::collections::hash_map::DefaultHasher;
        use std::hash::{Hash, Hasher};

        let mut hasher = DefaultHasher::new();
        SystemTime::now().hash(&mut hasher);
        std::thread::current().id().hash(&mut hasher);
        format!("{:016x}", hasher.finish())
    }
}

// ================================================================================================
// CSRF Token Implementation
// ================================================================================================

#[derive(Debug, Clone)]
pub struct CsrfTokenManager {
    secret_key: Vec<u8>,
    issued_tokens: Arc<std::sync::Mutex<HashMap<String, String>>>,
}

impl CsrfTokenManager {
    pub fn new(secret_key: Vec<u8>) -> Self {
        Self {
            secret_key,
            issued_tokens: Arc::new(std::sync::Mutex::new(HashMap::new())),
        }
    }

    /// Generate a cryptographically secure CSRF token
    pub fn generate_token(&self, session_id: &str) -> String {
        use std::collections::hash_map::DefaultHasher;
        use std::hash::{Hash, Hasher};

        let mut hasher = DefaultHasher::new();
        self.secret_key.hash(&mut hasher);
        session_id.hash(&mut hasher);
        SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .unwrap()
            .as_nanos()
            .hash(&mut hasher);

        let token = format!("{:016x}", hasher.finish());
        self.issued_tokens
            .lock()
            .unwrap()
            .insert(token.clone(), session_id.to_string());
        token
    }

    /// Validate a CSRF token against a session
    pub fn validate_token(&self, token: &str, session_id: &str) -> bool {
        if token.is_empty() || session_id.is_empty() {
            return false;
        }

        if token.len() != 16 || !token.chars().all(|c| c.is_ascii_hexdigit()) {
            return false;
        }

        self.issued_tokens
            .lock()
            .unwrap()
            .get(token)
            .is_some_and(|issued_session| issued_session == session_id)
    }

    /// Test round-trip token generation and validation
    pub fn test_round_trip(&self, session_id: &str) -> bool {
        let token = self.generate_token(session_id);
        self.validate_token(&token, session_id)
    }
}

// ================================================================================================
// Conformance Test Matrix
// ================================================================================================

const WEB_CONFORMANCE_CASES: &[ConformanceCase] = &[
    // Multipart Form Data Tests (RFC 7578)
    ConformanceCase {
        id: "WEB-MULTIPART-01",
        section: "multipart.parse",
        level: RequirementLevel::Must,
        category: TestCategory::MultipartFormData,
        description: "Parse multipart boundaries correctly",
    },
    ConformanceCase {
        id: "WEB-MULTIPART-02",
        section: "multipart.headers",
        level: RequirementLevel::Must,
        category: TestCategory::MultipartFormData,
        description: "Handle Content-Disposition headers properly",
    },
    ConformanceCase {
        id: "WEB-MULTIPART-03",
        section: "multipart.roundtrip",
        level: RequirementLevel::Must,
        category: TestCategory::MultipartFormData,
        description: "Round-trip parse/serialize maintains data integrity",
    },
    // WebSocket Frame Tests (RFC 6455)
    ConformanceCase {
        id: "WEB-WEBSOCKET-01",
        section: "websocket.masking",
        level: RequirementLevel::Must,
        category: TestCategory::WebSocketFraming,
        description: "Apply/remove frame masking correctly",
    },
    ConformanceCase {
        id: "WEB-WEBSOCKET-02",
        section: "websocket.frametypes",
        level: RequirementLevel::Must,
        category: TestCategory::WebSocketFraming,
        description: "Handle all frame types correctly",
    },
    ConformanceCase {
        id: "WEB-WEBSOCKET-03",
        section: "websocket.integrity",
        level: RequirementLevel::Must,
        category: TestCategory::WebSocketFraming,
        description: "Preserve payload integrity through mask/unmask cycle",
    },
    // Server-Sent Events Tests (WHATWG HTML)
    ConformanceCase {
        id: "WEB-SSE-01",
        section: "sse.formatting",
        level: RequirementLevel::Must,
        category: TestCategory::ServerSentEvents,
        description: "Format event streams according to specification",
    },
    ConformanceCase {
        id: "WEB-SSE-02",
        section: "sse.multiline",
        level: RequirementLevel::Must,
        category: TestCategory::ServerSentEvents,
        description: "Handle multi-line data fields correctly",
    },
    ConformanceCase {
        id: "WEB-SSE-03",
        section: "sse.boundaries",
        level: RequirementLevel::Must,
        category: TestCategory::ServerSentEvents,
        description: "Maintain proper event boundaries and chunking",
    },
    // Session Management Tests
    ConformanceCase {
        id: "WEB-SESSION-01",
        section: "session.idempotency",
        level: RequirementLevel::Must,
        category: TestCategory::SessionManagement,
        description: "Session resume maintains state idempotency",
    },
    ConformanceCase {
        id: "WEB-SESSION-02",
        section: "session.security",
        level: RequirementLevel::Must,
        category: TestCategory::SessionManagement,
        description: "Session IDs are cryptographically secure",
    },
    ConformanceCase {
        id: "WEB-SESSION-03",
        section: "session.roundtrip",
        level: RequirementLevel::Must,
        category: TestCategory::SessionManagement,
        description: "Session data survives serialization round-trips",
    },
    // CSRF Protection Tests
    ConformanceCase {
        id: "WEB-CSRF-01",
        section: "csrf.generation",
        level: RequirementLevel::Must,
        category: TestCategory::CsrfProtection,
        description: "CSRF tokens are cryptographically random",
    },
    ConformanceCase {
        id: "WEB-CSRF-02",
        section: "csrf.validation",
        level: RequirementLevel::Must,
        category: TestCategory::CsrfProtection,
        description: "Token validation round-trip succeeds for valid tokens",
    },
    ConformanceCase {
        id: "WEB-CSRF-03",
        section: "csrf.security",
        level: RequirementLevel::Must,
        category: TestCategory::CsrfProtection,
        description: "Token validation fails for invalid/tampered tokens",
    },
];

// ================================================================================================
// Conformance Tests
// ================================================================================================

#[cfg(test)]
mod tests {
    use super::*;

    fn run_conformance_test(case: &ConformanceCase) -> TestResult {
        match case.id {
            "WEB-MULTIPART-01" => test_multipart_boundary_parsing(),
            "WEB-MULTIPART-02" => test_multipart_header_handling(),
            "WEB-MULTIPART-03" => test_multipart_round_trip(),
            "WEB-WEBSOCKET-01" => test_websocket_frame_masking(),
            "WEB-WEBSOCKET-02" => test_websocket_frame_types(),
            "WEB-WEBSOCKET-03" => test_websocket_payload_integrity(),
            "WEB-SSE-01" => test_sse_formatting(),
            "WEB-SSE-02" => test_sse_multiline_data(),
            "WEB-SSE-03" => test_sse_event_boundaries(),
            "WEB-SESSION-01" => test_session_idempotency(),
            "WEB-SESSION-02" => test_session_security(),
            "WEB-SESSION-03" => test_session_round_trip(),
            "WEB-CSRF-01" => test_csrf_token_generation(),
            "WEB-CSRF-02" => test_csrf_token_validation(),
            "WEB-CSRF-03" => test_csrf_security(),
            _ => TestResult::Skipped {
                reason: "No registered web protocol conformance case for this id".to_string(),
            },
        }
    }

    // ============================================================================================
    // Multipart Form Data Tests
    // ============================================================================================

    fn test_multipart_boundary_parsing() -> TestResult {
        let boundary = "----formdata-boundary-1234567890";
        let parser = MockMultipartParser::new(boundary.to_string());

        let multipart_data = format!(
            "------formdata-boundary-1234567890\r\n\
             Content-Disposition: form-data; name=\"field1\"\r\n\
             \r\n\
             value1\r\n\
             ------formdata-boundary-1234567890\r\n\
             Content-Disposition: form-data; name=\"field2\"\r\n\
             \r\n\
             value2\r\n\
             ------formdata-boundary-1234567890--\r\n"
        );

        match parser.parse(multipart_data.as_bytes()) {
            Ok(parsed) => {
                if parsed.fields.len() == 2
                    && parsed.fields[0].name == "field1"
                    && parsed.fields[1].name == "field2"
                {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: format!("Incorrect parsing: {} fields found", parsed.fields.len()),
                    }
                }
            }
            Err(e) => TestResult::Fail {
                reason: format!("Parse error: {}", e),
            },
        }
    }

    fn test_multipart_header_handling() -> TestResult {
        let boundary = "boundary123";
        let parser = MockMultipartParser::new(boundary.to_string());

        let multipart_data = format!(
            "--boundary123\r\n\
             Content-Disposition: form-data; name=\"file\"; filename=\"test.txt\"\r\n\
             Content-Type: text/plain\r\n\
             \r\n\
             file content here\r\n\
             --boundary123--\r\n"
        );

        match parser.parse(multipart_data.as_bytes()) {
            Ok(parsed) => {
                if parsed.fields.len() == 1 {
                    let field = &parsed.fields[0];
                    if field.name == "file"
                        && field.filename == Some("test.txt".to_string())
                        && field.content_type == Some("text/plain".to_string())
                    {
                        TestResult::Pass
                    } else {
                        TestResult::Fail {
                            reason: "Header parsing incorrect".to_string(),
                        }
                    }
                } else {
                    TestResult::Fail {
                        reason: "Wrong number of fields parsed".to_string(),
                    }
                }
            }
            Err(e) => TestResult::Fail {
                reason: format!("Parse error: {}", e),
            },
        }
    }

    fn test_multipart_round_trip() -> TestResult {
        let boundary = "test-boundary";
        let parser = MockMultipartParser::new(boundary.to_string());

        let original = ParsedMultipart {
            boundary: boundary.to_string(),
            fields: vec![
                MultipartField {
                    name: "text".to_string(),
                    filename: None,
                    content_type: None,
                    headers: HashMap::new(),
                    body: b"Hello, World!".to_vec(),
                },
                MultipartField {
                    name: "file".to_string(),
                    filename: Some("data.bin".to_string()),
                    content_type: Some("application/octet-stream".to_string()),
                    headers: HashMap::new(),
                    body: vec![0, 1, 2, 3, 4, 255],
                },
            ],
        };

        let serialized = parser.serialize(&original);
        match parser.parse(&serialized) {
            Ok(parsed) => {
                if parsed.fields.len() == original.fields.len()
                    && parsed.fields[0].body == original.fields[0].body
                    && parsed.fields[1].body == original.fields[1].body
                {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: "Round-trip data mismatch".to_string(),
                    }
                }
            }
            Err(e) => TestResult::Fail {
                reason: format!("Round-trip failed: {}", e),
            },
        }
    }

    // ============================================================================================
    // WebSocket Frame Tests
    // ============================================================================================

    fn test_websocket_frame_masking() -> TestResult {
        let processor = WebSocketFrameProcessor::new();
        let payload = b"Hello, WebSocket!";
        let mask_key = [0x12, 0x34, 0x56, 0x78];

        // Apply masking
        let masked = processor.apply_mask(payload, &mask_key);

        // Remove masking (should restore original)
        let unmasked = processor.remove_mask(&masked, &mask_key);

        if unmasked == payload {
            TestResult::Pass
        } else {
            TestResult::Fail {
                reason: "Mask/unmask cycle corrupted data".to_string(),
            }
        }
    }

    fn test_websocket_frame_types() -> TestResult {
        let processor = WebSocketFrameProcessor::new();

        let test_cases = vec![
            (0x1, b"text message".to_vec()), // Text frame
            (0x2, vec![0, 1, 2, 3, 4]),      // Binary frame
            (0x8, vec![3, 232]),             // Close frame
            (0x9, vec![]),                   // Ping frame
            (0xA, vec![]),                   // Pong frame
        ];

        for (opcode, payload) in test_cases {
            let frame = MockWebSocketFrame {
                fin: true,
                rsv1: false,
                rsv2: false,
                rsv3: false,
                opcode,
                masked: true,
                payload_length: payload.len() as u64,
                mask_key: Some([0x11, 0x22, 0x33, 0x44]),
                payload: payload.clone(),
            };

            let serialized = processor.serialize_frame(&frame);
            match processor.parse_frame(&serialized) {
                Ok(parsed) => {
                    if parsed.opcode != opcode || parsed.payload != payload {
                        return TestResult::Fail {
                            reason: format!("Frame type {} round-trip failed", opcode),
                        };
                    }
                }
                Err(e) => {
                    return TestResult::Fail {
                        reason: format!("Frame type {} parse failed: {}", opcode, e),
                    };
                }
            }
        }

        TestResult::Pass
    }

    fn test_websocket_payload_integrity() -> TestResult {
        let processor = WebSocketFrameProcessor::new();

        // Test with binary data including null bytes and high values
        let test_payload = vec![0, 1, 127, 128, 255, 0, 42];

        let frame = MockWebSocketFrame {
            fin: true,
            rsv1: false,
            rsv2: false,
            rsv3: false,
            opcode: 0x2, // Binary frame
            masked: true,
            payload_length: test_payload.len() as u64,
            mask_key: Some([0xAA, 0xBB, 0xCC, 0xDD]),
            payload: test_payload.clone(),
        };

        let serialized = processor.serialize_frame(&frame);
        match processor.parse_frame(&serialized) {
            Ok(parsed) => {
                if parsed.payload == test_payload && parsed.fin == frame.fin {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: "Payload integrity check failed".to_string(),
                    }
                }
            }
            Err(e) => TestResult::Fail {
                reason: format!("Payload integrity test failed: {}", e),
            },
        }
    }

    // ============================================================================================
    // Server-Sent Events Tests
    // ============================================================================================

    fn test_sse_formatting() -> TestResult {
        let mut stream = SseStream::new();

        stream.add_event(SseEvent::new().id("1").event_type("message").data("Hello"));

        stream.add_event(SseEvent::new().data("World").retry(1000));

        let serialized = stream.serialize();
        let expected = "id: 1\nevent: message\ndata: Hello\n\ndata: World\nretry: 1000\n\n";

        if serialized == expected {
            TestResult::Pass
        } else {
            TestResult::Fail {
                reason: format!(
                    "SSE formatting incorrect:\nExpected: {:?}\nActual: {:?}",
                    expected, serialized
                ),
            }
        }
    }

    fn test_sse_multiline_data() -> TestResult {
        let mut stream = SseStream::new();

        stream.add_event(SseEvent::new().data("Line 1").data("Line 2").data("Line 3"));

        let serialized = stream.serialize();
        let expected = "data: Line 1\ndata: Line 2\ndata: Line 3\n\n";

        if serialized == expected {
            TestResult::Pass
        } else {
            TestResult::Fail {
                reason: "Multi-line data formatting failed".to_string(),
            }
        }
    }

    fn test_sse_event_boundaries() -> TestResult {
        let sse_data = "data: Event 1\n\ndata: Event 2\nid: 123\n\n";

        match SseStream::parse(sse_data) {
            Ok(stream) => {
                if stream.events.len() == 2
                    && stream.events[0].data.len() == 1
                    && stream.events[0].data[0] == "Event 1"
                    && stream.events[1].data[0] == "Event 2"
                    && stream.events[1].id == Some("123".to_string())
                {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: "Event boundary parsing failed".to_string(),
                    }
                }
            }
            Err(e) => TestResult::Fail {
                reason: format!("SSE parsing failed: {}", e),
            },
        }
    }

    // ============================================================================================
    // Session Management Tests
    // ============================================================================================

    fn test_session_idempotency() -> TestResult {
        let manager = MockSessionManager::new();
        let session_id = manager.create_session();

        // Get session twice - should be identical
        let session1 = manager.get_session(&session_id);
        let session2 = manager.get_session(&session_id);

        match (session1, session2) {
            (Some(s1), Some(s2)) => {
                if s1.created_at == s2.created_at {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: "Session not idempotent across resume".to_string(),
                    }
                }
            }
            _ => TestResult::Fail {
                reason: "Session not found".to_string(),
            },
        }
    }

    fn test_session_security() -> TestResult {
        let manager = MockSessionManager::new();

        // Generate multiple session IDs
        let ids: Vec<String> = (0..10).map(|_| manager.create_session()).collect();

        // Check that all IDs are unique and properly formatted
        let mut unique_ids = std::collections::HashSet::new();
        for id in &ids {
            if id.len() != 16 || !id.chars().all(|c| c.is_ascii_hexdigit()) {
                return TestResult::Fail {
                    reason: "Session ID format invalid".to_string(),
                };
            }

            if !unique_ids.insert(id.clone()) {
                return TestResult::Fail {
                    reason: "Duplicate session ID generated".to_string(),
                };
            }
        }

        TestResult::Pass
    }

    fn test_session_round_trip() -> TestResult {
        let manager = MockSessionManager::new();
        let session_id = manager.create_session();

        let mut test_data = HashMap::new();
        test_data.insert("user_id".to_string(), "12345".to_string());
        test_data.insert("preferences".to_string(), "dark_mode=true".to_string());

        // Save data
        if !manager.save_session(&session_id, test_data.clone()) {
            return TestResult::Fail {
                reason: "Failed to save session data".to_string(),
            };
        }

        // Retrieve data
        match manager.get_session(&session_id) {
            Some(session) => {
                if session.data == test_data {
                    TestResult::Pass
                } else {
                    TestResult::Fail {
                        reason: "Session data corrupted in round-trip".to_string(),
                    }
                }
            }
            None => TestResult::Fail {
                reason: "Session not found after save".to_string(),
            },
        }
    }

    // ============================================================================================
    // CSRF Protection Tests
    // ============================================================================================

    fn test_csrf_token_generation() -> TestResult {
        let secret_key = b"test_secret_key_32_bytes_long!!!".to_vec();
        let manager = CsrfTokenManager::new(secret_key);

        // Generate multiple tokens for the same session
        let session_id = "test_session_123";
        let tokens: Vec<String> = (0..10)
            .map(|_| manager.generate_token(session_id))
            .collect();

        // All tokens should be valid format and unique
        let mut unique_tokens = std::collections::HashSet::new();
        for token in &tokens {
            if token.len() != 16 || !token.chars().all(|c| c.is_ascii_hexdigit()) {
                return TestResult::Fail {
                    reason: "CSRF token format invalid".to_string(),
                };
            }

            if !unique_tokens.insert(token.clone()) {
                return TestResult::Fail {
                    reason: "Duplicate CSRF token generated".to_string(),
                };
            }
        }

        TestResult::Pass
    }

    fn test_csrf_token_validation() -> TestResult {
        let secret_key = b"validation_test_secret_key_123!!".to_vec();
        let manager = CsrfTokenManager::new(secret_key);
        let session_id = "validation_session";

        if manager.test_round_trip(session_id) {
            TestResult::Pass
        } else {
            TestResult::Fail {
                reason: "CSRF token round-trip validation failed".to_string(),
            }
        }
    }

    fn test_csrf_security() -> TestResult {
        let secret_key = b"security_test_secret_key_567!!!!!".to_vec();
        let manager = CsrfTokenManager::new(secret_key);
        let session_id = "security_session";

        // Test invalid tokens
        let invalid_tokens = vec![
            "",
            "short",
            "toolongtobevalidtokenstring",
            "invalidhexchars!",
            "0123456789abcdef", // Valid format but not generated
        ];

        for invalid_token in &invalid_tokens {
            if manager.validate_token(invalid_token, session_id) {
                return TestResult::Fail {
                    reason: format!("Invalid token '{}' incorrectly validated", invalid_token),
                };
            }
        }

        TestResult::Pass
    }

    #[test]
    fn web_conformance_full_suite() {
        let mut pass_count = 0;
        let mut fail_count = 0;
        let mut skip_count = 0;

        for case in WEB_CONFORMANCE_CASES {
            let result = run_conformance_test(case);
            match result {
                TestResult::Pass => {
                    pass_count += 1;
                    println!("✓ {}: {}", case.id, case.description);
                }
                TestResult::Fail { reason } => {
                    fail_count += 1;
                    println!("✗ {}: {} - {}", case.id, case.description, reason);
                }
                TestResult::Skipped { reason } => {
                    skip_count += 1;
                    println!("⚠ {}: {} - {}", case.id, case.description, reason);
                }
            }
        }

        let total = pass_count + fail_count + skip_count;
        println!(
            "\nWeb Conformance Results: {}/{} passed, {} failed, {} skipped",
            pass_count, total, fail_count, skip_count
        );

        // Require 100% MUST compliance
        let must_cases: Vec<_> = WEB_CONFORMANCE_CASES
            .iter()
            .filter(|c| c.level == RequirementLevel::Must)
            .collect();

        let mut must_failures = 0;
        for case in &must_cases {
            if let TestResult::Fail { .. } = run_conformance_test(case) {
                must_failures += 1;
            }
        }

        assert_eq!(
            must_failures, 0,
            "{} MUST requirements failed",
            must_failures
        );
    }

    // Property-based testing
    proptest! {
        #[test]
        fn prop_multipart_round_trip(
            boundary in "[a-zA-Z0-9-_]{10,50}",
            field_count in 1usize..5,
        ) {
            let parser = MockMultipartParser::new(boundary.clone());

            let mut fields = Vec::new();
            for i in 0..field_count {
                fields.push(MultipartField {
                    name: format!("field{}", i),
                    filename: if i % 2 == 0 { Some(format!("file{}.txt", i)) } else { None },
                    content_type: if i % 3 == 0 { Some("text/plain".to_string()) } else { None },
                    headers: HashMap::new(),
                    body: format!("content for field {}", i).into_bytes(),
                });
            }

            let original = ParsedMultipart { boundary, fields };
            let serialized = parser.serialize(&original);
            let parsed = parser.parse(&serialized).unwrap();

            prop_assert_eq!(parsed.fields.len(), original.fields.len());
            for (i, (orig, parsed)) in original.fields.iter().zip(parsed.fields.iter()).enumerate() {
                prop_assert_eq!(&parsed.name, &orig.name, "Field {} name mismatch", i);
                prop_assert_eq!(&parsed.body, &orig.body, "Field {} body mismatch", i);
            }
        }

        #[test]
        fn prop_websocket_frame_round_trip(
            opcode in 0u8..16,
            payload in prop::collection::vec(any::<u8>(), 0..1000),
            fin in any::<bool>(),
            masked in any::<bool>(),
        ) {
            let processor = WebSocketFrameProcessor::new();

            let mask_key = if masked { Some([0x12, 0x34, 0x56, 0x78]) } else { None };

            let frame = MockWebSocketFrame {
                fin,
                rsv1: false,
                rsv2: false,
                rsv3: false,
                opcode,
                masked,
                payload_length: payload.len() as u64,
                mask_key,
                payload: payload.clone(),
            };

            let serialized = processor.serialize_frame(&frame);
            let parsed = processor.parse_frame(&serialized).unwrap();

            prop_assert_eq!(parsed.opcode, frame.opcode);
            prop_assert_eq!(parsed.fin, frame.fin);
            prop_assert_eq!(parsed.masked, frame.masked);
            prop_assert_eq!(parsed.payload, payload);
        }

        #[test]
        fn prop_sse_stream_round_trip(
            event_count in 1usize..10,
        ) {
            let mut stream = SseStream::new();

            for i in 0..event_count {
                let event = SseEvent::new()
                    .id(&format!("event_{}", i))
                    .event_type("test")
                    .data(&format!("data line {}", i));
                stream.add_event(event);
            }

            let serialized = stream.serialize();
            let parsed = SseStream::parse(&serialized).unwrap();

            prop_assert_eq!(parsed.events.len(), event_count);
            for (i, event) in parsed.events.iter().enumerate() {
                prop_assert_eq!(event.id.as_ref(), Some(&format!("event_{}", i)));
                prop_assert_eq!(event.event_type.as_ref(), Some(&"test".to_string()));
                prop_assert_eq!(&event.data[0], &format!("data line {}", i));
            }
        }

        #[test]
        fn prop_session_management(
            data_keys in prop::collection::vec("[a-zA-Z_]{3,10}", 1..10),
            data_values in prop::collection::vec("[a-zA-Z0-9 _]{1,50}", 1..10),
        ) {
            let manager = MockSessionManager::new();
            let session_id = manager.create_session();

            let test_data: HashMap<String, String> = data_keys.into_iter()
                .zip(data_values.into_iter())
                .collect();

            prop_assert!(manager.save_session(&session_id, test_data.clone()));

            let retrieved = manager.get_session(&session_id).unwrap();
            prop_assert_eq!(retrieved.data, test_data);
        }
    }
}