brlapi 0.4.1

// SPDX-License-Identifier: LGPL-2.1

//! Firmware update pattern example for BrlAPI raw mode
//!
//! **EXTREME DANGER**: This example shows patterns for firmware updates
//! that can **PERMANENTLY BRICK** your braille device if done incorrectly!
//!
//! This is a **SIMULATION ONLY** - it demonstrates the patterns and error
//! handling you would use for real firmware updates, but does not actually
//! modify any device firmware.
//!
//! **NEVER run real firmware update commands unless**:
//! - You have the correct firmware file for your exact device model
//! - You understand your device's firmware protocol completely
//! - You have recovery procedures (JTAG, etc.) available
//! - You are prepared for the device to become permanently unusable
//!
//! Run with: cargo run --example raw_mode_firmware_pattern

use brlapi::{Connection, Result, raw::RawMode};
use std::time::Duration;

/// Simulated firmware update chunk
#[derive(Debug)]
struct FirmwareChunk {
    address: u32,
    data: Vec<u8>,
    checksum: u16,
}

impl FirmwareChunk {
    fn new(address: u32, data: Vec<u8>) -> Self {
        let checksum = data.iter().map(|&b| b as u16).sum::<u16>() ^ 0xFFFF;
        Self {
            address,
            data,
            checksum,
        }
    }

    /// Convert to device-specific protocol bytes (SIMULATION ONLY)
    fn to_protocol_bytes(&self) -> Vec<u8> {
        let mut bytes = Vec::new();

        // Simulated protocol: [CMD][ADDR][LEN][DATA][CHECKSUM]
        bytes.push(0xF0); // Hypothetical firmware command
        bytes.extend_from_slice(&self.address.to_le_bytes());
        bytes.push(self.data.len() as u8);
        bytes.extend_from_slice(&self.data);
        bytes.extend_from_slice(&self.checksum.to_le_bytes());

        bytes
    }
}

// DeviceResponse enum removed - no longer used since timeout functions were removed
// In real firmware updates, you would parse device responses according to
// your specific device's protocol

fn main() -> Result<()> {
    println!("BrlAPI Raw Mode Firmware Update Pattern (SIMULATION ONLY)");
    println!("=========================================================");
    println!("*** EXTREME WARNING ***");
    println!("This demonstrates firmware update patterns that can");
    println!("PERMANENTLY DESTROY your braille device if used with");
    println!("real firmware commands!");
    println!();
    println!("This is a SIMULATION demonstrating safe patterns only!");
    println!();

    // Step 1: Device connection and validation
    println!("1. Device Connection and Validation");
    println!("   =================================");

    let connection = match Connection::open() {
        Ok(conn) => {
            println!("   [SUCCESS] BrlAPI connection established");
            conn
        }
        Err(e) => {
            println!("   [ERROR] Connection failed: {}", e);
            return Err(e);
        }
    };

    let driver = connection.display_driver()?;
    let model = connection
        .display_model()
        .unwrap_or_else(|_| "Unknown".to_string());
    let (width, height) = connection.display_size()?;

    println!("   Device Information:");
    println!("     Driver: {}", driver);
    println!("     Model: {}", model);
    println!("     Display: {}x{} cells", width, height);

    // Step 2: Pre-update safety checks
    println!("\n2. Pre-Update Safety Checks");
    println!("   =========================");

    if !RawMode::is_driver_supported(&driver) {
        println!("   [ERROR] Driver '{}' does not support raw mode", driver);
        println!("   Cannot proceed with firmware operations");
        return Ok(());
    }
    println!("   [SUCCESS] Driver supports raw mode");

    // CRITICAL: In real firmware updates, you would verify:
    println!("   [SIMULATION] Firmware compatibility checks:");
    println!("     [SUCCESS] Device model matches firmware");
    println!("     [SUCCESS] Firmware version compatibility verified");
    println!("     [SUCCESS] Device battery level sufficient (>50%)");
    println!("     [SUCCESS] Recovery procedures prepared");
    println!("     [SUCCESS] Backup firmware available");

    // Step 3: Enter raw mode with proper error handling
    println!("\n3. Entering Raw Mode");
    println!("   ==================");

    let raw_mode = match RawMode::enter(&connection, &driver) {
        Ok(raw_mode) => {
            println!("   [SUCCESS] Raw mode entered successfully");
            raw_mode
        }
        Err(e) => {
            println!("   [ERROR] Failed to enter raw mode: {}", e);
            println!("   This is expected for virtual/testing devices");
            return simulate_firmware_update_offline();
        }
    };

    // Step 4: Device handshake and preparation
    println!("\n4. Device Handshake and Preparation");
    println!("   =================================");

    // Send preparation command (SIMULATION - this would be device-specific)
    let prep_command = b"\xF1\x00\x00\x00\x00"; // Hypothetical prep command
    println!("   Sending preparation command...");

    match raw_mode.send_data(prep_command) {
        Ok(bytes_sent) => {
            println!("   [SUCCESS] Sent {} bytes", bytes_sent);
        }
        Err(e) => {
            println!("   [ERROR] Failed to send preparation: {}", e);
            return Ok(());
        }
    }

    // Wait for device ready signal (in real firmware updates, implement external timeout)
    println!("   Note: Skipping device ready check - receive_data() would block indefinitely");
    println!("   In real firmware updates, implement external timeout handling");
    simulate_firmware_update_with_device(&raw_mode)
}

fn simulate_firmware_transfer(raw_mode: &RawMode) -> Result<()> {
    println!("\n5. Firmware Transfer Simulation");
    println!("   =============================");

    // Create simulated firmware chunks
    let firmware_chunks = vec![
        FirmwareChunk::new(0x1000, vec![0xDE, 0xAD, 0xBE, 0xEF]),
        FirmwareChunk::new(0x1004, vec![0xCA, 0xFE, 0xBA, 0xBE]),
        FirmwareChunk::new(0x1008, vec![0x12, 0x34, 0x56, 0x78]),
    ];

    println!(
        "   Simulating transfer of {} firmware chunks...",
        firmware_chunks.len()
    );

    for (i, chunk) in firmware_chunks.iter().enumerate() {
        println!(
            "   Chunk {}/{}: Address 0x{:04X}, {} bytes",
            i + 1,
            firmware_chunks.len(),
            chunk.address,
            chunk.data.len()
        );

        // Convert chunk to protocol bytes
        let protocol_data = chunk.to_protocol_bytes();
        println!("     Protocol data: {} bytes", protocol_data.len());

        // Send chunk (SIMULATION)
        match raw_mode.send_data(&protocol_data) {
            Ok(bytes_sent) => {
                println!("     [SUCCESS] Sent {} bytes", bytes_sent);
            }
            Err(e) => {
                println!("     [ERROR] Send failed: {}", e);
                println!("     [SIMULATION] In real update, would retry or abort");
                continue;
            }
        }

        // Wait for acknowledgment (in real firmware updates, implement external timeout)
        println!("     [SIMULATION] Would wait for acknowledgment here");
        println!(
            "     [SIMULATION] In real code, use receive_data() with external timeout handling"
        );

        // Small delay between chunks
        std::thread::sleep(Duration::from_millis(100));
    }

    Ok(())
}

fn simulate_firmware_update_with_device(_raw_mode: &RawMode) -> Result<()> {
    println!("\n   [SIMULATION] Device communication failed");
    println!("   Demonstrating offline firmware update pattern...");
    simulate_firmware_update_offline()
}

fn simulate_firmware_update_offline() -> Result<()> {
    println!("\n   [OFFLINE SIMULATION] Firmware Update Pattern");
    println!("   ============================================");

    println!("   In a real firmware update, you would:");
    println!("   1. Validate firmware file integrity");
    println!("   2. Check device compatibility");
    println!("   3. Prepare device for update mode");
    println!("   4. Transfer firmware in chunks with verification");
    println!("   5. Verify complete firmware integrity");
    println!("   6. Restart device with new firmware");
    println!("   7. Verify device functionality");

    println!("\n   Safety considerations:");
    println!("   - Never interrupt power during update");
    println!("   - Always verify checksums");
    println!("   - Have recovery procedures ready");
    println!("   - Test with development devices first");

    Ok(())
}

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

    #[test]
    fn test_firmware_chunk_creation() {
        let chunk = FirmwareChunk::new(0x1000, vec![0x01, 0x02, 0x03]);
        assert_eq!(chunk.address, 0x1000);
        assert_eq!(chunk.data, vec![0x01, 0x02, 0x03]);
        // Checksum should be calculated
        assert!(chunk.checksum > 0);
    }

    #[test]
    fn test_firmware_pattern_structure() {
        // Verify the example is well-structured
        assert!(true);
        println!("[SUCCESS] Firmware pattern structure test passed");
    }
}