fieldlens-desktop/src-tauri/src/lib.rs

mod capture;
mod fieldlens;
mod model;
mod printers;
mod state;
mod zpl;

use parking_lot::Mutex;
use tauri::{AppHandle, Manager, State};

use capture::CaptureRuntime;
use model::{AppConfig, CaptureStatus, JobSummary, LoginPoll, LoginStart, SyncResult};
use printers::{SystemPrinter, VirtualPrinterStatus};
use state::SharedState;

struct AppState {
    shared: SharedState,
    runtime: Mutex<Option<CaptureRuntime>>,
}

#[tauri::command]
fn get_config(state: State<'_, AppState>) -> AppConfig {
    state.shared.config.lock().clone()
}

#[tauri::command]
fn save_config(config: AppConfig, state: State<'_, AppState>) -> Result<AppConfig, String> {
    state
        .shared
        .replace_config(config)
        .map_err(|error| error.to_string())
}

#[tauri::command]
fn get_status(state: State<'_, AppState>) -> CaptureStatus {
    CaptureStatus {
        running: state.runtime.lock().is_some(),
        mode: state.shared.config.lock().mode.clone(),
        pending: state.shared.pending_count(),
        jobs: state.shared.jobs.lock().len(),
    }
}

#[tauri::command]
fn recent_jobs(state: State<'_, AppState>) -> Vec<JobSummary> {
    state.shared.jobs.lock().iter().cloned().collect()
}

#[tauri::command]
fn start_capture(app: AppHandle, state: State<'_, AppState>) -> Result<(), String> {
    let mut runtime = state.runtime.lock();
    if runtime.is_some() {
        return Ok(());
    }

    let config = state.shared.config.lock().clone();
    let next = capture::start(config, state.shared.clone(), app).map_err(|error| error.to_string())?;
    *runtime = Some(next);
    Ok(())
}

#[tauri::command]
fn stop_capture(state: State<'_, AppState>) {
    if let Some(runtime) = state.runtime.lock().take() {
        runtime.stop();
    }
}

#[tauri::command]
fn list_system_printers() -> Result<Vec<SystemPrinter>, String> {
    printers::list_system_printers().map_err(|error| error.to_string())
}

#[tauri::command]
fn get_virtual_printer_status() -> Result<VirtualPrinterStatus, String> {
    printers::virtual_printer_status().map_err(|error| error.to_string())
}

#[tauri::command]
fn install_virtual_printer(target_printer: String) -> Result<VirtualPrinterStatus, String> {
    printers::install_virtual_printer(&target_printer).map_err(|error| error.to_string())
}

#[tauri::command]
fn remove_virtual_printer() -> Result<VirtualPrinterStatus, String> {
    printers::remove_virtual_printer().map_err(|error| error.to_string())
}

#[tauri::command]
fn begin_login(state: State<'_, AppState>) -> Result<LoginStart, String> {
    fieldlens::begin_login(&state.shared).map_err(|error| error.to_string())
}

#[tauri::command]
fn poll_login(state: State<'_, AppState>) -> Result<LoginPoll, String> {
    fieldlens::poll_login(&state.shared).map_err(|error| error.to_string())
}

#[cfg(target_os = "linux")]
fn build_self_test_pdf() -> Vec<u8> {
    let objects = [
        "1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n".to_string(),
        "2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n".to_string(),
        "3 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] /Resources << /Font << /F1 5 0 R >> >> /Contents 4 0 R >>\nendobj\n".to_string(),
        {
            let stream = "BT /F1 18 Tf 72 720 Td (FieldLens capture self-test) Tj ET\n";
            format!("4 0 obj\n<< /Length {} >>\nstream\n{}endstream\nendobj\n", stream.len(), stream)
        },
        "5 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>\nendobj\n".to_string(),
    ];

    let mut pdf = b"%PDF-1.4\n".to_vec();
    let mut offsets = Vec::new();
    for object in &objects {
        offsets.push(pdf.len());
        pdf.extend_from_slice(object.as_bytes());
    }

    let xref = pdf.len();
    pdf.extend_from_slice(format!("xref\n0 {}\n", objects.len() + 1).as_bytes());
    pdf.extend_from_slice(b"0000000000 65535 f \n");
    for offset in offsets {
        pdf.extend_from_slice(format!("{offset:010} 00000 n \n").as_bytes());
    }
    pdf.extend_from_slice(
        format!(
            "trailer\n<< /Size {} /Root 1 0 R >>\nstartxref\n{}\n%%EOF\n",
            objects.len() + 1,
            xref
        )
        .as_bytes(),
    );
    pdf
}

#[tauri::command]
fn run_capture_self_test() -> Result<String, String> {
    #[cfg(target_os = "linux")]
    {
        let path = std::env::temp_dir().join(format!(
            "fieldlens-capture-self-test-{}.pdf",
            uuid::Uuid::new_v4()
        ));
        std::fs::write(&path, build_self_test_pdf()).map_err(|error| error.to_string())?;

        let output = std::process::Command::new("lp")
            .args(["-d", "FieldLens-Test-Capture"])
            .arg(&path)
            .output()
            .map_err(|error| error.to_string());
        let _ = std::fs::remove_file(&path);
        let output = output?;

        if !output.status.success() {
            return Err(format!(
                "CUPS self-test submission failed: {}",
                String::from_utf8_lossy(&output.stderr).trim()
            ));
        }

        let detail = String::from_utf8_lossy(&output.stdout).trim().to_string();
        return Ok(if detail.is_empty() {
            "Self-test submitted to FieldLens Test Capture.".into()
        } else {
            detail
        });
    }

    #[cfg(not(target_os = "linux"))]
    {
        Err("Capture self-test is currently available on Linux only.".into())
    }
}

#[tauri::command]
fn sync_pending(state: State<'_, AppState>) -> Result<SyncResult, String> {
    fieldlens::sync_pending(&state.shared).map_err(|error| error.to_string())
}

pub fn run() {
    tauri::Builder::default()
        .plugin(tauri_plugin_opener::init())
        .plugin(tauri_plugin_process::init())
        .plugin(tauri_plugin_updater::Builder::new().build())
        .setup(|app| {
            let data_dir = app.path().app_data_dir()?;
            let shared = SharedState::load(data_dir)
                .map_err(|error| std::io::Error::other(error.to_string()))?;
            app.manage(AppState {
                shared,
                runtime: Mutex::new(None),
            });
            Ok(())
        })
        .invoke_handler(tauri::generate_handler![
            get_config,
            save_config,
            get_status,
            recent_jobs,
            start_capture,
            stop_capture,
            list_system_printers,
            get_virtual_printer_status,
            install_virtual_printer,
            remove_virtual_printer,
            run_capture_self_test,
            begin_login,
            poll_login,
            sync_pending
        ])
        .run(tauri::generate_context!())
        .expect("error while running FieldLens Print");
}