frontend: example: csv-import helper

* cli to import a given csv configured text file

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

frontend/examples/csv-import/main.rs

@@ -0,0 +1,114 @@
+/// Commandline program testing csv imports
+use serde::Deserialize;
+use std::env;
+use std::{
+     error::Error,
+     io,
+//     process,
+//     thread,
+    //     time::{Duration, Instant}
+};
+use tracing::{debug, trace, Level};
+
+mod parse_args;
+
+#[derive(Debug, Deserialize)]
+struct Environment {
+    test_lang: String,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct CsvImportRecord {
+    // dion               => Allianz Dion: 1
+    // policy_code        => Policy Typ: "AS"
+    // policy_number      => Versicherungsscheinnummer: "1515735810"
+    pub dion: String,
+    pub policy_code: String,
+    pub policy_number: u32,
+}
+
+/// import from csv format (Standard in)
+fn import() -> Result<(), Box<dyn Error>> {
+    // Build the CSV reader and iterate over each record.
+    let mut csv_reader = csv::Reader::from_reader(io::stdin());
+    for result in csv_reader.deserialize() {
+        // The iterator yields Result<StringRecord, Error>, so we check the
+        // error here.
+        let record: CsvImportRecord = result?;
+        println!("{:?}", record);
+    }
+    Ok(())
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    use dotenv::dotenv;
+    use parse_args::parse_args;
+    use locales::t;
+    //use std::process;
+    //use std::sync::Arc;
+    use tracing_subscriber::fmt;
+    use viperus::Viperus;
+
+    // initialize the tracing subsystem
+    // a drop in replacement for classical logging
+    // reference: https://tokio.rs/blog/2019-08-tracing/
+    let span = tracing::span!(Level::TRACE, "csv-import");
+    let _enter = span.enter();
+    let subscriber = fmt::Subscriber::builder()
+        .with_env_filter("csv-import=trace")
+        .finish();
+
+    // initialize logger
+    //env_logger::init();
+    //info!("Commencing the import Test-Run!");
+
+    tracing::subscriber::with_default(subscriber, || {
+        // get system environment
+        let mut lang = env::var("LANG").unwrap_or("en".to_string());
+        let mut res = t!("parse.environment", lang);
+        let mut state = t!("state.started", lang);
+        trace!(target: "csv-import", message = ?res, state = ?state);
+        //debug!(message = ?res, state = ?state);
+        trace!(target: "csv-import", environment = "system", lang = ?lang);
+
+        // get testing environment (.env)
+        dotenv().ok();
+        match envy::from_env::<Environment>() {
+            Ok(environment) => {
+                if environment.test_lang != lang { lang = environment.test_lang; }
+            },
+            Err(e) => { debug!(target: "csv-import", "{}", e); }
+        }
+        res = t!("parse.environment", lang);
+        trace!(target: "csv-import", environment = "envy", lang = ?lang);
+        state = t!("state.finished", lang);
+        trace!(target: "csv-import", message = ?res, state = ?state);
+
+        // initialize viperus structure
+        let mut v = Viperus::new();
+
+        // parse commandline arguments
+        res = t!("parse.arguments", lang);
+        state = t!("state.started", lang);
+        trace!(target: "csv-import", process = ?res, state = ?state);
+
+        let _ = parse_args(&mut v);
+        state = t!("state.finished", lang);
+        trace!(target: "csv-import", process = ?res, state = ?state);
+        //trace!(target: "Viperus", "Config results: {:?}", v);
+
+        // Starting the program logic
+        res = t!("main.started", lang);
+        state = t!("state.started", lang);
+        trace!(target: "csv-import", process = ?res, state = ?state);
+
+        // import the given import file
+        let csv_file = v.get::<String>("import_file").unwrap();
+
+        state = t!("state.finished", lang);
+        res = t!("main.finished", lang);
+        trace!(target: "csv-import", process = ?res, state = ?state);
+    });
+
+    Ok(())
+}