From 7d66b1ff3104b5824505762285aed1805251fe31 Mon Sep 17 00:00:00 2001
From: 132nd-Professor <132nd-Professor>
Date: Thu, 11 Aug 2022 20:56:49 +0200
Subject: [PATCH] start adding error handling (WIP)

---
 src/main.rs   | 12 +++++++++++-
 src/reader.rs | 46 +++++++++++++++++++++-------------------------
 2 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 668b45f..cc6517f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,10 +4,19 @@ mod reader;
 mod tacview;
 mod writer;
 
+use std::process;
+
 use crate::{tacview::Coalition, writer::StringWriter};
 
 fn main() {
-    let (input_filename, is_zip) = reader::find_input_file();
+    if let Err(err) = main_inner() {
+        eprintln!("{err}");
+        process::exit(1);
+    }
+}
+
+fn main_inner() -> Result<(), Box<dyn std::error::Error>> {
+    let (input_filename, is_zip) = reader::find_input_file()?;
     println!("Processing {}", input_filename);
     let lines = reader::read_data(&input_filename, is_zip);
     let (header, body) = processor::split_into_header_and_body(&lines);
@@ -25,4 +34,5 @@ fn main() {
     let mut purple_writer = writer::create_writer(is_zip, &input_filename);
     purple_writer.write_strings(header);
     purple_writer.write_for_coalition(body, &coalition_per_line, Coalition::Purple);
+    Ok(())
 }
diff --git a/src/reader.rs b/src/reader.rs
index df76ca2..46b8227 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -1,48 +1,44 @@
 use crate::constants::{EXTENSION_TXT, EXTENSION_ZIP};
 use std::fs::{self, File};
-use std::io::{BufRead, BufReader};
+use std::io::{BufRead, BufReader, Error, ErrorKind};
 
-pub fn find_input_file() -> (String, bool) {
-    let read_dir = fs::read_dir(".").expect("Could not read current directory");
+pub fn find_input_file() -> Result<(String, bool), Error> {
+    let read_dir = fs::read_dir(".")?;
 
     for entry_result in read_dir {
-        let entry = entry_result.expect("Could not parse DirEntry");
-        let path_buf = entry.path();
+        let path_buf = entry_result?.path();
         let filename = path_buf.to_string_lossy().to_string();
 
         if filename.ends_with(EXTENSION_TXT) {
-            return (filename, false);
+            return Ok((filename, false));
         } else if filename.ends_with(EXTENSION_ZIP) {
-            return (filename, true);
+            return Ok((filename, true));
         }
     }
-    println!("No tacview input file found in current directory.");
-    std::process::exit(1);
+    Err(Error::new(
+        ErrorKind::NotFound,
+        "No tacview input file found in current directory.",
+    ))
 }
 
-pub fn read_data(filename: &str, is_zip: bool) -> Vec<String> {
-    let file = fs::File::open(filename).expect("Could not read from input file");
+pub fn read_data(filename: &str, is_zip: bool) -> Result<Vec<String>, Error> {
+    let file = fs::File::open(filename)?;
     let buf = BufReader::new(file);
     if is_zip {
-        read_zip(buf)
+        Ok(read_zip(buf)?)
     } else {
-        read_txt(buf)
+        Ok(read_txt(buf)?)
     }
 }
 
-fn read_zip(buf: BufReader<File>) -> Vec<String> {
-    let mut archive = zip::ZipArchive::new(buf).expect("Could not read zip data");
-    let inner_file = archive
-        .by_index(0)
-        .expect("Could not read telemetry file from zip archive");
+fn read_zip(buf: BufReader<File>) -> Result<Vec<String>, Error> {
+    let mut archive = zip::ZipArchive::new(buf)?;
+    let inner_file = archive.by_index(0)?;
     let inner_buf = BufReader::new(inner_file);
-    read_txt(inner_buf)
+    Ok(read_txt(inner_buf)?)
 }
 
-fn read_txt<T: BufRead>(buf: T) -> Vec<String> {
-    let lines: Vec<String> = buf
-        .lines()
-        .map(|l| l.expect("Could not parse line"))
-        .collect();
-    lines
+fn read_txt<T: BufRead>(buf: T) -> Result<Vec<String>, Error> {
+    let lines: Vec<String> = buf.lines().map(|l|).collect();
+    Ok(lines)
 }