Implement the dry-run cmd line parameter and flow

README.md

@@ -7,24 +7,35 @@ The software is still in early developments. I'm using it as a way to introduce
 # Usage
 The simplest way to use this program is to simply call it on a comic folder. This way it will ensure the pages are formatted with just the right number of leading 0 to pad the number part of the page.
 ```
-cbb comic/
+$ cbb comic/
 ```
 
 You may want to customize the number of leading 0, it is useful when you plan on adding more pages later.
 ```
-cbb comic/ --pad=3
+$ cbb comic/ --pad=3 --dry-run
+7.txt	-> 07.txt
+10.txt	-> 10.txt
+5.txt	-> 05.txt
+3.txt	-> 03.txt
+4.txt	-> 04.txt
+8.txt	-> 08.txt
+2.txt	-> 02.txt
+6.txt	-> 06.txt
+1.txt	-> 01.txt
+9.txt	-> 09.txt
 ```
 
 # TODO
-* [ ] Add tests: I'm not used to create tests on projects (unit & integration).
+* [ ] Add tests: I am not used to create tests on projects (unit & integration)
 * [ ] Add tests: HELP WANTED: how can I tests operations on the filesystem?
 * [ ] Add some quality of life features:
-    * [ ] Dry-run: Show how the files will be changed without modifying anything
+    * [X] Dry-run: Show how the files will be changed without modifying anything
     * [ ] Recursivity: user select a "library" folder for which each sub-folder is considered to be a comic book (or an other library)
-    * [ ] Prefix: let the user set the prefix of the pages: Useful when the name contains a number: "Name-Season5-chapter02-page10.png" => prefix = "Name-Season5-chapter02-page".
-        * [ ] Deduce the prefix from the file name (nice to have, not sure it is used that often)
-* [ ] Integrate an archive crate to be able to open/create `.cba`, `.cbr` `.cbt`, or `.cbz` archives.
+    * [ ] Prefix (name pattern?): let the user set the prefix of the pages: Useful when the name contains a number: "Name-Season5-Chapter02-Page10.png" => prefix = "Name-Season5-Chapter02-Page"
+        * [ ] Deduce the prefix from the file name: try to find the invariant part and the bumping number (nice to have, not sure it is used that often)
+    * [ ] Rename: Totally erase the current name of the file to replace with the cross-platform numerotation based named. The input list should be sorted (possibly coupled with the option prefix/name pattern to have a powerfull renaming tool)
+* [ ] Integrate an archive crate to be able to open/create `.cba`, `.cbr` `.cbt`, or `.cbz` archives
 * [ ] Add documentation
-* [ ] Maybe integrate rayon (test with a benchmark if it really help: part 1 of the tool is listing the files, part 2 is based on `os::rename` operations).
+* [ ] Maybe integrate rayon (test with a benchmark if it really help: part 1 of the tool is listing the files, part 2 is based on `os::rename` operations)
 
 Also I saw on Wikipedia that it is possible to include metadata such as [artists, story information, table of contents or even a separate text layer for comic book translations](https://en.wikipedia.org/wiki/Comic_book_archive). If the feature is requested I could check if the different way to include this metadata are well spread. This however will not be discussed before (almost) releasing the 1.0.

src/lib.rs

@@ -15,6 +15,12 @@ pub struct Opt {
     // TODO: check if I really do this or not when implementing the recursive option
     pub comic_folder: PathBuf,
 
+    /// Do a dry run of the program printing to stdout the action it would take
+    ///
+    /// Print how each file would be renamed.
+    #[structopt(long)]
+    pub dry_run: bool,
+
     /// Set the pad you want to use
     ///
     /// If not set or set to a value inferior to the maximum pad of the comic, the value is
@@ -55,7 +61,6 @@ struct Page {
 
 impl Page {
     fn new(prefix: String, number: String, suffix: String) -> Page {
-        eprintln!("N p:{} n: {} s: {}", prefix, number, suffix);
         Page {
             prefix,
             number,
@@ -64,15 +69,10 @@ impl Page {
     }
 
     fn original_filename(&self) -> String {
-        eprintln!("OF p:{} n: {} s: {}", self.prefix, self.number, self.suffix);
         format!("{}{}{}", self.prefix, self.number, self.suffix)
     }
 
     fn new_filename(&self, pad: usize) -> String {
-        eprintln!(
-            "NF p: '{}' n: '{}' s: '{}'",
-            self.prefix, self.number, self.suffix
-        );
         // format!("{:0pad$}-{}{}{}", number, self.prefix, self.number, self.suffix, pad = pad)
         // TODO I think I will need this on in the end
         format!(
@@ -111,17 +111,18 @@ impl ComicBook {
         }
     }
 
-    pub fn bind(&mut self) {
-        let pad = self.get_pad_size().expect("get_pad_size");   // TODO have a nice error message (the user may habe specifyed a folder that does not contains cb pages)
+    pub fn bind<T>(&mut self, transform_page: T)
+    where
+        T: Fn(String, String),
+    {
+        let pad = self.get_pad_size().expect("get_pad_size"); // TODO have a nice error message (the user may habe specifyed a folder that does not contains cb pages)
 
         for page in self.pages.iter() {
             //if let Some(pos) = page.position {
             let original_file = page.original_filename();
             let new_file = page.new_filename(pad);
 
-            eprintln!("{} -> {}", original_file, new_file);
-
-            // fs::rename(original_file, new_file).expect("RENAME FAILED");
+            transform_page(original_file, new_file);
             //}
         }
     }

src/main.rs

@@ -22,5 +22,17 @@ fn main() {
     env::set_current_dir(opt.comic_folder).unwrap();
     let mut book = ComicBook::new(fs::read_dir(".").unwrap(), opt.pad);
 
-    book.bind();
+    let bind_func = if opt.dry_run { dry_run } else { rename };
+    book.bind(bind_func);
+}
+
+fn dry_run(original: String, new: String) {
+    // TODO: Is it possible to be certain that the alignment is kept (like in a table)?
+    // I think there is at least a crate doing that. But I do not want to add bloat only for this
+    // => To benchmark (binary size, clean compile)
+    println!("{}\t-> {}", original, new);
+}
+
+fn rename(original: String, new: String) {
+    fs::rename(original, new).expect("RENAME FAILED");
 }