1 files changed, 117 insertions, 0 deletions
diff --git a/src/embedded.rs b/src/embedded.rs
new file mode 100644
index 0000000..56b4b61
--- /dev/null
+++ b/src/embedded.rs
@@ -0,0 +1,117 @@
+use std::{
+    fs::{create_dir, File, OpenOptions},
+    io::{self, Write},
+    path::Path,
+};
+
+pub static EMBEDDED_FILES: EmbeddedFiles = rustlings_macros::include_files!();
+
+#[derive(Clone, Copy)]
+pub enum WriteStrategy {
+    IfNotExists,
+    Overwrite,
+}
+
+impl WriteStrategy {
+    fn open<P: AsRef<Path>>(self, path: P) -> io::Result<File> {
+        match self {
+            Self::IfNotExists => OpenOptions::new().create_new(true).write(true).open(path),
+            Self::Overwrite => OpenOptions::new()
+                .create(true)
+                .write(true)
+                .truncate(true)
+                .open(path),
+        }
+    }
+}
+
+struct EmbeddedFile {
+    path: &'static str,
+    content: &'static [u8],
+}
+
+impl EmbeddedFile {
+    fn write_to_disk(&self, strategy: WriteStrategy) -> io::Result<()> {
+        strategy.open(self.path)?.write_all(self.content)
+    }
+}
+
+struct EmbeddedFlatDir {
+    path: &'static str,
+    readme: EmbeddedFile,
+    content: &'static [EmbeddedFile],
+}
+
+impl EmbeddedFlatDir {
+    fn init_on_disk(&self) -> io::Result<()> {
+        let path = Path::new(self.path);
+
+        if let Err(e) = create_dir(path) {
+            if !path.is_dir() {
+                return Err(e);
+            }
+        }
+
+        self.readme.write_to_disk(WriteStrategy::Overwrite)?;
+
+        Ok(())
+    }
+}
+
+struct ExercisesDir {
+    readme: EmbeddedFile,
+    files: &'static [EmbeddedFile],
+    dirs: &'static [EmbeddedFlatDir],
+}
+
+pub struct EmbeddedFiles {
+    pub info_toml_content: &'static str,
+    exercises_dir: ExercisesDir,
+}
+
+impl EmbeddedFiles {
+    pub fn init_exercises_dir(&self) -> io::Result<()> {
+        create_dir("exercises")?;
+
+        self.exercises_dir
+            .readme
+            .write_to_disk(WriteStrategy::IfNotExists)?;
+
+        for file in self.exercises_dir.files {
+            file.write_to_disk(WriteStrategy::IfNotExists)?;
+        }
+
+        for dir in self.exercises_dir.dirs {
+            dir.init_on_disk()?;
+
+            for file in dir.content {
+                file.write_to_disk(WriteStrategy::IfNotExists)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn write_exercise_to_disk(&self, path: &Path, strategy: WriteStrategy) -> io::Result<()> {
+        if let Some(file) = self
+            .exercises_dir
+            .files
+            .iter()
+            .find(|file| Path::new(file.path) == path)
+        {
+            return file.write_to_disk(strategy);
+        }
+
+        for dir in self.exercises_dir.dirs {
+            if let Some(file) = dir.content.iter().find(|file| Path::new(file.path) == path) {
+                dir.init_on_disk()?;
+                return file.write_to_disk(strategy);
+            }
+        }
+
+        Err(io::Error::new(
+            io::ErrorKind::NotFound,
+            format!("{} not found in the embedded files", path.display()),
+        ))
+    }
+}