1 files changed, 110 insertions, 0 deletions
diff --git a/src/zizek_db.rs b/src/zizek_db.rs
new file mode 100644
index 0000000..1195822
--- /dev/null
+++ b/src/zizek_db.rs
@@ -0,0 +1,110 @@
+//! Handling of a database of Slavoj Žižek quotes
+
+use std::fs::File;
+use std::io::{self, BufRead, BufReader, BufWriter, Write};
+use std::path::Path;
+
+use rand::seq::SliceRandom;
+
+/// Struct containing all currently loaded Žižek quotes and the means to
+/// manipulate them.
+pub struct ZizekDb
+{
+    quotes: Vec<String>,
+}
+
+impl ZizekDb
+{
+    /// Read quotes from the file with the given name.
+    ///
+    /// # Return
+    /// Database containing the quotes in case the load was successful or an
+    /// `io::Error` in case it could not be loaded.
+    pub fn from_file<P>(filename: P) -> Result<Self, io::Error>
+    where
+        P: AsRef<Path>,
+    {
+        let file = File::open(filename)?;
+        let lines = BufReader::new(file).lines();
+
+        let mut quotes: Vec<String> = Vec::new();
+        for line in lines {
+            let line = line?.trim().to_owned();
+            if !line.is_empty() {
+                quotes.push(line);
+            }
+        }
+
+        Ok(Self { quotes })
+    }
+
+    /// Write contents of the database to the file.
+    /// The file is overwritten by the contents of the database, so be careful
+    /// if you want to concatenate the quotes of this database to the ones
+    /// of a different one.
+    pub fn write_to_file<P>(&self, filename: P) -> Result<(), io::Error>
+    where
+        P: AsRef<Path>,
+    {
+        let file = File::create(filename)?;
+        let mut writer = BufWriter::new(file);
+
+        for q in &self.quotes {
+            write!(writer, "{}\n", q)?;
+        }
+
+        writer.flush()
+    }
+
+    /// Check if a quote exists in the database
+    ///
+    /// # Return
+    /// `true` if the quote is registered, `false` if not
+    pub fn has_quote(&self, quote: &str) -> bool { self.quotes.iter().any(|q| q == quote) }
+
+    /// Get a random piece of philosophic goodness
+    pub fn random_quote(&self) -> Option<&String>
+    {
+        let mut rng = rand::thread_rng();
+        self.quotes.choose(&mut rng)
+    }
+
+    /// Add a quote to the index
+    ///
+    /// # Return
+    /// `true` in case the quote was successfully added or `false` if it could
+    /// not, in case the quote already exists or an empty string was given.
+    pub fn add_quote(&mut self, quote: &str) -> bool
+    {
+        let quote = quote.trim();
+
+        if quote.is_empty() {
+            return false;
+        }
+
+        if !self.has_quote(quote) {
+            self.quotes.push(quote.to_owned());
+            true
+        }
+        else {
+            false
+        }
+    }
+
+    /// Remove a quote from the database
+    ///
+    /// # Return
+    /// `true` if the quote was found and removed, `false` if there was no such
+    /// quote
+    pub fn remove_quote(&mut self, quote: &str) -> bool
+    {
+        for (i, q) in &mut self.quotes.iter_mut().enumerate() {
+            if q == quote {
+                self.quotes.remove(i);
+                return true;
+            }
+        }
+
+        false
+    }
+}