refactor: split up main.rs into multiple modules

1 files changed, 86 insertions, 0 deletions

diff --git a/src/diff.rs b/src/diff.rs
new file mode 100644
index 0000000..382c7db
--- /dev/null
+++ b/src/diff.rs
@@ -0,0 +1,86 @@
+use difference::Changeset;
+use difference::Difference;
+use sputnik::html_escape;
+use std::cmp;
+use std::fmt::Write as FmtWrite;
+
+pub fn diff(first: &str, second: &str) -> String {
+    if first == second {
+        return "<em>(no changes)</em>".into();
+    }
+
+    let Changeset { diffs, .. } = Changeset::new(&first, &second, "\n");
+
+    let mut output = String::new();
+
+    output.push_str("<pre>");
+
+    for i in 0..diffs.len() {
+        match diffs[i] {
+            Difference::Same(ref text) => {
+                let text = html_escape(text);
+                let lines: Vec<_> = text.split('\n').collect();
+                if i == 0 {
+                    output.push_str(&lines[lines.len().saturating_sub(3)..].join("\n"));
+                } else if i == diffs.len() - 1 {
+                    output.push_str(&lines[..cmp::min(3, lines.len())].join("\n"));
+                } else {
+                    output.push_str(&text);
+                }
+            }
+            Difference::Add(ref text) => {
+                output.push_str("<div class=addition>");
+                if i == 0 {
+                    output.push_str(&html_escape(text).replace("\n", "<br>"));
+                } else {
+                    match diffs.get(i - 1) {
+                        Some(Difference::Rem(ref rem)) => {
+                            word_diff(&mut output, rem, text, "ins");
+                        }
+                        _ => {
+                            output.push_str(&html_escape(text).replace("\n", "<br>"));
+                        }
+                    }
+                }
+                output.push_str("\n</div>");
+            }
+            Difference::Rem(ref text) => {
+                output.push_str("<div class=deletion>");
+                match diffs.get(i + 1) {
+                    Some(Difference::Add(ref add)) => {
+                        word_diff(&mut output, add, text, "del");
+                    }
+                    _ => {
+                        output.push_str(&html_escape(text).replace("\n", "<br>"));
+                    }
+                }
+                output.push_str("\n</div>");
+            }
+        }
+    }
+
+    output.push_str("</pre>");
+    output
+}
+
+fn word_diff(out: &mut String, text1: &str, text2: &str, tagname: &str) {
+    let Changeset { diffs, .. } = Changeset::new(text1, text2, " ");
+    for c in diffs {
+        match c {
+            Difference::Same(ref z) => {
+                out.push_str(&html_escape(z).replace("\n", "<br>"));
+                out.push(' ');
+            }
+            Difference::Add(ref z) => {
+                write!(
+                    out,
+                    "<{0}>{1}</{0}> ",
+                    tagname,
+                    html_escape(z).replace("\n", "<br>")
+                )
+                .expect("write error");
+            }
+            _ => {}
+        }
+    }
+}