#[derive(PartialEq, Debug, Clone)]
enum DiffOp {
    Insert,
    Delete,
    Equal,
}

#[derive(Clone, Debug)]
struct Diff {
    operation: DiffOp,
    data: String,
}

struct DiffMatchPatch {
    diff_timeout: f64,
    diff_edit_cost: isize,
    match_threshold: f64,
    match_distance: isize,
    patch_delete_threshold: f64,
    patch_margin: isize,
}

impl DiffMatchPatch {
    fn new() -> DiffMatchPatch {
        DiffMatchPatch {
            diff_timeout: 1.0,
            diff_edit_cost: 4,
            match_threshold: 0.5,
            match_distance: 1000,
            patch_delete_threshold: 0.5,
            patch_margin: 4,
        }
    }

    fn diff_main(&self, text1: &str, text2: &str) -> Vec<Diff> {
        if text1 == text2 {
            if text1.is_empty() {
                Vec::new()
            } else {
                vec![Diff {
                    operation: DiffOp::Equal,
                    data: text1.to_string(),
                }]
            }
        } else {
            let mut diffs = Vec::new();
            if text1.is_empty() {
                diffs.push(Diff {
                    operation: DiffOp::Insert,
                    data: text2.to_string(),
                });
            } else if text2.is_empty() {
                diffs.push(Diff {
                    operation: DiffOp::Delete,
                    data: text1.to_string(),
                });
            } else {
                // Here, a real diff algorithm would be implemented
                diffs.push(Diff {
                    operation: DiffOp::Delete,
                    data: text1.to_string(),
                });
                diffs.push(Diff {
                    operation: DiffOp::Insert,
                    data: text2.to_string(),
                });
            }
            diffs
        }
    }
}

fn main() {
    let dmp = DiffMatchPatch::new();
    let text1 = "Hello World";
    let text2 = "Hello Rust!";
    let diffs = dmp.diff_main(text1, text2);
    println!("Diffs: {:?}", diffs);
}