From c1fdfbdcc88d741ebae68ff7b552cd8bc54716d3 Mon Sep 17 00:00:00 2001
From: Paul Campbell <pcampbell@kemitix.net>
Date: Tue, 21 Mar 2023 20:43:10 +0000
Subject: [PATCH] skip until matching lines seen

---
 src/lib.rs  | 82 ++++++++++++++++++++++++++++++++++++++++++++++-------
 src/main.rs |  4 +--
 2 files changed, 73 insertions(+), 13 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index c82db68..7e89d00 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,23 +22,69 @@ pub struct Cli {
     ignore_extras: bool,
 }
 
-pub fn skip<F>(cli: Cli, mut out: F) -> io::Result<()>
+pub fn skip<F>(cli: &Cli, mut out: F) -> io::Result<()>
     where F: FnMut(String) -> ()
 {
     match &cli.file {
-        Some(file) => {
-            let content = fs::read_to_string(file).expect("Could not read file");
-            let mut counter = 0usize;
-            for current_line in content.lines() {
-                counter += 1;
-                if counter > cli.lines {
-                    out(String::from(current_line));
-                }
+        Some(ref file) => {
+            if let Some(line) = &cli.line {
+                skip_file_lines_matching(&cli, out, file, line)
+            } else if let Some(ref token) = cli.token {
+                skip_file_tokens(cli, out, file, token)
+            } else {
+                skip_file_lines(cli, out, file)
             }
         },
         None => todo!("reading from stdin")
     }
+}
 
+fn skip_file_lines<F>(cli: &Cli, mut out: F, file: &PathBuf) -> io::Result<()> 
+    where F: FnMut(String) -> ()
+{
+    eprintln!("skip_file_lines");
+    let content = fs::read_to_string(file).expect("Could not read file");
+    let mut counter = 0usize;
+    for current_line in content.lines() {
+        if counter >= cli.lines {
+            out(String::from(current_line));
+        }
+        counter += 1;
+    }
+    Ok(())
+}
+
+fn skip_file_lines_matching<F>(cli: &Cli, mut out: F, file: &PathBuf, line: &str) -> io::Result<()> 
+    where F: FnMut(String) -> ()
+{
+    eprintln!("skip_file_lines_matching");
+    let content = fs::read_to_string(file).expect("Could not read file");
+    let mut counter = 0usize;
+    for current_line in content.lines() {
+        if counter >= cli.lines {
+            out(String::from(current_line));
+        }
+        if line == current_line {
+            counter += 1;
+        }
+    }
+    Ok(())
+}
+
+fn skip_file_tokens<F>(cli: &Cli, mut out: F, file: &PathBuf, token: &str) -> io::Result<()> 
+    where F: FnMut(String) -> ()
+{
+    eprintln!("skip_file_lines_tokens");
+    let content = fs::read_to_string(file).expect("Could not read file");
+    let mut counter = 0usize;
+    for current_line in content.lines() {
+        if counter >= cli.lines {
+            out(String::from(current_line));
+        }
+        if current_line.contains(&token) {
+            counter += 1;
+        }
+    }
     Ok(())
 }
 
@@ -54,7 +100,7 @@ mod tests {
         let mut lines: Vec<String> = Vec::new();
 
         //when
-        skip(cli, |line| lines.push(line))?;
+        skip(&cli, |line| lines.push(line))?;
 
         //then
         assert_eq!(lines, vec!["line 2"]);
@@ -68,11 +114,25 @@ mod tests {
         let mut lines: Vec<String> = Vec::new();
 
         //when
-        skip(cli, |line| lines.push(line))?;
+        skip(&cli, |line| lines.push(line))?;
 
         //then
         assert_eq!(lines, vec!["alpha", "gamma"]);
         Ok(())
     }
 
+    #[test]
+    fn skip_two_matching_lines_of_alpha() -> io::Result<()> {
+        //given
+        let cli = Cli { lines: 2, file: Some(PathBuf::from("tests/four-lines.txt")), line: Some(String::from("alpha")), token: None, ignore_extras: false };
+        let mut lines: Vec<String> = Vec::new();
+
+        //when
+        skip(&cli, |line| lines.push(line))?;
+
+        //then
+        assert_eq!(lines, vec!["gamma"]);
+        Ok(())
+    }
+
 }
diff --git a/src/main.rs b/src/main.rs
index 6c73ba1..418d4ca 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,12 +3,12 @@ use clap::Parser;
 use std::io::Write;
 
 fn main() -> std::io::Result<()> {
-    let args = Cli::parse();
+    let cli = Cli::parse();
 
     let stdout = std::io::stdout();
     let mut output = stdout.lock();
 
-    skip(args, |line| {
+    skip(&cli, |line| {
         match writeln!(output, "{}", line) {
             Err(_) => (),
             Ok(_) => ()