rust_mini_grep 0.1.0

use std::{env, fs};
use std::error::Error;
///
///find line string from  file
///
///
///
///


pub struct Config {
    pub file_name: String,
    pub query: String,
    pub case_insensitive: bool,
}

impl Config {
    pub fn new() -> Result<Config, &'static str> {
        let args: Vec<String> = env::args().collect();
        if args.len() < 3 {
            return Err("not enough arguments");
        }
        let file_name = args[1].clone();
        let query = args[2].clone();
        let case_insensitive = env::var("CASE_INSENSITIVE").is_ok();

        Ok(Config { file_name, query, case_insensitive })
    }
}

pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.file_name)?;
    if config.case_insensitive {
        search_case_insensitive(&*config.query, &contents).into_iter().for_each(|line| println!("{line}"));
    } else {
        search(&*config.query, &contents).into_iter().for_each(|line| println!("{line}"));
    }

    Ok(())
}

pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    contents.lines()
        .filter(|line| line.contains(query))
        .collect()
}

pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    contents.lines()
        .filter(|line| line.to_lowercase().contains(&query.to_lowercase()))
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn one_result() {
        let query = "duct";
        let contents = "\
Rust
safe, fast, productive.
Pick three.
Duct.
";
        assert_eq!(vec!["safe, fast, productive."], search(query, contents))
    }

    #[test]
    fn case_insensitive() {
        let query = "rust";
        let contents = "\
Rust.
safe, fast, productive.
Pick three.
trUst me.
Duct.
";
        assert_eq!(vec!["Rust.", "trUst me."], search_case_insensitive(query, contents))
    }
}