minigrepwebdot 0.1.0

//! # minigrepwebdot
//! 
//! minigrepwebdot is a command-line utility tool that helps to search for occurences of words on a file.


use std::{env, fs};
use std::error::Error;

/// # Config
/// 
/// This is a struct used to hold information about user's arguments on file search.
/// 
/// # Examples
/// 
/// ```
/// minigrepwebdot::Config::build(vec!["hey".to_string(), "hey".to_string(), "poem.txt".to_string()].into_iter());
/// ```
pub struct Config {
    pub query: String,
    pub  file_path: String,
    pub ignore_case: bool
}

impl Config {
    pub fn build(mut args: impl Iterator<Item = String>) -> Result<Config, &'static str> {
        args.next();
        
        let query = match args.next() {
            Some(arg) => arg,
            None => return Err("Didn't get a query string")
        };

        let file_path = match args.next() {
            Some(arg) => arg,
            None => return Err("Didn't get a file path")
        };

        let ignore_case = env::var("IGNORE_CASE").is_ok();
        
        Ok(Config {query, file_path, ignore_case})
    }
}

pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.file_path)?;

    let results = if config.ignore_case {
        search_case_insensitive(&config.query, &contents)
    } else {
        search(&config.query, &contents)
    };

    for line in results {
        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_ascii_lowercase().contains(&query.to_ascii_lowercase())).collect()
}


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

    #[test]
    fn case_sensitive() {
        let query = "duct";
        let contents = "\
Rust:
safe, fast, productive.
Pick three.
Duct tape.";

        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.";

        assert_eq!(vec!["Rust:", "Trust me."], search_case_insensitive(query, contents));
    }
}