minigrep_learn 0.1.0

use std::fs;
use std::error::Error;
use std::env;

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

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

    for line in found {
        println!("{line}");
    }

    Ok(())
}

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>{

        // Ignoring first value, since it is the name of the program
        args.next();
        let query= match args.next() {
            Some(x) => x,
            None => return Err("Did not get a query string"),
        };
        let file_path = match args.next() {
            Some(x) => x,
            None => return Err("Did not get a file path"),
        };

        let ignore_case = env::var("IGNORE_CASE").is_ok();

        Ok(Config {query, file_path, ignore_case})
    }
}

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>{
    let query = query.to_lowercase();

    contents
        .lines()
        .filter(|line| line.to_lowercase().contains(&query))
        .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)
        )
    }
}