my_minigrepio 0.1.0

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

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

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

    for line in res {
        println!("{}", line);
    }

    return Ok(());
}

pub struct Config {
    pub query: String,
    pub filename: String,
    pub case_sensitive: bool,
}

impl Config {
    pub fn new(mut args: std::env::Args) -> Result<Config, &'static str> {
        if args.len() < 3 {
            return Err("Not Enough Arguments!");
        }

        args.next();

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

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

        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
        Ok(Config {
            query: (query),
            filename: (filename),
            case_sensitive: (case_sensitive),
        })
    }
}

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 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)
        )
    }
}