文件搜索

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

pub fn search_case_insensitive<'a>(query: &str,contents: &'a str,) -> Vec<&'a str> {
    let query = query.to_lowercase();
    let mut results = Vec::new();

    for line in contents.lines() {
        if line.to_lowercase().contains(&query) {
            results.push(line);
        }
    }

    results
}


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{
        vec!["NULL"]
    };

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

    Ok(())
}


pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool
}

impl Config {
    pub fn build(args: &[String]) -> Result<Config, &'static str> {
        if args.len() < 3 {
            return Err("not enough arguments");
        }

        let query = args[1].clone();
        let file_path = args[2].clone();

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

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

use std::env;
use std::process;

use minigrep::Config;

fn main() {
    let args: Vec<String> = env::args().collect();

    let config = Config::build(&args).unwrap();

    println!("Searching for {}", config.query);
    println!("In file {}", config.file_path);

    if let Err(e) = minigrep::run(config) {
        println!("Application error: {e}");
        process::exit(1);
    }
}