use anyhow::{Context, Result};
use clap::Parser;
use indicatif::ProgressBar;
use std::fs::File;
use std::io::{self, BufRead, Write};
use std::path::PathBuf;
use std::thread;
use std::time::Duration;

/// 在文件中搜索模式并显示包含它的行。
#[derive(Parser)]
struct Cli {
    /// 要查找的模式
    pattern: String,
    /// 要读取的文件的路径
    path: PathBuf,
}

fn main() -> Result<()> {
    let args = Cli::parse();

    // 打开文件并创建一个 BufReader 来逐行读取
    let file = File::open(&args.path).with_context(|| format!("无法打开文件 {:?}", &args.path))?;
    let reader = io::BufReader::new(file);

    let stdout = io::stdout();
    let stdout_lock = stdout.lock();
    let mut handle = io::BufWriter::new(stdout_lock);
    let pb = ProgressBar::new(100);
    for line in reader.lines() {
        do_hard_work();
        pb.println(format!("[+] 查找到了 #{:?}项", line));
        pb.inc(1);
        let line = line.with_context(|| "无法读取行")?;
        if line.contains(&args.pattern) {
            writeln!(handle, "{}", line)?;
        }
    }

    Ok(())
}

fn do_hard_work() {
    thread::sleep(Duration::from_millis(250));
}