use crate::builtins::{Builtin, BuiltinConfig};
use crate::error::ShellError;
use colored::Colorize;
use sysinfo::{CpuExt, System, SystemExt};
use uname::uname;
use whoami::{hostname, username};

pub struct Fetch;

impl Builtin for Fetch {
    fn execute(&mut self, _: &mut BuiltinConfig, _: Vec<String>) -> Result<(), ShellError> {
        let mut sys = System::new();
        sys.refresh_all();

        let line = "-".repeat(username().len() + hostname().len() + 1);

        println!(
            "\n{}{}{}",
            username().bright_green().bold(),
            "@".bold(),
            hostname().bright_green().bold()
        );
        println!("{}", line);
        println!(
            "{} {} {}",
            "OS".bright_blue().bold(),
            sys.name().unwrap_or_default(),
            uname().unwrap().machine
        );
        println!(
            "{} {}",
            "KERNEL".yellow().bold(),
            sys.kernel_version().unwrap_or_default()
        );
        println!("{} {}", "UPTIME".red().bold(), format_uptime(sys.uptime()));
        println!("{} {}", "CPU".magenta().bold(), sys.cpus()[0].brand());
        println!(
            "{} {}MiB / {}MiB",
            "MEMORY".cyan().bold(),
            bytes_to_mebi_bytes(sys.used_memory()),
            bytes_to_mebi_bytes(sys.total_memory())
        );

        Ok(())
    }
}

fn format_uptime(uptime: u64) -> String {
    let h = uptime / 3600;
    let m = (uptime - h * 3600) / 60;
    let s = uptime - (h * 3600 + m * 60);

    format!("{:.0}h {:.0}m {:.0}s", h, m, s)
}

fn bytes_to_mebi_bytes(bytes: u64) -> u64 {
    bytes / 1024 / 1024
}

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

    #[test]
    fn test_format_uptime_seconds() {
        assert_eq!(format_uptime(35), "0h 0m 35s");
    }

    #[test]
    fn test_format_uptime_minutes() {
        assert_eq!(format_uptime(135), "0h 2m 15s");
    }

    #[test]
    fn test_format_uptime_hours() {
        assert_eq!(format_uptime(3735), "1h 2m 15s");
    }

    #[test]
    fn test_bytes_to_mebi_bytes() {
        assert_eq!(bytes_to_mebi_bytes(7628144640), 7274);
    }
}