use anyhow::Result;
use colored::*;

use crate::board;

#[derive(Debug)]
pub struct SystemHealth {
    pub arduino_cli_ok: bool,
    pub arduino_cli_path: Option<String>,
    pub avr_core_ok: bool,
    pub avr_size_ok: bool,
    pub dialout_ok: bool,
    pub cmake_ok: bool,
    pub cpp_compiler_ok: bool,
    pub git_ok: bool,
    pub ports_found: usize,
}

impl SystemHealth {
    pub fn is_healthy(&self) -> bool {
        self.arduino_cli_ok && self.avr_core_ok
    }
}

pub fn run_diagnostics() -> Result<()> {
    println!(
        "{}",
        "Checking system health...".bright_yellow().bold()
    );
    println!();

    let health = check_system_health();
    print_diagnostics(&health);

    println!();
    if health.is_healthy() {
        println!(
            "{}",
            "System is ready for Arduino development."
                .bright_green()
                .bold()
        );
    } else {
        println!(
            "{}",
            "Issues found. Run 'anvil setup' to fix."
                .bright_yellow()
                .bold()
        );
    }
    println!();

    Ok(())
}

pub fn check_system_health() -> SystemHealth {
    // arduino-cli
    let (arduino_cli_ok, arduino_cli_path) = match board::find_arduino_cli() {
        Some(path) => (true, Some(path.display().to_string())),
        None => (false, None),
    };

    // AVR core
    let avr_core_ok = if let Some(ref path_str) = arduino_cli_path {
        let path = std::path::Path::new(path_str);
        board::is_avr_core_installed(path)
    } else {
        false
    };

    // avr-size (optional)
    let avr_size_ok = which::which("avr-size").is_ok();

    // dialout group (Linux only)
    let dialout_ok = check_dialout();

    // cmake (optional -- for host tests)
    let cmake_ok = which::which("cmake").is_ok();

    // C++ compiler (optional -- for host tests)
    let cpp_compiler_ok = which::which("g++").is_ok() || which::which("clang++").is_ok();

    // git
    let git_ok = which::which("git").is_ok();

    // Serial ports
    let ports_found = board::list_ports().len();

    SystemHealth {
        arduino_cli_ok,
        arduino_cli_path,
        avr_core_ok,
        avr_size_ok,
        dialout_ok,
        cmake_ok,
        cpp_compiler_ok,
        git_ok,
        ports_found,
    }
}

fn print_diagnostics(health: &SystemHealth) {
    println!("{}", "Required:".bright_yellow().bold());
    println!();

    // arduino-cli
    if health.arduino_cli_ok {
        println!(
            "  {} arduino-cli  {}",
            "ok".green(),
            health
                .arduino_cli_path
                .as_ref()
                .unwrap_or(&String::new())
                .bright_black()
        );
    } else {
        println!("  {} arduino-cli  {}", "MISSING".red(), "not found in PATH".red());
    }

    // AVR core
    if health.avr_core_ok {
        println!("  {} arduino:avr core installed", "ok".green());
    } else if health.arduino_cli_ok {
        println!(
            "  {} arduino:avr core  {}",
            "MISSING".red(),
            "run: anvil setup".red()
        );
    } else {
        println!(
            "  {} arduino:avr core  {}",
            "MISSING".red(),
            "(needs arduino-cli first)".bright_black()
        );
    }

    println!();
    println!("{}", "Optional:".bright_yellow().bold());
    println!();

    // avr-size
    if health.avr_size_ok {
        println!("  {} avr-size (binary size reporting)", "ok".green());
    } else {
        println!(
            "  {} avr-size  {}",
            "--".bright_black(),
            "install: sudo apt install gcc-avr".bright_black()
        );
    }

    // dialout
    #[cfg(unix)]
    {
        if health.dialout_ok {
            println!("  {} user in dialout group", "ok".green());
        } else {
            println!(
                "  {} dialout group  {}",
                "WARN".yellow(),
                "run: sudo usermod -aG dialout $USER".yellow()
            );
        }
    }

    // cmake
    if health.cmake_ok {
        println!("  {} cmake (for host-side tests)", "ok".green());
    } else {
        println!(
            "  {} cmake  {}",
            "--".bright_black(),
            "install: sudo apt install cmake".bright_black()
        );
    }

    // C++ compiler
    if health.cpp_compiler_ok {
        println!("  {} C++ compiler (g++/clang++)", "ok".green());
    } else {
        println!(
            "  {} C++ compiler  {}",
            "--".bright_black(),
            "install: sudo apt install g++".bright_black()
        );
    }

    // git
    if health.git_ok {
        println!("  {} git", "ok".green());
    } else {
        println!(
            "  {} git  {}",
            "--".bright_black(),
            "install: sudo apt install git".bright_black()
        );
    }

    println!();
    println!("{}", "Hardware:".bright_yellow().bold());
    println!();

    if health.ports_found > 0 {
        println!(
            "  {} {} serial port(s) detected",
            "ok".green(),
            health.ports_found
        );
    } else {
        println!(
            "  {} no serial ports  {}",
            "--".bright_black(),
            "(plug in a board to detect)".bright_black()
        );
    }
}

fn check_dialout() -> bool {
    #[cfg(unix)]
    {
        let output = std::process::Command::new("groups")
            .output();
        match output {
            Ok(out) => {
                let groups = String::from_utf8_lossy(&out.stdout);
                groups.contains("dialout")
            }
            Err(_) => false,
        }
    }

    #[cfg(not(unix))]
    {
        true // Not applicable on Windows
    }
}