use crate::models::{CookieSource, DependencyStatus};
use std::process::Command;

pub fn check_tool_exists(name: &str) -> Option<String> {
    let output = Command::new("which").arg(name).output().ok()?;

    if output.status.success() {
        let version_output = Command::new(name).arg("--version").output().ok()?;
        let version = String::from_utf8_lossy(&version_output.stdout)
            .lines()
            .next()
            .unwrap_or("")
            .trim()
            .to_string();
        Some(version)
    } else {
        None
    }
}

pub fn check_js_runtime() -> Option<String> {
    check_tool_exists("deno").or_else(|| check_tool_exists("node"))
}

pub fn check_pot_plugin(cookie_source: &CookieSource) -> bool {
    let mut command = Command::new("yt-dlp");
    command
        .arg("-v")
        .arg("--simulate")
        .args(cookie_source.to_ytdlp_args())
        .arg("https://www.youtube.com/watch?v=dQw4w9WgXcQ");
    let output = command.output();

    match output {
        Ok(out) => {
            let stderr = String::from_utf8_lossy(&out.stderr);
            stderr.contains("GetPOT")
        }
        Err(_) => false,
    }
}

pub fn get_all_dependency_statuses(cookie_source: &CookieSource) -> Vec<DependencyStatus> {
    let ffmpeg = check_tool_exists("ffmpeg");
    let ytdlp = check_tool_exists("yt-dlp");
    let js_runtime = check_js_runtime();
    let pot_plugin = if ytdlp.is_some() {
        check_pot_plugin(cookie_source)
    } else {
        false
    };

    vec![
        DependencyStatus {
            name: "ffmpeg".to_string(),
            installed: ffmpeg.is_some(),
            version: ffmpeg,
            install_command: "brew install ffmpeg".to_string(),
        },
        DependencyStatus {
            name: "yt-dlp".to_string(),
            installed: ytdlp.is_some(),
            version: ytdlp,
            install_command: "brew install yt-dlp".to_string(),
        },
        DependencyStatus {
            name: "JavaScript runtime (deno/node)".to_string(),
            installed: js_runtime.is_some(),
            version: js_runtime,
            install_command: "brew install deno".to_string(),
        },
        DependencyStatus {
            name: "bgutil-ytdlp-pot-provider".to_string(),
            installed: pot_plugin,
            version: None,
            install_command: "python3 -m pip install -U bgutil-ytdlp-pot-provider".to_string(),
        },
    ]
}

pub fn get_install_args(dep_name: &str) -> Result<Vec<String>, String> {
    match dep_name {
        "ffmpeg" => Ok(vec![
            "brew".into(), "install".into(), "ffmpeg".into(),
        ]),
        "yt-dlp" => Ok(vec![
            "brew".into(), "install".into(), "yt-dlp".into(),
        ]),
        "JavaScript runtime (deno/node)" => Ok(vec![
            "brew".into(), "install".into(), "deno".into(),
        ]),
        "bgutil-ytdlp-pot-provider" => Ok(vec![
            "python3".into(), "-m".into(), "pip".into(), "install".into(), "-U".into(), "bgutil-ytdlp-pot-provider".into(),
        ]),
        _ => Err(format!("Unknown dependency: {dep_name}")),
    }
}

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

    #[test]
    fn test_get_install_args_ffmpeg() {
        let args = get_install_args("ffmpeg").unwrap();
        assert_eq!(args, vec!["brew", "install", "ffmpeg"]);
    }

    #[test]
    fn test_get_install_args_ytdlp() {
        let args = get_install_args("yt-dlp").unwrap();
        assert_eq!(args, vec!["brew", "install", "yt-dlp"]);
    }

    #[test]
    fn test_get_install_args_pot_provider() {
        let args = get_install_args("bgutil-ytdlp-pot-provider").unwrap();
        assert_eq!(args, vec!["python3", "-m", "pip", "install", "-U", "bgutil-ytdlp-pot-provider"]);
    }

    #[test]
    fn test_get_install_args_unknown() {
        assert!(get_install_args("unknown-tool").is_err());
    }

    #[test]
    fn test_dependency_statuses_has_four_entries() {
        let statuses = get_all_dependency_statuses(&CookieSource::default());
        assert_eq!(statuses.len(), 4);
        assert_eq!(statuses[0].name, "ffmpeg");
        assert_eq!(statuses[1].name, "yt-dlp");
        assert_eq!(statuses[2].name, "JavaScript runtime (deno/node)");
        assert_eq!(statuses[3].name, "bgutil-ytdlp-pot-provider");
    }
}