use crate::errors::BumperError;
use glob::glob;
use log::{debug, info};
use std::path::{Path, PathBuf};
use std::process::Command;

pub struct Python {
    dirname: PathBuf,
    version_pys: Vec<PathBuf>,
}

impl Python {
    pub fn new(dirname: &Path) -> Result<Self, BumperError> {
        let setup_py = dirname.join("setup.py");
        debug!("does {} exist? {}", setup_py.display(), setup_py.exists());
        if setup_py.exists() {
            let files = find_version_py_files(dirname);
            if files.is_empty() {
                debug!("no version.py files in {}", dirname.display());
                Err(BumperError::NoVersionPy(dirname.to_path_buf()))
            } else {
                Ok(Self {
                    dirname: dirname.to_path_buf(),
                    version_pys: files,
                })
            }
        } else {
            Err(BumperError::UnknownProjectKind(dirname.to_path_buf()))
        }
    }

    pub fn name(&mut self) -> Result<String, BumperError> {
        let output = Command::new("./setup.py")
            .arg("--name")
            .current_dir(&self.dirname)
            .output()
            .map_err(|err| BumperError::Setupnvoke(self.dirname.to_path_buf(), err))?;
        if output.status.success() {
            let name = String::from_utf8_lossy(&output.stdout).into_owned();
            Ok(name.trim_end().to_string())
        } else {
            let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
            Err(BumperError::Setup(self.dirname.to_path_buf(), stderr))
        }
    }

    pub fn set_version(&mut self, version: &str) -> Result<String, BumperError> {
        for filename in self.version_pys.iter() {
            info!("writing Python version to {}", filename.display());
            std::fs::write(filename, format!("__version__ = \"{}\"\n", version))
                .map_err(|err| BumperError::PythonWrite(filename.to_path_buf(), err))?;
        }
        Ok(version.to_string())
    }
}

fn find_version_py_files(dirname: &Path) -> Vec<PathBuf> {
    glob(&dirname.join("*/version.py").display().to_string())
        .expect("glob pattern error")
        .filter(|x| x.is_ok())
        .map(|x| x.unwrap())
        .collect()
}