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

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

impl Python {
    pub fn new(dirname: &Path) -> Result<Self, BumperError> {
        debug!("considering {} as a Python project", dirname.display());
        let setup_py = dirname.join("setup.py");
        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 {
                info!("Looks like a Python project: {}", dirname.display());
                Ok(Self { version_pys: files })
            }
        } else {
            debug!("{} does not exist", setup_py.display());
            Err(BumperError::UnknownProjectKind(dirname.to_path_buf()))
        }
    }

    pub fn set_version(&mut self, version: &str) -> Result<(), 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(())
    }
}

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()
}