use std::path::Path;
use std::path::PathBuf;

use crate::cli::parameters::BuildArgs;
use crate::config::Config;
use tokio::task::JoinHandle;
use walkdir::WalkDir;

pub(crate) async fn build_site(args: BuildArgs) -> Result<(), Box<dyn std::error::Error>> {
    let config = Config::load_from_file(args.config).await?;
    let org_files = {
        let mut ret = Vec::new();
        let org_files_iter = get_org_files(config.get_root_directory())?;
        for entry in org_files_iter {
            ret.push(entry.await??);
        }
        ret
    };
    let parsed_org_files = {
        let mut ret = Vec::new();
        for (path, contents) in org_files.iter() {
            let parsed = organic::parser::parse_file(contents.as_str(), Some(path))?;
            ret.push((path, contents, parsed));
        }
        ret
    };

    Ok(())
}

async fn read_file(path: PathBuf) -> std::io::Result<(PathBuf, String)> {
    let contents = tokio::fs::read_to_string(&path).await?;
    Ok((path, contents))
}

fn get_org_files<P: AsRef<Path>>(
    root_dir: P,
) -> Result<impl Iterator<Item = JoinHandle<std::io::Result<(PathBuf, String)>>>, walkdir::Error> {
    let org_files = WalkDir::new(root_dir)
        .into_iter()
        .filter(|e| match e {
            Ok(dir_entry) => {
                dir_entry.file_type().is_file()
                    && Path::new(dir_entry.file_name())
                        .extension()
                        .map(|ext| ext.to_ascii_lowercase() == "org")
                        .unwrap_or(false)
            }
            Err(_) => true,
        })
        .collect::<Result<Vec<_>, _>>()?;
    let org_files = org_files
        .into_iter()
        .map(walkdir::DirEntry::into_path)
        .map(|path| tokio::spawn(read_file(path)));
    Ok(org_files)
}