use crate::make_parent_directory;
use crate::{get_entry, get_optional_entry, list_directory};
use crate::{EntryType, EntryWriteError};
use std::path::Path;

pub fn copy<P, Q>(source_path: P, target_path: Q) -> Result<(), EntryWriteError>
where
    P: AsRef<Path>,
    Q: AsRef<Path>,
{
    let source = get_entry(&source_path)?;
    let target = get_optional_entry(&target_path)?;
    let target_type = target.and_then(|e| Some(e.entry_type));

    match (source.entry_type, target_type) {
        (EntryType::File, Some(EntryType::File)) => {
            copy_file(source_path, target_path)?;
        }
        (EntryType::File, Some(EntryType::Directory)) => {
            let target_path = target_path.as_ref().join(source.name);
            copy_file(source_path, target_path)?;
        }
        (EntryType::File, None) => {
            make_parent_directory(&target_path)?;
            copy_file(source_path, target_path)?;
        }
        (EntryType::Directory, Some(EntryType::File)) => {
            std::fs::remove_file(&target_path)?;
            copy_directory(&source_path, &target_path)?;
        }
        (EntryType::Directory, Some(EntryType::Directory)) => {
            let target_path = target_path.as_ref().join(source.name);
            copy_directory(source_path, target_path)?;
        }
        (EntryType::Directory, None) => {
            make_parent_directory(&target_path)?;
            copy_directory(source_path, target_path)?;
        }
    }
    Ok(())
}

fn copy_file<P, Q>(source_path: P, target_path: Q) -> Result<(), EntryWriteError>
where
    P: AsRef<Path>,
    Q: AsRef<Path>,
{
    std::fs::copy(source_path, target_path)?;
    Ok(())
}

fn copy_directory<P, Q>(source_path: P, target_path: Q) -> Result<(), EntryWriteError>
where
    P: AsRef<Path>,
    Q: AsRef<Path>,
{
    for entry in list_directory(&source_path)? {
        let target_path = target_path.as_ref().join(entry.name);
        copy(entry.path, &target_path)?;
    }
    Ok(())
}