use std::path::PathBuf;

use crate::error::CustomError;

use super::RenderContext;

#[derive(Debug)]
pub(crate) enum Dependency {
    StaticFile { absolute_path: PathBuf },
    CssFile { name: String },
}

impl Dependency {
    pub(crate) async fn perform(
        &self,
        render_context: RenderContext<'_>,
    ) -> Result<(), CustomError> {
        match self {
            Dependency::StaticFile { absolute_path } => {
                let input_root_directory = render_context.config.get_root_directory();
                let relative_path_to_file = absolute_path.strip_prefix(input_root_directory)?;
                let path_to_output = render_context
                    .output_root_directory
                    .join(relative_path_to_file);
                tokio::fs::create_dir_all(
                    path_to_output
                        .parent()
                        .ok_or("Output file should have a containing directory.")?,
                )
                .await?;

                if tokio::fs::metadata(&path_to_output).await.is_ok() {
                    // TODO: compare hash and error out if they do not match.
                    println!(
                        "Not copying {} to {} because the output file already exists.",
                        absolute_path.display(),
                        path_to_output.display()
                    );
                } else {
                    tokio::fs::copy(absolute_path, path_to_output).await?;
                }
                Ok(())
            }
            Dependency::CssFile { name: _ } => {
                // We don't do anything because the CSS files are already copied into the output from natter's default environment.
                // TODO: When we add support for CSS outside the default environment, we should add support for dynamically picking which ones to copy here.
                Ok(())
            }
        }
    }
}