use pile_config::Label;
use std::sync::Arc;

mod epub_meta;
pub use epub_meta::*;

mod epub_text;
pub use epub_text::*;

use crate::{
	extract::traits::{ExtractState, ObjectExtractor},
	value::{Item, PileValue},
};

pub struct EpubExtractor {
	text: Arc<EpubTextExtractor>,
	meta: Arc<EpubMetaExtractor>,
}

impl EpubExtractor {
	pub fn new(item: &Item) -> Self {
		Self {
			text: Arc::new(EpubTextExtractor::new(item)),
			meta: Arc::new(EpubMetaExtractor::new(item)),
		}
	}
}

#[async_trait::async_trait]
impl ObjectExtractor for EpubExtractor {
	async fn field(
		&self,
		state: &ExtractState,
		name: &pile_config::Label,
		args: Option<&str>,
	) -> Result<Option<PileValue>, std::io::Error> {
		match (name.as_str(), args) {
			("text", args) => Ok(Some(
				self.text
					.field(state, name, args)
					.await
					.map(|x| x.unwrap_or(PileValue::Null))?,
			)),

			("meta", None) => Ok(Some(PileValue::ObjectExtractor(self.meta.clone()))),
			_ => Ok(None),
		}
	}

	#[expect(clippy::unwrap_used)]
	async fn fields(&self) -> Result<Vec<Label>, std::io::Error> {
		Ok(vec![
			Label::new("text").unwrap(),
			Label::new("meta").unwrap(),
		])
	}

	async fn to_json(&self, state: &ExtractState) -> Result<serde_json::Value, std::io::Error> {
		let keys = self.fields().await?;
		let mut map = serde_json::Map::new();
		for k in &keys {
			let v = match self.field(state, k, None).await? {
				Some(x) => x,
				None => continue,
			};

			if k.as_str() == "text" {
				map.insert(
					k.to_string(),
					serde_json::Value::String(format!(
						"<String ({} bytes)",
						match v {
							PileValue::String(x) => x.len(),
							_ => 0,
						}
					)),
				);
				continue;
			}

			map.insert(k.to_string(), Box::pin(v.to_json(state)).await?);
		}

		Ok(serde_json::Value::Object(map))
	}
}