use crate::{config::Config, db::*, locales::Locales, queries::*};

use fluent_bundle::FluentArgs;
use log::error;
use std::{net::IpAddr, str::FromStr};
use unic_langid::LanguageIdentifier;

pub fn new_pending_comment(
	comment: &Comment,
	addr: Option<IpAddr>,
	dbs: &Dbs,
) -> Result<CommentId, sled::Error> {
	let comment_id = CommentId::new();
	dbs.comment.insert(&comment_id, comment)?;
	dbs.comment_pending.insert(
		&(
			comment.topic_hash.clone(),
			comment.post_time,
			comment_id.clone(),
		),
		&addr,
	)?;
	Ok(comment_id)
}

pub fn approve_comment(comment_id: CommentId, dbs: &Dbs) -> Result<(), sled::Error> {
	if let Some(comment) = dbs.comment.get(&comment_id)? {
		dbs.comment_pending.remove(&(
			comment.topic_hash.clone(),
			comment.post_time,
			comment_id.clone(),
		))?;
		dbs.comment_approved
			.insert(&(comment.topic_hash, comment.post_time, comment_id), &())?;
	}
	Ok(())
}

pub fn remove_comment(comment_id: CommentId, dbs: &Dbs) -> Result<Option<Comment>, sled::Error> {
	if let Some(comment) = dbs.comment.remove(&comment_id)? {
		dbs.comment_pending.remove(&(
			comment.topic_hash.clone(),
			comment.post_time,
			comment_id.clone(),
		))?;
		dbs.comment_approved.remove(&(
			comment.topic_hash.clone(),
			comment.post_time,
			comment_id,
		))?;
		return Ok(Some(comment));
	}
	Ok(None)
}

pub fn iter_comments_by_topic<'a, V: typed_sled::KV>(
	topic_hash: TopicHash,
	tree: &'a Tree<(TopicHash, Time, CommentId), V>,
	dbs: &'a Dbs,
) -> impl Iterator<Item = (CommentId, Comment, V)> + 'a {
	tree.range(
		(topic_hash.clone(), 0, CommentId::zero())..=(topic_hash, Time::MAX, CommentId::max()),
	)
	.filter_map(|entry| {
		let ((_topic_hash, _time, comment_id), val) = entry
			.map_err(|e| error!("Reading comment_by_topic_and_time: {:?}", e))
			.ok()?;
		let comment = dbs
			.comment
			.get(&comment_id)
			.map_err(|e| error!("Reading comment: {:?}", e))
			.ok()?
			.or_else(|| {
				error!("Comment not found");
				None
			})?;
		Some((comment_id, comment, val))
	})
}

pub fn iter_approved_comments_by_topic(
	topic_hash: TopicHash,
	dbs: &Dbs,
) -> impl Iterator<Item = (CommentId, Comment)> + '_ {
	iter_comments_by_topic(topic_hash, &dbs.comment_approved, dbs)
		.map(|(comment_id, comment, ())| (comment_id, comment))
}

pub fn iter_pending_comments_by_topic(
	topic_hash: TopicHash,
	dbs: &Dbs,
) -> impl Iterator<Item = (CommentId, Comment, Option<IpAddr>)> + '_ {
	iter_comments_by_topic(topic_hash, &dbs.comment_pending, dbs)
}

/// Returns Some(time_left) if the client is banned.
pub fn antispam_check_client_mutation(
	addr: &IpAddr,
	dbs: &Dbs,
	config: &Config,
) -> Result<Option<Time>, sled::Error> {
	let time = std::time::SystemTime::now()
		.duration_since(std::time::UNIX_EPOCH)
		.unwrap()
		.as_secs();
	Ok(dbs
		.client_mutation
		.get(addr)?
		.and_then(|(last_mutation, mutation_count)| {
			let timeout = last_mutation + config.antispam_duration;
			if timeout > time && mutation_count >= config.antispam_mutation_limit {
				Some(timeout - time)
			} else {
				None
			}
		}))
}

pub fn antispam_update_client_mutation(addr: &IpAddr, dbs: &Dbs) -> Result<(), sled::Error> {
	let time = std::time::SystemTime::now()
		.duration_since(std::time::UNIX_EPOCH)
		.unwrap()
		.as_secs();
	dbs.client_mutation.fetch_and_update(addr, |entry| {
		if let Some((_last_mutation, mutation_count)) = entry {
			Some((time, mutation_count.saturating_add(1)))
		} else {
			Some((time, 1))
		}
	})?;
	Ok(())
}

/*pub fn new_client_mutation(
	addr: &IpAddr,
	dbs: &Dbs,
	config: &Config,
) -> Result<Option<Time>, sled::Error> {
	let time = std::time::SystemTime::now()
		.duration_since(std::time::UNIX_EPOCH)
		.unwrap()
		.as_secs();
	let mut res = None;
	dbs.client_mutation.fetch_and_update(addr, |entry| {
		if let Some((last_mutation, mutation_count)) = entry {
			if last_mutation + config.antispam_duration > time {
				if mutation_count >= config.antispam_mutation_limit {
					res = Some(last_mutation + config.antispam_duration);
					Some((last_mutation, mutation_count))
				} else {
					Some((time, mutation_count.saturating_add(1)))
				}
			} else {
				Some((time, 1))
			}
		} else {
			Some((time, 1))
		}
	})?;
	Ok(res)
}*/

pub fn get_client_addr<State>(
	config: &Config,
	req: &tide::Request<State>,
) -> Option<Result<IpAddr, std::net::AddrParseError>> {
	Some(IpAddr::from_str(
		if config.reverse_proxy {
			req.remote()
		} else {
			req.peer_addr()
		}?
		.rsplit_once(':')?
		.0,
	))
}

pub fn check_comment(
	config: &Config,
	locales: &Locales,
	langs: &[LanguageIdentifier],
	comment: &CommentForm,
	errors: &mut Vec<String>,
) {
	if comment.author.len() > config.comment_author_max_len {
		let mut args = FluentArgs::new();
		args.set("len", comment.author.len());
		args.set("max_len", config.comment_author_max_len);
		errors.push(
			locales
				.tr(langs, "error-comment-author_name_too_long", Some(&args))
				.unwrap()
				.to_string(),
		);
	}
	if comment.email.len() > config.comment_email_max_len {
		let mut args = FluentArgs::new();
		args.set("len", comment.email.len());
		args.set("max_len", config.comment_email_max_len);
		errors.push(
			locales
				.tr(langs, "error-comment-email_too_long", Some(&args))
				.unwrap()
				.to_string(),
		);
	}
	if comment.text.len() > config.comment_text_max_len {
		let mut args = FluentArgs::new();
		args.set("len", comment.text.len());
		args.set("max_len", config.comment_text_max_len);
		errors.push(
			locales
				.tr(langs, "error-comment-text_too_long", Some(&args))
				.unwrap()
				.to_string(),
		);
	}
}

#[cfg(test)]
mod test {
	use super::*;

	#[test]
	fn test_comment() {
		let comment = Comment {
			topic_hash: TopicHash::from_topic("test"),
			author: String::from("Emmanuel Goldstein"),
			email: None,
			last_edit_time: None,
			post_time: 42,
			text: String::from("Hello world!"),
		};

		let dbs = load_dbs(None);
		let comment_id = new_pending_comment(&comment, &dbs).unwrap();

		let mut iter = dbs.comment.iter();
		assert_eq!(iter.next(), Some(Ok((comment_id.clone(), comment.clone()))));
		assert_eq!(iter.next(), None);

		let mut iter = dbs.comment_pending.iter();
		assert_eq!(
			iter.next(),
			Some(Ok((
				(
					comment.topic_hash.clone(),
					comment.post_time,
					comment_id.clone()
				),
				()
			)))
		);
		assert_eq!(iter.next(), None);

		approve_comment(comment_id.clone(), &dbs).unwrap();

		let mut iter = dbs.comment_pending.iter();
		assert_eq!(iter.next(), None);

		let mut iter = dbs.comment_approved.iter();
		assert_eq!(
			iter.next(),
			Some(Ok((
				(
					comment.topic_hash.clone(),
					comment.post_time,
					comment_id.clone()
				),
				()
			)))
		);
		assert_eq!(iter.next(), None);
	}
}