/*
 * @author Mike 'PhiSyX' S. (https://github.com/PhiSyX)
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

use core::fmt;
use std::collections::HashMap;
use std::path;
use std::sync::Mutex;

mod comment;
mod doctype;
mod element;
mod fragment;
mod text;

// ------ //
// Static //
// ------ //

lazy_static::lazy_static! {
	pub static ref MEMOIZE_FILE: Mutex<
		HashMap<path::PathBuf, String>
	> = Mutex::new(HashMap::default());
}

// ----------- //
// Énumération //
// ----------- //

pub enum Node {
	/// Commentaire HTML.
	Comment(comment::CommentNode),
	/// Type de document HTML.
	Doctype(doctype::DoctypeNode),
	/// Fragments HTML.
	Fragment(fragment::FragmentNode),
	/// Elements HTML.
	Element(element::ElementNode),
	/// Noeud texte.
	Text(text::TextNode),
	/// Noeud texte (json).
	Json(text::JsonTextNode),
	/// Noeud texte non sûr
	UnsafeHtml(text::DangerousTextNode),
}

// -------------- //
// Implémentation //
// -------------- //

// Comment
impl Node {
	pub fn create_comment(comment: impl ToString) -> Self {
		Self::Comment(comment::CommentNode {
			content: comment.to_string(),
		})
	}
}

// Doctype
impl Node {
	pub fn create_doctype(public_identifier: impl ToString) -> Self {
		Self::Doctype(doctype::DoctypeNode {
			public_identifier: public_identifier.to_string(),
		})
	}
}

// Fragment
impl Node {
	pub fn create_fragment(children: Vec<Node>) -> Self {
		Self::Fragment(fragment::FragmentNode { children })
	}
}

// Element
impl Node {
	pub fn create_element(
		tag_name: String,
		attributes: Vec<(String, Option<String>)>,
		children: Option<Vec<Node>>,
	) -> Self {
		Self::Element(element::ElementNode {
			tag_name,
			attributes,
			children,
		})
	}
}

// Text
impl Node {
	pub fn create_text(text: impl ToString) -> Self {
		Self::Text(text::TextNode {
			text: text.to_string(),
		})
	}

	pub fn create_json(text: impl ToString) -> Self {
		Self::Json(text::JsonTextNode {
			text: text.to_string(),
		})
	}
}

// Unsafe HTML
impl Node {
	pub fn create_unsafe_html(raw_text: impl ToString) -> Self {
		Self::UnsafeHtml(text::DangerousTextNode {
			raw_text: raw_text.to_string(),
		})
	}

	pub fn create_unsafe_html_from_file(file: impl AsRef<path::Path>) -> Self {
		let mut memoize = MEMOIZE_FILE.lock().expect("cache guard");

		if let Some(content_of_file) = memoize.get(file.as_ref()) {
			return Self::UnsafeHtml(text::DangerousTextNode {
				raw_text: content_of_file.to_owned(),
			});
		}

		let raw_text = std::fs::read_to_string(&file).unwrap_or_else(|_| {
			panic!("le fichier « {} » n'existe pas.", file.as_ref().display())
		});
		memoize.insert(file.as_ref().to_owned(), raw_text.clone());
		Self::UnsafeHtml(text::DangerousTextNode { raw_text })
	}
}

// -------- //
// Fonction //
// -------- //

fn with_children(
	f: &mut fmt::Formatter<'_>,
	children: &[Node],
	is_fragment: bool,
) -> fmt::Result {
	if f.alternate() {
		let mut children = children.iter();

		if is_fragment {
			if let Some(first_child) = children.next() {
				write!(f, "{first_child:#}")?;

				for child in children {
					write!(f, "\n{child:#}")?;
				}
			}
		} else {
			for child in children.map(|child| format!("{child:#}")) {
				for line in child.lines() {
					write!(f, "\n\t{line}")?;
				}
			}
			writeln!(f)?;
		}
	} else {
		use std::fmt::Display;

		for child in children {
			child.fmt(f)?;
		}
	}

	Ok(())
}

// -------------- //
// Implémentation // -> Interface
// -------------- //

impl Default for Node {
	fn default() -> Self {
		Self::create_fragment(vec![])
	}
}

impl fmt::Display for Node {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		match &self {
			| Self::Comment(comment) => comment.fmt(f),
			| Self::Doctype(doctype) => doctype.fmt(f),
			| Self::Fragment(fragment) => fragment.fmt(f),
			| Self::Element(element) => element.fmt(f),
			| Self::Text(text) => text.fmt(f),
			| Self::Json(text) => text.fmt(f),
			| Self::UnsafeHtml(danger) => danger.fmt(f),
		}
	}
}

impl<It, F> From<It> for Node
where
	It: IntoIterator<Item = F>,
	F: Into<Self>,
{
	fn from(it: It) -> Self {
		Self::Fragment(it.into())
	}
}

impl From<comment::CommentNode> for Node {
	fn from(comment_node: comment::CommentNode) -> Self {
		Self::Comment(comment_node)
	}
}

impl From<doctype::DoctypeNode> for Node {
	fn from(doctype_node: doctype::DoctypeNode) -> Self {
		Self::Doctype(doctype_node)
	}
}

impl From<fragment::FragmentNode> for Node {
	fn from(fragment_node: fragment::FragmentNode) -> Self {
		Self::Fragment(fragment_node)
	}
}

impl From<element::ElementNode> for Node {
	fn from(element_node: element::ElementNode) -> Self {
		Self::Element(element_node)
	}
}

impl From<text::TextNode> for Node {
	fn from(text_node: text::TextNode) -> Self {
		Self::Text(text_node)
	}
}