mod sectiondata;
mod tags;

pub use sectiondata::SectionData;
pub use tags::Tags;

use core::fmt;
use std::str::FromStr;

use camino::{Utf8Path, Utf8PathBuf};
use tokio::sync::RwLock;

use crate::{WikError, WikFile, fs::Open, git::GitContext, quotes_decode, quotes_encode};

pub struct Tables {
	posts: Table<Tags>,
	sections: Table<SectionData>,
}

impl Tables {
	const POSTS: &'static str = ".wikarden/table/posts";
	const SECTIONS: &'static str = ".wikarden/table/sections";

	pub async fn new(root: &Utf8Path) -> Result<Self, WikError> {
		Self::init(root)?;

		let posts_path = root.join(Self::POSTS);
		let sections_path = root.join(Self::SECTIONS);

		let posts = Table::new_and_load(posts_path).await?;
		let sections = Table::new_and_load(sections_path).await?;

		Ok(Self { posts, sections })
	}

	fn init(root: &Utf8Path) -> Result<(), WikError> {
		let mut parent = root.join(Self::POSTS);
		parent.pop();

		if let Err(_e) = std::fs::create_dir_all(&parent) {
			Err(WikError::DirectoryCreation { path: parent })
		} else {
			Ok(())
		}
	}

	pub async fn has_page<S: AsRef<str>>(&self, name: S) -> bool {
		self.posts.has(name).await
	}

	pub async fn has_section<S: AsRef<str>>(&self, section: S) -> bool {
		self.sections.has(section).await
	}

	pub async fn get_sections(&self) -> Vec<TableEntry<SectionData>> {
		self.sections.entries().await
	}

	pub async fn add_page<S: Into<String>>(&self, name: S, data: Tags) -> Result<(), WikError> {
		self.posts
			.add(TableEntry {
				name: name.into(),
				data,
			})
			.await;
		self.posts.save().await
	}

	pub async fn add_section<S: Into<String>>(
		&self,
		section: S,
		data: SectionData,
	) -> Result<(), WikError> {
		self.sections
			.add(TableEntry {
				name: section.into(),
				data,
			})
			.await;
		self.sections.save().await
	}

	pub async fn del_page<S: AsRef<str>>(&self, name: S) -> Result<(), WikError> {
		self.posts.del(name.as_ref()).await;
		self.posts.save().await
	}

	pub async fn del_section<S: AsRef<str>>(&self, section: S) -> Result<(), WikError> {
		self.sections.del(section.as_ref()).await;
		self.sections.save().await
	}

	pub async fn replace_sections(
		&self,
		data: Vec<TableEntry<SectionData>>,
	) -> Result<(), WikError> {
		self.sections.replace_entries(data).await;
		self.sections.save().await
	}

	pub fn sections(&self) -> &Table<SectionData> {
		&self.sections
	}

	pub fn posts(&self) -> &Table<Tags> {
		&self.posts
	}

	pub fn git_add(gtx: &mut GitContext) {
		gtx.add_rel(Self::POSTS.into()).unwrap();
		gtx.add_rel(Self::SECTIONS.into()).unwrap();
	}
}

pub(crate) struct Table<D: TableData> {
	path: Utf8PathBuf,
	entries: RwLock<Vec<TableEntry<D>>>,
}

impl<D: TableData> Table<D> {
	pub async fn new_and_load(path: Utf8PathBuf) -> Result<Self, WikError> {
		let entries = Self::load(&path).await?;

		Ok(Self {
			path,
			entries: RwLock::new(entries),
		})
	}

	pub async fn replace_entries(&self, entries: Vec<TableEntry<D>>) {
		let mut lock = self.entries.write().await;
		*lock = entries;
	}

	pub async fn has<S: AsRef<str>>(&self, name: S) -> bool {
		let lock = self.entries.read().await;
		lock.iter()
			.position(|te| te.name.eq(name.as_ref()))
			.is_some()
	}

	//TODO: gen 2026-08: this should insert in sorted order instead of then sorting
	pub async fn add(&self, entry: TableEntry<D>) {
		let mut lock = self.entries.write().await;
		lock.push(entry);
		Self::sort(&mut lock);
	}

	pub async fn del(&self, name: &str) -> Option<TableEntry<D>> {
		let mut lock = self.entries.write().await;
		match lock.iter().position(|e| e.name == name) {
			None => return None,
			Some(idx) => Some(lock.remove(idx)),
		}
	}

	pub async fn entry_data(&self, name: &str) -> Option<D> {
		let lock = self.entries.read().await;
		match lock.iter().position(|e| e.name == name) {
			None => return None,
			Some(idx) => Some(lock[idx].data.clone()),
		}
	}

	pub async fn modify_entry<F>(&self, name: &str, f: F) -> Result<bool, WikError>
	where
		F: FnOnce(&mut TableEntry<D>),
	{
		let mut lock = self.entries.write().await;
		match lock.iter().position(|e| e.name == name) {
			None => return Ok(false),
			Some(idx) => {
				let mut entry = &mut lock[idx];
				f(&mut entry);
				Self::sort(&mut lock);
				drop(lock);

				self.save().await?;
				Ok(true)
			}
		}
	}

	pub async fn modify_entry_data<F>(&self, name: &str, f: F) -> Result<bool, WikError>
	where
		F: FnOnce(&mut D),
	{
		let mut lock = self.entries.write().await;
		let actioned = match lock.iter().position(|e| e.name == name) {
			None => false,
			Some(idx) => {
				let entry = &mut lock[idx];
				f(&mut entry.data);
				true
			}
		};
		drop(lock);

		self.save().await.map(|_| actioned)
	}

	pub async fn entries(&self) -> Vec<TableEntry<D>> {
		let lock = self.entries.read().await;
		lock.clone()
	}

	fn sort(entries: &mut [TableEntry<D>]) {
		entries.sort_by(|a, b| a.name.cmp(&b.name));
	}

	pub async fn save(&self) -> Result<(), WikError> {
		let mut lock = self.entries.write().await;
		Self::sort(&mut lock);

		let mut file = WikFile::open(self.path.clone(), Open::Create).await?;
		file.write_all_strs(lock.iter()).await
	}

	async fn load(path: &Utf8Path) -> Result<Vec<TableEntry<D>>, WikError> {
		let file = WikFile::open(path.to_owned(), Open::CreateAppend).await?;
		let content = file.read_to_string().await?;

		let mut entries = vec![];
		for line in content.lines() {
			let entry = TableEntry::from_str(line).unwrap();
			entries.push(entry);
		}

		Self::sort(&mut entries);
		Ok(entries)
	}
}

pub trait TableData: std::fmt::Debug + std::fmt::Display + Clone {
	fn parse(raw: &str) -> Result<Self, &'static str>
	where
		Self: Sized;
}

#[derive(Clone, Debug)]
pub struct TableEntry<D: TableData> {
	name: String,
	data: D,
}

impl<D: TableData> TableEntry<D> {
	pub fn new(name: String, data: D) -> Self {
		Self { name, data }
	}

	pub fn into_name(self) -> String {
		self.name
	}

	pub fn name(&self) -> &str {
		&self.name
	}

	pub fn set_name(&mut self, name: String) {
		self.name = name;
	}

	pub fn data(&self) -> &D {
		&self.data
	}
}

impl<D: TableData> fmt::Display for TableEntry<D> {
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		let quoted = quotes_encode(&self.name);

		writeln!(f, "{quoted}\t{}", self.data)
	}
}

impl<D: TableData> FromStr for TableEntry<D> {
	type Err = &'static str;

	fn from_str(raw: &str) -> Result<Self, &'static str> {
		let decode = quotes_decode(raw);

		match decode {
			None => Err("string does not start with a quote"),
			Some((name, rest)) => {
				let data_str = rest.trim_start();
				let data = D::parse(data_str)?;

				Ok(Self { name, data })
			}
		}
	}
}

/*
impl FromStr for JournalLine {
	type Err = &'static str;

	fn from_str(raw: &str) -> Result<Self, Self::Err> {
		let decode = quotes_decode(raw);

		match decode {
			None => Err("string does not start with quote"),
			Some((path, rest)) => {
				let time_str = rest.trim_start();
				let time: i64 = match time_str.parse() {
					Err(_) => return Err("time is not a number"),
					Ok(stamp) => stamp,
				};

				match OffsetDateTime::from_unix_timestamp(time) {
					Err(_) => Err("timestamp is not valid"),
					Ok(time) => Ok(Self {
						path: path.into(),
						time,
					}),
				}
			}
		}
	}
}
*/