use sqlx::postgres::PgPoolOptions;
use sqlx::Row;
use sqlx::Done; // .rows_affected()

#[macro_use]
extern crate lazy_static;

use anyhow::{anyhow, Context, Result};

#[derive(Clone)]
struct Core {
	owner: i64,
	api_key: String,
	owner_chat: UserId,
	tg: telegram_bot::Api,

				.connect_timeout(std::time::Duration::new(300, 0))
				.idle_timeout(std::time::Duration::new(60, 0))
				.connect_lazy(&settings.get_str("pg")?)?,
		};
		let clone = core.clone();
		tokio::spawn(async move {
			if let Err(err) = &clone.autofetch().await {
				if let Err(err) = clone.debug(&format!("{:?}", err)) {
					eprintln!("Autofetch error: {}", err);
				};
			}
		});
		Ok(core)
	}

	fn stream(&self) -> telegram_bot::UpdatesStream {
		self.tg.stream()
	}

	fn debug(&self, msg: &str) -> Result<()> {
		self.tg.spawn(SendMessage::new(self.owner_chat, msg));
		Ok(())
	}

	async fn check<S>(&self, id: &i32, owner: S, real: bool) -> Result<()>
	where S: Into<i64> {
		let owner: i64 = owner.into();
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 Query queue fetch conn:\n{:?}", &self.pool))?;
		let row = sqlx::query("select source_id, channel_id, url, iv_hash, owner from rsstg_source where source_id = $1 and owner = $2")
			.bind(id)
			.bind(owner)
			.fetch_one(&mut conn).await
			.with_context(|| format!("🛑 Query source:\n{:?}", &self.pool))?;
		drop(conn);
		let channel_id: i64 = row.try_get("channel_id")?;
		let destination = match real {
			true => UserId::new(channel_id),
			false => UserId::new(row.try_get("owner")?),
		};
		let url: &str = row.try_get("url")?;
		let mut this_fetch: Option<DateTime<chrono::FixedOffset>> = None;
		let iv_hash: Option<&str> = row.try_get("iv_hash")?;
		let mut posts: BTreeMap<DateTime<chrono::FixedOffset>, String> = BTreeMap::new();
		let feed = rss::Channel::from_url(url)
			.with_context(|| format!("🛑 Problem opening feed url:\n{}", &url))?;
		for item in feed.items() {
			let date = match item.pub_date() {
				Some(feed_date) => DateTime::parse_from_rfc2822(feed_date),
				None => DateTime::parse_from_rfc3339(&item.dublin_core_ext().unwrap().dates()[0]),
			}?;
			let url = item.link().unwrap().to_string();
			posts.insert(date.clone(), url.clone());
		};
		for (date, url) in posts.iter() {
			let mut conn = self.pool.acquire().await
				.with_context(|| format!("🛑 Check post fetch conn:\n{:?}", &self.pool))?;
			let row = sqlx::query("select exists(select true from rsstg_post where url = $1 and source_id = $2) as exists;")
				.bind(&url)
				.bind(id)
				.fetch_one(&mut conn).await
				.with_context(|| format!("🛑 Check post:\n{:?}", &conn))?;
			let exists: bool = row.try_get("exists")?;
			if ! exists {
				if this_fetch == None || *date > this_fetch.unwrap() {
					this_fetch = Some(*date);
				};
				self.tg.send( match iv_hash {
						Some(x) => SendMessage::new(destination, format!("<a href=\"https://t.me/iv?url={}&rhash={}\"> </a>{0}", url, x)),
						None => SendMessage::new(destination, format!("{}", url)),
					}.parse_mode(types::ParseMode::Html)).await
					.context("🛑 Can't post message:")?;
				sqlx::query("insert into rsstg_post (source_id, posted, url) values ($1, $2, $3);")
					.bind(id)
					.bind(date)
					.bind(url)
					.execute(&mut conn).await
					.with_context(|| format!("🛑Record post:\n{:?}", &conn))?;
				drop(conn);
				tokio::time::delay_for(std::time::Duration::new(4, 0)).await;
			};
		};
		posts.clear();
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 Update scrape fetch conn:\n{:?}", &self.pool))?;
		sqlx::query("update rsstg_source set last_scrape = now() where source_id = $1;")
			.bind(id)
			.execute(&mut conn).await
			.with_context(|| format!("🛑 Update scrape:\n{:?}", &conn))?;
		Ok(())
	}

















	async fn clean<S>(&self, source_id: &i32, id: S) -> Result<String>
	where S: Into<i64> {
		let id: i64 = id.into();
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 Clean fetch conn:\n{:?}", &self.pool))?;
		match sqlx::query("delete from rsstg_post p using rsstg_source s where p.source_id = $1 and owner = $2 and p.source_id = s.source_id;")
			.bind(source_id)
			.bind(id)
			.execute(&mut conn).await
			.with_context(|| format!("🛑 Clean seen posts:\n{:?}", &self.pool))?
			.rows_affected() {
			0 => { Ok("No data found found\\.".to_string()) },
			x => { Ok(format!("{} posts purged\\.", x)) },
		}
	}

	async fn enable<S>(&self, source_id: &i32, id: S) -> Result<&str>
	where S: Into<i64> {
		let id: i64 = id.into();
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 Enable fetch conn:\n{:?}", &self.pool))?;
		match sqlx::query("update rsstg_source set enabled = true where source_id = $1 and owner = $2")
			.bind(source_id)
			.bind(id)
			.execute(&mut conn).await
			.with_context(|| format!("🛑 Enable source:\n{:?}", &self.pool))?

















			.rows_affected() {
			1 => { Ok("Source disabled\\.") },
			0 => { Ok("Source not found\\.") },
			_ => { Err(anyhow!("Database error.")) },
		}
	}

	async fn disable<S>(&self, source_id: &i32, id: S) -> Result<&str>
	where S: Into<i64> {
		let id: i64 = id.into();
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 Disable fetch conn:\n{:?}", &self.pool))?;
		match sqlx::query("update rsstg_source set enabled = false where source_id = $1 and owner = $2")









			.bind(source_id)
			.bind(id)


			.execute(&mut conn).await
			.with_context(|| format!("🛑 Disable source:\n{:?}", &self.pool))?
			.rows_affected() {



			1 => { Ok("Source disabled\\.") },


			0 => { Ok("Source not found\\.") },
			_ => { Err(anyhow!("Database error.")) },
		}









	}

	async fn autofetch(&self) -> Result<()> {
		let mut delay = chrono::Duration::minutes(5);
		let mut now;
		loop {
			let mut conn = self.pool.acquire().await
				.with_context(|| format!("🛑 Autofetch fetch conn:\n{:?}", &self.pool))?;
			now = chrono::Local::now();
			let mut queue = sqlx::query("select source_id, next_fetch, owner from rsstg_order natural left join rsstg_source natural left join rsstg_channel where next_fetch < now();")
				.fetch_all(&mut conn).await?;
			for row in queue.iter() {
				let source_id: i32 = row.try_get("source_id")?;
				let owner: i64 = row.try_get("owner")?;
				let next_fetch: DateTime<chrono::Local> = row.try_get("next_fetch")?;
				if next_fetch < now {
					sqlx::query("update rsstg_source set last_scrape = now() + interval '1 hour' where source_id = $1;")
						.bind(source_id)
						.execute(&mut conn).await
						.with_context(|| format!("🛑 Lock source:\n\n{:?}", &self.pool))?;
					let clone = self.clone();
					tokio::spawn(async move {
						if let Err(err) = clone.check(&source_id, owner, true).await {
							if let Err(err) = clone.debug(&format!("{:?}", err)) {
								eprintln!("Check error: {}", err);
							};
						};
					});
				} else {
					if next_fetch - now < delay {
						delay = next_fetch - now;
					}
				}
			};
			queue.clear();
			tokio::time::delay_for(delay.to_std()?).await;
			delay = chrono::Duration::minutes(5);
		}
	}

	async fn list(&self, id: telegram_bot::UserId) -> Result<Vec<String>> {

		let id = i64::from(id);
		let mut reply = vec![];
		let mut conn = self.pool.acquire().await
			.with_context(|| format!("🛑 List fetch conn:\n{:?}", &self.pool))?;
		reply.push("Channels:".to_string());
		let rows = sqlx::query("select source_id, username, enabled, url, iv_hash from rsstg_source left join rsstg_channel using (channel_id) where owner = $1 order by source_id")
			.bind(id)
			.fetch_all(&mut conn).await?;
		for row in rows.iter() {
			let source_id: i32 = row.try_get("source_id")?;
			let username: &str = row.try_get("username")?;
			let enabled: bool = row.try_get("enabled")?;
			let url: &str = row.try_get("url")?;
			let iv_hash: Option<&str> = row.try_get("iv_hash")?;
			reply.push(format!("\n\\#️⃣ {} \\*️⃣ `{}` {}\n🔗 `{}`", source_id, username,  
				match enabled {
					true  => "🔄 enabled",
					false => "⛔ disabled",

	let core = Core::new(settings).await?;

	let mut stream = core.stream();

	while let Some(update) = stream.next().await {
		if let Err(err) = handle(update?, &core).await {
			core.debug(&format!("{:?}", err))?;
		};
	}

	Ok(())
}

async fn handle(update: telegram_bot::Update, core: &Core) -> Result<()> {

						"/list" => {
							reply.append(&mut core.list(message.from.id).await?);
						},

// add

						"/add" | "/update" => {
							let mut source_id: i32 = 0;

							if cmd == "/update" {
								source_id = words.next().unwrap().parse::<i32>()?;



							}
							let (channel, url, iv_hash) = (words.next().unwrap(), words.next().unwrap(), words.next());







							let ok_link = RE_LINK.is_match(&url);
							let ok_hash = match iv_hash {
								Some(hash) => RE_IV_HASH.is_match(&hash),
								None => true,
							};
							if ! ok_link {
								reply.push("Link should be link to atom/rss feed, something like \"https://domain/path\"\\.".to_string());
								core.debug(&format!("Url: {:?}", &url))?;
							}
							if ! ok_hash {
								reply.push("IV hash should be 14 hex digits.".to_string());
								core.debug(&format!("IV: {:?}", &iv_hash))?;
							}
							if ok_link && ok_hash {
								let chan: Option<i64> = match sqlx::query("select channel_id from rsstg_channel where username = $1")
									.bind(channel)
									.fetch_one(&core.pool).await {
										Ok(chan) => Some(chan.try_get("channel_id")?),
										Err(sqlx::Error::RowNotFound) => {
											let chan_id = i64::from(core.tg.send(telegram_bot::GetChat::new(telegram_bot::types::ChatRef::ChannelUsername(channel.to_string()))).await?.id());
											sqlx::query("insert into rsstg_channel (channel_id, username) values ($1, $2);")
												.bind(chan_id)
												.bind(channel)
												.execute(&core.pool).await?;
											Some(chan_id)
										},
										Err(err) => {
											reply.push("Sorry, unknown error\\.".to_string());
											core.debug(&format!("Sorry, unknown error:\n{:#?}\n", err))?;
											None
										},
								};
								if let Some(chan) = chan {
									match if cmd == "/update" {
											sqlx::query("update rsstg_source set channel_id = $2, url = $3, iv_hash = $4, owner = $4 where source_id = $1").bind(source_id)
										} else {
											sqlx::query("insert into rsstg_source (channel_id, url, iv_hash, owner) values ($1, $2, $3, $4)")
										}
										.bind(chan)
										.bind(url)
										.bind(iv_hash)
										.bind(i64::from(message.from.id))
										.execute(&core.pool).await {
										Ok(_) => reply.push("Channel added\\.".to_string()),
										Err(sqlx::Error::Database(err)) => {
											match err.downcast::<sqlx::postgres::PgDatabaseError>().routine() {
												Some("_bt_check_unique", ) => {
													reply.push("Duplicate key\\.".to_string());
												},
												Some(_) => {

													reply.push("Database error\\.".to_string());
												},
												None => {
													reply.push("No database error extracted\\.".to_string());
												},
											};
										},
										Err(err) => {
											reply.push("Sorry, unknown error\\.".to_string());
											core.debug(&format!("Sorry, unknown error:\n{:#?}\n", err))?;
										},
									};
								};
							};
						},

// addchan

						"/addchan" => {
							let channel = words.next().unwrap();
							if ! RE_USERNAME.is_match(&channel) {
								reply.push("Usernames should be something like \"@\\[a\\-zA\\-Z]\\[a\\-zA\\-Z0\\-9\\_]+\", aren't they?".to_string());
							} else {
								let chan: Option<i64> = match sqlx::query("select channel_id from rsstg_channel where username = $1")
									.bind(channel)
									.fetch_one(&core.pool).await {
										Ok(chan) => Some(chan.try_get("channel_id")?),
										Err(sqlx::Error::RowNotFound) => None,
										Err(err) => {
											reply.push("Sorry, unknown error\\.".to_string());
											core.debug(&format!("Sorry, unknown error:\n{:#?}", err))?;
											None
										},
								};
								match chan {
									Some(chan) => {
										let new_chan = core.tg.send(telegram_bot::GetChat::new(telegram_bot::types::ChatId::new(chan))).await?;
										if i64::from(new_chan.id()) == chan {
											reply.push("I already know that channel\\.".to_string());
										} else {
											reply.push("Hmm, channel has changed… I'll fix it later\\.".to_string());
										};
									},
									None => {
										match core.tg.send(telegram_bot::GetChatAdministrators::new(telegram_bot::types::ChatRef::ChannelUsername(channel.to_string()))).await {
											Ok(chan_adm) => {

												let (mut me, mut user) = (false, false);
												for admin in &chan_adm {
													if admin.user.id == core.my.id {
														me = true;
													};
													if admin.user.id == message.from.id {
														user = true;
													};
												};
												if ! me   { reply.push("I need to be admin on that channel\\.".to_string()); };
												if ! user { reply.push("You should be admin on that channel\\.".to_string()); };
												if me && user {
													let chan_id = core.tg.send(telegram_bot::GetChat::new(telegram_bot::types::ChatRef::ChannelUsername(channel.to_string()))).await?;
													sqlx::query("insert into rsstg_channel (channel_id, username) values ($1, $2);")
														.bind(i64::from(chan_id.id()))
														.bind(channel)
														.execute(&core.pool).await?;
													reply.push("Good, I know that channel now\\.\n".to_string());
												};
											},
											Err(_) => {
												reply.push("Sorry, I have no access to that chat\\.".to_string());
											},
										};
									},
								};
							};
						},

// check

						"/check" => {
							match &words.next().unwrap().parse::<i32>() {
								Err(err) => {
									reply.push(format!("I need a number\\.\n{}", &err));
								},
								Ok(number) => {
									core.check(&number, message.from.id, false).await
										.context("🛑 Channel check failed.")?;
								},
							};
						},

// clean

						"/clean" => {

								},
								Ok(number) => {
									let result = core.enable(&number, message.from.id).await?;
									reply.push(result.to_string());
								},
							};
						},















// disable

						"/disable" => {
							match &words.next().unwrap().parse::<i32>() {
								Err(err) => {
									reply.push(format!("I need a number\\.\n{}", &err));