use anyhow::{bail, Context, Result};
use crate::core::Core;
use regex::Regex;
use sedregex::ReplaceCommand;
use telegram_bot;

lazy_static! {
	static ref RE_USERNAME: Regex = Regex::new(r"^@[a-zA-Z][a-zA-Z0-9_]+$").unwrap();
	static ref RE_LINK: Regex = Regex::new(r"^https?://[a-zA-Z.0-9-]+/[-_a-zA-Z.0-9/?=]+$").unwrap();
	static ref RE_IV_HASH: Regex = Regex::new(r"^[a-f0-9]{14}$").unwrap();
}

pub async fn start(core: &Core, sender: telegram_bot::UserId) -> Result<()> {
	core.send("We are open\\. Probably\\. Visit [channel](https://t.me/rsstg_bot_help/3) for details\\.", Some(sender), None)?;
	Ok(())
}

pub async fn list(core: &Core, sender: telegram_bot::UserId) -> Result<()> {
	core.send(core.list(sender).await?, Some(sender), Some(telegram_bot::types::ParseMode::MarkdownV2))?;
	Ok(())
}

pub async fn command(core: &Core, sender: telegram_bot::UserId, command: Vec<&str>) -> Result<()> {
	core.send( match &command[1].parse::<i32>() {
		Err(err) => format!("I need a number\\.\n{}", &err),
		Ok(number) => match command[0] {
			"/check" => core.check(&number, sender, false).await
				.context("Channel check failed.")?,
			"/clean" => core.clean(&number, sender).await?,
			"/enable" => core.enable(&number, sender).await?
				.to_string(),
			"/delete" => core.delete(&number, sender).await?,
			"/disable" => core.disable(&number, sender).await?
				.to_string(),
			_ => bail!("Command {} not handled.", &command[0]),
		},
	}, Some(sender), None)?;
	Ok(())
}

pub async fn update(core: &Core, sender: telegram_bot::UserId, command: Vec<&str>) -> Result<()> {
	let mut source_id: Option<i32> = None;
	let at_least = "Requires at least 3 parameters.";
	let first_word = command[0];

	let mut i_command = command.into_iter();
	let (channel, url, iv_hash, url_re) = (
		i_command.next().context(at_least)?,
		i_command.next().context(at_least)?,
		i_command.next(),
		i_command.next());
	if ! RE_USERNAME.is_match(&channel) {
		core.send(format!("Usernames should be something like \"@\\[a\\-zA\\-Z]\\[a\\-zA\\-Z0\\-9\\_]+\", aren't they?\nNot {:?}", &channel), Some(sender), None)?;
		return Ok(())
	}
	if ! RE_LINK.is_match(&url) {
		core.send(format!("Link should be a link to atom/rss feed, something like \"https://domain/path\".\nNot {:?}", &url), Some(sender), None)?;
		return Ok(())
	}
	let iv_hash = match iv_hash {
		Some(hash) => {
			if ! RE_IV_HASH.is_match(hash) {
				core.send(format!("IV hash should be 14 hex digits.\nNot {:?}", hash), Some(sender), None)?;
				return Ok(())
			};
			Some(*hash)
		}
		None => None,
	};
	if let Some(rex) = url_re {

		};
		if admin.user.id == sender {
			user = true;
		};
	};
	if ! me   { bail!("I need to be admin on that channel\\."); };
	if ! user { bail!("You should be admin on that channel\\."); };
	core.send(core.update(source_id, channel, channel_id, url, iv_hash, None, sender).await?, Some(sender), None)?;
	Ok(())
}

				.idle_timeout(std::time::Duration::new(60, 0))
				.connect_lazy(&settings.get_str("pg")?)?,
			sources: Arc::new(Mutex::new(HashSet::new())),
		};
		let clone = core.clone();
		tokio::spawn(async move {
			if let Err(err) = &clone.autofetch().await {
				if let Err(err) = clone.send(&format!("🛑 {:?}", err), None, None) {
					eprintln!("Autofetch error: {}", err);
				};
			}
		});
		Ok(core)
	}

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

	pub fn send<S>(&self, msg: S, target: Option<telegram_bot::UserId>, parse_mode: Option<telegram_bot::types::ParseMode>) -> Result<()>
	where S: Into<String> {
		let msg: String = msg.into();
		let parse_mode = match parse_mode {
			Some(mode) => mode,
			None => telegram_bot::types::ParseMode::Html,
		};
		self.tg.spawn(telegram_bot::SendMessage::new(match target {
			Some(user) => user,
			None => self.owner_chat,
		}, msg.to_owned()).parse_mode(parse_mode));
		Ok(())
	}

	pub async fn check<S>(&self, id: &i32, owner: S, real: bool) -> Result<String>
	where S: Into<i64> {
		let mut posted: i32 = 0;
		let owner: i64 = owner.into();

					//clone.owner_chat(UserId::new(owner));
					let clone = Core {
						owner_chat: telegram_bot::UserId::new(owner),
						..self.clone()
					};
					tokio::spawn(async move {
						if let Err(err) = clone.check(&source_id, owner, true).await {
							if let Err(err) = clone.send(&format!("🛑 {:?}", err), None, None) {
								eprintln!("Check error: {}", err);
							};
						};
					});
				} else {
					if next_fetch - now < delay {
						delay = next_fetch - now;
					}
				}
			};
			queue.clear();
			tokio::time::sleep(delay.to_std()?).await;
			delay = chrono::Duration::minutes(1);
		}
	}

	pub async fn list<S>(&self, owner: S) -> Result<String>
	where S: Into<i64> {
		let owner = owner.into();
		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, channel, enabled, url, iv_hash from rsstg_source where owner = $1 order by source_id")

					true  => "🔄 enabled",
					false => "⛔ disabled",
				}, url));
			if let Some(hash) = iv_hash {
				reply.push(format!("IV `{}`", hash));
			}
		};
		Ok(reply.join("\n"))
	}
}

mod command;
mod core;

use config;
use futures::StreamExt;
use tokio;

use telegram_bot;

#[macro_use]
extern crate lazy_static;

use anyhow::Result;

#[tokio::main]
async fn main() -> Result<()> {
	let mut settings = config::Config::default();
	settings.merge(config::File::with_name("rsstg"))?;

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

	let mut stream = core.stream();
	stream.allowed_updates(&[telegram_bot::AllowedUpdate::Message]);
	let mut reply_to: Option<telegram_bot::UserId>;

	loop {
		reply_to = None;
		match stream.next().await {
			Some(update) => {
				if let Err(err) = handle(update?, &core, &mut reply_to).await {
					core.send(&format!("🛑 {:?}", err), reply_to, None)?;
				};
			},
			None => {
				core.send(&format!("🛑 None error."), None, None)?;
			}
		};
	}

	//Ok(())
}

async fn handle(update: telegram_bot::Update, core: &core::Core, mut _reply_to: &Option<telegram_bot::UserId>) -> Result<()> {
	match update.kind {
		telegram_bot::UpdateKind::Message(message) => {
			match message.kind {
				telegram_bot::MessageKind::Text { ref data, .. } => {
					let sender = message.from.id;
					let words: Vec<&str> = data.split_whitespace().collect();
					match words[0] {
						"/check" | "/clean" | "/enable" | "/delete" | "/disable" => command::command(core, sender, words).await?,
						"/start" => command::start(core, sender).await?,
						"/list" => command::list(core, sender).await?,
						"/add" | "/update" => command::update(core, sender, words).await?,