use std::collections::BTreeMap;

use config;

use tokio;

use rss;

use chrono::DateTime;

use regex::Regex;

use tokio::stream::StreamExt;
use telegram_bot::*;


use sqlx::postgres::PgPoolOptions;
use sqlx::Row;
use sqlx::Done;

#[macro_use]
extern crate lazy_static;

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

//type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;

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

			tg: tg,
			owner_chat: UserId::new(owner),
			pool: PgPoolOptions::new()
				.max_connections(5)
				.connect_timeout(std::time::Duration::new(300, 0))
				.idle_timeout(std::time::Duration::new(60, 0))
				.connect_lazy(&settings.get_str("pg")?)?,
				//.connect(&settings.get_str("pg")?).await?,
		};
		let clone = core.clone();
		tokio::spawn(async move {

			if let Err(err) = clone.autofetch().await {
				eprintln!("connection 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(&self, id: &i32, real: bool) -> Result<()> {
		match self.pool.acquire().await {
			Err(err) => {
				self.debug(&format!("🛑 Query queue fetch conn:\n{}\n{:?}", &err, &self.pool))?;
			},
			Ok(mut conn) => {
				match sqlx::query("select source_id, channel_id, url, iv_hash, owner from rsstg_source where source_id = $1")
					.bind(id)
					.fetch_one(&mut conn).await {
					Err(err) => {
						self.debug(&format!("🛑 Query queue:\n{}\n{:?}", &err, &conn))?;
					},
					Ok(row) => {
						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();
						match rss::Channel::from_url(url) {
							Err(err) => {
								self.debug(&format!("🛑 Problem opening feed url:\n{}\n{}", &url, &err))?;
							},
							Ok(feed) => {
								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() {
									match self.pool.acquire().await {
										Err(err) => {
											self.debug(&format!("🛑 Check post fetch conn:\n{}\n{:?}", &err, &self.pool))?;
										},
										Ok(mut conn) => {
											match 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 {
												Err(err) => {
													self.debug(&format!("🛑 Check post:\n{}\n{:?}", &err, &conn))?;
												},
												Ok(row) => {
													let exists: bool = row.try_get("exists")?;
													if ! exists {
														if this_fetch == None || *date > this_fetch.unwrap() {
															this_fetch = Some(*date);
														}
														match 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 {
															Err(err) => {
																self.debug(&format!("🛑 Can't post message:\n{}", &err))?;
															},
															Ok(_) => {
																match sqlx::query("insert into rsstg_post (source_id, posted, url) values ($1, $2, $3);")
																	.bind(id)
																	.bind(date)
																	.bind(url)
																	.execute(&mut conn).await {
																		Ok(_) => {},
																		Err(err) => {
																			self.debug(&format!("🛑Rrecord post:\n{}\n{:?}", &err, &conn))?;
																		},
																};

															},
														};








														drop(conn);
														tokio::time::delay_for(std::time::Duration::new(4, 0)).await;
													}
												},
											};
										}
									};
								};
								posts.clear();
							},
						};
						match self.pool.acquire().await {
							Err(err) => {
								self.debug(&format!("🛑 Update scrape fetch conn:\n{}\n{:?}", &err, &self.pool))?;
							},
							Ok(mut conn) => {
								match sqlx::query("update rsstg_source set last_scrape = now() where source_id = $1;")
									.bind(id)
									.execute(&mut conn).await {
									Err(err) => {
										self.debug(&format!("🛑 Update scrape:\n{}\n{:?}", &err, &conn))?;
									},
									Ok(_) => {},
								};
							},
						};
					},
				};
			},
		};
		Ok(())
	}

	async fn clean(&self, source_id: i32) -> Result<()> {
		match self.pool.acquire().await {
			Err(err) => {
				self.debug(&format!("🛑 Clean fetch conn:\n{}\n{:?}", &err, &self.pool))?;
			},
			Ok(mut conn) => {
				match sqlx::query("delete from rsstg_post where source_id = $1;")
					.bind(source_id)
					.execute(&mut conn).await {
					Err(err) => {
						self.debug(&format!("🛑 Clean seen posts:\n{}\n{:?}", &err, &self.pool))?;
					},
					Ok(_) => {},
				};
			},
		};
		Ok(())
	}

	async fn enable(&self, source_id: &i32, id: telegram_bot::UserId) -> Result<&str> {
		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")

		}
	}

	async fn autofetch(&self) -> Result<()> {
		let mut delay = chrono::Duration::minutes(5);
		let mut now;
		loop {
			match self.pool.acquire().await {
				Err(err) => {
					self.debug(&format!("🛑 Autofetch fetch conn:\n{}\n{:?}", &err, &self.pool))?;
				},
				Ok(mut conn) => {
					now = chrono::Local::now();
					let mut queue = sqlx::query("select source_id, next_fetch 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 next_fetch: DateTime<chrono::Local> = row.try_get("next_fetch")?;
						if next_fetch < now {
							match sqlx::query("update rsstg_source set last_scrape = now() + interval '1 hour' where source_id = $1;")
								.bind(source_id)
								.execute(&mut conn).await {
								Ok(_) => {},
								Err(err) => {
									self.debug(&err.to_string())?;
								},
							};
							let clone = self.clone();
							tokio::spawn(async move {
								if let Err(err) = clone.check(&source_id.clone(), true).await {

									eprintln!("connection 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);
		}
	}

}

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

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

	let mut stream = core.stream();

	while let Some(update) = stream.next().await {
		match handle(update?, &core).await {
			Ok(_) => {},
			Err(err) => {
				core.debug(&err.to_string())?;
			}
		};
	}

	Ok(())
}

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

					};
				},
				_ => {
				},
			};

			if reply.len() > 0 {
				match core.tg.send(message.text_reply(reply.join("\n")).parse_mode(types::ParseMode::MarkdownV2)).await {
					Ok(_) => {},
					Err(err) => {
						dbg!(reply.join("\n"));
						println!("{}", err);
					},
				}
			}
		},
		_ => {},
	};

	Ok(())
}