use std::collections::HashMap;
use std::convert::TryFrom;

use rusqlite::params;

use crate::database::Db;
use crate::id::Id;
use crate::result::RudeResult;
use crate::try_log;
use crate::world::{Exit, Room};

impl Db {
	/// Save a room to the database.
	pub fn save_room(&self, room: &Room) -> RudeResult<()> {
		let mut statement = try_log!(
			self.0.prepare(
				"insert into rooms (id, zone, name, description, users_visible) values (?, ?, ?, ?, ?) on conflict(id) do update set id=?, zone=?, name=?, description=?, users_visible=?;"
			),
			"Unable to prepare sql statement"
		);

		let _ = try_log!(
			statement.execute(params![
				room.id,
				room.zone,
				room.name,
				room.description.join("\n"),
				room.users_visible,
				room.id,
				room.zone,
				room.name,
				room.description.join("\n"),
				room.users_visible,
			]),
			"Unable to perform query"
		);

		for (_, exit) in room.exits.iter() {
			let mut statement = try_log!(
				self.0
					.prepare("insert into exits (room, target, direction) values (?, ?, ?);"),
				"Unable to prepare sql statement"
			);

			let _ = try_log!(
				statement.execute(params![room.id, exit.target, exit.direction,]),
				"Unable to perform query"
			);
		}

		Ok(())
	}

	/// Load a room from the database.
	pub fn load_room(&self, id: Id) -> RudeResult<Option<Room>> {
		let mut statement = try_log!(
			self.0.prepare(
				"select id, zone, name, description, users_visible from rooms where id = ?"
			),
			"Unable to prepare sql statement"
		);

		let mut rows = try_log!(statement.query(params![id]), "Unable to perform query");

		let mut room = if let Some(row) = try_log!(rows.next(), "Unable to retrieve row") {
			try_log!(Room::try_from(row), "Unable to get Room from Row")
		} else {
			return Ok(None);
		};

		room.exits = {
			let mut e = HashMap::new();

			let mut statement = try_log!(
				self.0
					.prepare("select room, target, direction from exits where room = ?"),
				"Unable to prepare sql statement"
			);

			let mut rows = try_log!(statement.query(params![id]), "Unable to perform query");

			while let Some(row) = try_log!(rows.next(), "Unable to retrieve row") {
				let exit = try_log!(Exit::try_from(row), "Unable to get Exit from Row");
				e.insert(exit.direction, exit);
			}

			e
		};

		Ok(Some(room))
	}
}