use std::collections::HashMap;
use std::fmt;
use std::str::{FromStr, Lines};

use crate::errors::RequestError;

const HTTP_VERSION: &'static str = "HTTP/1.1";

#[derive(Debug)]
pub struct Request {
	pub method: String,
	pub uri: String,
	pub headers: Vec<(String, String)>,
	pub body: String,
}

#[derive(Debug)]
pub struct Response {
	pub status: Status,
	pub headers: Vec<(String, String)>,
	pub body: String,
}

#[derive(Debug, Clone, Copy)]
pub enum Status {
	Ok = 200,
	NotFound = 404,
	BadRequest = 400,
	Unauthorized = 401,
	InternalServerError = 500,
}

impl Status {
	pub fn message(&self) -> &'static str {
		match self {
			Self::Ok => "OK",
			Self::NotFound => "NOT FOUND",
			Self::BadRequest => "BAD REQUEST",
			Self::Unauthorized => "UNAUTHORIZED",
			Self::InternalServerError => "INTERNAL SERVER ERROR",
		}
	}
}

impl Request {
	pub fn form(&self) -> Result<HashMap<&str, &str>, RequestError> {
		let mut hashmap = HashMap::new();
		for mut x in self.body.split("&").map(|x| x.split("=")) {
			hashmap.insert(
				x.next().ok_or(RequestError::NotAForm)?,
				x.next().ok_or(RequestError::NotAForm)?
			);
		}
		Ok(hashmap)
	}
}

impl FromStr for Request {
	type Err = RequestError;

	fn from_str(s: &str) -> Result<Self, Self::Err> {
		//dbg!(&s);
		let mut iter = s.lines();
		let mut first = iter.next().ok_or(RequestError::BadRequest)?
			.split_whitespace();
		let method = first.next().ok_or(RequestError::BadRequest)?;
		let uri = first.next().ok_or(RequestError::BadRequest)?;
		let mut headers: Vec<(String, String)> = vec![];

		for line in &mut iter {
			if line.is_empty() {
				break;
			}
			let line: Vec<&str> = line.split(":").take(2).collect();
			headers.push((line[0].into(), line[1].into()));
		}
		let body: String = iter.fold(String::new(), |a, b| format!("{}{}", a, b));

		Ok(Self {
			method: method.to_string(),
			uri: uri.to_string(),
			headers: headers,
			body: body.to_string(),
		})
	}
}

impl Response {
	pub fn new(status: Status, headers: Vec<(String, String)>, body: String) -> Self {
		Self {
			status,
			headers,
			body,
		}
	}
}

impl fmt::Display for Response {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		let headers: String = self
			.headers
			.iter()
			.map(|x| format!("{}:{}", x.0, x.1))
			.fold(String::from(""), |a, b| format!("{}\n{}", a, b)); // possibly slow

		write!(
			f,
			"{} {} {}\n{}\n\n{}",
			HTTP_VERSION,
			self.status as i32,
			self.status.message(),
			headers,
			self.body,
		)
	}
}