use std::io::{Write, BufReader, BufRead, Read};
use std::thread;
use std::net::{TcpListener, TcpStream};
use std::fs;
use std::fs::File;
use std::string::{String};
use std::process::Command;
use packeteer::http1::*;
use frostwalker;
use packeteer::{generate_kvheader, unwrap_url_into_segments};

struct Resource {
	contents: Vec<u8>,
	status_code: i32,
	mime: String,
	iscgi: bool,
}

struct GetPageResult {
	is500: bool,
	is502: bool,
	is403: bool,
	contents: Vec<u8>,
	iscgi: bool,
}

#[derive(Clone)]
struct Settings {
	cgi: bool,
	index_generation: bool,
	address: String,
    logging: bool,
}

impl Settings {
	fn new() -> Settings {
		return Settings { cgi: true, index_generation: true, address: "0.0.0.0:8080".to_string(), logging: false};
	}
}

fn process_cgi(filename: String) -> Option<Vec<u8>> {
	// This is gonna be the bodgiest implementation of CGI that anyone
	// has ever seen in the history of the fucking world

	let query;
	let script;

	if filename.contains("?") {
		let vars = filename.to_string().find("?").unwrap();
		let vars1 = vars + 1;
		query = &filename[vars1..];
		script = &filename[..vars];
	} else {
		query = "";
		script = &filename;
	}

	let output;
	if query != "" {
		output = Command::new(format!("./{}", script))
					.env("GATEWAY_INTERFACE", "CGI/1.1")
					.env("SERVER_SOFTWARE", format!("herb/{}", env!("CARGO_PKG_VERSION")))
					.env("REQUEST_METHOD", "GET")
					.env("QUERY_STRING", query)
					.env("SCRIPT_NAME", script)
					.output();
	} else {
		output = Command::new(format!("./{}", script))
					.env("GATEWAY_INTERFACE", "CGI/1.1")
					.env("SERVER_SOFTWARE", format!("herb/{}", env!("CARGO_PKG_VERSION")))
					.env("REQUEST_METHOD", "GET")
					.env("SCRIPT_NAME", script)
					.output();
	}
	if output.is_ok() {
		return Some(output.unwrap().stdout);
	} else {
		return None;
	}
}

fn process_cgi_with_path(filename: String, segments: Vec<String>, location: i32) -> Option<Vec<u8>> {
	let mut query: String = "".to_string();
	let script = filename;

	let mut i = 0;
	let mut path = "".to_string();
	for seg in segments {
		if !(i <= location) && !(seg.contains("?")) {
			if path == "".to_string() {
				path = format!("/{}", seg);
			} else {
				path = format!("{}/{}", path, seg);
			}
		}

		if !(i <= location) && seg.contains("?") {
			let split: Vec<&str> = seg.as_str().split("?").collect();
			query = split[split.len()-1].to_string();
			path = format!("{}/{}", path, split[0].to_string());
		}
		i = i + 1;
	}

	path = format!("{}/", path);
	let output;
	if query != "".to_string() {
		output = Command::new(format!("./{}", script))
					.env("GATEWAY_INTERFACE", "CGI/1.1")
					.env("SERVER_SOFTWARE", format!("herb/{}", env!("CARGO_PKG_VERSION")))
					.env("REQUEST_METHOD", "GET")
					.env("QUERY_STRING", query)
					.env("PATH_INFO", path)
					.env("SCRIPT_NAME", script)
					.output();
	} else {
		output = Command::new(format!("./{}", script))
					.env("GATEWAY_INTERFACE", "CGI/1.1")
					.env("SERVER_SOFTWARE", format!("herb/{}", env!("CARGO_PKG_VERSION")))
					.env("REQUEST_METHOD", "GET")
					.env("PATH_INFO", path)
					.env("SCRIPT_NAME", script)
					.output();
	}
	if output.is_ok() {
		return Some(output.unwrap().stdout);
	} else {
		return None;
	}
}

fn detect_media_type(filename: String) -> String {

	// The Lynx terminal browser made me do this.

	let path = filename.to_string();
	let paths = check_if_path_exists(path);
	let path = filename.to_string();
	let dir = check_if_dir(path);

	if paths == true && dir == false && filename.contains(".") == false {
		return "text/html".to_string();
	} else {
		let ext_index = filename.as_str().split(".").collect::<Vec<&str>>();
		let ext = ext_index[ext_index.len()-1];

		match ext {
			"aac" => "audio/aac".to_string(),
			"avi" => "video/x-msvideo".to_string(),
			"bmp" => "image/bmp".to_string(),
			"bz2" => "application/x-bzip2".to_string(),
			"css" => "text/css".to_string(),
			"gz" => "application/gzip".to_string(),
			"gif" => "image/gif".to_string(),
			"png" => "image/png".to_string(),
			"pdf" => "application/pdf".to_string(),
			"jpeg" => "image/jpeg".to_string(),
			"jpg" => "image/jpeg".to_string(),
			"js" => "text/javascript".to_string(),
			"mid" => "audio/midi".to_string(),
			"midi" => "audio/midi".to_string(),
			"mp3" => "audio/mpeg".to_string(),
			"mp4" => "video/mp4".to_string(),
			"mpeg" => "video/mpeg".to_string(),
			"ogg" => "audio/ogg".to_string(),
			"oga" => "audio/ogg".to_string(),
			"ogv" => "video/ogg".to_string(),
			"opus" => "audio/opus".to_string(),
			"txt" => "text/plain".to_string(),
			"html" => "text/html".to_string(),
			"htm" => "text/html".to_string(),
			_ => "application/octet-stream".to_string(),
		}
	}

}

fn check_if_path_exists(path: String) -> bool {

	// This is probably not the best way of checking if a path
	// exists but I don't care :)

	let file = fs::metadata(path);

	match file {
		Ok(_) => true,
		Err(_) => false,
	}

}

fn check_if_dir(directory: String) -> bool {
	let path = directory + "/index.html";
	let result = check_if_path_exists(path);

	return result;
}

fn generate_index(directory: String) -> String {

	let mut index = format!("<!DOCTYPE HTML><html><body><h1>Directory of {}</h1><hr/><a href=\"/{}/../\">Parent Directory</a><br/>", directory, directory);
	for file in fs::read_dir(directory).unwrap() {
		index = format!("{}<a href={}>{}</a><br/>", index, format!("\"/{}\"", file.as_ref().unwrap().path().display().to_string()), file.unwrap().file_name().into_string().unwrap_or("!!".to_string()));
	}

	return format!("{}<hr/><i>Generated by herb/{}</i>", index, env!("CARGO_PKG_VERSION")).to_string();

}

fn get_page(filename: String, settings: Settings) -> GetPageResult {

	// The loaded page should be left immutable as it does
	// not need to be modified by the server.

	let path = filename.to_string();
	let checks = check_if_path_exists(path.clone());
	let index = check_if_dir(path.clone());

	let mut resultstruct = GetPageResult { is500: false, is502: false, is403: false, contents: vec![], iscgi: false };

    if settings.logging {
     	println!("{} {} {}", path, checks, index);
    }

	if checks == true && index == false {
		if path.contains(".") != true && path.contains(".cgi?") != true {
			let result;
			if settings.index_generation == false {
				result = "<!DOCTYPE HTML><html><body><h1>403 Forbidden</h1><p>You do not have permission to access this resource</p></body></html>".to_string();
				resultstruct.is403 = true;
			} else {
				result = generate_index(filename);
			}

			resultstruct.contents = result.to_string().into_bytes();
			return resultstruct;
		} else if path.contains(".cgi?")  {
			if settings.cgi == false {
				let result = "<!DOCTYPE HTML><html><body><h1>403 Forbidden</h1><p>You do not have permission to access this resource</p></body></html>".to_string();
				resultstruct.contents = result.into_bytes();
				resultstruct.is403 = true;
				return resultstruct;
			}

			let result = process_cgi(filename);
			if result.is_some() {
				resultstruct.contents = result.unwrap();
				resultstruct.iscgi = true;
				return resultstruct;
			} else {
				resultstruct.contents = "<!DOCTYPE HTML><html><body><h1>500 Internal Server Error</h1><p>The resource you are trying to access cannot be read by the server.</p></body></html>".to_string().into_bytes();
				resultstruct.is500 = true;
				return resultstruct;
			}
		}
	}

	if filename.contains(".cgi") {
		if settings.cgi == false {
			let result = "<!DOCTYPE HTML><html><body><h1>403 Forbidden</h1><p>You do not have permission to access this resource</p></body></html>".to_string();
			resultstruct.contents = result.into_bytes();
			resultstruct.is403 = true;
			return resultstruct;
		}

		let result = process_cgi(filename);
		if result.is_some() {
			resultstruct.contents = result.unwrap();
			resultstruct.iscgi = true;
			return resultstruct;
		} else {
			resultstruct.contents = "<!DOCTYPE HTML><html><body><h1>502 Bad Gateway</h1><p>The server is unable to complete your request due to an error.</p></body></html>".to_string().into_bytes();
			resultstruct.is502 = true;
			return resultstruct;
		}
	} else {
		let f = File::open(filename.clone());
		if f.is_ok() {
			let mut buf: Vec<u8> = vec![];
			let result = f.unwrap().read_to_end(&mut buf);
			if result.is_ok() {
				resultstruct.contents = buf;
				return resultstruct;
			} else {
				resultstruct.contents = "<!DOCTYPE HTML><html><body><h1>502 Bad Gateway</h1><p>The server is unable to complete your request due to an error.</p></body></html>".to_string().into_bytes();
				resultstruct.is502 = true;
				return resultstruct;
			}
		} else {
			if filename == "index.html" {
				let newresult;
				if settings.index_generation == false {
					newresult = "<!DOCTYPE HTML><html><body><h1>403 Forbidden</h1><p>You do not have permission to access this resource</p></body></html>".to_string();
					resultstruct.is403 = true;
				} else {
					newresult = generate_index(".".to_string());
				}
				resultstruct.contents = newresult.to_string().into_bytes();
				return resultstruct;
			}
			resultstruct.contents = "<!DOCTYPE HTML><html><body><h1>500 Internal Server Error</h1><p>The resource you are trying to access cannot be read by the server.</p></body></html>".to_string().into_bytes();
			resultstruct.is500 = true;
			return resultstruct;
		}
	}
}

fn grab_time() -> String{
	let output = Command::new("date")
				.arg("+'%a, %d %b %Y %H:%m:%S %Z'")
				.output()
				.expect("failed to execute process");

	return String::from_utf8_lossy(&output.stdout).to_string().replace("'","").replace("\n","");
}


fn process_request(request: Vec<u8>, settings: Settings) -> Resource {
	let input = String::from_utf8_lossy(&request).to_string();
	let prerequest = construct_request(&input);
	let request;
	if prerequest.is_some() {
		request = prerequest.unwrap();
	} else {
		let resource = Resource { contents: "<!DOCTYPE HTML><html><body><h1>400 Bad Request</h1><p>The request you sent appears to be malformed.</p></body></html>".to_string().into_bytes(), status_code: 400, mime: "text/html".to_string(), iscgi: false };
		return resource;
	}
	let mut path: String;

	let mut index = String::new();
	let output;

	if &request.method == "GET" {
        if settings.logging {
 		    println!("Stream sent GET request.");
        }
		if request.location.segments.len() != 0 {
			let segclone = request.location.segments.clone();
			path = unwrap_url_into_segments(request.location);
			if path.contains(".cgi/") {
				let mut cgiscript = 0;
				let mut i = 0;
				let mut cgipath: Vec<String> = vec![];
				for segment in &segclone {
					if segment.contains(".cgi") {
						cgipath.push(segment.to_string());
						cgiscript = i;
						break;
					} else {
						cgipath.push(segment.to_string());
						i = i + 1;
					}
				}
				let mut cgipathraw = "".to_string();
				for seg in cgipath {
					if cgipathraw == "".to_string() {
						cgipathraw = seg;
					} else {
						cgipathraw = format!("{}/{}", cgipathraw, seg);
					}
				}
				if settings.cgi == false {
					let newcontents = "<!DOCTYPE HTML><html><body><h1>403 Forbidden</h1><p>You do not have permission to access this resource</p></body></html>".to_string().into_bytes();
					let resource = Resource { contents: newcontents, status_code: 403, mime: "text/html".to_string(), iscgi: false };
					return resource;
				}

				let contents = process_cgi_with_path(cgipathraw, segclone, cgiscript);
				if contents.is_some() {
					let resource = Resource { contents: contents.unwrap(), status_code: 200, mime: "text/html".to_string(), iscgi: true };
					return resource;
				} else {
					let newcontents = "<!DOCTYPE HTML><html><body><h1>502 Bad Gateway</h1><p>The server is unable to complete your request due to an error.</p></body></html>".to_string().into_bytes();
					let resource = Resource { contents: newcontents, status_code: 502, mime: "text/html".to_string(), iscgi: false };
					return resource;
				}
			}
			path.remove(0);
			let exists = check_if_path_exists(path.clone());

			if exists == false && path.contains(".cgi?") == false {
				let resource = Resource { contents: "<!DOCTYPE HTML><html><body><h1>404 Not Found</h1><p>The resource you are trying to locate cannot be accessed!</p></body></html>".to_string().into_bytes(), status_code: 404, mime: "text/html".to_string(), iscgi: false };
				return resource;
			} else {
				let dir = check_if_dir(path.clone());
				if dir == true {
					index += &path;
					index += "/index.html";
					output = index.as_str();
				} else {
					output = path.as_str();
				}
			}
		} else {
			output = "index.html";
		}
	} else {
		let resource = Resource { contents: "<!DOCTYPE HTML><html><body><h1>501 Not Implemented</h1><p>The request sent by your web browser cannot be handled by this server software.</p></body></html>".to_string().into_bytes(), status_code: 501, mime: "text/html".to_string(), iscgi: false };
        if settings.logging {
		    println!("Stream sent unhandlable request.");
        }
		return resource;
	}

	// Did you want to see chars.as_str().to_string()?
	let rescontents = get_page(output.to_string(), settings.clone());
	let mut resource = Resource { contents: rescontents.contents, status_code: 200, mime: detect_media_type(output.split("?").collect::<Vec<&str>>()[0].to_string()), iscgi: false };
	if rescontents.is500 {
		resource.status_code = 500;
		resource.mime = "text/html".to_string();
	}

	if rescontents.is502 {
		resource.status_code = 502;
		resource.mime = "text/html".to_string();
	}

	if rescontents.is403 {
		resource.status_code = 403;
		resource.mime = "text/html".to_string();
	}

	if rescontents.iscgi {
		resource.iscgi = true;
	}

	return resource;

}

fn serve(mut stream: TcpStream, settings: Settings) {
	thread::spawn(move || {
        if settings.logging {
		    println!("Stream thread created.");
        }

		let mut request = Vec::new();
		let mut reader = BufReader::new(&mut stream);
		reader
		    .read_until(b'\n', &mut request)
		    .expect("Failed to read from stream!");

		let resource = process_request(request, settings.clone());

		let mut response_constructed = generate_response(resource.status_code, "");
		response_constructed.headers.push(generate_kvheader("Content-Type", &resource.mime));
		response_constructed.headers.push(generate_kvheader("Server", &format!("herb/{}", env!("CARGO_PKG_VERSION"))));

		if cfg!(unix) {
			response_constructed.headers.push(generate_kvheader("Date", &grab_time()))
		}

		if resource.iscgi {
			let header = "HTTP/1.1 200 OK\r\n".to_string().into_bytes();
			stream.write(header.as_slice()).unwrap();
			stream.write(&resource.contents).unwrap();
			stream.flush().unwrap();
			return;
		}

		let mut contents_clone = resource.contents.clone();
		let mut unpacked_response = unpack_response(response_constructed).into_bytes();
		unpacked_response.append(&mut contents_clone);

		stream.write(unpacked_response.as_slice()).unwrap();
		stream.flush().unwrap();
	});
}

fn process_settings() -> Settings {
	let string = fs::read_to_string("../settings.toml");
	if string.is_err() {
		return Settings::new();
	}
	let parsed = frostwalker::parse(&string.unwrap());
	if parsed.is_err() {
		return Settings::new();
	}
	let hashmap = parsed.unwrap();
	let mut settings = Settings::new();
	if hashmap.get("cgi").is_some() {
		if hashmap.get("cgi").unwrap_or(&"".to_string()).parse::<bool>().is_ok() {
			settings.cgi = hashmap.get("cgi").unwrap_or(&"true".to_string()).parse::<bool>().unwrap_or(true);
		}
	}

	if hashmap.get("index_generation").is_some() {
		if hashmap.get("index_generation").unwrap_or(&"".to_string()).parse::<bool>().is_ok() {
			settings.index_generation = hashmap.get("index_generation").unwrap_or(&"true".to_string()).parse::<bool>().unwrap_or(true);
		}
	}

	if hashmap.get("logging").is_some() {
		if hashmap.get("logging").unwrap_or(&"".to_string()).parse::<bool>().is_ok() {
			settings.logging = hashmap.get("logging").unwrap_or(&"false".to_string()).parse::<bool>().unwrap_or(true);
		}
	}

	if hashmap.get("address").is_some() {
		settings.address = hashmap.get("address").unwrap_or(&"0.0.0.0:8080".to_string()).to_string();
	}

	return settings;
} 

fn main() -> std::io::Result<()> {
	let settings = process_settings();
	let listen = TcpListener::bind(settings.address.clone())?;

	for stream in listen.incoming() {
        if settings.logging {
	    	println!("Serving incoming stream.");
        }
		serve(stream?, settings.clone());
	}
	Ok(())
}