-module(markov).
-include_lib("stdlib/include/qlc.hrl").
-include("markov.hrl").
-export([init/0]).

init() ->
	receive
		{markov, X, P} ->
			P ! markov_respond(X)
	end,
	init().

markov_respond_x(X, P) ->
	P ! markov_respond(X),
	io:write(standard_io, "Generating response...").

markov_respond(M) ->
	markov_feed(M),
	markov_generate_response(M).

markov_feed_r([], _, _) ->
	[];

markov_feed_r([H|T], N, M) ->
	X=mnesia:transaction(fun() -> X = qlc:q([P#states.state_id || P <- states, P#states.state == H, P#states.type == 0]),
	qlc:e(X) end),
	Y=mnesia:transaction(fun() -> Y = qlc:q([P#states.state_id || P <- states, P#states.state == hd(T), P#states.type==0]),
	qlc:e(Y) end),
	Z= mnesia:transaction(fun() -> Z = qlc:q([P || P <- links, P#links.state_id1 == X, P#links.state_id2 == Y, P#links.distance == 1]),
	qlc:e(Z) end),
	mnesia:write(Z#links{weight = Z#links.weight + 1}),
	Q = mnesia:transaction(fun() -> Q = qlc:q([P#states.state_id || P <- states, P#states.state == hd(M), P#states.type==0]),
	qlc:e(Q) end),
	R = mnesia:transaction(fun() -> R = qlc:q([P#links.weight || P <- links, P#links.state_id1 == Q, P#links.state_id2 == X, P#links.distance == N]),
	qlc:e(R) end),
	mnesia:write(links, {state_id1 = Q, state_id2 = X, distance = N, weight = R + 1}),
	markov_feed_r(T, N+1, lists:append(M, H)),
	markov_feed_r(tl(M), 1, []).

markov_feed(M) ->
	markov_feed_r(M, 1, []).

sum([]) ->
	0;

sum(F) ->
	hd(F) + sum(tl(F)).

weighting({N, W, S}, N) ->
	{W, S}.

markov_generate_chain_r([], _) ->
	{0, ''};

markov_generate_chain_r(X, N) ->
	lists:append(hd(lists:sort(lists:append(weighting(hd(X), N), markov_generate_chain_r(tl(X), N)))), lists:sort(markov_generate_chain_r(X, N + 1))).


markov_generate_chain(Y) ->
	X = mnesia:transaction(fun() -> X = qlc:q([P#states.state_id || P <- states, P#states.state == Y, P#states.type==0]), qlc:e(X) end),
	D = lists:sort(mnesia:transaction(fun() -> V = qlc:q([{ P#links.distance, P#links.weight, P#links.state_id2 } || P <- links, P#links.state_id1 == X, P#links.distance < 3]), qlc:e(V) end)),
	hd(lists:sort(markov_generate_chain_r(D, 1))).
	

markov_generate_response_r([]) ->
	[];

markov_generate_response_r(M) ->
	X = mnesia:transaction(fun() ->
	X = qlc:q([P#states.state_id || P <- states, P#states.state == hd(M), P#states.type==0]),
	qlc:e(X) end),
	Y = sum(lists:append(mnesia:transaction(fun() -> V = qlc:q([P#links.weight || P <- links, P#links.state_id1 ==X]), qlc:q([P#links.weight || P <- links, P#links.state_id2 == X]), qlc:e(V) end) )),
	lists:append([{Y, hd(M)}], markov_generate_response_r(tl(M))). 

markov_generate_response(M) ->
	X = lists:sort(markov_generate_response_r(M)),
	Y = lists:nth(X, length(X) / 2),
	markov_generate_chain(Y).