#include "checkouts.h"
#include "comp.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include <emscripten/emscripten.h>

int delay_ms = 500;

enum match_mode {
	M_PVC = 1,
	M_P,
	M_PVP
};

// TODO refactor *everything*

struct match_state {
	enum match_mode mode;
	struct leg *l1, *l2, *active_l;
	int active_p;
	int undone_count;
	bool num_darts;
};

struct match_state *state;

void set_active_player(int player)
{
	state->active_p = player;
	state->active_l = player == 1 ? state->l1 : state->l2;
	EM_ASM({setPlayerActive($0)}, player);

	if (state->mode == M_PVC && player == 2) {
		EM_ASM({promptMsgL($0)}, "Bot is throwing…");
		EM_ASM({setPromptHandler($0)}, "");
	} else {
		EM_ASM({promptMsgL($0)}, "Enter points:");
		EM_ASM({setPromptHandler($0)}, "visit");
	}
	EM_ASM({promptMsgR($0)}, "");
}

void toggle_active_player()
{
	set_active_player(3 - state->active_p);
}

void update_player_sugg(int player, int rem)
{
	char str[15] = {0}, *p = str;

	if (rem > 1 && rem <= 170) {
		char *target;
		int i = 3, trem = rem;
		while (i && trem && (target = CHECKOUTS[--i][trem-1])) {
			p += sprintf(p, i == 2 ? "%s" : "-%s", target);
			trem -= segment_points(segment_from_name(target));
		}
	}

	EM_ASM({updatePlayerSugg($0, $1)}, player, str);
}

bool is_match_over()
{
	return state->l1->rem <= 0 || state->l2->rem <= 0;
}

void prompt_end_match()
{
	EM_ASM(setPlayerActive()); // sets all inactive
	EM_ASM({setPromptHandler($0)}, "end_match");
	EM_ASM({promptMsgR($0)}, "Press OK to end match.");
}

void draw_visits()
{
	EM_ASM({clearVisits()});

	char visit_no[10], p1_pts[10], p1_rem[10],
		p2_pts[10], p2_rem[10], p2_darts[100];

	sprintf(p1_rem, "%d", state->l1->start);
	sprintf(p2_rem, "%d", state->l2->start);
	EM_ASM({drawVisit($0, $1, $2, $3, $4, $5)},
		"0", "", p1_rem, "", state->mode == M_P ? "" : p2_rem, "");

	int n_visits = state->l1->n_visits > state->l2->n_visits ?
		state->l1->n_visits : state->l2->n_visits;
	for (int i = 0; i < n_visits; ++i) {
		visit_no[0] = p1_pts[0] = p1_rem[0] =
			p2_pts[0] = p2_rem[0] = p2_darts[0] = 0;

		sprintf(visit_no, "%d", i + 1);

		struct visit *v = state->l1->visits + i;
		sprintf(p1_pts, "%d", v->points);
		sprintf(p1_rem, "%d", v->rem);

		if (i < state->l2->n_visits) {
			v = state->l2->visits + i;
			sprintf(p2_pts, "%d", v->points);
			sprintf(p2_rem, "%d", v->rem);

			for (int j = 0; j < v->n_darts; ++j) {
				char *n = segment_name(v->darts[j]);
				sprintf(p2_darts + (j ? (j*5 - 1) : 0),
					j == 0 ? "%4s" : " %4s", n);
				free(n);
			}
		}

		EM_ASM({drawVisit($0, $1, $2, $3, $4, $5)},
			visit_no, p1_pts, p1_rem, p2_pts, p2_rem, p2_darts);
	}
}

void update_player_rem(int player, int rem)
{
	char str[5];
	if (rem < 0 || rem == 1)
		strcpy(str, "BUST");
	else
		sprintf(str, "%d", rem);

	EM_ASM({updatePlayerRem($0, $1)}, player, str);
	if (player == 1 || state->mode != M_PVC)
		update_player_sugg(player, rem);
}

EMSCRIPTEN_KEEPALIVE void update_user_rem_from_pts(int pts)
{
	update_player_rem(state->active_p, state->active_l->rem - pts);
}

EMSCRIPTEN_KEEPALIVE void draw_boat_throwing(int pts, char *str)
{
	char pts_str[10];
	sprintf(pts_str, "%d", pts);

	int rem = state->l2->n_visits > 1 ?
		state->l2->visits[state->l2->n_visits-2].rem : state->l2->start;

	update_player_rem(2, rem - pts);
	EM_ASM({setPromptInput($0)}, pts_str);
	EM_ASM({promptMsgR($0)}, str);
}

void handle_next();
EMSCRIPTEN_KEEPALIVE void end_boat_throwing(int rem, double avg)
{
	update_player_rem(2, rem);
	EM_ASM({updatePlayerAvg($0, $1)}, 2, avg);
	EM_ASM({setPromptInput($0)}, "");
	EM_ASM({promptMsgR($0)}, "");

	draw_visits();
	handle_next();
}

EMSCRIPTEN_KEEPALIVE void boat_visit()
{
	struct leg *l = state->l2;
	if (state->undone_count) {
		--state->undone_count;
		l->rem = l->visits[l->n_visits++].rem;
	} else {
		comp_visit(l);
	}

	struct visit *v = l->visits + l->n_visits - 1;
	double avg = v->rem > 0 ?
		(double)(l->start - l->rem) / l->n_visits :
		(double)l->start / (((l->n_visits - 1) * 3) + v->n_darts) * 3;

	if (!delay_ms) {
		end_boat_throwing(l->rem, avg);
		return;
	}

	int pts = 0;
	char str[15] = {0};

	for (int i = 0; i < v->n_darts; ++i) {
		pts += segment_points(v->darts[i]);
		char *seg_name = segment_name(v->darts[i]);
		strcat(i ? strcat(str, "-") : str, seg_name);
		free(seg_name);

		EM_ASM({scheduleCCall($0, $1, $2, $3, $4, $5)},
			"draw_boat_throwing", delay_ms * (i+1),
			"number", pts, "string", str);
	}

	EM_ASM({scheduleCCall($0, $1, $2, $3, $4, $5)},
		"end_boat_throwing", delay_ms * (v->n_darts + 1),
		"number", l->rem, "number", avg);
}

void clear_player_info(int pn)
{
	EM_ASM({updatePlayerName($0, $1)}, pn, "");
	EM_ASM({updatePlayerRem($0, $1)}, pn, "");
	EM_ASM({updatePlayerSugg($0, $1)}, pn, "");
	EM_ASM({updatePlayerAvg($0, $1)}, pn, 0);
}

EMSCRIPTEN_KEEPALIVE void prompt_match_mode()
{
	for (int pn = 1; pn < 3; ++pn) {
		EM_ASM({hidePlayerInfo($0)}, pn);
		clear_player_info(pn);
	}
	EM_ASM(clearVisits());

	EM_ASM({setPromptHandler($0)}, "match_mode");
	EM_ASM({promptMsgR($0)}, "");
	EM_ASM({promptMsgL($0)}, "Select match mode:");
}

void handle_next()
{
	if (!state) {
		prompt_match_mode();
	} else if (is_match_over()) {
		if (state->mode == M_PVC && state->l2->rem <= 0) {
			EM_ASM({promptMsgL($0)}, "Bot wins. :(");
			prompt_end_match();
		} else if (!state->num_darts) {
			EM_ASM({setPromptHandler($0)}, "num_darts");
			EM_ASM({promptMsgL($0)}, "Darts needed?");
		} else {
			EM_ASM({promptMsgL($0)}, "You win! :)");
			prompt_end_match();
		}
	} else {
		if (state->mode == M_P) {
			set_active_player(1);
		} else {
			toggle_active_player();

			if (state->mode == M_PVC && state->active_p == 2)
				boat_visit();
		}
	}
}

EMSCRIPTEN_KEEPALIVE void user_visit(int points)
{
	if (points < 0 || state->l1->rem <= 0 || state->l2->rem <= 0 ||
		points > state->active_l->rem || state->active_l->rem - points == 1 ||
		points > 180 || points == 179 || points == 178 || points == 176 ||
		points == 175 || points == 173 || points == 172 || points == 169 ||
		points == 166 || points == 163 ||
		(state->active_l->rem - points == 0 &&
			(points == 168 || points == 165 || points == 162 || points == 159))) {

		EM_ASM(oi());
		return;
	}

	struct leg *l = state->active_l;
	struct visit *v = l->visits + l->n_visits++;
	v->points = points;
	l->rem -= points;
	v->rem = l->rem;
	update_player_rem(state->active_p, l->rem);

	if (v->rem > 0)
		EM_ASM({updatePlayerAvg($0, $1)}, state->active_p,
			(double)(l->start-l->rem)/l->n_visits);

	draw_visits();
	handle_next();
}

EMSCRIPTEN_KEEPALIVE void user_visit_to_rem(int rem)
{
	user_visit(state->l1->rem - rem);
}

EMSCRIPTEN_KEEPALIVE void user_undo()
{
	if (!state->l1->n_visits) {
		EM_ASM(oi());
		return;
	}

	if (state->mode == M_PVC) {
		set_active_player(1);
	} else if (state->mode == M_PVP) {
		if (is_match_over())
			set_active_player(state->active_p);
		else
			toggle_active_player();
	}

	struct leg *l = state->active_l;
	struct visit *v = l->visits + --l->n_visits;
	l->rem += v->points;
	memcpy(v, 0, sizeof(*v));
	state->num_darts = 0;

	if (state->mode == M_PVC && state->l2->n_visits > l->n_visits) {
		state->l2->rem += state->l2->visits[--state->l2->n_visits].points;
		++state->undone_count;
	}

	EM_ASM({updatePlayerAvg($0, $1)}, 1,
		state->l1->n_visits ?
			(double)(state->l1->start - state->l1->rem) / state->l1->n_visits :
			0);
	EM_ASM({updatePlayerAvg($0, $1)}, 2,
		state->l2->n_visits ?
			(double)(state->l2->start - state->l2->rem) / state->l2->n_visits :
			0);
	update_player_rem(state->active_p, l->rem);
	if (state->mode == M_PVC)
		update_player_rem(2, state->l2->rem);

	draw_visits();

	if (state->mode != M_P) // FIXME avoid double toggle?
		toggle_active_player();
	handle_next();
}

EMSCRIPTEN_KEEPALIVE void user_num_darts(int n)
{
	if (n < 1 || n > 3) {
		EM_ASM(oi());
		return;
	}

	state->num_darts = n;

	struct leg *l = state->active_l;
	EM_ASM({updatePlayerAvg($0, $1)}, state->active_p,
		((double)l->start / (((l->n_visits - 1) * 3) + n)) * 3);

	handle_next();
}

void free_state()
{
	state->l2->n_visits += state->undone_count; // avoid memory leak
	leg_free(state->l1);
	leg_free(state->l2);
	free(state);
	state = NULL;
}

EMSCRIPTEN_KEEPALIVE void start_match(int mode)
{
	if (mode != M_PVP && mode != M_PVC && mode != M_P) {
		EM_ASM(oi());
		return;
	}

	if (state) free_state(); // FIXME
	state = calloc(1, sizeof(*state));
	state->mode = mode;
	state->l1 = leg_init(501, mode == M_PVP ? "Player 1" : "User");
	state->l2 = leg_init(501, mode == M_PVC ? "Bot" : "Player 2");
	set_active_player(1);

	EM_ASM({showPlayerInfo($0)}, 1);
	EM_ASM({updatePlayerName($0, $1)}, 1, state->l1->name);
	update_player_rem(1, state->l1->rem);
	EM_ASM({updatePlayerAvg($0, $1)}, 1, 0);

	if (mode != M_P) {
		EM_ASM({showPlayerInfo($0)}, 2);
		EM_ASM({updatePlayerName($0, $1)}, 2, state->l2->name);
		update_player_rem(2, state->l2->rem);
		EM_ASM({updatePlayerAvg($0, $1)}, 2, 0);
	}

	draw_visits();
}

EMSCRIPTEN_KEEPALIVE void end_match()
{
	if (state) free_state();
	handle_next();
}

EMSCRIPTEN_KEEPALIVE void set_delay(int delay)
{
	delay_ms = delay;
}

EMSCRIPTEN_KEEPALIVE void set_stdev(float hstdev, float vstdev)
{
	horizontal_stdev = hstdev;
	vertical_stdev = vstdev;
}

void init_boat()
{
	srand(time(NULL));
	init_board();

	EM_ASM(readOpts());
	EM_ASM({updateDelay($0)}, delay_ms);
	EM_ASM({updateStdev($0)}, horizontal_stdev);
}

int main()
{
	init_boat();
	handle_next();
}