import csv
import math
import operator
import os
import re
from collections import deque

import matplotlib.pyplot as plot


def load(directory):
	def _read(iterable):
		for x, y in iterable:
			yield float(x), float(y)

	def _load(filename):
		with open(filename) as fd:
			reader = csv.reader(fd)
			return list(_read(reader))

	def _files(directory):
		for file in os.listdir(directory):
			match = re.match(r"SWI_(-?\d+)\.csv", file)
			if match:
				yield int(match.group(1)), os.path.join(directory, file)

	return [(x, _load(y)) for x, y in sorted(_files(directory), key=lambda x: x[0])]


def increment(x):
	return x + 1


def decrement(x):
	return x - 1


def find_boundary_curves(swis, x, y):
	segments = deque()
	for index, data in swis:
		width = data[-1][0] - data[0][0]
		relative = x - data[0][0]
		candidate = math.floor(relative / width * len(data)) + 1
		condition = operator.lt if data[candidate][0] > x else operator.gt
		step = decrement if data[candidate][0] > x else increment
		j = candidate
		i = candidate
		while not condition(data[i][0], x):
			j = i
			i = step(i)
		if i > j:
			i, j = j, i
		if data[i][1] > y and data[j][1] > y:
			segments.append((index, data, i, j))
			break
		if data[i][1] < y and data[j][1] < y:
			if segments:
				segments.popleft()
		segments.append((index, data, i, j))
	return segments


swis = load("dataset")

def onclick(event):
	if event.button != 1:
		return
	plot.clf()
	segments = find_boundary_curves(swis, event.xdata, event.ydata)
	plot.plot([event.xdata], [event.ydata], "rx")
	for index, data, i, j in segments:
		plot.plot([x[0] for x in data], [x[1] for x in data], ".", label=index)
	plot.show()

fig, _ = plot.subplots()
fig.canvas.mpl_connect('button_press_event', onclick)
plot.show()