# -*- coding: utf-8 -*-
#
# AWL simulator - FUP - Grid classes
#
# Copyright 2016-2018 Michael Buesch <m@bues.ch>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

from __future__ import division, absolute_import, print_function, unicode_literals
#from awlsim.common.cython_support cimport * #@cy
from awlsim.common.compat import *

from awlsim.common.xmlfactory import *

from awlsim.awloptimizer.awloptimizer import *

from awlsim.gui.geo2d import *
from awlsim.gui.fup.fup_base import *
from awlsim.gui.fup.fup_wire import *
from awlsim.gui.fup.fup_elem import *
from awlsim.gui.fup.fup_elembool import *
from awlsim.gui.fup.fup_elemoperand import *
from awlsim.gui.fup.fup_elemmove import *


class FupGrid_factory(XmlFactory):
	def parser_open(self, tag=None):
		self.__haveGridTag = False
		if tag:
			self.__parseGridTag(tag)
		XmlFactory.parser_open(self, tag)

	def __parseGridTag(self, tag):
		self.grid.clear()
		width = tag.getAttrInt("width")
		height = tag.getAttrInt("height")
		uuid = tag.getAttr("uuid", None)
		self.grid.resize(width, height)
		self.grid.uuid = uuid
		self.__haveGridTag = True

	def parser_beginTag(self, tag):
		if tag.name == "grid" and not self.__haveGridTag:
			self.__parseGridTag(tag)
			return
		if tag.name == "wires":
			self.parser_switchTo(FupWire.factory(grid=self.grid))
			return
		if tag.name == "elements":
			self.parser_switchTo(FupElem.factory(grid=self.grid))
			return
		if tag.name == "optimizers":
			optType = tag.getAttr("type")
			if optType == "awl":
				optSettingsCont = self.grid.optSettingsCont
				self.parser_switchTo(optSettingsCont.factory(
					settingsContainer=optSettingsCont))
				return
		XmlFactory.parser_beginTag(self, tag)

	def parser_endTag(self, tag):
		if tag.name == "grid":
			self.grid.removeOrphanWires()
			self.parser_finish()
			return
		XmlFactory.parser_endTag(self, tag)

	# Composer filters:
	composer_withOptSettings	= lambda self: True
	composer_withWireRenum		= lambda self: True
	composer_wireFilter		= lambda self, wire: True
	composer_elemFilter		= lambda self, wire: True

	def composer_getTags(self):
		grid = self.grid
		childTags = []

		if self.composer_withOptSettings():
			optSettingsCont = grid.optSettingsCont
			childTags.extend(
				optSettingsCont.factory(
					settingsContainer=optSettingsCont).composer_getTags())

		if self.composer_withWireRenum():
			grid.renumberWires()
		wireTags = []
		for wire in sorted(grid.wires, key=lambda w: w.idNum):
			if self.composer_wireFilter(wire):
				wireTags.extend(wire.factory(wire=wire).composer_getTags())
		childTags.append(self.Tag(name="wires",
					  tags=wireTags))

		elemTags = []
		for elem in grid.elems:
			if self.composer_elemFilter(elem):
				elemTags.extend(elem.factory(elem=elem).composer_getTags())
		childTags.append(self.Tag(name="elements",
					  tags=elemTags))

		return [
			self.Tag(name="grid",
				tags=childTags,
				attrs={
					"width" : str(grid.width),
					"height" : str(grid.height),
					"uuid" : str(grid.uuid),
				}),
		]

class FupGrid(FupBaseClass):
	"""FUP/FBD element grid.
	"""

	factory = FupGrid_factory

	# Resize event callback.
	# If this is a callable, it it called with (width, height) on resize events.
	resizeEvent = None

	# Infinite width/height
	INFINITE = -1

	class CollLines(object):
		"""Collision cache line descriptor.
		This is used for describing drawn wires and
		detecting collisions among them.
		"""

		def __init__(self, lineSegments, wire=None, elem=None):
			"""lineSeg => Tuple of LineSeg2D() line segments.
			wire => FupWire() that this line belongs to, if any.
			elem => FupElem() that this line belongs to, if any.
			"""
			self.lineSegments = lineSegments
			self.wire = wire
			self.elem = elem

		def dup(self):
			"""Make a shallow copy of this Line.
			"""
			return self.__class__(self.lineSegments,
					      self.wire,
					      self.elem)

	def __init__(self, drawWidget, width, height, uuid=None):
		"""drawWidget => FupDrawWidget() instance.
		width => The grid width.
		height => The grid height.
		"""
		FupBaseClass.__init__(self, uuid=uuid)

		self.__drawWidget = drawWidget
		self.width = width
		self.height = height

		self.elems = []			# The FupElem_xxx()s in this grid
		self.__elemsByUUID = {}
		self.wires = set()		# The FupConnIn/Out()s in this grid

		self.selectedCells = set()	# Set of tuples (gridX, gridY) of selected cells
		self.selectedElems = set()	# Set of selected elements in this grid
		self.expandedElems = set()	# Set of expanded elements in this grid
		self.clickedElem = None		# The recently clicked element in this grid
		self.clickedConn = None		# The recently clicked connection in this grid
		self.clickedArea = None		# The recently clicked area in this grid

		self.optSettingsCont = AwlOptimizerSettingsContainer()

		self.collisionCacheClear()

	def getFont(self, size=8, bold=False):
		if self.__drawWidget:
			return self.__drawWidget.getFont(size=size, bold=bold)
		return QFont()

	@property
	def zoom(self):
		if self.__drawWidget:
			return self.__drawWidget.zoom
		return 1.0

	def clear(self):
		for wire in set(self.wires):
			wire.disconnectAll()
		self.wires.clear()
		self.elems = []
		self.__elemsByUUID = {}
		self.selectedCells.clear()
		self.selectedElems.clear()
		self.collisionCacheClear()

	def collisionCacheClear(self):
		"""Clear the collision cache of drawn lines.
		"""
		# __collCacheLines is a list of FupGrid.CollLines() instances.
		self.__collCacheLines = []

	def collisionCacheAdd(self, line):
		"""Add a line entry to the collision cache.
		line => A FupGrid.CollLines() instance
		"""
		assert(isinstance(line, self.CollLines))
		self.__collCacheLines.append(line)

	def resize(self, width, height):
		"""Resize the grid.
		Returns True, if the resize was successfull.
		"""
		if width == self.width and height == self.height:
			return True
		if self.elems:
			minWidth = max(e.x + e.width for e in self.elems)
			minHeight = max(e.y + e.height for e in self.elems)
		else:
			minWidth = minHeight = 0
		if (width < minWidth and width != self.INFINITE) or\
		   (height < minHeight and height != self.INFINITE):
			return False
		self.width = width
		self.height = height
		if callable(self.resizeEvent):
			self.resizeEvent(width, height)
		return True

	@property
	def interfDef(self):
		"""Get the block interface definition (AwlInterfDef() instance).
		"""
		if self.__drawWidget:
			return self.__drawWidget.interfDef
		return None

	def getUnusedWireIdNum(self):
		"""Get an unused wire idNum.
		"""
		if self.wires:
			return max(w.idNum for w in self.wires) + 1
		return 0

	def addWire(self, wire):
		"""Add a wire to the grid.
		Does nothing, if the wire does exist already.
		"""
		self.wires.add(wire)

	def removeWire(self, wire):
		"""Remove a wire to the grid.
		Does nothing, if the wire does not exist.
		"""
		with contextlib.suppress(KeyError):
			self.wires.remove(wire)
		# Remove CollLines()s that belong to 'wire' from the collision cache.
		self.__collCacheLines = [ line for line in self.__collCacheLines
					  if line.wire is None or\
					     line.wire is not wire ]

	def getWireById(self, wireIdNum):
		"""Get a wire by its idNum.
		"""
		if wireIdNum >= 0:
			for wire in self.wires:
				if wire.idNum == wireIdNum:
					return wire
		return None

	def removeOrphanWires(self, dangling=True):
		"""Remove all unconnected wires.
		If 'dangling' is True, wires that only have a single connection
		are also removed.
		"""
		connLimit = 1 if dangling else 0
		newWiresSet = set()
		while self.wires:
			wire = self.wires.pop()
			if len(wire.connections) > connLimit:
				# Keep this wire.
				newWiresSet.add(wire)
			else:
				# Drop this wire and remove all
				# connections from it.
				for conn in set(wire.connections):
					wire.disconnect(conn)
		self.wires = newWiresSet

	def renumberWires(self, idNumOffset=0):
		"""Re-assign all wire idNums.
		"""
		for i, wire in enumerate(sorted(self.wires,
						key=lambda w: w.idNum)):
			wire.idNum = i + idNumOffset

	def checkWireLine(self, painter, excludeWires, lineSeg):
		"""Checks if a wire line would be drawable and does not collide
		with another wire line.
		excludeWires => Iterable if FupWire()s to exclude from the check.
		lineSeg => The LineSeg2D() that should be drawn.
		Returns a set of colliding self.CollLines() instances.
		"""
		collisions = set()
		for line in self.__collCacheLines:
			if line.wire in excludeWires:
				continue
			for otherLineSeg in line.lineSegments:
				inter = lineSeg.intersection(otherLineSeg)
				if inter:
					# We have a collision.
					collisions.add(line.dup())
		return collisions

	def drawWireLine(self, painter, wire, lineSeg):
		"""Draw a wire line on 'painter'.
		wire => The FupWire() this line segment belongs to.
		lineSeg => The LineSeg2D() that describes the line to draw.
		"""
		if not lineSeg:
			return # Zero length line
		painter.drawLine(lineSeg.pointA.xInt, lineSeg.pointA.yInt,
				 lineSeg.pointB.xInt, lineSeg.pointB.yInt)
		self.collisionCacheAdd(self.CollLines((lineSeg,), wire=wire))

	def checkWireCollisions(self):
		"""Mark all wires as must-check-collisions.
		The collision check will be done at the next wire re-draw.
		"""
		for wire in self.wires:
			wire.checkCollisions()

	@property
	def cellPixWidth(self):
		if self.__drawWidget:
			return self.__drawWidget.cellPixWidth
		return 0

	@property
	def cellPixHeight(self):
		if self.__drawWidget:
			return self.__drawWidget.cellPixHeight
		return 0

	def __haveCollision(self, x, y, height, width, excludeElems=set()):
		if (self.width != self.INFINITE) and\
		   (x < 0 or x >= self.width):
			return True # Position is not on grid.
		if (self.height != self.INFINITE) and\
		   (y < 0 or y >= self.height):
			return True # Position is not on grid.
		for xx in range(x, x + width):
			for yy in range(y, y + height):
				elem = self.getElemAt(xx, yy)
				if elem in excludeElems:
					continue # Element is ignored.
				if elem:
					return True # Collision with other element.
		return False

	def canPlaceElem(self, elem, offsetX=0, offsetY=0):
		"""Check it we could place the element,
		but do not actually insert it into the grid.
		"""
		return not self.__haveCollision(elem.x + offsetX,
						elem.y + offsetY,
						elem.height,
						elem.width)

	def placeElem(self, elem):
		"""Insert an element into the grid.
		Returns False, if it was not possible to place the element.
		"""
		# Check if we already have this UUID.
		# A bug in old Awlsim versions generated duplicate UUIDs.
		if self.getElemByUUID(elem.uuid):
			printWarning("FUP element %s duplicate UUID. "
				"Generating new UUID." % elem)
			elem.regenAllUUIDs()
		# Check if we have a collision.
		if not self.canPlaceElem(elem):
			return False
		# Add the element.
		self.elems.append(elem)
		self.__elemsByUUID[elem.uuid] = elem
		# Reparent the element and all connected wires.
		elem.grid = self
		for conn in elem.connections:
			if conn.wire:
				conn.wire.grid = self
		return True

	def removeElem(self, elem):
		with contextlib.suppress(ValueError):
			self.elems.remove(elem)
		self.__elemsByUUID.pop(elem.uuid, None)
		elem.breakConnections()
		with contextlib.suppress(ValueError):
			self.selectedElems.remove(elem)
		# Remove CollLines()s that belong to 'elem' from the collision cache.
		self.__collCacheLines = [ line for line in self.__collCacheLines
					  if line.elem is None or\
					     line.elem is not elem ]

	def moveElemTo(self, elem, toX, toY,
		       relativeCoords=False,
		       checkOnly=False,
		       excludeCheckElems=set()):
		"""Move elem to position (toX, toY).
		If relativeCoords=True, the (toX, toY) coodinates are relative
		to the current position.
		If checkOnly=True, the actual move is not performed.
		All elements included in excludeCheckElems are excluded from
		the collision check.
		"""
		if relativeCoords:
			toX, toY = elem.x + toX, elem.y + toY
		if toX == elem.x and toY == elem.y:
			return True # No move needed
		# Check collision
		excludeElems = excludeCheckElems.copy()
		excludeElems.add(elem) # Can't collide with ourselves.
		if self.__haveCollision(toX, toY,
					elem.height, elem.width,
					excludeElems=excludeElems):
			return False # Collision. Cannot move.
		# Move the element.
		if not checkOnly:
			elem.x = toX
			elem.y = toY
			elem.checkWireCollisions()
		return True

	def getElemByUUID(self, uuid):
		"""Get an element by UUID string.
		Returns None, if no such element was found.
		"""
		return self.__elemsByUUID.get(uuid, None)

	def getElemAt(self, x, y):
		for elem in self.elems:
			ex, ey = elem.x, elem.y
			ew, eh = elem.width, elem.height
			if x >= ex and x < ex + ew and\
			   y >= ey and y < ey + eh:
				return elem
		return None

	def haveElemAt(self, x, y):
		return self.getElemAt(x, y) is not None

	def getElemsInRect(self, x0, y0, x1, y1):
		"""Get all elements placed within the given grid rectangle.
		"""
		return (elem for elem in self.elems
			if elem.isInGridRect(x0, y0, x1, y1))

	def selectElem(self, elem):
		if elem:
			self.selectedElems.add(elem)

	def selectElemAt(self, x, y):
		elem = self.getElemAt(x, y)
		if elem:
			self.selectElem(elem)
		else:
			self.deselectAllElems()

	def selectElemsInRect(self, x0, y0, x1, y1, clear=False):
		"""Select all elements within the given grid rectangle.
		"""
		if clear:
			self.deselectAllElems()
		for elem in self.getElemsInRect(x0, y0, x1, y1):
			self.selectElem(elem)

	def deselectElem(self, elem):
		with contextlib.suppress(KeyError):
			self.selectedElems.remove(elem)

	def deselectElemAt(self, x, y):
		elem = self.getElemAt(x, y)
		if elem:
			self.deselectElem(elem)

	def deselectAllElems(self):
		self.selectedElems.clear()

	def expandElem(self, elem, expand=True, area=None):
		ok = False
		if elem and expand and not elem in self.expandedElems:
			ok = elem.expand(expand, area)
			if ok:
				self.expandedElems.add(elem)
		if elem and not expand and elem in self.expandedElems:
			ok = elem.expand(expand, area)
			if ok:
				self.expandedElems.remove(elem)
		return ok

	def unexpandAllElems(self):
		if self.expandedElems:
			for elem in self.expandedElems.copy():
				self.expandElem(elem, False)
			return True
		return False

	def selectCell(self, x, y):
		"""Select the cell at grid coordinate X/Y.
		This does not affect element selection.
		"""
		self.selectedCells.add((x, y))

	def deselectCell(self, x, y):
		"""Deselect the cell at grid coordinate X/Y.
		This does not affect element selection.
		"""
		self.selectedCells.remove((x, y))

	def deselectAllCells(self):
		"""Deselect all cells.
		This does not affect element selection.
		"""
		self.selectedCells.clear()

	def cellIsSelected(self, x, y):
		"""Check if a cell is selected.
		"""
		return (x, y) in self.selectedCells

	def merge(self, otherGrid,
		  offsetX=0, offsetY=0,
		  selectInsertedElems=True):
		"""Merge another grid 'otherGrid' into this grid.
		'offsetX' and 'offsetY' are the positions in 'self'
		by which 'otherGrid' shall be shifted.
		If 'selectInsertedElems' is True, all inserted elements
		will be selected and other elements will be deselected.
		Returns True, if the merge was successful without collisions.
		Returns False and does nothing, if there are collisions.
		"""

		oldWidth, oldHeight = self.width, self.height

		def fail():
			self.resize(oldWidth, oldHeight)
			return False

		# Resize the grid, if it is too small to old all
		# elements from otherGrid.
		maxXElem = sorted((e for e in otherGrid.elems),
				  key=lambda e: e.x,
				  reverse=True)[0]
		maxYElem = sorted((e for e in otherGrid.elems),
				  key=lambda e: e.y,
				  reverse=True)[0]
		newWidth = max(offsetX + maxXElem.x + maxXElem.width,
			       oldWidth)
		newHeight = max(offsetY + maxYElem.y + maxYElem.height,
				oldHeight)
		if not self.resize(newWidth, newHeight):
			return fail()

		# Check if we can place all elements.
		for elem in otherGrid.elems:
			if not self.canPlaceElem(elem, offsetX, offsetY):
				return fail()

		# Actually place all elements.
		for elem in otherGrid.elems:
			elem.x += offsetX
			elem.y += offsetY
			self.placeElem(elem)

		# Merge the wires with this grid.
		# Renumber all wires to ensure we don't have duplications.
		self.renumberWires()
		freeIdNum = len(self.wires)
		otherGrid.renumberWires(idNumOffset=freeIdNum)
		self.wires |= otherGrid.wires

		# Update selections.
		self.deselectAllCells()
		if selectInsertedElems:
			self.deselectAllElems()
			for elem in otherGrid.elems:
				self.selectElem(elem)
		return True

	def regenAllUUIDs(self):
		"""Re-generate all UUIDs that belong to this grid,
		all its elements, connections and all wires.
		"""
		self.uuid = None # regenerate
		for elem in self.elems:
			elem.regenAllUUIDs()
		for wire in self.wires:
			wire.uuid = None # regenerate