from vector3d import vector3d
from tech import drc
import debug

class pin_group:
    """
    A class to represent a group of touching rectangular design pin. 
    It requires a router to define the track widths and blockages which 
    determine how pin shapes get mapped to tracks. 
    """
    def __init__(self, name, pin_shapes, router):
        self.name = name
        # Flag for when it is routed
        self.routed = False
        self.shapes = pin_shapes
        self.router = router
        # These are the corresponding pin grids for each pin group.
        self.grids = set()
        # The corresponding set of partially blocked grids for each pin group.
        # These are blockages for other nets but unblocked for routing this group.
        self.blockages = set()

    def set_routed(self, value=True):
        self.routed = value

    def is_routed(self):
        return self.routed
        
    def remove_redundant_shapes(self, pin_list):
        """
        Remove any pin layout that is contained within another.
        """
        local_debug = False
        if local_debug:
            debug.info(0,"INITIAL:",pin_list)
        
        # Make a copy of the list to start
        new_pin_list = pin_list.copy()
        
        # This is n^2, but the number is small
        for pin1 in pin_list:
            for pin2 in pin_list:
                # Can't contain yourself
                if pin1 == pin2:
                    continue
                if pin2.contains(pin1):
                    # It may have already been removed by being enclosed in another pin
                    if pin1 in new_pin_list:
                        new_pin_list.remove(pin1)
                        
        if local_debug:
            debug.info(0,"FINAL  :",new_pin_list)
        return new_pin_list

    # FIXME: This relies on some technology parameters from router which is not clearn.
    def compute_enclosures(self):
        """
        Find the minimum rectangle enclosures of the given tracks.
        """
        # Enumerate every possible enclosure
        pin_list = []
        for seed in self.grids:
            (ll, ur) = self.enclose_pin_grids(seed)
            enclosure = self.router.compute_pin_enclosure(ll, ur, ll.z)
            pin_list.append(enclosure)

        #return pin_list
        # We used to do this, but smaller enclosures can be
        return self.remove_redundant_shapes(pin_list)
        
    def compute_enclosure(self, pin, enclosure):
        """ 
        Compute an enclosure to connect the pin to the enclosure shape. 
        This assumes the shape will be the dimension of the pin.
        """
        if pin.xoverlaps(enclosure):
            # Is it vertical overlap, extend pin shape to enclosure
            plc = pin.lc()
            prc = pin.rc()
            elc = enclosure.lc()
            erc = enclosure.rc()
            ymin = min(plc.y,elc.y)
            ymax = max(plc.y,elc.y)
            ll = vector(plc.x, ymin)
            ur = vector(prc.x, ymax)
            p = pin_layout(pin.name, [ll, ur], pin.layer) 
        elif pin.yoverlaps(enclosure):
            # Is it horizontal overlap, extend pin shape to enclosure
            pbc = pin.bc()
            puc = pin.uc()
            ebc = enclosure.bc()
            euc = enclosure.uc()
            xmin = min(pbc.x,ebc.x)
            xmax = max(pbc.x,ebc.x)
            ll = vector(xmin, pbc.y)
            ur = vector(xmax, puc.y)
            p = pin_layout(pin.name, [ll, ur], pin.layer)
        else:
            # Neither, so we must do a corner-to corner
            pc = pin.center()
            ec = enclosure.center()
            xmin = min(pc.x, ec.x)
            xmax = max(pc.x, ec.x)
            ymin = min(pc.y, ec.y)
            ymax = max(pc.y, ec.y)
            ll = vector(xmin, ymin)
            ur = vector(xmax, ymax)
            p = pin_layout(pin.name, [ll, ur], pin.layer)

        return p

    def find_smallest_connector(self, enclosure_list):
        """
        Compute all of the connectors between non-overlapping pins and enclosures.
        Return the smallest.
        """
        smallest = None
        for pin in self.shapes:
            for enclosure in enclosure_list:
                new_enclosure = self.compute_enclosure(pin, enclosure)
                if smallest == None or new_enclosure.area()<smallest.area():
                    smallest = new_enclosure
                    
        return smallest

    def find_smallest_overlapping(self, shape_list):
        """
        Find the smallest area shape in shape_list that overlaps with any 
        pin in pin_list by a min width.
        """

        smallest_shape = None
        for pin in self.shapes:
            # They may not be all on the same layer... in the future.
            zindex=self.router.get_zindex(pin.layer_num)
            (min_width,min_space) = self.router.get_layer_width_space(zindex)

            # Now compare it with every other shape to check how much they overlap
            for other in shape_list:
                overlap_length = pin.overlap_length(other)
                if overlap_length > min_width:
                    if smallest_shape == None or other.area()<smallest_shape.area():
                        smallest_shape = other
                        
        return smallest_shape
    
    def overlap_any_shape(self, pin_list, shape_list):
        """
        Does the given pin overlap any of the shapes in the pin list.
        """
        for pin in pin_list:
            for other in shape_list:
                if pin.overlaps(other):
                    return True

        return False

    
    def max_pin_layout(self, pin_list):
        """ 
        Return the max area pin_layout
        """
        biggest = pin_list[0]
        for pin in pin_list:
            if pin.area() > biggest.area():
                biggest = pin
                
        return pin

    def enclose_pin_grids(self, seed):
        """
        This encloses a single pin component with a rectangle
        starting with the seed and expanding right until blocked
        and then up until blocked.
        """

        # We may have started with an empty set
        if not self.grids:
            return None

        # Start with the seed
        ll = seed

        # Start with the ll and make the widest row
        row = [ll]
        # Move right while we can
        while True:
            right = row[-1] + vector3d(1,0,0)
            # Can't move if not in the pin shape 
            if right in self.grids and right not in self.router.blocked_grids:
                row.append(right)
            else:
                break
        # Move up while we can
        while True:
            next_row = [x+vector3d(0,1,0) for x in row]
            for cell in next_row:
                # Can't move if any cell is not in the pin shape 
                if cell not in self.grids or cell in self.router.blocked_grids:
                    break
            else:
                row = next_row
                # Skips the second break
                continue
            # Breaks from the nested break
            break

        # Add a shape from ll to ur
        ur = row[-1]
        return (ll,ur)

    
    def enclose_pin(self):
        """
        This will find the biggest rectangle enclosing some grid squares and
        put a rectangle over it. It does not enclose grid squares that are blocked
        by other shapes.
        """
        # Compute the enclosure pin_layout list of the set of tracks
        enclosure_list = self.compute_enclosures()
        self.enclosure = self.find_smallest_overlapping(enclosure_list)
        if not self.enclosure:
            self.enclosure = self.find_smallest_connector(enclosure_list)
        debug.info(2,"Computed enclosure {0} {1}".format(self.name, self.enclosure))  
            
    def add_enclosure(self, cell):
        """
        Add the enclosure shape to the given cell.
        """
        debug.info(2,"Adding enclosure {0} {1}".format(self.name, self.enclosure))  
        self.router.cell.add_rect(layer=self.enclosure.layer,
                                  offset=self.enclosure.ll(),
                                  width=self.enclosure.width(),
                                  height=self.enclosure.height())