# -*- coding: utf-8 -*-

'''layout module

VerticalLayout

HorizontalLayout

TableLayout

'''

import math

from tuikit.common import Rect

class Layout:

    def __init__(self):

        self._container = None

    @property

    def container(self):

        return self._container

    @container.setter

    def container(self, value):

        self._container = value

    def _on_container_resize(self, ev):

        self.resize()

    def _getchildren(self):

        return [child for child in self.container.children

            if child.allow_layout and not child.hidden]

    def _getregion(self):

        c = self.container

        bl, bt, br, bb = c.borders

        return Rect(bl, bt, c.width - bl - br, c.height - bt - bb)

class LinearLayout(Layout):

    def __init__(self, homogeneous=False, spacing=0):

        super().__init__()

        self.homogeneous = homogeneous

        self.spacing = spacing

    def _resize(self, ax1, ax2):

        children = self._getchildren()

        c = self.container

        b1 = c.borders[ax1]

        b2 = c.borders[ax2]

        # available space

        space1 = c.size[ax1] - b1 - c.borders[ax1+2]

        space2 = c.size[ax2] - b2 - c.borders[ax2+2]

        # all space minus spacing

        space_to_divide = space1 - (len(children) - 1) * self.spacing

        if not self.homogeneous:

            # reduce by space acquired by children

            space_to_divide -= sum([child.sizereq[ax1] for child in children])

            # number of children with expanded hint

            expanded_num = len([ch for ch in children if ch.hint('expand')])

        else:

            # all children are implicitly expanded

            expanded_num = len(children)

        if expanded_num:

            # reserved space for each expanded child

            space_child = space_to_divide / expanded_num

        offset = 0.

        for child in children:

            child.position[ax1] = b1 + int(offset)

            child.position[ax2] = b2

            child.size[ax1] = child.sizereq[ax1]

            child.size[ax2] = space2

            if child.hint('expand') or self.homogeneous:

                maxsize = int(round(space_child + math.modf(offset)[0], 2))

                offset += space_child + self.spacing

                if not self.homogeneous:

                    maxsize += child.sizereq[ax1]

                    offset += child.sizereq[ax1]

                if child.hint('fill'):

                    child.size[ax1] = maxsize

                else:

                    child.position[ax1] += int((maxsize - child.size[ax1])/2)

            else:

                offset += child.size[ax1]

            child.emit('resize')

        c.redraw()

class VerticalLayout(LinearLayout):

    def resize(self):

        ax1 = 1 # primary dimension - y

        ax2 = 0 # secondary dimension - x

        self._resize(ax1, ax2)

class HorizontalLayout(LinearLayout):

    def resize(self):

        ax1 = 0 # primary dimension - x

        ax2 = 1 # secondary dimension - y

        self._resize(ax1, ax2)

class GridLayout(Layout):

    def __init__(self, numcols=2):

        super().__init__()

        self.numcols = numcols

    def _fillgrid(self):

        ''' fill grid with widgeds '''

        self._grid = []

        rown = 0

        coln = 0

        for child in self._getchildren():

            if coln == 0:

                row = []

                for _i in range(self.numcols):

                    row.append({'widget': None, 'colspan': 0, 'rowspan': 0})

            colspan = 1

            if 'colspan' in child.hints:

                colspan = child.hints['colspan']

            colspan = min(colspan, self.numcols - coln + 1)

            row[coln]['widget'] = child

            row[coln]['colspan'] = colspan

            coln += colspan

            if coln >= self.numcols:

                coln = 0

                self._grid.append(row)

                rown += 1

        # autospan last child

        if coln > 0:

            row[coln-1]['colspan'] = self.numcols - coln + 1

            self._grid.append(row)

    def _computesizes(self):

        self._colminw = [0] * self.numcols

        # compute min column width for all widgets with colspan = 1

        for row in self._grid:

            for coln in range(self.numcols):

                w = row[coln]['widget']

                if row[coln]['colspan'] == 1:

                    self._colminw[coln] = max(w.sizemin[0], self._colminw[coln])

        # adjust min width for widgets with colspan > 1

        for row in self._grid:

            for coln in range(self.numcols):

                w = row[coln]['widget']

                colspan = row[coln]['colspan']

                if colspan > 1:

                    # find min width over spanned columns

                    totalminw = 0

                    for i in range(colspan):

                        totalminw += self._colminw[coln + i]

                    # check if spanned widget fits in

                    if w.sizemin[0] > totalminw:

                        # need to adjust colminw

                        addspace = w.sizemin[0] - totalminw

                        addall = addspace // colspan

                        rest = addspace % colspan

                        for i in range(colspan):

                            self._colminw[coln + i] += addall

                            if i < rest:

                                self._colminw[coln + i] += 1

        self._rowminh = [0] * len(self._grid)

        rown = 0

        for row in self._grid:

            for col in row:

                w = col['widget']

                if w is not None:

                    self._rowminh[rown] = max(self._rowminh[rown], w.sizemin[1])

            rown += 1

        self._gridminw = sum(self._colminw)

        self._gridminh = sum(self._rowminh)

    def resize(self):

        self._fillgrid()

        self._computesizes()

        # enlarge container if needed

        lreg = self._getregion() # layout region

        cont = self.container

        bl, bt, br, bb = cont.borders

        if self._gridminw > lreg.w:

            cont.width = self._gridminw + bl + br

        if self._gridminh > lreg.h:

            cont.height = self._gridminh + bt + bb

        # compute actual width of columns

        colw = [0] * self.numcols

        lreg = self._getregion() # layout region

        restw = lreg.w - self._gridminw

        resth = lreg.h - self._gridminh

        for c in range(self.numcols):

            colw[c] = self._colminw[c] + restw // self.numcols

            if c < restw % self.numcols:

                colw[c] += 1

        # place widgets

        colx = lreg.x

        coly = lreg.y

        rown = 0

        numrows = len(self._grid)

        for row in self._grid:

            coln = 0

            rowh = self._rowminh[rown] + resth // numrows

            if rown < resth % numrows:

                rowh += 1

            for col in row:

                w = col['widget']

                if w is not None:

                    w.x = colx

                    w.y = coly

                    w.width = colw[coln]

                    w.height = rowh

                    w.emit('resize')

                    colspan = col['colspan']

                    if colspan > 1:

                        for i in range(1,colspan):

                            w.width += colw[coln + i]

                colx += colw[coln]

            rown += 1

            colx = lreg.x

            coly += rowh

        cont.redraw()