from collections import defaultdict

from PyQt5.QtGui import QPainter, QColor, QPainterPath, QTransform, QBrush, QPolygonF, QPalette
from PyQt5.QtWidgets import QWidget, QToolTip, QApplication
from PyQt5.QtCore import Qt, QSize, QRect, QPointF, pyqtSignal, QEvent, QRectF

from constants import KEY_SIZE_RATIO, KEY_SPACING_RATIO, KEYBOARD_WIDGET_PADDING, KEYBOARD_WIDGET_MASK_PADDING, KEYBOARD_WIDGET_MASK_HEIGHT


class KeyWidget:

    def __init__(self, desc, scale, shift_x=0, shift_y=0):
        self.active = False
        self.masked = False
        self.desc = desc
        self.text = ""
        self.mask_text = ""
        self.tooltip = ""
        self.color = None
        self.scale = 0

        self.rotation_angle = desc.rotation_angle

        self.has2 = desc.width2 != desc.width or desc.height2 != desc.height or desc.x2 != 0 or desc.y2 != 0

        self.update_position(scale, shift_x, shift_y)

    def update_position(self, scale, shift_x=0, shift_y=0):
        if self.scale != scale or self.shift_x != shift_x or self.shift_y != shift_y:
            self.scale = scale
            size = self.scale * (KEY_SIZE_RATIO + KEY_SPACING_RATIO)
            spacing = self.scale * KEY_SPACING_RATIO

            self.rotation_x = size * self.desc.rotation_x
            self.rotation_y = size * self.desc.rotation_y

            self.shift_x = shift_x
            self.shift_y = shift_y
            self.x = size * self.desc.x
            self.y = size * self.desc.y
            self.w = size * self.desc.width - spacing
            self.h = size * self.desc.height - spacing

            self.rect = QRect(self.x, self.y, self.w, self.h)

            self.x2 = self.x + size * self.desc.x2
            self.y2 = self.y + size * self.desc.y2
            self.w2 = size * self.desc.width2 - spacing
            self.h2 = size * self.desc.height2 - spacing

            self.bbox = self.calculate_bbox(self.rect)
            self.polygon = QPolygonF(self.bbox + [self.bbox[0]])
            self.draw_path = self.calculate_draw_path()
            self.draw_path2 = self.calculate_draw_path2()

            # calculate areas where the inner keycode will be located
            # nonmask = outer (e.g. Rsft_T)
            # mask = inner (e.g. KC_A)
            self.nonmask_rect = QRectF(int(self.x), int(self.y), int(self.w), int(self.h * (1 - KEYBOARD_WIDGET_MASK_HEIGHT)))
            self.mask_rect = QRectF(int(self.x + KEYBOARD_WIDGET_MASK_PADDING), 
                                    int(self.y) + int(self.h * (1 - KEYBOARD_WIDGET_MASK_HEIGHT)),
                                    int(self.w - 2 * KEYBOARD_WIDGET_MASK_PADDING), 
                                    int(self.h * KEYBOARD_WIDGET_MASK_HEIGHT - KEYBOARD_WIDGET_MASK_PADDING) + 1)
            self.mask_bbox = self.calculate_bbox(self.mask_rect)
            self.mask_polygon = QPolygonF(self.mask_bbox + [self.mask_bbox[0]])

    def calculate_bbox(self, rect):
        x1 = rect.topLeft().x()
        y1 = rect.topLeft().y()
        x2 = rect.bottomRight().x()
        y2 = rect.bottomRight().y()
        points = [(x1, y1), (x1, y2), (x2, y2), (x2, y1)]
        bbox = []
        for p in points:
            t = QTransform()
            t.translate(self.shift_x, self.shift_y)
            t.translate(self.rotation_x, self.rotation_y)
            t.rotate(self.rotation_angle)
            t.translate(-self.rotation_x, -self.rotation_y)
            p = t.map(QPointF(p[0], p[1]))
            bbox.append(p)
        return bbox

    def calculate_draw_path(self):
        path = QPainterPath()
        path.addRect(int(self.x), int(self.y), int(self.w), int(self.h))

        # second part only considered if different from first
        if self.has2:
            path2 = QPainterPath()
            path2.addRect(int(self.x2), int(self.y2), int(self.w2), int(self.h2))
            path = path.united(path2)

        return path

    def calculate_draw_path2(self):
        return QPainterPath()

    def setText(self, text):
        self.text = text

    def setMaskText(self, text):
        self.mask_text = text

    def setToolTip(self, tooltip):
        self.tooltip = tooltip

    def setActive(self, active):
        self.active = active

    def setColor(self, color):
        self.color = color


class EncoderWidget(KeyWidget):

    def calculate_draw_path(self):
        path = QPainterPath()
        path.addEllipse(int(self.x), int(self.y), int(self.w), int(self.h))
        return path

    def calculate_draw_path2(self):
        path = QPainterPath()
        if self.desc.encoder_dir == 0:
            path.moveTo(int(self.x), int(self.y + self.h / 2))
            path.lineTo(int(self.x - self.w / 5), int(self.y + self.h / 3))
            path.moveTo(int(self.x), int(self.y + self.h / 2))
            path.lineTo(int(self.x + self.w / 5), int(self.y + self.h / 3))
        else:
            path.moveTo(int(self.x), int(self.y + self.h / 2))
            path.lineTo(int(self.x - self.w / 5), int(self.y + self.h - self.h / 3))
            path.moveTo(int(self.x), int(self.y + self.h / 2))
            path.lineTo(int(self.x + self.w / 5), int(self.y + self.h - self.h / 3))
        return path


class KeyboardWidget(QWidget):

    clicked = pyqtSignal()
    anykey = pyqtSignal()

    def __init__(self, layout_editor):
        super().__init__()

        self.enabled = True
        self.scale = 1

        self.setMouseTracking(True)

        self.layout_editor = layout_editor

        # widgets common for all layouts
        self.common_widgets = []

        # layout-specific widgets
        self.widgets_for_layout = []

        # widgets in current layout
        self.widgets = []

        self.width = self.height = 0
        self.active_key = None
        self.active_mask = False

    def set_keys(self, keys, encoders):
        self.common_widgets = []
        self.widgets_for_layout = []

        self.add_keys([(x, KeyWidget) for x in keys] + [(x, EncoderWidget) for x in encoders])
        self.update_layout()

    def add_keys(self, keys):
        scale_factor = self.fontMetrics().height()

        for key, cls in keys:
            if key.layout_index == -1:
                self.common_widgets.append(cls(key, scale_factor))
            else:
                self.widgets_for_layout.append(cls(key, scale_factor))

    def place_widgets(self):
        top_x = top_y = 1e6
        scale_factor = self.fontMetrics().height()

        self.widgets = []

        # find the global top-left position, all the keys will be shifted to the left/up by that position
        for widget in self.common_widgets:
            widget.update_position(scale_factor)
            p = widget.polygon.boundingRect().topLeft()
            top_x = min(top_x, p.x())
            top_y = min(top_y, p.y())

        # place common widgets, that is, ones which are always displayed and require no extra transforms
        for widget in self.common_widgets:
            widget.update_position(scale_factor, -top_x + KEYBOARD_WIDGET_PADDING, -top_y + KEYBOARD_WIDGET_PADDING)
            self.widgets.append(widget)

        # top-left position for specific layout
        layout_x = defaultdict(lambda: defaultdict(lambda: 1e6))
        layout_y = defaultdict(lambda: defaultdict(lambda: 1e6))

        # determine top-left position for every layout option
        for widget in self.widgets_for_layout:
            widget.update_position(scale_factor)
            idx, opt = widget.desc.layout_index, widget.desc.layout_option
            p = widget.polygon.boundingRect().topLeft()
            layout_x[idx][opt] = min(layout_x[idx][opt], p.x())
            layout_y[idx][opt] = min(layout_y[idx][opt], p.y())

        # obtain widgets for all layout options now that we know how to shift them
        for widget in self.widgets_for_layout:
            idx, opt = widget.desc.layout_index, widget.desc.layout_option
            if opt == self.layout_editor.get_choice(idx):
                shift_x = layout_x[idx][opt] - layout_x[idx][0]
                shift_y = layout_y[idx][opt] - layout_y[idx][0]
                widget.update_position(scale_factor, -shift_x - top_x + KEYBOARD_WIDGET_PADDING, -shift_y - top_y + KEYBOARD_WIDGET_PADDING)
                self.widgets.append(widget)

    def update_layout(self):
        """ Updates self.widgets for the currently active layout """

        # determine widgets for current layout
        self.place_widgets()
        self.widgets = list(filter(lambda w: not w.desc.decal, self.widgets))

        self.widgets.sort(key=lambda w: (w.y, w.x))

        # determine maximum width and height of container
        max_w = max_h = 0
        for key in self.widgets:
            p = key.polygon.boundingRect().bottomRight()
            max_w = max(max_w, p.x() * self.scale)
            max_h = max(max_h, p.y() * self.scale)

        self.width = max_w + 2 * KEYBOARD_WIDGET_PADDING
        self.height = max_h + 2 * KEYBOARD_WIDGET_PADDING

        self.update()
        self.updateGeometry()

    def paintEvent(self, event):
        qp = QPainter()
        qp.begin(self)
        qp.setRenderHint(QPainter.Antialiasing)

        # for regular keycaps
        regular_pen = qp.pen()
        regular_pen.setColor(QApplication.palette().color(QPalette.ButtonText))
        qp.setPen(regular_pen)

        regular_brush = QBrush()
        regular_brush.setColor(QApplication.palette().color(QPalette.Button))
        regular_brush.setStyle(Qt.SolidPattern)
        qp.setBrush(regular_brush)

        # for currently selected keycap
        active_pen = qp.pen()
        active_pen.setColor(QApplication.palette().color(QPalette.HighlightedText))

        active_brush = QBrush()
        active_brush.setColor(QApplication.palette().color(QPalette.Highlight))
        active_brush.setStyle(Qt.SolidPattern)

        mask_font = qp.font()
        mask_font.setPointSize(mask_font.pointSize() * 0.8)

        for idx, key in enumerate(self.widgets):
            qp.save()

            qp.scale(self.scale, self.scale)
            qp.translate(key.shift_x, key.shift_y)
            qp.translate(key.rotation_x, key.rotation_y)
            qp.rotate(key.rotation_angle)
            qp.translate(-key.rotation_x, -key.rotation_y)

            active = key.active or (self.active_key == key and not self.active_mask)
            if active:
                qp.setPen(active_pen)
                qp.setBrush(active_brush)

            # draw the keycap
            qp.drawPath(key.draw_path)
            qp.strokePath(key.draw_path2, regular_pen)

            # if this is a mask key, draw the inner key
            if key.masked:
                qp.setFont(mask_font)
                qp.save()
                if key.color is not None and not active:
                    qp.setPen(key.color)
                qp.drawText(key.nonmask_rect, Qt.AlignCenter, key.text)
                qp.restore()

                if self.active_key == key and self.active_mask:
                    qp.setPen(active_pen)
                    qp.setBrush(active_brush)

                qp.drawRect(key.mask_rect)
                if key.color is not None and not active:
                    qp.setPen(key.color)
                qp.drawText(key.mask_rect, Qt.AlignCenter, key.mask_text)
            else:
                # draw the legend
                if key.color is not None and not active:
                    qp.setPen(key.color)
                qp.drawText(key.rect, Qt.AlignCenter, key.text)

            qp.restore()

        qp.end()

    def minimumSizeHint(self):
        return QSize(self.width, self.height)

    def hit_test(self, pos):
        """ Returns key, hit_masked_part """

        for key in self.widgets:
            if key.masked and key.mask_polygon.containsPoint(pos, Qt.OddEvenFill):
                return key, True
            if key.polygon.containsPoint(pos, Qt.OddEvenFill):
                return key, False

        return None, False

    def mousePressEvent(self, ev):
        if not self.enabled:
            return

        self.active_key, self.active_mask = self.hit_test(ev.pos())
        if self.active_key is not None:
            self.clicked.emit()
        self.update()

    def resizeEvent(self, ev):
        self.update_layout()

    def select_next(self):
        """ Selects next key based on their order in the keymap """

        keys_looped = self.widgets + [self.widgets[0]]
        for x, key in enumerate(keys_looped):
            if key == self.active_key:
                self.active_key = keys_looped[x + 1]
                self.active_mask = False
                self.clicked.emit()
                return

    def deselect(self):
        if self.active_key is not None:
            self.active_key = None
            self.update()

    def event(self, ev):
        if not self.enabled:
            super().event(ev)

        if ev.type() == QEvent.ToolTip:
            key = self.hit_test(ev.pos())[0]
            if key is not None:
                QToolTip.showText(ev.globalPos(), key.tooltip)
            else:
                QToolTip.hideText()
        elif ev.type() == QEvent.LayoutRequest:
            self.update_layout()
        elif ev.type() == QEvent.MouseButtonDblClick and self.active_key:
            self.anykey.emit()
        return super().event(ev)

    def set_enabled(self, val):
        self.enabled = val

    def set_scale(self, scale):
        self.scale = scale