# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

import uuid
import svgwrite
from svgwrite.filters import Filter

from lvestats.lib.chart.util import frange, xfrange, X_LEGEND_POINTS, Y_LEGEND_POINTS


class SvgChart(object):
    def __init__(self):
        self.dwg = svgwrite.Drawing()
        self.padding_y = 20
        self.width = 480
        self.height = 120
        self.left_legend_width = 55
        self.graph_offset_y = 0
        self._svg_id = 0
        self.x_legend_points = X_LEGEND_POINTS
        self.y_legend_points = Y_LEGEND_POINTS
        self.font_size = 10
        self.point_radius = 2

        self.dwg.update({'width': self.width + 2 * self.left_legend_width + 40})

        defs = self.dwg.defs
        # defs.add(self.dwg.style('.line:hover {stroke-width: 5;}'))
        # TODO make tips with background
        # TODO let tips show and disappear with animate effect

        script = """
                                     function show_tip(evt, svg_id, x1, y1, x2, y2, t1, v1, t2, v2){
                                        var rootDocument = evt.target.ownerDocument;

                                        var tip_group = rootDocument.getElementById('tip_group');
                                        var tip_text = rootDocument.getElementById('tip_text');
                                        var tip_rect = rootDocument.getElementById('tip_rect');

                                        var svgDocument = rootDocument.getElementById(svg_id);
                                        var y_offset = parseInt(svgDocument.getAttribute("y"));

                                        var x = evt.layerX;
                                        var y;
                                        var v;
                                        var t;

                                        if (x< x1+((x2-x1)/2)) {
                                            x = x1;
                                            y = y1 + y_offset;
                                            v = v1;
                                            t = t1;
                                        } else {
                                            x = x2;
                                            y = y2 + y_offset;
                                            v = v2;
                                            t = t2;
                                        }

                                        tip_text.firstChild.data = t +', ' + v;
                                        var width = tip_text.getComputedTextLength();

                                        tip_rect.setAttribute("x",x - ((width+10) / 2));
                                        tip_rect.setAttribute("y",y - 25);
                                        tip_rect.setAttribute("width",width + 10);

                                        tip_text.setAttribute("x",x - (width / 2));
                                        tip_text.setAttribute("y",y - 25 + %font_size%);
                                        tip_text.setAttribute("width",width);

                                        tip_group.setAttribute("visibility","visible");
                                     }"""
        defs.add(self.dwg.script(content=script.replace('%font_size%', str(self.font_size))))

        filters = Filter()
        shadow_filter = defs.add(self.dwg.filter(id="shadow", x=0, y=0, width="200%", height="200%"))
        shadow_filter.add(filters.feOffset("SourceAlpha", result="offOut", dx=5, dy=5))
        shadow_filter.add(filters.feGaussianBlur("offOut", result="blurOut", stdDeviation="10"))
        shadow_filter.add(filters.feBlend("SourceGraphic", in2="blurOut", mode="normal"))

    def _finalize(self):
        tip = self.dwg.add(self.dwg.g(id_='tip_group', visibility='hidden', style='pointer-events: none;'))
        tip.add(self.dwg.rect(
            id_='tip_rect',
            insert=(0, 0),
            size=(20, self.font_size * 1.5),
            rx=2,
            ry=2,
            stroke='black',
            fill='yellow',
        ))
        tip.add(self.dwg.text('T', id_='tip_text', insert=(0, 0), font_size=self.font_size))

    def add_graph(self,
                  datasets,
                  colors,
                  title=None,
                  minimum_y=None,
                  maximum_y=None,
                  x_legend=None,
                  x_legend_generate=None,
                  y_legend=None,
                  y_legend_converter=lambda v: v,
                  x_legend_converter=lambda v: v,
                  names=None,
                  unit=None,
                  message=None,
                  fault_lines=None,
                  fault_color="red"):
        """
        :param datasets: list of datasets. each dataset is list of tuples [(x, y), (x, y) ... ]
        :param colors: list of html-like color strings, for ex: ['red', 'green', '#FFAAED'], for each of the dataset
        :param title: name of the graph
        :param minimum_y: minimum value for dataset's values
        :param maximum_y: maximum value for dataset's values
        :param names: list of dataset names. If provided, then it's used for legend
        :param x_legend: if provided then it's used as titles for x axis
        :param x_legend_generate: if provided and x_legend is not provided, then using x_legend_converter generate
               up to x_legend_generate marks
        :param x_legend_converter: function to convert x values to x_legend values.
        :param y_legend: if provided then it's used as titles for y axis
        :param y_legend_converter: if y_legend is not provided, it is generated from range(min_y, max_y). Converter can
               be applied to make it look better. For example sizeutil.convert_bytes
        :param unit: if provided, then it's used as suffix for y values
        :param message: if provided, the graph will contain the text message in the middle, like "No faults" or
               "No data"
        :param fault_lines: LVES-602. If provided, the graph will contain vertical lines from average to limit
        :param fault_color: LVES-602. Color of the fault lines
        :type fault_lines: list[tuple[(float, float)]]
        :type fault_color: str

        >>> svgchart = SvgChart()
        >>> d1 = [(0,1), (1,1.5), (4,2), (5,6), (5.1,6), (5.6,6), (9,3), (10,10)]
        >>> d2 = [(0,0), (1.5,1.5), (2,2), (2.5,3), (3,4), (5,4), (7,3), (8,2), (9,1), (10,1)]
        >>> datasets = [d1, d2]
        >>> colors = ['red', 'green']
        >>> names = ['foo', 'bar']
        >>> svgchart.add_graph(datasets, colors, 0, 10, unit='DD', names=names)
        >>> svgchart.add_graph(datasets, colors, 0, 10, x_legend=[1,2,3,4,5,6,7,8,9], unit='Kg', message="No Faults")
        >>> print svgchart.dump()
        >>> svgchart.save('/tmp/1.svg')
        """
        average_names = ['average', 'database']
        # random suffix to distinguish svg's from each other
        suffix = self._gen_suffix()

        try:
            if minimum_y is None:
                minimum_y = min(min((y for (_, y) in dataset)) for dataset in datasets)
            if maximum_y is None:
                maximum_y = max(max((y for (_, y) in dataset)) for dataset in datasets)

            maximum_x = max(max((x for (x, _) in dataset)) for dataset in datasets)
            minimum_x = min(min((x for (x, _) in dataset)) for dataset in datasets)
        except ValueError:
            maximum_x = 0
            minimum_x = 0
            minimum_y = 0
            maximum_y = 0
            datasets = [[] for _ in datasets]

        y_offset = self.height / 20.0

        # Create values for y-axis
        if not y_legend:
            dy = (maximum_y - minimum_y) / self.y_legend_points
            y_legend = [y_legend_converter(y) for y in frange(minimum_y, maximum_y + dy, dy)]

        if not y_legend:
            y_legend = ['0' + (unit or '')]

        if not x_legend:
            pattern_width = self.width // self.x_legend_points
        else:
            pattern_width = (1.0 * self.width) // (len(x_legend) - 1)

        if len(y_legend) > 1:
            pattern_height = (1.0 * self.height - 2 * y_offset) // (len(y_legend) - 1)
        else:
            pattern_height = self.height // 2.0

        svg_id = f'svg-{suffix}'
        svg = self.dwg.add(self.dwg.svg(id_=svg_id, insert=(0, self.graph_offset_y)))

        defs = svg.defs
        clippath = defs.add(self.dwg.clipPath(id=f'cut_lines_{suffix}'))
        clippath.add(self.dwg.rect(insert=(self.left_legend_width, self.padding_y), size=(self.width, self.height)))

        if title:
            svg.add(self.dwg.text(title, insert=(self.left_legend_width, self.font_size), font_size=self.font_size))

        self._draw_y_legend(svg, y_legend, unit, pattern_height, y_offset)

        lines_group = svg.add(self.dwg.g(id='lines', filter="url(#shadow)"))
        boundary = lines_group.add(self.dwg.g(clip_path=f'url(#cut_lines_{suffix})'))
        boundary.add(self.dwg.rect(insert=(self.left_legend_width, self.padding_y),
                                   size=(self.width + 1, self.height + 1),
                                   fill='white', stroke="black"))

        self._draw_grid(boundary, pattern_height, pattern_width, y_offset)

        lines = []
        # circles = []

        # list of activity for of lines from average_names
        is_average_empty = []
        if maximum_y - minimum_y > 0:
            for dataset, color in list(zip(datasets, colors)):
                coords = self.convert_coordinates(dataset, maximum_x, maximum_y, minimum_x, minimum_y, y_offset)
                # Shadows removed by ticket LVES-251
                # coords_shadow = [(x + 3, y + 3) for (x, y) in coords]
                # boundary.add(self.dwg.polyline(points=coords_shadow, class_="line_shadow",
                #                               fill='none', stroke='lightgray', stroke_width="2"))

                value = [y for (_, y) in dataset]

                if dict(zip(colors, names))[color] in average_names:
                    is_average_empty.append(names and not any(value))

                # zip coords together with shift by 1, in order to get data like this [(p1, p2), (p2, p3), ...]
                _lines = list(zip(coords, coords[1:]))
                # same as for lines, but for real values, corresponding to that lines
                _datas = list(zip(dataset, dataset[1:]))
                # finally, combine coords and datas
                data_list = list(zip(_lines, _datas))
                for (line, data) in data_list:
                    p1, p2 = line
                    d1, d2 = data
                    x1, y1 = p1
                    x2, y2 = p2
                    t1, v1 = d1
                    t2, v2 = d2

                    # Draw graph line
                    lines.append(
                        self.dwg.line(
                            p1, p2,
                            stroke=color,
                            stroke_width=1,
                            onmousemove=(
                                f"show_tip(evt, '{svg_id}', {x1}, {y1}, {x2}, {y2}, "
                                f"'{x_legend_converter(t1)}', '{str(y_legend_converter(v1)) + (unit or '')}', "
                                f"'{x_legend_converter(t2)}', '{str(y_legend_converter(v2)) + (unit or '')}')"
                            )
                        )
                    )
            if fault_lines is not None:
                for fault_line in fault_lines:
                    fault_coords = self.convert_coordinates(
                        fault_line,
                        maximum_x,
                        maximum_y,
                        minimum_x,
                        minimum_y,
                        y_offset,
                    )
                    lines.append(
                        self.dwg.line(
                            fault_coords[0], fault_coords[1],
                            stroke=fault_color,
                            stroke_width=1))

            # if is_average_empty is empty => no average lines, do not write label
            # all(is_average_empty) == True => all average lines are empty
            # all(is_average_empty) == False => some average line is not empty
            if is_average_empty and all(is_average_empty):
                self._draw_no_activity(boundary)
        else:
            # add ZERO line to graph in no data in dataset
            for color in colors:
                x0, y0 = (self.left_legend_width, self.height - y_offset + self.padding_y)
                x1, y1 = (self.width + self.left_legend_width, y0)
                lines.append(self.dwg.line((x0, y0), (x1, y1), fill='none', stroke=color,
                                           stroke_width='2'),)
                if names and dict(zip(colors, names))[color] in average_names:
                    self._draw_no_activity(boundary)

        for line in lines:
            boundary.add(line)

        self._draw_names(svg, names, colors)

        self.graph_offset_y += self.height + 20 + self.padding_y
        self.dwg.update({'height': self.graph_offset_y})

        if x_legend:
            self._add_x_legend(x_legend)
        if not x_legend and x_legend_generate:
            self._add_x_legend(None, minimum_x, maximum_x, x_legend_generate, x_legend_converter)

        self._draw_message(svg, message)

    def _draw_names(self, svg, names, colors):
        if names:
            s = 10
            i = 0
            font_size = s
            for (name, color) in zip(names, colors):
                x = self.width + self.left_legend_width + 20
                y = 10 + self.padding_y + i * (s + 3)
                svg.add(self.dwg.rect(insert=(x, y), size=(s, s), fill=color, stroke='black'))
                svg.add(self.dwg.text(name, insert=(x + s + 5, y + s), font_size=font_size))
                i += 1

    def _draw_message(self, svg, message):
        if message:
            # Draw message in the middle of the graph
            message_font_size = 24
            svg.add(self.dwg.text(message, insert=(self.left_legend_width + self.width // 3,
                                                   self.padding_y + self.height // 2), font_size=message_font_size))

    def _draw_y_legend(self, svg, y_legend, unit, pattern_height, y_offset):
        ylg = svg.add(self.dwg.g(id='y_legend'))
        i = 0
        font_size = min(self.font_size, pattern_height - 1)
        for legend in y_legend:
            txt = f'{legend}{unit or ""}'
            ylg.add(self.dwg.text(
                txt,
                insert=(5, self.height - y_offset - pattern_height * i + font_size // 2 + self.padding_y),
                font_size=font_size))
            i += 1

    def _draw_grid(self, boundary, pattern_height, pattern_width, y_offset):
        # Draw grid
        # 1. Verticals
        for x in xfrange(0, self.width, pattern_width):
            boundary.add(self.dwg.line(start=(x + self.left_legend_width, self.height + self.padding_y),
                                       end=(x + self.left_legend_width, self.padding_y),
                                       stroke='black', stroke_width=1,
                                       # stroke_linecap="round",
                                       stroke_dasharray="1 2"))
        # 2. Horisontals
        for y in xfrange(0 + y_offset, self.height, pattern_height):
            boundary.add(self.dwg.line(start=(self.left_legend_width, self.height - y + self.padding_y),
                                       end=(self.left_legend_width + self.width, self.height - y + self.padding_y),
                                       stroke='black', stroke_width=1,
                                       stroke_dasharray="1 2"))

    def _draw_no_activity(self, boundary):
        boundary.add(
            self.dwg.text(
                'No activity',
                insert=(
                    self.width // 2 + self.left_legend_width // 2 - len('No activity') // 2,
                    self.height // 2),
                fill='black')
        )

    def convert_coordinates(self, dataset, maximum_x, maximum_y, minimum_x, minimum_y, y_offset):
        """
        :type y_offset: float
        :type minimum_y: float
        :type minimum_x: float
        :type maximum_y: float
        :type maximum_x: float
        :type dataset: tuple
        :rtype: list
        """
        try:
            dx = (1.0 * self.width) / (maximum_x - minimum_x)
        except ZeroDivisionError:
            dx = 0
        dy = (1.0 * self.height - 2 * y_offset) / (maximum_y - minimum_y)
        coords = [
            (
                (x - minimum_x) * dx + self.left_legend_width,
                self.height - y_offset - y * dy + self.padding_y
            )
            for (x, y) in dataset
        ]
        return coords

    @staticmethod
    def _is_peak(data_list, idx, p1, p2):
        result = False

        list_len = len(data_list)
        y2 = p2[1]
        y1 = p1[1]

        if y2 < y1:
            if idx < list_len - 1:
                # Line is not last
                next_line, _ = data_list[idx + 1]
                _, (_, n_y2) = next_line
                if y2 <= n_y2:
                    result = True
            else:
                result = True
        return result

    def _add_x_legend(self, x_values, min_x=None, max_x=None, number=None, x_legend_converter=str):
        # TODO add support of str values of x_values
        if not x_values:
            assert number, "Number should be specified and not zero"
            pattern_width = self.width // number

            if not all(v is not None for v in (min_x, max_x, number)):
                # "min_x, max_x, and number should be not None in order to draw legend"
                return

            x_legend = [x_legend_converter(x) for x in
                        xfrange(min_x, max_x, (max_x - min_x) / number)]
        else:
            if not number:
                number = X_LEGEND_POINTS
            x_legend = frange(min(x_values),
                              max(x_values) + (max(x_values) - min(x_values)) / number,
                              (max(x_values) - min(x_values)) / number)

            x_legend = [x_legend_converter(x) for x in x_legend]

            parts = len(x_legend) - 1
            parts = max(parts, 1)

            pattern_width = (1.0 * self.width) / parts

        svg_id = f'svg-{str(uuid.uuid4())}'
        svg = self.dwg.add(self.dwg.svg(id_=svg_id, insert=(0, self.graph_offset_y)))

        max_x_legend_text = 0
        font_size = min(pattern_width, 10)

        i = 0
        for legend in x_legend:
            txt = str(legend)
            if len(txt) > max_x_legend_text:
                max_x_legend_text = len(txt)

            x = self.left_legend_width + pattern_width * i
            y = 0 + self.padding_y

            svg.add(self.dwg.text(
                txt,
                insert=(x, y),
                font_size=font_size,
                transform=f"rotate(90, {x},{y})"
            ))
            i += 1

        self.graph_offset_y += 20 + max_x_legend_text * font_size
        self.dwg.update({'height': self.graph_offset_y})

    def add_text_box(self, text, font_size=None):
        """
        :param text: text in box
        :param font_size: font size for text
        """
        # use default font size
        font_size = font_size or 24
        # get svg suffix
        suffix = self._gen_suffix()

        svg_id = f'svg-{suffix}'
        svg = self.dwg.add(self.dwg.svg(id_=svg_id, insert=(0, self.graph_offset_y)))

        defs = svg.defs
        clippath = defs.add(self.dwg.clipPath(id=f'cut_lines_{suffix}'))
        clippath.add(self.dwg.rect(insert=(self.left_legend_width, self.padding_y), size=(self.width, self.height)))

        lines_group = svg.add(self.dwg.g(id='lines', filter="url(#shadow)"))
        boundary = lines_group.add(self.dwg.g(clip_path=f'url(#cut_lines_{suffix})'))
        boundary.add(self.dwg.rect(insert=(self.left_legend_width, self.padding_y),
                                   size=(self.width + 1, self.height + 1), fill='white',
                                   stroke="black"))

        svg.add(self.dwg.text(text, insert=(self.left_legend_width + self.width // 3,
                                            self.padding_y + self.height // 2), font_size=font_size))

        self.graph_offset_y += self.height + 20 + self.padding_y
        self.dwg.update({'height': self.graph_offset_y})

    def _gen_suffix(self):
        """
        Generate suffix for graph methods
        random suffix to distinguish svg's from each other
        """
        suffix = str(self._svg_id)
        self._svg_id += 1
        return suffix

    def dump(self):
        self._finalize()
        xml_header = '<?xml version="1.0" encoding="utf-8" ?>\n'
        return xml_header + self.dwg.tostring()

    def save(self, file_name):
        self._finalize()
        self.dwg.saveas(file_name)