from __future__ import annotations
import json
from os import X_OK, PathLike
import os
from typing import Optional, Union
import shelve
from pydub import AudioSegment
import svgwrite
import tempfile
import io
import logging

logger = logging.getLogger('svganim.strokes')


class Annotation:
    def __init__(self, tag: str, drawing: Drawing, t_in: float, t_out: float) -> None:
        self.tag = tag
        self.t_in = t_in
        self.t_out = t_out
        self.drawing = drawing

    @property
    def id(self) -> str:
        return f'{self.drawing.id}:{self.tag}:{self.t_in}:{self.t_out}'

    def getAnimationSlice(self) -> AnimationSlice:
        return self.drawing.get_animation().getSlice(self.t_in, self.t_out)

    def get_as_svg(self) -> str:
        return self.getAnimationSlice().get_as_svg()


Filename = Union[str, bytes, PathLike[str], PathLike[bytes]]


class Drawing:
    def __init__(self, filename: Filename, metadata_dir: Filename, basedir: Filename) -> None:
        self.eventfile = filename
        self.id = os.path.splitext(os.path.basename(self.eventfile))[0]
        self.metadata_fn = os.path.join(metadata_dir, f"{self.id}.json")
        self.basedir = basedir

    def get_url(self) -> str:
        return f"/files/{self.id}"

    def get_annotations_url(self) -> str:
        return f"/annotations/{self.id}"

    def get_canvas_metadata(self) -> list:
        logger.info(f'metadata for {self.id}')
        with open(self.eventfile, "r") as fp:
            first_line = fp.readline().strip()

        if first_line.endswith(","):
            first_line = first_line[:-1]
        data = json.loads(first_line)
        return {
            "date": data[0],
            "dimensions": {
                "width": data[1],
                "height": data[2],
            },
        }

    def get_audio(self) -> Optional[AudioSlice]:
        md = self.get_metadata()
        if 'audio' not in md:
            return None
        if 'file' not in md['audio']:
            return None

        return AudioSlice(filename=os.path.join(self.basedir, md['audio']['file'][1:]), offset=md['audio']['offset']*1000)

    def get_animation(self) -> AnimationSlice:
        # with open(self.eventfile, "r") as fp:
        strokes = []
        with open(self.eventfile, "r") as fp:
            events = json.loads("[" + fp.read() + "]")
            for i, event in enumerate(events):
                if i == 0:
                    # metadata on first line
                    pass
                else:
                    if type(event) is list:
                        # ignore double metadatas, which appear when continuaing an existing drawing
                        continue

                    if event["event"] == "viewbox":
                        pass
                    if event["event"] == "stroke":
                        # points = []
                        # for i in range(int(len(stroke) / 4)):
                        #     p =  stroke[i*4:i*4+4]
                        #     points.append([float(p[0]), float(p[1]), int(p[2]), float(p[3])])
                        strokes.append(
                            Stroke(
                                event["color"],
                                [Point.fromTuple(tuple(p))
                                 for p in event["points"]],
                            )
                        )
        return AnimationSlice(strokes, audioslice=self.get_audio())

    def get_metadata(self):
        canvas = self.get_canvas_metadata()
        if os.path.exists(self.metadata_fn):
            with open(self.metadata_fn, "r") as fp:
                metadata = json.load(fp)
        else:
            metadata = {}
        metadata["canvas"] = canvas
        return metadata

    def get_absolute_viewbox(self) -> Viewbox:
        return self.get_animation().get_bounding_box()


class Viewbox:
    def __init__(self, x: float, y: float, width: float, height: float):
        self.x = x
        self.y = y
        self.width = width
        self.height = height

    def __str__(self) -> str:
        return f"{self.x} {self.y} {self.width} {self.height}"


FrameIndex = tuple[int, int]


class AnimationSlice:
    # either a whole drawing or the result of applying an annotation to a drawing (an excerpt)
    # TODO rename to AnimationSlice to include audio as well
    def __init__(
        self, strokes: list[Stroke], t_in: float = 0, t_out: float = None, audioslice: AudioSlice = None
    ) -> None:
        self.strokes = strokes
        self.t_in = t_in
        self.t_out = t_out
        self.audio = audioslice
        # TODO: Audio

    def get_bounding_box(self) -> Viewbox:
        min_x, max_x = float("inf"), float("-inf")
        min_y, max_y = float("inf"), float("-inf")

        for s in self.strokes:
            for p in s.points:
                if p.x < min_x:
                    min_x = p.x
                if p.x > max_x:
                    max_x = p.x
                if p.y < min_y:
                    min_y = p.y
                if p.y > max_y:
                    max_y = p.y
        return Viewbox(min_x, min_y, max_x - min_x, max_y - min_y)

    def getSlice(self, t_in: float, t_out: float) -> AnimationSlice:
        frame_in = self.getIndexForInPoint(t_in)
        frame_out = self.getIndexForOutPoint(t_out)
        strokes = self.getStrokeSlices(frame_in, frame_out)
        audio = self.audio.getSlice(t_in, t_out) if self.audio else None
        return AnimationSlice(strokes, t_in, t_out, audio)

    def get_as_svg_dwg(self) -> svgwrite.Drawing:
        box = self.get_bounding_box()
        (_, fn) = tempfile.mkstemp(suffix='.svg', text=True)
        dwg = svgwrite.Drawing(fn, size=(box.width, box.height))
        dwg.viewbox(box.x, box.y, box.width, box.height)
        self.add_to_dwg(dwg)
        return dwg

    def get_as_svg(self) -> str:
        dwg = self.get_as_svg_dwg()
        fp = io.StringIO()
        dwg.write(fp, pretty=True)
        return fp.getvalue()

    def add_to_dwg(self, dwg: SvgDrawing):
        group = svgwrite.container.Group()
        for stroke in self.strokes:
            stroke.add_to_dwg(group)
        dwg.add(group)

    def getStrokeSlices(
        self, index_in: FrameIndex, index_out: FrameIndex
    ) -> list[Stroke]:
        """Get list of Stroke/StrokeSlice based in in and out indexes
        Based on annotation.js getStrokesSliceForPathRange(in_point, out_point)
        """
        slices = []
        for i in range(index_in[0], index_out[0] + 1):
            try:
                stroke = self.strokes[i]
            except IndexError:
                # out point can be Infinity. So interrupt whenever the end is reached
                break

            in_i = index_in[1] if index_in[0] == i else 0
            out_i = index_out[1] if index_out[0] == i else len(
                stroke.points) - 1

            slices.append(StrokeSlice(stroke, in_i, out_i))
        return slices

    def getIndexForInPoint(self, ms) -> FrameIndex:
        """Get the frame index (path, point) based on the given time
        The In point version (so the first index after ms)
        Equal to annotations.js findPositionForTime(ms)
        """
        path_i = 0
        point_i = 0
        for i, stroke in enumerate(self.strokes):
            start_at = stroke.points[0].t
            end_at = stroke.points[-1].t
            if end_at < ms:
                # certainly not the right point yet
                continue
            if start_at > ms:
                path_i = i
                point_i = 0
                break  # too far, so this is the first point after in point
            else:
                # our in-point is inbetween first and last of the stroke
                # we are getting close, find the right point_i
                path_i = i
                for pi, point in enumerate(stroke.points):
                    point_i = pi
                    if point.t > ms:
                        break  # stop when finding the next point after in point
                break  # done :-)
        return (path_i, point_i)

    def getIndexForOutPoint(self, ms) -> FrameIndex:
        """Get the frame index (path, point) based on the given time
        The Out point version (so the last index before ms)
        Equal to annotations.js findPositionForTime(ms)
        """
        return self.getIndexForTime( ms)

    def getIndexForTime(self, ms) -> FrameIndex:
        """Get the frame index (path, point) based on the given time
        Equal to annotations.js findPositionForTime(ms)
        """
        path_i = 0
        point_i = 0
        for i, stroke in enumerate(self.strokes):
            start_at = stroke.points[0].t
            end_at = stroke.points[-1].t

            if start_at > ms:
                break  # too far
            if end_at > ms:
                # we are getting close, find the right point_i
                path_i = i
                for pi, point in enumerate(stroke.points):
                    if point.t > ms:
                        break  # too far
                    point_i = pi
                break  # done :-)
            else:
                # in case this is our last path, stroe this as
                # best option thus far
                path_i = i
                point_i = len(stroke.points) - 1
        return (path_i, point_i)


class AudioSlice:
    def __init__(self, filename: Filename, t_in: float = None, t_out: float = None, offset: float = None):
        self.filename = filename
        self.t_in = t_in  # in ms
        self.t_out = t_out  # in ms
        self.offset = offset  # in ms

    def getSlice(self, t_in: float, t_out: float) -> AnimationSlice:
        return AudioSlice(self.filename, t_in, t_out, self.offset)

    def export(self, format="mp3"):
        """Returns file descriptor of tempfile"""
        # Opening file and extracting segment
        song = AudioSegment.from_file(self.filename)
        start = self.t_in - self.offset
        end = self.t_out - self.offset

        if start < 0 and end < 0:
            extract = AudioSegment.silent(
                duration=end-start, frame_rate=song.frame_rate)
        else:
            if start < 0:
                preroll = AudioSegment.silent(
                    duration=start * -1, frame_rate=song.frame_rate)
                start = 0
            else:
                preroll = None
            if end > len(song):
                postroll = AudioSegment.silent(
                    duration=end - len(song), frame_rate=song.frame_rate)
                end = len(song) - 1
            else:
                postroll = None

            extract = song[start: end]
            if preroll:
                extract = preroll + extract
            if postroll:
                extract += postroll

        # Saving
        return extract.export(None, format=format)


class AnnotationIndex:
    def __init__(
        self, filename: Filename, drawing_dir: Filename, metadata_dir: Filename
    ) -> None:
        self.filename = filename
        self.drawing_dir = drawing_dir
        self.metadata_dir = metadata_dir

        # disable disk cache because of glitches shelve.open(filename, writeback=True)
        self.shelve = {}

    def refresh(self):
        # reset the index
        for key in list(self.shelve.keys()):
            print(key)
            del self.shelve[key]

        self.shelve["_drawings"] = {
            d.id: d
            for d in [
                Drawing(fn, self.metadata_dir, self.drawing_dir) for fn in self.get_drawing_filenames()
            ]
        }
        self.shelve['_tags'] = {}
        self.shelve['_annotations'] = {}

        drawing: Drawing
        for drawing in self.shelve['_drawings'].values():
            meta = drawing.get_metadata()
            if 'annotations' not in meta:
                continue
            for ann in meta['annotations']:
                annotation = Annotation(
                    ann['tag'], drawing, ann['t_in'], ann['t_out'])
                self.shelve['_annotations'][annotation.id] = annotation
                if annotation.tag not in self.shelve['_tags']:
                    self.shelve['_tags'][annotation.tag] = [annotation]
                else:
                    self.shelve['_tags'][annotation.tag].append(
                        annotation
                    )

    @property
    def drawings(self) -> dict[str, Drawing]:
        return self.shelve["_drawings"]

    @property
    def tags(self) -> dict[str, list[Annotation]]:
        return self.shelve["_tags"]

    @property
    def annotations(self) -> dict[str, Annotation]:
        return self.shelve["_annotations"]

    def get_annotations(self, tag) -> list[Annotation]:
        if tag not in self.tags:
            return []
        return self.tags[tag]

    def get_drawing_names(self) -> list[str]:
        return [
            name[:-16]
            for name in os.listdir(self.drawing_dir)
            if name.endswith("json_appendable") and os.stat(os.path.join(self.drawing_dir, name)).st_size > 0
        ]

    def get_drawing_filenames(self) -> list[Filename]:
        return [
            os.path.join(self.drawing_dir, f"{name}.json_appendable")
            for name in self.get_drawing_names()
        ]

    def __del__(self):
        self.shelve.close()


# Point = tuple[float, float, float]


class Point:
    def __init__(self, x: float, y: float, last: bool, t: float):
        self.x = float(x)
        self.y = float(y)  # if y == 0 it can still be integer.... odd python
        self.last = last
        self.t = t

    @classmethod
    def fromTuple(cls, p: tuple[float, float, int, float]):
        return cls(p[0], p[1], bool(p[2]), p[3])

    def scaledToFit(self, dimensions: dict[str, float]) -> Point:
        # TODO: change so that it actually scales to FIT dimensions
        return Point(self.x, self.y, self.last, self.t)


Points = list[Point]
SvgDrawing = Union[svgwrite.container.SVG, svgwrite.container.Group]


class Stroke:
    def __init__(self, color: str, points: Points) -> None:
        self.color = color
        self.points = points

    def add_to_dwg(self, dwg: SvgDrawing):
        path = svgwrite.path.Path(d=self.get_as_d()).stroke(
            self.color, 1).fill("none")
        dwg.add(path)

    def get_bounding_box(self) -> Viewbox:
        min_x, max_x = float("inf"), float("-inf")
        min_y, max_y = float("inf"), float("-inf")

        for p in self.points:
            if p.x < min_x:
                min_x = p.x
            if p.x > max_x:
                max_x = p.x
            if p.y < min_y:
                min_y = p.y
            if p.y > max_y:
                max_y = p.y
        return Viewbox(min_x, min_y, max_x - min_x, max_y - min_y)

    def get_as_d(self):
        d = ""
        prev_point = None
        cmd = ""
        for point in self.points:
            if not prev_point:
                # TODO multiply points by scalars for dimensions (height widht of drawing)
                d += f'M{point.x:.6},{point.y:.6} '
                cmd = 'M'
            else:
                if prev_point.last:
                    d += " m"
                    cmd = "m"
                elif cmd != 'l':
                    d += ' l '
                    cmd = 'l'
                diff_point = {
                    "x": point.x - prev_point.x,
                    "y": point.y - prev_point.y,
                }
                # TODO multiply points by scalars for dimensions (height widht of drawing)
                d += f'{diff_point["x"]:.6},{diff_point["y"]:.6} '
            prev_point = point
        return d


class StrokeSlice(Stroke):
    def __init__(self, stroke: Stroke, i_in: int = None, i_out: int = None) -> None:
        self.stroke = stroke
        self.i_in = 0 if i_in is None else i_in
        self.i_out = len(self.stroke.points) - 1 if i_out is None else i_out

    def slice_id(self):
        return f"{self.i_in}-{self.i_out}"

    @property
    def points(self) -> Points:
        return self.stroke.points[self.i_in: self.i_out + 1]

    @property
    def color(self) -> str:
        return self.stroke.color


def strokes2D(strokes):
    # strokes to a d attribute for a path
    d = ""
    last_stroke = None
    cmd = ""
    for stroke in strokes:
        if not last_stroke:
            d += f"M{stroke[0]},{stroke[1]} "
            cmd = 'M'
        else:
            if last_stroke[2] == 1:
                d += " m"
                cmd = 'm'
            elif cmd != 'l':
                d += ' l '
                cmd = 'l'

            rel_stroke = [stroke[0] - last_stroke[0],
                          stroke[1] - last_stroke[1]]
            d += f"{rel_stroke[0]},{rel_stroke[1]} "
        last_stroke = stroke
    return d