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


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:
        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 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)).scaled(self.get_canvas_metadata()['dimensions']) 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.getIndexForTime(t_in)
        frame_out = self.getIndexForTime(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 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:
                        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

        self.shelve = shelve.open(filename, writeback=True)

    def refresh(self):
        # reset the index
        for key in self.shelve:
            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")
        ]

    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 = x
        self.y = y
        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 scaled(self, dimensions: dict[str, float]) -> Point:
        return Point(self.x*dimensions['width'], self.y * dimensions['height'], 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