from queue import Full, Empty
from threading import Thread

from PIL import Image
import os
from multiprocessing import Value, Process
from queue import Queue
import ffmpeg
import config

if config.cairosvg:
    import cairosvg


class ThumbnailGenerator:

    def __init__(self, size, quality=85, color="FF00FF"):
        self.size = (size, size)
        self.quality = quality
        self.color = tuple(bytes.fromhex(color))

    def generate(self, path, dest_path, mime):

        if mime is None:
            return

        tmpfile = dest_path + "_tmp"
        if mime == "image/svg+xml" and config.cairosvg:

            try:
                p = Process(target=cairosvg.svg2png, kwargs={"url": path, "write_to": tmpfile})
                p.start()
                p.join(5)

                if p.is_alive():
                    p.terminate()
                    print("Timed out: " + path)
                else:
                    self.generate_image(tmpfile, dest_path)
            except Exception:
                print("Couldn't make thumbnail for " + path)

            if os.path.exists(tmpfile):
                os.remove(tmpfile)

        elif mime.startswith("image"):

            try:
                self.generate_image(path, dest_path)
            except Exception:
                print("Couldn't make thumbnail for " + path)

        elif mime.startswith("video"):
            try:
                (ffmpeg.
                 input(path)
                 .output(tmpfile, vframes=1, f="image2", loglevel="error")
                 .run()
                 )
                self.generate_image(tmpfile, dest_path)
            except Exception:
                print("Couldn't make thumbnail for " + path)

            if os.path.exists(tmpfile):
                os.remove(tmpfile)

    def worker(self, in_q: Queue, counter: Value, dest_path, directory):

        while True:
            try:
                doc = in_q.get(timeout=1)
                if doc is None:
                    break
            except Empty:
                break

            extension = "" if doc["_source"]["extension"] == "" else "." + doc["_source"]["extension"]
            full_path = os.path.join(directory.path, doc["_source"]["path"], doc["_source"]["name"] + extension)

            if os.path.isfile(full_path) and "mime" in doc["_source"]:
                self.generate(full_path, os.path.join(dest_path, doc["_id"]), doc["_source"]["mime"])

            if counter is not None:
                counter.value += 1

            in_q.task_done()

    def generate_all(self, docs, dest_path, counter: Value = None, directory=None, total_count=None):

        os.makedirs(dest_path, exist_ok=True)

        in_q = Queue(50000)  # TODO: load from config?
        threads = []
        for _ in range(config.tn_threads):
            t = Thread(target=self.worker, args=[in_q, counter, dest_path, directory])
            threads.append(t)
            t.start()

        for doc in docs:
            while True:
                try:
                    in_q.put(doc, timeout=10)
                    if total_count:
                        total_count.value += 1
                    break
                except Full:
                    continue

        in_q.join()
        for _ in threads:
            in_q.put(None)
        for t in threads:
            t.join()

    def generate_image(self, path, dest_path):

        try:
            with open(path, "rb") as image_file:
                with Image.open(image_file) as image:

                    # https://stackoverflow.com/questions/43978819
                    if image.mode == "I;16":
                        image.mode = "I"
                        image.point(lambda i: i * (1. / 256)).convert('L')

                    image.thumbnail(self.size, Image.BICUBIC)
                    canvas = Image.new("RGB", image.size, self.color)

                    if image.mode in ('RGBA', 'LA') or (image.mode == 'P' and 'transparency' in image.info):

                        try:
                            canvas.paste(image, mask=image.split()[-1])
                        except ValueError:
                            canvas.paste(image)
                    else:
                        canvas.paste(image)

                    canvas.save(dest_path, "JPEG", quality=self.quality, optimize=True)
                    canvas.close()
        except Exception as e:
            print(e)