from typing import Optional, Union
from tags import Tags
from pathlib import Path
from datetime import datetime
import fluentpy as _
import logging
import json
import re
import requests
import subprocess

class Metadata:
    def __init__(self, dir_tmp: Path):
        self.dir_tmp = dir_tmp
        self.tmp_image_file = Path(self.dir_tmp, "tmp.jpg")

    def process(self, url: str) -> Optional[Union[Path, Tags]]:
        logging.info("Retrieving metadata for %s", url)
        meta = self.__get_metadata(url)
        status = self.__download_file(meta)
        if not status:
            logging.warn("Download failed")
            return None
        return self.__write_tags(url, meta)

    def __get_metadata(self, url: str) -> dict:
        return requests.get(url + ".json").json()
        # with open('test/test.json', 'rt', encoding='utf8') as f:
            # r = json.load(f)
        # return r

    def __download_file(self, r: dict) -> bool:
        ext = r.get("file_ext", "")
        w = int(r.get("image_width", "0"))
        h = int(r.get("image_height", "0"))
        if (ext not in ["jpg", "jpeg", "png", "webp"]) or w == 0 or h == 0:
            return False
        file_url = r.get("file_url")
        file_size_kb = int(r.get('file_size', "0")) / 1024

        logging.info("Downloading image")
        recompress = self.__need_recompress(ext, w, h, file_size_kb)
        return self.__download(file_url, recompress=recompress)
    
    def __need_recompress(self, ext, w, h, size_kb):
        return ext == 'jpg' and size_kb > 1400 and w < 2500 and h < 2500
    
    def __download(self, img_url: str, recompress: bool = False):
        opt_args = []
        if recompress:
            opt_args = ['-quality', 80]
        ret = subprocess.call([
            'magick', img_url,
            '-resize', '2500x2500>',
            *opt_args, self.tmp_image_file
        ], stdout=subprocess.PIPE)
        return ret == 0


    def __write_tags(self, url: str, r: dict) -> tuple:
        tag_general = r.get('tag_string_general', "")
        tag_copyrights = r.get('tag_string_copyright', "")
        tag_characters = r.get('tag_string_character', "")
        tag_artists = r.get('tag_string_artist', "")
        tags = Tags(tag_general, tag_copyrights, tag_characters, tag_artists)

        tags_file = Path(self.dir_tmp, "tags.txt")
        with open(tags_file, "w") as f:
            content = _(tags.tags) \
                .map(lambda s: "-IPTC:keywords=" + s) \
                .join("\n") \
                ._
            content += "\n-Exif:ImageDescription=" + url
            content += "\n-Iptc:Caption-Abstract=" + url
            content += "\n-Xmp:Description=" + url
            f.write(content)
        
        logging.info("Writing tags")
        subprocess.call([
            'exiftool', '-q', '-overwrite_original',
            '-@', tags_file,
            self.tmp_image_file
        ], stdout=subprocess.PIPE)

        filename = self.__format_filename(tags)
        result_file = Path(self.tmp_image_file.parent, filename)
        self.tmp_image_file.rename(result_file)
        return result_file, tags


    def __format_filename(self, tags: Tags):
        filename = '{} {} by {} at {}.jpg'.format(
            tags.copyrights.split(" ")[0] or "",
            ", ".join(tags.characters_sanitized()[:2]),
            tags.artists.split(" ")[0] or "",
            datetime.now().strftime('%Y%m%d_%H%M%S')
        )
        return re.sub(r'\s+', ' ', filename).strip()