#!/usr/bin/env python
#
# See docs/emoji.md for a high-level explanation of how this system
# works.
from __future__ import print_function
import os
import glob
import shutil
import subprocess
import json
import sys
import hashlib
import xml.etree.ElementTree as ET
from six import unichr
from typing import Union, Text
from os.path import dirname
from PIL import Image, ImageDraw, ImageFont

from emoji_setup_utils import emoji_names_for_picker

ZULIP_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), '../../../')
sys.path.append(ZULIP_PATH)

from scripts.lib.zulip_tools import run

AA_SCALE = 8
SIZE = (136, 136)
SPRITE_SIZE = (50, 50)
BIG_SIZE = tuple([x * AA_SCALE for x in SIZE])

EMOJI_DUMP_DIR_PATH = os.path.join(ZULIP_PATH, 'var', 'emoji_dump')
EMOJI_DUMP_PATH = lambda p: os.path.join(EMOJI_DUMP_DIR_PATH, p)
TARGET_EMOJI_DUMP = os.path.join(ZULIP_PATH, 'static', 'generated', 'emoji')
EMOJI_CACHE_PATH = "/srv/zulip-emoji-cache"
EMOJI_SCRIPT_DIR_PATH = os.path.join(ZULIP_PATH, 'tools', 'setup', 'emoji')

EMOJI_CODES_FILE_TEMPLATE = """\
var emoji_codes = (function () {
var exports = {};

exports.names = %(names)s;

exports.codepoints = %(codepoints)s;

exports.name_to_codepoint = %(name_to_codepoint)s;

return exports;
}());
if (typeof module !== 'undefined') {
    module.exports = emoji_codes;
}
"""

# change directory
os.chdir(EMOJI_SCRIPT_DIR_PATH)

if 'TRAVIS' in os.environ:
    # In Travis CI, we don't have root access
    EMOJI_CACHE_PATH = "/home/travis/zulip-emoji-cache"

class MissingGlyphError(Exception):
    pass

def color_font(name, code_point, code_point_to_fname_map):
    # type: (str, str, Dict[int, Union[Text, bytes]]) -> None
    glyph_name = code_point_to_fname_map[int(code_point, 16)]

    in_name = 'bitmaps/strike0/{}.png'.format(glyph_name)
    out_name = 'out/unicode/{}.png'.format(code_point)
    out_sprite_name = 'out/sprite/{}.png'.format(name)

    # These emojis are colored white and need to be recolored
    white_emojis = ['eight', 'five', 'four', 'hash', 'nine', 'one',
                    'seven', 'six', 'three', 'two', 'zero']

    try:
        if name in white_emojis:
            white_emoji_image = Image.open(in_name).convert('RGBA')
            # Paste blue onto the image using the number as a mask
            white_emoji_image.paste('#40C0E7', white_emoji_image)
            white_emoji_image.save(in_name)
        shutil.copyfile(in_name, out_name)
        image = Image.new('RGBA', SIZE)
        image.paste(Image.open(out_name), (0, 2))
        image.resize(SPRITE_SIZE, Image.ANTIALIAS).save(out_sprite_name, 'PNG')
    except IOError:
        raise MissingGlyphError('code_point: %r' % (code_point))


def bw_font(name, code_point):
    # type: (str, str) -> None
    char = unichr(int(code_point, 16))

    # AndroidEmoji.ttf is from
    # https://android.googlesource.com/platform/frameworks/base.git/+/master/data/fonts/AndroidEmoji.ttf
    # commit 07912f876c8639f811b06831465c14c4a3b17663
    font = ImageFont.truetype('AndroidEmoji.ttf', 65 * AA_SCALE)
    image = Image.new('RGBA', BIG_SIZE)
    draw = ImageDraw.Draw(image)
    draw.text((0, 0), char, font=font, fill='black')
    image.resize(SIZE, Image.ANTIALIAS).save(
        'out/unicode/{}.png'.format(code_point), 'PNG'
    )
    image.resize(SPRITE_SIZE, Image.ANTIALIAS).save(
        'out/sprite/{}.png'.format(name), 'PNG'
    )

def code_point_to_file_name_map(ttx):
    # type: (str) -> Dict[int, Union[Text, bytes]]
    """Given the NotoColorEmoji.ttx file, parse it to generate a map from
    codepoint to filename (a la glyph0****.png)
    """
    result = {}  # type: Dict[int, Union[Text, bytes]]
    xml = ET.parse(ttx)
    for elem in xml.find("*cmap_format_12"):
        code_point = int(elem.attrib["code"], 16)
        fname = elem.attrib["name"]
        result[code_point] = fname
    return result


def main():
    # type: () -> None
    # ttx is in the fonttools pacakge, the -z option is only on master
    # https://github.com/behdad/fonttools/

    # NotoColorEmoji.tff is from
    # https://android.googlesource.com/platform/external/noto-fonts/+/marshmallow-release/other/NotoColorEmoji.ttf
    # note that you have to run it though base64 -D before being able
    # to use it, since it downloads from that page base64 encoded

    # this is so we don't accidently leave ttx files from previous
    # runs of this script lying around
    for fname in glob.glob(EMOJI_DUMP_PATH("*ttx*")):
        os.remove(fname)

    # check if directory `var/emoji_dump` exists
    subprocess.check_call(['mkdir', '-p', EMOJI_DUMP_DIR_PATH])
    success_stamp = get_success_stamp()
    source_emoji_dump = dirname(success_stamp)

    if not os.path.exists(success_stamp):
        print("Dumping emojis ...")
        dump_emojis(source_emoji_dump)
        run(['touch', success_stamp])

    print("Using cached emojis from {}".format(source_emoji_dump))
    run(['rm', '-rf', TARGET_EMOJI_DUMP])
    try:
        os.symlink(
            source_emoji_dump,
            TARGET_EMOJI_DUMP
        )
    except OSError:
        print("Error: Unable to create symlinks. Make sure you have permission to create symbolic links.")

def get_success_stamp():
    # type: () -> str
    sha = hashlib.sha1()

    filenames = ['NotoColorEmoji.ttf', 'emoji_map.json', 'AndroidEmoji.ttf',
                 'build_emoji', 'emoji_setup_utils.py']

    for filename in filenames:
        with open(filename, 'rb') as reader:
            sha.update(reader.read())

    return os.path.join(EMOJI_CACHE_PATH, sha.hexdigest(), 'emoji', '.success-stamp')

def dump_emojis(cache_path):
    # type: (str) -> None
    subprocess.call('ttx -v -z extfile -d {} NotoColorEmoji.ttf'.format(EMOJI_DUMP_DIR_PATH), shell=True)

    emoji_map = json.load(open('emoji_map.json'))
    code_point_to_fname_map = code_point_to_file_name_map(EMOJI_DUMP_PATH("NotoColorEmoji.ttx"))

    os.chdir(EMOJI_DUMP_DIR_PATH)

    try:
        shutil.rmtree('out')
    except OSError:
        pass

    for fname in glob.glob("sprite*"):
        os.remove(fname)

    os.mkdir('out')
    os.mkdir('out/sprite')
    os.mkdir('out/unicode')

    failed = False
    for name, code_point in emoji_map.items():
        try:
            color_font(name, code_point, code_point_to_fname_map)
        except MissingGlyphError:
            print("Warning: Missing color glyph for %s; using black/white." % (name,))
            try:
                bw_font(name, code_point)
            except Exception as e:
                print(e)
                print('Missing {}, {}'.format(name, code_point))
                failed = True
                continue

        try:
            os.symlink(
                'unicode/{}.png'.format(code_point),
                'out/{}.png'.format(name)
            )
        except OSError:
            print("Error: Unable to create symlinks. Make sure you have permission to create symbolic links.")
            failed = True
            # probably should not try to create additional links
            break

    if failed:
        print("Errors dumping emoji!")
        sys.exit(1)

    subprocess.call('glue --quiet out/sprite . --margin=1 --namespace=emoji --sprite-namespace= --retina',
                    shell=True)

    cache_emoji = os.path.join(cache_path, 'images', 'emoji')
    cache_emoji_unicode = os.path.join(cache_path, 'images', 'emoji', 'unicode')
    run(['rm', '-rf', cache_path])
    run(['mkdir', '-p', cache_emoji])
    run(['mv', 'out/*', cache_emoji], shell=True)
    run(['mv', 'sprite*', cache_path], shell=True)
    assets = "{}/static/assets/zulip-emoji/*".format(ZULIP_PATH)
    run(['cp', '-RPp', assets, cache_emoji_unicode], shell=True)

    for fn in [os.path.basename(file_name) for file_name in glob.glob(assets)]:
        os.symlink(
            os.path.join(cache_emoji_unicode, fn),
            os.path.join(cache_emoji, fn)
        )

    # Add zulip emoji to `emoji_map` so that we can avoid
    # adding unnecessary exceptions to the rendering logic.
    emoji_map['zulip'] = 'zulip'

    EMOJI_CODES_PATH = os.path.join(cache_path, 'emoji_codes.js')
    emoji_codes_file = open(EMOJI_CODES_PATH, 'w')

    # put thumbs_up before thumbs_down
    names = emoji_names_for_picker(emoji_map)
    down_index = names.index('thumbs_down')
    up_index = names.index('thumbs_up')
    names[down_index], names[up_index] = ('thumbs_up', 'thumbs_down')

    emoji_codes_file.write(EMOJI_CODES_FILE_TEMPLATE % {
        'names': names,
        'codepoints': sorted([str(code_point) for code_point in set(emoji_map.values())]),
        'name_to_codepoint': {str(key): str(emoji_map[key]) for key in emoji_map}
    })
    emoji_codes_file.close()

    NAME_TO_CODEPOINT_PATH = os.path.join(cache_path, 'name_to_codepoint.json')
    name_to_codepoint_file = open(NAME_TO_CODEPOINT_PATH, 'w')

    name_to_codepoint_file.write(json.dumps(emoji_map))
    name_to_codepoint_file.close()

if __name__ == "__main__":
    main()