# -*- coding: utf-8 -*-
# Generated by Django 1.10.5 on 2017-02-27 17:03

import os
from typing import Text

from boto.s3.connection import S3Connection
from django.conf import settings
from django.db import migrations
from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
from django.db.migrations.state import StateApps

from zerver.lib.avatar_hash import user_avatar_hash, user_avatar_path

def mkdirs(path: Text) -> None:
    dirname = os.path.dirname(path)
    if not os.path.isdir(dirname):
        os.makedirs(dirname)

class MissingAvatarException(Exception):
    pass

def move_local_file(type: Text, path_src: Text, path_dst: Text) -> None:
    src_file_path = os.path.join(settings.LOCAL_UPLOADS_DIR, type, path_src)
    dst_file_path = os.path.join(settings.LOCAL_UPLOADS_DIR, type, path_dst)
    if os.path.exists(dst_file_path):
        return
    if not os.path.exists(src_file_path):
        # This is likely caused by a user having previously changed their email
        raise MissingAvatarException()
    mkdirs(dst_file_path)
    os.rename(src_file_path, dst_file_path)

def move_avatars_to_be_uid_based(apps: StateApps, schema_editor: DatabaseSchemaEditor) -> None:
    user_profile_model = apps.get_model('zerver', 'UserProfile')
    if settings.LOCAL_UPLOADS_DIR is not None:
        for user_profile in user_profile_model.objects.filter(avatar_source="U"):
            src_file_name = user_avatar_hash(user_profile.email)
            dst_file_name = user_avatar_path(user_profile)
            try:
                move_local_file('avatars', src_file_name + '.original', dst_file_name + '.original')
                move_local_file('avatars', src_file_name + '-medium.png', dst_file_name + '-medium.png')
                move_local_file('avatars', src_file_name + '.png', dst_file_name + '.png')
            except MissingAvatarException:
                # If the user's avatar is missing, it's probably
                # because they previously changed their email address.
                # So set them to have a gravatar instead.
                user_profile.avatar_source = "G"
                user_profile.save(update_fields=["avatar_source"])
    else:
        conn = S3Connection(settings.S3_KEY, settings.S3_SECRET_KEY)
        bucket_name = settings.S3_AVATAR_BUCKET
        bucket = conn.get_bucket(bucket_name, validate=False)
        for user_profile in user_profile_model.objects.filter(avatar_source="U"):
            uid_hash_path = user_avatar_path(user_profile)
            email_hash_path = user_avatar_hash(user_profile.email)
            if bucket.get_key(uid_hash_path):
                continue
            if not bucket.get_key(email_hash_path):
                # This is likely caused by a user having previously changed their email
                # If the user's avatar is missing, it's probably
                # because they previously changed their email address.
                # So set them to have a gravatar instead.
                user_profile.avatar_source = "G"
                user_profile.save(update_fields=["avatar_source"])
                continue

            bucket.copy_key(uid_hash_path + ".original",
                            bucket_name,
                            email_hash_path + ".original")
            bucket.copy_key(uid_hash_path + "-medium.png",
                            bucket_name,
                            email_hash_path + "-medium.png")
            bucket.copy_key(uid_hash_path,
                            bucket_name,
                            email_hash_path)

        # From an error handling sanity perspective, it's best to
        # start deleting after everything is copied, so that recovery
        # from failures is easy (just rerun one loop or the other).
        for user_profile in user_profile_model.objects.filter(avatar_source="U"):
            bucket.delete_key(user_avatar_hash(user_profile.email) + ".original")
            bucket.delete_key(user_avatar_hash(user_profile.email) + "-medium.png")
            bucket.delete_key(user_avatar_hash(user_profile.email))

class Migration(migrations.Migration):

    dependencies = [
        ('zerver', '0059_userprofile_quota'),
    ]

    operations = [
        migrations.RunPython(move_avatars_to_be_uid_based)
    ]