post.py

from flask_login import current_user


from utils import _
from utils import *
from pipeline import (
    pipeline, split_lines, process_code_block, process_line_without_format,
    join_lines
)
from models import (
    db, fn, User, Topic, Post, DeleteRecord, Message, Image
)
from config import NOTIFICATION_SIGN, IMAGE_SIGN, SUMMARY_LENGTH
from validation import REGEX_SHA256_PART


def filter_images(lines, images):
    found = {}
    def process_segment(segment):
        if (
            segment.startswith(IMAGE_SIGN)
            and REGEX_SHA256_PART.fullmatch(segment[len(IMAGE_SIGN):])
        ):
            image_query = (
                Image
                .select()
                .where(
                    Image.sha256.startswith(
                        segment[len(IMAGE_SIGN):]
                    )
                )
            )
            if image_query:
                image = image_query.get()
                if not found.get(image.sha256):
                    images.append(image)
                    found[image.sha256] = True
                return _('[Image]')
        return segment
    for line in lines:
        if isinstance(line, str):
            yield (
                ' '.join(process_segment(segment) for segment in line.split(' '))
            )
        else:
            yield str(line)


def gen_summary(content):
    images = []
    def get_images(lines):
        return filter_images(lines, images)
    content_processor = pipeline(
        split_lines, process_code_block, get_images, join_lines
    )
    processed = content_processor(content)
    if len(processed) > SUMMARY_LENGTH:
        summary = processed[:SUMMARY_LENGTH-3] + '...'
    else:
        summary = processed
    summary_images = ','.join(image.sha256[:10] for image in images[:3])
    return (summary, summary_images)


def filter_at_messages(lines, callees):
    called = {}
    def process_segment(segment):
        if segment.startswith(NOTIFICATION_SIGN):
            callee_name = segment[1:]
            callee = find_record(User, name=callee_name)
            if (
                    callee
                    and callee.id != current_user.id
                    and not called.get(callee.id)
            ):
                callees.append(callee)
                called[callee.id] = True
                # use "@@" to indicate this call is valid
                return NOTIFICATION_SIGN + segment
        return segment
    text = ''
    for line in lines:
        if isinstance(line, str):
            yield ''.join(
                snippet
                for snippet in process_line_without_format(
                        line, process_segment
                )
            )
        else:
            yield str(line)


def create_post(topic, parent, content, add_reply_count=True, is_sys_msg=False, is_pm=False, author=None):
    if not is_sys_msg:
        if not author:
            author = find_record(User, id=current_user.id)
    callees = []
    def process_at(lines):
        return filter_at_messages(lines, callees)
    content_processor = pipeline(
        split_lines, process_code_block, process_at, join_lines
    )
    if not is_sys_msg and not is_pm:
        content = content_processor(content)
    if parent:
        parent_path = parent.path
        parent_sort_path = parent.sort_path
    else:
        parent_path = ''
        parent_sort_path = ''
        
    total = Post.select(fn.COUNT(Post.id)).where(
        Post.topic == topic,
        Post.parent == parent
    )
    new_post = Post.create(
        topic = topic,
        parent = parent,
        ordinal = total,
        content = content,
        date = now(),
        author = author
    )

    new_post.path = '%s/%d' % (parent_path, new_post.id)
    new_post.sort_path = (
        '%s/%s-%d' % (
            parent_sort_path,
            new_post.date.isoformat(),
            random.randrange(0, 10)
        )
    )
    new_post.save()
    if topic:
        topic.last_reply_date = new_post.date
        topic.last_reply_author = new_post.author
        topic.save()
        if add_reply_count:
            (
                Topic
                .update(reply_count = Topic.reply_count+1)
                .where(Topic.id == topic.id)
            ).execute()
    for callee in callees:
        # self-to-self already filtered
        # use try_to_create() to update unread count
        Message.try_to_create(
            msg_type = 'at',
            post = new_post,
            caller = author,
            callee = callee       
        )
    p = parent
    while p:
        Message.try_to_create(
            msg_type = 'reply',
            post = new_post,
            caller = author,
            callee = p.author
        )
        p = p.parent
    if not is_sys_msg and not is_pm:
        Message.try_to_create(
            msg_type = 'reply',
            post = new_post,
            caller = author,
            callee = topic.author
        )
    return new_post


def create_system_message(content, target):
    post = create_post(None, None, content, is_sys_msg=True)
    message = Message.try_to_create(
        msg_type = 'sys',
        post = post,
        caller = None,
        callee = target
    )
    return message


def create_pm(content, target):
    post = create_post(None, None, content, is_pm=True)
    message = Message.try_to_create(
        msg_type = 'pm',
        post = post,
        caller = find_record(User, id=current_user.id),
        callee = target
    )
    return message