Implements DB model and preliminary select queries

src/database/ddl.py

@@ -0,0 +1,159 @@
+import json
+import logging
+
+import math
+import timeit
+
+import typing
+
+from peewee import ModelSelect
+from playhouse.shortcuts import model_to_dict
+from peewee import *
+
+
+def get_database_connection():
+    # for now it's an sqlite database
+    db = SqliteDatabase()
+    return db
+
+
+database = get_database_connection()
+
+
+class BaseModel(Model):
+    class Meta:
+        database = database
+
+
+class Channel(BaseModel):
+    claim_id = TextField(column_name='ClaimId', primary_key=True)
+    name = TextField(column_name='Name')
+
+    class Meta:
+        table_name = 'CHANNEL'
+
+
+class Comment(BaseModel):
+    comment = TextField(column_name='Body')
+    channel = ForeignKeyField(
+        backref='comments',
+        column_name='ChannelId',
+        field='claim_id',
+        model=Channel,
+        null=True
+    )
+    comment_id = TextField(column_name='CommentId', primary_key=True)
+    is_hidden = BooleanField(column_name='IsHidden', constraints=[SQL("DEFAULT FALSE")])
+    claim_id = TextField(column_name='LbryClaimId')
+    parent = ForeignKeyField(
+        column_name='ParentId',
+        field='comment_id',
+        model='self',
+        null=True,
+        backref='replies'
+    )
+    signature = TextField(column_name='Signature', null=True, unique=True)
+    signing_ts = TextField(column_name='SigningTs', null=True)
+    timestamp = IntegerField(column_name='Timestamp')
+
+    class Meta:
+        table_name = 'COMMENT'
+        indexes = (
+            (('author', 'comment_id'), False),
+            (('claim_id', 'comment_id'), False),
+        )
+
+
+COMMENT_FIELDS = [
+    Comment.comment,
+    Comment.comment_id,
+    Comment.claim_id,
+    Comment.timestamp,
+    Comment.signature,
+    Comment.signing_ts,
+    Comment.is_hidden,
+    Comment.parent.alias('parent_id'),
+]
+
+CHANNEL_FIELDS = [
+    Channel.claim_id.alias('channel_id'),
+    Channel.name.alias('channel_name')
+]
+
+
+def get_comment_list(claim_id: str = None, parent_id: str = None,
+                     top_level: bool = False, exclude_mode: str = None,
+                     page: int = 1, page_size: int = 50, expressions=None) -> dict:
+    query = Comment.select(*COMMENT_FIELDS, *CHANNEL_FIELDS)
+    if claim_id:
+        query = query.where(Comment.claim_id == claim_id)
+        if top_level:
+            query = query.where(Comment.parent.is_null())
+
+    if parent_id:
+        query = query.where(Comment.ParentId == parent_id)
+
+    if exclude_mode:
+        show_hidden = exclude_mode.lower() == 'hidden'
+        query = query.where((Comment.is_hidden == show_hidden))
+    total = query.count()
+    query = (query
+             .join(Channel, JOIN.LEFT_OUTER)
+             .where(expressions)
+             .order_by(Comment.timestamp.desc())
+             .paginate(page, page_size))
+    items = [clean(item) for item in query.dicts()]
+    # has_hidden_comments is deprecated
+    data = {
+        'page': page,
+        'page_size': page_size,
+        'total_pages': math.ceil(total / page_size),
+        'total_items': total,
+        'items': items,
+        'has_hidden_comments': exclude_mode is not None and exclude_mode == 'hidden',
+    }
+    return data
+
+
+def clean(thing: dict) -> dict:
+    return {k: v for k, v in thing.items() if v is not None}
+
+
+def get_comment(comment_id: str) -> dict:
+    try:
+        comment: Comment = Comment.get_by_id(comment_id)
+    except DoesNotExist as e:
+        raise ValueError from e
+    else:
+        as_dict = model_to_dict(comment)
+        if comment.channel:
+            as_dict.update({
+                'channel_id': comment.channel_id,
+                'channel_name': comment.channel.name,
+                'signature': comment.signature,
+                'signing_ts': comment.signing_ts,
+                'channel_url': f'lbry://{comment.channel.name}#{comment.channel_id}'
+            })
+        if comment.parent:
+            as_dict.update({
+                'parent_id': comment.parent_id
+            })
+        return clean(as_dict)
+
+
+if __name__ == '__main__':
+    logger = logging.getLogger('peewee')
+    logger.addHandler(logging.StreamHandler())
+    logger.setLevel(logging.DEBUG)
+
+    comment_list = get_comment_list(
+        page_size=1,
+        expressions=(Comment.channel.is_null())
+    )
+
+    comment = comment_list['items'].pop()
+    print(json.dumps(comment, indent=4))
+    other_comment = get_comment(comment['comment_id'])
+
+    print(json.dumps(other_comment, indent=4))
+    print(comment == other_comment)