Begin implementing better DB layer

lib/nntp/tiny/db.py

@@ -1,28 +1,141 @@
+import enum
 import sqlite3
 
-from nntp.tiny.message import Message
+class DatabaseOrder(enum.Enum):
+    DEFAULT = 0
+    ASC     = 1
+    DESC    = 2
+
+class DatabaseTable():
+    pass
+
+class DatabaseTableCursor():
+    __slots__ = 'cr', 'table',
+
+    def __init__(self, table, cr):
+        self.cr    = cr
+        self.table = table
+
+    def __getattr__(self, name):
+        return getattr(self.cr, name)
+
+    def __map__(self, row):
+        obj = self.table()
+
+        for name in self.table.columns:
+            try:
+                setattr(obj, name, row[name])
+            except IndexError:
+                setattr(obj, name, None)
+
+        return obj
+
+    def fetchone(self):
+        return self.__map__(self.cr.fetchone())
+
+    def fetchall(self):
+        return map(self.__map__, self.cr.fetchall())
 
 class Database():
     __slots__ = 'db',
 
-    def __init__(self, path: str):
-        self.db = sqlite3.connect(path)
+    def __init__(self, db):
+        self.db = db
 
-    def message_add(self, newsgroup_id: int, message: Message):
-        sql = """
-            insert into
-                newsgroup_message
-            (newsgroup_id, message_id, created_on, sender, subject, content) values (?, ?, ?, ?, ?, ?)
-        """
+    def __getattr__(self, name):
+        return getattr(self.db, name)
 
-        self.db.execute(sql, (
-            newsgroup_id,
-            message.id(),
-            message.date().isoformat(),
-            message.sender(),
-            message.subject(),
-            message.content
-        ))
+    @staticmethod
+    def connect(path):
+        db = sqlite3.connect(path)
+        db.row_factory = sqlite3.Row
 
-    def commit(self):
-        self.db.commit()
+        return Database(db)
+
+    def add(self, obj):
+        table = type(obj)
+        sql   = f"insert into {table.name} ("
+
+        first = True
+
+        for column in table.columns:
+            if column == table.key:
+                continue
+
+            if first:
+                sql  += column
+                first = False
+            else:
+                sql += ', ' + column
+
+        sql += ') values ('
+
+        first = True
+
+        for column in table.columns:
+            if column == table.key:
+                continue
+
+            if first:
+                first = False
+            else:
+                sql += ', '
+
+            sql += '?'
+
+        sql += ')'
+
+        fn = getattr(obj, '__values__')
+
+        if fn is not None:
+            values = fn()
+        else:
+            values = list()
+
+            for column in table.columns:
+                if column != table.key:
+                    values.append(getattr(obj, column))
+
+        self.db.execute(sql, values)
+
+    def query(self, table, values=dict(), order_by=list()):
+        sql = f"select * from {table.name}"
+
+        params = list()
+        first  = True
+
+        for key in values.keys():
+            if first:
+                sql += f" where {table.name}.{key} = ?"
+
+                first = False
+            else:
+                sql += f" and {table.name}.{key} = ?"
+
+            params.append(values[key])
+
+        first = True
+
+        if len(order_by) > 0:
+            sql += " order by"
+
+            for column, order in order_by:
+                if first:
+                    first = False
+                else:
+                    sql += ", "
+
+                if order is None or order is DatabaseOrder.DEFAULT:
+                    sql += f" {column}"
+                elif order is DatabaseOrder.ASC:
+                    sql += f" {column} asc"
+                elif order is DatabaseOrder.DESC:
+                    sql += f" {column} desc"
+
+        cr = DatabaseTableCursor(table, self.db.cursor())
+        cr.execute(sql, params)
+
+        return cr
+
+    def get(self, table, values=dict()):
+        return self.query(table, values).fetchone()

lib/nntp/tiny/message.py

@@ -5,6 +5,8 @@ import datetime
 from dateparser.search import search_dates
 from email.header      import decode_header
 
+from nntp.tiny.db import DatabaseTable
+
 def decode(text: str):
     decoded = decode_header(text)[0]
 
@@ -21,19 +23,41 @@ class MessageState(enum.Enum):
     HEADER = 1
     BODY   = 2
 
-class Message():
-    __slots__ = 'state', 'headers', 'line', 'content', 'body', 'key',
+class Message(DatabaseTable):
+    __slots__ = 'newsgroup_id', 'state', 'headers', 'line', 'content', 'body', '_key',
+
+    name    = 'newsgroup_message'
+    key     = 'id'
+    columns = (
+        'newsgroup_id',
+        'message_id',
+        'created_on',
+        'sender',
+        'subject',
+        'content'
+    )
 
     RE_HEADER     = re.compile(r'^([A-Za-z0-9\-]+): (.*)$')
     RE_MESSAGE_ID = re.compile(r'^<([^<>]+)>$')
 
     def __init__(self):
-        self.state   = MessageState.EMPTY
-        self.headers = dict()
-        self.line    = None
-        self.content = ''
-        self.body    = None
-        self.key     = None
+        self.newsgroup_id = None
+        self.state        = MessageState.EMPTY
+        self.headers      = dict()
+        self.line         = None
+        self.content      = ''
+        self.body         = None
+        self._key         = None
+
+    def __values__(self):
+        return (
+            self.newsgroup_id,
+            self.id(),
+            self.date(),
+            self.sender(),
+            self.subject(),
+            self.content
+        )
 
     def add(self, line: str):
         if self.line is not None:
@@ -46,14 +70,14 @@ class Message():
             if line == '\n' or line == '\r\n':
                 self.state = MessageState.BODY
             elif line[0] == ' ' or line[0] == '\t':
-                self.headers[self.key] += ' ' + decode(line.strip())
+                self.headers[self._key] += ' ' + decode(line.strip())
             else:
                 match = self.RE_HEADER.match(line)
 
                 if match:
-                    self.key = match[1].lower()
+                    self._key = match[1].lower()
 
-                    self.headers[self.key] = decode(match[2].rstrip())
+                    self.headers[self._key] = decode(match[2].rstrip())
         elif self.state is MessageState.BODY:
             if self.body is None:
                 self.body = ''

lib/nntp/tiny/newsgroup.py

@@ -0,0 +1,6 @@
+from nntp.tiny.db import DatabaseTable
+
+class Newsgroup(DatabaseTable):
+    name    = 'newsgroup'
+    key     = 'id'
+    columns = 'id', 'name', 'description',