feature: establish sqlite and tables

src/cli.py

@@ -2,9 +2,9 @@ import argparse
 import importlib
 
 from controllers.controller import Controller
+from services.database_service import DatabaseService
 
 importlib.invalidate_caches()
-
 file_path = "/home/thomas/repos/eolas-db/dev-data/Turing_completeness.md"
 
 
@@ -12,15 +12,21 @@ def main():
     parser = argparse.ArgumentParser(
         prog="eolas-db", description="Eolas database manager."
     )
-    parser.add_argument("command", choices=["parse"], help="Command to execute")
+    parser.add_argument(
+        "command", choices=["parse", "populate"], help="Command to execute"
+    )
     args = parser.parse_args()
 
-    controller = Controller()
+    database_service = DatabaseService("eolas")
+    controller = Controller(database_service)
 
     if args.command == "parse":
         parsed_entry = controller.parse_entry(file_path)
         print(parsed_entry)
 
+    if args.command == "populate":
+        controller.populate_database()
+
 
 if __name__ == "__main__":
     main()

src/controllers/controller.py

@@ -1,10 +1,20 @@
 from services.parse_file_service import ParseFileService
+from services.sqlite_service import SqliteService
 
 
 class Controller:
-    def __init__(self):
+    def __init__(self, database_service):
-        pass
+        self.database_service = database_service
 
     def parse_entry(self, file_path):
         parse_file_service = ParseFileService(file_path)
         return parse_file_service.parse()
+
+    def populate_database(self):
+        connection = self.database_service.connect()
+
+        if connection is None:
+            raise Exception("Failed to establish database connection")
+
+        sqlite_service = SqliteService(connection)
+        sqlite_service.create_tables()

src/scratch.py

@@ -1 +0,0 @@
-

src/services/database_service.py

@@ -0,0 +1,29 @@
+import sqlite3
+from typing import Optional
+
+
+class DatabaseService:
+    def __init__(self, db_name):
+        self.db_name = db_name
+        self.db_path = "/home/thomas/repos/eolas-db/db"
+        self.connection: Optional[sqlite3.Connection] = None
+
+    def connect(self) -> Optional[sqlite3.Connection]:
+        if self.connection is not None:
+            return self.connection
+
+        try:
+            self.connection = sqlite3.connect(f"{self.db_path}/{self.db_name}.db")
+            print("INFO Database connection established")
+            return self.connection
+
+        except Exception as e:
+            raise Exception(f"Problem connecting to database: {e}")
+
+    def disconnect(self) -> None:
+        try:
+            if self.connection is not None:
+                self.connection.close()
+                self.connection = None
+        except Exception as e:
+            raise Exception(f"ERROR Problem disconnecting from database: {e}")

src/services/sqlite_service.py

@@ -0,0 +1,27 @@
+from sql.create_tables import (
+    CREATE_BACKLINKS_TABLE,
+    CREATE_ENTRIES_TABLE,
+    CREATE_ENTRIES_TAGS_TABLE,
+    CREATE_TAGS_TABLE,
+)
+
+
+class SqliteService:
+    def __init__(self, connection):
+        self.connection = connection
+        self.cursor = connection.cursor()
+
+    def create_tables(self):
+        tables = [
+            CREATE_ENTRIES_TABLE,
+            CREATE_TAGS_TABLE,
+            CREATE_BACKLINKS_TABLE,
+            CREATE_ENTRIES_TAGS_TABLE,
+        ]
+        for create_statement in tables:
+            self.cursor.execute(create_statement)
+
+        self.connection.commit()
+
+        self.cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
+        print(self.cursor.fetchall())

src/sql/create_tables.py

@@ -0,0 +1,33 @@
+CREATE_ENTRIES_TABLE = """
+CREATE TABLE IF NOT EXISTS entries (
+    title TEXT PRIMARY KEY UNIQUE, 
+    last_modified STRING, 
+    size INTEGER, 
+    body TEXT
+)
+"""
+
+CREATE_TAGS_TABLE = """
+CREATE TABLE IF NOT EXISTS tags (
+    name TEXT PRIMARY KEY UNIQUE,
+)
+"""
+
+CREATE_BACKLINKS_TABLE = """
+CREATE TABLE IF NOT EXISTS backlinks (
+    source_entry_title TEXT,
+    target_entry_title TEXT,
+    FOREIGN KEY (source_entry_title) REFERENCES entries(title),
+    FOREIGN KEY (target_entry_title) REFERENCES entries(title),
+    PRIMARY KEY (source_entry_title, target_entry_title) 
+)
+"""
+
+CREATE_ENTRIES_TAGS_TABLE = """
+CREATE TABLE IF NOT EXISTS entries_tags (
+    entry_title TEXT,
+    tag_name TEXT,
+    FOREIGN KEY (entry_title) REFERENCES entries(title),
+    FOREIGN KEY (tag_name) REFERENCES tags(name),
+    PRIMARY KEY (entry_title, tag_name)
+)"""

src/sql/table_exists.py

@@ -0,0 +1,3 @@
+TABLE_EXISTS = (
+    "SELECT count(*) FROM sqlite_master WHERE type ='table' AND name=:table_name"
+)