Merge pull request #61 from ZFordDev/55-migration-system-json-sqlite

migration from legacy JSON storage

Author: ZFordDev

src/storage/migration.py

@@ -0,0 +1,103 @@
+"""
+migration.py
+------------
+Handles migration from legacy JSON storage to the new SQLite database.
+
+This module:
+- Detects old JSON file
+- Loads legacy tasks
+- Inserts them into the DB via Repository
+- Writes migration version into metadata
+- Archives the old JSON file
+"""
+
+import json
+import os
+from typing import List
+
+from storage.paths import get_json_path
+from storage.models import Entry
+from storage.repository import Repository
+
+
+MIGRATION_VERSION = "1"
+
+
+def needs_migration(repo: Repository) -> bool:
+    """
+    Returns True if migration has not been performed yet.
+    """
+    cursor = repo.conn.cursor()
+    row = cursor.execute(
+        "SELECT value FROM metadata WHERE key = 'migration_version'"
+    ).fetchone()
+
+    if row:
+        return False  # already migrated
+
+    # If JSON exists, migration is needed
+    return os.path.exists(get_json_path())
+
+
+def run_migration(repo: Repository) -> None:
+    """
+    Performs JSON → DB migration.
+    """
+    json_path = get_json_path()
+
+    if not os.path.exists(json_path):
+        return  # nothing to migrate
+
+    print("[MIGRATION] Legacy JSON detected. Migrating to SQLite...")
+
+    # Load JSON
+    try:
+        with open(json_path, "r", encoding="utf-8") as f:
+            data = json.load(f)
+    except Exception as e:
+        print(f"[MIGRATION ERROR] Failed to read JSON: {e}")
+        return
+
+    tasks = data.get("tasks", [])
+
+    # Insert tasks into DB
+    for t in tasks:
+        title = t.get("text", "Untitled Task")
+        date = t.get("date")
+        time = t.get("time")
+
+        # Combine date + time into ISO 8601
+        due_date = None
+        if date and time:
+            due_date = f"{date}T{time}"
+
+        entry = repo.create_entry(
+            title=title,
+            description=None,
+            due_date=due_date,
+        )
+
+        # Overwrite timestamps to preserve history
+        repo.update_entry(
+            entry.id,
+            created_at=t.get("createdAt"),
+            updated_at=t.get("updatedAt"),
+        )
+
+    # Write migration version
+    cursor = repo.conn.cursor()
+    cursor.execute(
+        "INSERT INTO metadata (key, value) VALUES ('migration_version', ?)",
+        (MIGRATION_VERSION,),
+    )
+    repo.conn.commit()
+
+    # Archive JSON
+    backup_path = json_path + ".bak"
+    try:
+        os.rename(json_path, backup_path)
+        print(f"[MIGRATION] JSON archived to {backup_path}")
+    except Exception as e:
+        print(f"[MIGRATION WARNING] Could not archive JSON: {e}")
+
+    print("[MIGRATION] Completed successfully.")