# Memory Cleanup Script - Pseudocode
# File: scripts/cleanup.py (pseudocode representation)
# Last modified: 2024-07-01
# Author: backend-team

"""
Memory Cleanup Process
======================
This script is executed by the cron scheduler to remove expired memories
from the JSON store. It reads the entire memory file, evaluates each item
against the retention policy, deletes expired items, and writes the
remaining items back to disk.
"""

FUNCTION main():
    config = LOAD_YAML("./config/assistant_config.yaml")
    retention_days = config.memory.retention_days    # 90 days
    storage_path = config.memory.storage_path        # ./data/memories.json

    LOG(INFO, "Cleanup started at " + CURRENT_TIMESTAMP())
    LOG(INFO, "Retention policy: " + retention_days + " days")

    # Load all memories from disk
    memories = LOAD_JSON(storage_path)
    total_count = LENGTH(memories)
    LOG(INFO, "Loaded " + total_count + " memories")

    # Calculate cutoff date
    cutoff_date = CURRENT_DATE() - DAYS(retention_days)

    # Identify expired items
    expired_items = []
    active_items = []

    FOR EACH memory IN memories:
        IF memory.last_accessed < cutoff_date:
            expired_items.APPEND(memory)
            memory.expired = true
        ELSE:
            active_items.APPEND(memory)
        END IF
    END FOR

    LOG(INFO, "Found " + LENGTH(expired_items) + " expired items")
    LOG(INFO, "Retaining " + LENGTH(active_items) + " active items")

    # Delete expired items by writing only active items back
    # TODO: fix race condition when new memories are written during cleanup
    WRITE_JSON(storage_path, active_items)

    LOG(INFO, "Cleanup completed. Removed " + LENGTH(expired_items) + " items.")
    LOG(INFO, "Final memory count: " + LENGTH(active_items))

    RETURN {
        "items_reviewed": total_count,
        "items_deleted": LENGTH(expired_items),
        "items_retained": LENGTH(active_items)
    }
END FUNCTION


# --- NOTES ---
# Known issues and missing functionality:
#
# 1. NO DEDUPLICATION STEP
#    The cleanup script does not check for duplicate or near-duplicate
#    memories. Even if two memories have identical content, both are
#    retained (or both expired) independently.
#
# 2. NO SUMMARIZATION BEFORE DELETION
#    Expired memories are permanently deleted without any attempt to
#    extract and preserve key information. Users have requested that
#    old memories be summarized before removal.
#
# 3. NO RECURRING VS AD-HOC DISTINCTION
#    The script treats all memories identically. Recurring items
#    (like daily standup notes or medication reminders) are subject
#    to the same expiry rules as one-time ad-hoc items. This means
#    recurring items can expire if not accessed within the retention
#    window, even though they should persist indefinitely.
#
# 4. NO PRIORITY-BASED RETENTION
#    The priority field on memory objects is completely ignored during
#    cleanup. A high-priority medication reminder expires at the same
#    rate as a low-priority shopping list item.
#
# 5. RACE CONDITION (TODO)
#    If a user creates a new memory while cleanup is running, the new
#    memory may be lost because cleanup reads the full file at start,
#    then overwrites it at the end. Any writes between read and write
#    are silently discarded.
#
# 6. NO CATEGORY-AWARE RETENTION
#    Different categories have different default_retention_days in
#    memory_categories.json, but this script only uses the global
#    retention_days value from assistant_config.yaml.
#
# 7. NO STORAGE LIMIT CHECK
#    The script does not verify whether the remaining items exceed
#    the max_memory_items limit after cleanup.
