#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import fdb
from pathlib import Path

# ================== CONFIG ==================
DB_PATH = r"u:\MEDICUS 3\data\medicus.FDB"
HOST = "localhost"
USER = "sysdba"
PASSWORD = "masterkey"
LOG_FILE = Path("dropped_tables_full.txt")
# ============================================

con = fdb.connect(
    host=HOST,
    database=DB_PATH,
    user=USER,
    password=PASSWORD,
    charset="WIN1250",
)
cur = con.cursor()

print("💣 Aggressively removing all empty tables and their dependencies...")

# ---------------------------------------------------------------------
# Helper functions
# ---------------------------------------------------------------------
def commit_safe():
    try:
        con.commit()
    except Exception as e:
        print(f"   ⚠️ Commit failed: {e}")
        con.rollback()

def drop_objects(sql_query: str, drop_sql_template: str, obj_type: str, table_name: str):
    """Generic dropper for dependent objects (views, triggers, procedures)."""
    cur.execute(sql_query)
    objs = [r[0].strip() for r in cur.fetchall()]
    for name in objs:
        stmt = drop_sql_template.format(name=name)
        try:
            print(f"   🔧 Dropping {obj_type}: {name}")
            con.execute_immediate(stmt)
            commit_safe()
        except Exception as e:
            print(f"      ⚠️ Could not drop {obj_type} {name}: {e}")
            con.rollback()

def drop_fk_constraints_referring_to(table_name: str):
    cur.execute(f"""
        SELECT TRIM(rc.rdb$relation_name), TRIM(rc.rdb$constraint_name)
        FROM rdb$relation_constraints rc
        JOIN rdb$ref_constraints ref ON ref.rdb$constraint_name = rc.rdb$constraint_name
        JOIN rdb$relation_constraints pk ON pk.rdb$constraint_name = ref.rdb$const_name_uq
        WHERE rc.rdb$constraint_type = 'FOREIGN KEY'
          AND UPPER(pk.rdb$relation_name) = '{table_name.upper()}'
    """)
    for fk_table, fk_name in cur.fetchall():
        stmt = f'ALTER TABLE {fk_table} DROP CONSTRAINT {fk_name}'
        try:
            print(f"   🔧 Dropping FK {fk_name} in {fk_table}")
            con.execute_immediate(stmt)
            commit_safe()
        except Exception as e:
            print(f"      ⚠️ Could not drop FK {fk_name} in {fk_table}: {e}")
            con.rollback()

# ---------------------------------------------------------------------
# Collect all user tables
# ---------------------------------------------------------------------
cur.execute("""
    SELECT TRIM(rdb$relation_name)
    FROM rdb$relations
    WHERE rdb$system_flag = 0
    ORDER BY 1
""")
tables = [r[0] for r in cur.fetchall()]

dropped, skipped = [], []

# ---------------------------------------------------------------------
# Main loop
# ---------------------------------------------------------------------
for t in tables:
    try:
        cur.execute(f"SELECT COUNT(*) FROM {t}")
        count = cur.fetchone()[0]
    except Exception as e:
        print(f"⚠️ Skipping {t}: {e}")
        continue

    if count > 0:
        continue

    print(f"\n🧹 {t} → empty, removing dependencies and dropping...")

    # 1️⃣ Drop foreign keys referencing this table
    drop_fk_constraints_referring_to(t)

    # 2️⃣ Drop views referencing this table
    drop_objects(
        sql_query=f"""
            SELECT TRIM(rdb$view_name)
            FROM rdb$view_relations
            WHERE UPPER(rdb$relation_name) = '{t.upper()}'
        """,
        drop_sql_template="DROP VIEW {name}",
        obj_type="view",
        table_name=t
    )

    # 3️⃣ Drop triggers whose source mentions this table
    drop_objects(
        sql_query=f"""
            SELECT TRIM(rdb$trigger_name)
            FROM rdb$triggers
            WHERE rdb$trigger_source CONTAINING '{t.upper()}'
        """,
        drop_sql_template="DROP TRIGGER {name}",
        obj_type="trigger",
        table_name=t
    )

    # 4️⃣ Drop stored procedures referencing this table
    drop_objects(
        sql_query=f"""
            SELECT TRIM(rdb$procedure_name)
            FROM rdb$procedures
            WHERE rdb$procedure_source CONTAINING '{t.upper()}'
        """,
        drop_sql_template="DROP PROCEDURE {name}",
        obj_type="procedure",
        table_name=t
    )

    # 5️⃣ Finally, drop the table itself
    try:
        con.execute_immediate(f"DROP TABLE {t}")
        commit_safe()
        dropped.append(t)
        print(f"   ✅ Dropped table {t}")
    except Exception as e:
        print(f"   ⚠️ Could not drop {t}: {e}")
        con.rollback()
        skipped.append(t)

con.close()

# ---------------------------------------------------------------------
# Log results
# ---------------------------------------------------------------------
LOG_FILE.write_text(
    "=== DROPPED TABLES ===\n" + "\n".join(dropped) +
    "\n\n=== SKIPPED TABLES ===\n" + "\n".join(skipped),
    encoding="utf-8"
)
print("\n✅ Done.")
print(f"Total dropped: {len(dropped)}")
print(f"Skipped: {len(skipped)}")
print(f"Log saved to {LOG_FILE.resolve()}")