import sqlite3


class Database:
    def __init__(self):
        self.db_path = "data/shifts.db"
        self._setup_tables() 
        pass

    def _get_connection(self):
        return sqlite3.connect(self.db_path)

    def _setup_tables(self):
        # create the shifts table.
        con = self._get_connection()
        cur = con.cursor()
        cur.execute('''
        CREATE TABLE IF NOT EXISTS shifts (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            shift_start DATETIME NOT NULL,
            shift_end DATETIME NOT NULL,
            department TEXT NOT NULL,
            duration TEXT NOT NULL,
            description TEXT,
            fetched_at DATETIME DEFAULT CURRENT_TIMESTAMP,
            
            UNIQUE(shift_start, department)  -- No duplicates
        );
        ''')
        con.commit()
        con.close()


    def insert_shifts(self, shifts):
        # start db connection
        con = self._get_connection()
        cur = con.cursor()
        inserted = 0

        for shift in shifts:
            # parse all information from the shift
            start = shift.get('start_datetime', 'N/A')
            end = shift.get('end_datetime', 'N/A')

            department = shift.get('department_name', 'N/A')
            duration = shift.get('duration', 'N/A')
            description = shift.get('shift_remark', shift.get('description', 'N/A'))
            
            # insert it into the db.
            cur.execute("""
                INSERT OR IGNORE INTO shifts 
                (shift_start, shift_end, department, duration, description)
                VALUES (?, ?, ?, ?, ?)
            """, (start, end, department, duration, description))
            
            if cur.rowcount > 0:
                inserted += 1
    
        con.commit()
        con.close()
        print(f"✅ Inserted {inserted}/{len(shifts)} new shifts")
            
    def delete_future_shifts(self):
        con = self._get_connection()
        cur = con.cursor()
        cur.execute("DELETE FROM shifts WHERE shift_start > current_timestamp")
        con.commit()
        con.close()
        print(f"✅ Deleted all future shifts")