import sqlite3
from hashlib import sha256

class SeenIssuesDB:
    def __init__(self, db_path='seen_issues.db'):
        self.conn = sqlite3.connect(db_path)
        self._create_table()

    def _create_table(self):
        with self.conn:
            self.conn.execute('''
                CREATE TABLE IF NOT EXISTS seen_issues (
                    issue_hash TEXT PRIMARY KEY
                )
            ''')

    def mark_as_seen(self, issue_text: str):
        issue_hash = self._compute_hash(issue_text)
        with self.conn:
            self.conn.execute('INSERT OR IGNORE INTO seen_issues (issue_hash) VALUES (?)', (issue_hash,))

    def has_seen(self, issue_text: str) -> bool:
        issue_hash = self._compute_hash(issue_text)
        cursor = self.conn.execute('SELECT 1 FROM seen_issues WHERE issue_hash = ?', (issue_hash,))
        return cursor.fetchone() is not None

    def _compute_hash(self, text: str) -> str:
        return sha256(text.encode('utf-8')).hexdigest()