from __future__ import annotations

import sqlite3
from collections.abc import Iterator
from contextlib import contextmanager
from pathlib import Path


class Database:
    def __init__(self, path: Path, migrations_path: Path) -> None:
        self.path = path
        self.migrations_path = migrations_path

    @contextmanager
    def connect(self) -> Iterator[sqlite3.Connection]:
        self.path.parent.mkdir(parents=True, exist_ok=True)
        connection = sqlite3.connect(self.path, timeout=10, check_same_thread=False)
        connection.row_factory = sqlite3.Row
        connection.execute("PRAGMA foreign_keys = ON")
        connection.execute("PRAGMA journal_mode = WAL")
        connection.execute("PRAGMA busy_timeout = 10000")
        try:
            yield connection
        finally:
            connection.close()

    def migrate(self) -> None:
        with self.connect() as connection:
            connection.execute(
                """
                CREATE TABLE IF NOT EXISTS schema_migrations (
                    version INTEGER PRIMARY KEY,
                    name TEXT NOT NULL,
                    applied_at TEXT NOT NULL
                )
                """
            )
            connection.commit()
            applied = {
                row["version"]
                for row in connection.execute("SELECT version FROM schema_migrations").fetchall()
            }
            for path in sorted(self.migrations_path.glob("*.sql")):
                version = int(path.name.split("_", 1)[0])
                if version in applied:
                    continue
                sql = path.read_text(encoding="utf-8")
                name = path.stem.replace("'", "''")
                connection.executescript(
                    "BEGIN IMMEDIATE;\n"
                    f"{sql}\n"
                    "INSERT INTO schema_migrations(version, name, applied_at) "
                    f"VALUES ({version}, '{name}', strftime('%Y-%m-%dT%H:%M:%fZ', 'now'));\n"
                    "COMMIT;"
                )

    def health_check(self) -> bool:
        try:
            with self.connect() as connection:
                return connection.execute("SELECT 1").fetchone()[0] == 1
        except sqlite3.Error:
            return False