from __future__ import annotations
import logging
from pathlib import Path

logger = logging.getLogger(__name__)


def run_migrations(db_url: str, plugin_migration_dirs: list[Path] | None = None) -> None:
    """Run core + plugin Alembic migrations synchronously.

    Called during create_app() before the event loop starts.
    Applies all pending migrations in dependency order.
    Plugin migration dirs are included via Alembic's version_locations.
    """
    from alembic import command
    from alembic.config import Config

    core_migrations = Path(__file__).parent.parent / "migrations"
    core_versions = core_migrations / "versions"

    cfg = Config()
    cfg.set_main_option("script_location", str(core_migrations))
    cfg.set_main_option("sqlalchemy.url", db_url)

    # Build version_locations: core + any plugin version directories
    version_locs = [str(core_versions)]
    for plugin_dir in (plugin_migration_dirs or []):
        pv = plugin_dir / "versions"
        if pv.exists():
            version_locs.append(str(pv))

    cfg.set_main_option("version_locations", " ".join(version_locs))

    logger.info("Running migrations (version_locations: %s)", " ".join(version_locs))
    command.upgrade(cfg, "heads")
    logger.info("Migrations complete")


def get_plugin_migration_dirs(plugin_dir: Path, plugins_cfg: dict) -> list[Path]:
    """Return migration directories for all enabled plugins that have one.

    Does not import any Python code — filesystem scan only.
    Used to collect migration dirs before importing plugins, so migrations
    can run before plugin Python code is loaded.
    """
    dirs = []
    for name, cfg in plugins_cfg.items():
        if not cfg.get("enabled", False):
            continue
        mdir = plugin_dir / name / "migrations"
        if mdir.exists():
            dirs.append(mdir)
    return dirs