"""
Browsertrix API Mongo DB initialization
"""

import importlib.util
import os
import urllib
import asyncio
from uuid import UUID, uuid4

from typing import Optional, Union, TypeVar, Type, TYPE_CHECKING

from motor.motor_asyncio import AsyncIOMotorClient, AsyncIOMotorDatabase
from pydantic import BaseModel
from pymongo.errors import InvalidName

from .migrations import BaseMigration

if TYPE_CHECKING:
    from .users import UserManager
    from .orgs import OrgOps
    from .crawlconfigs import CrawlConfigOps
    from .crawls import CrawlOps
    from .colls import CollectionOps
    from .invites import InviteOps
    from .storages import StorageOps
    from .pages import PageOps
    from .background_jobs import BackgroundJobOps
else:
    UserManager = OrgOps = CrawlConfigOps = CrawlOps = CollectionOps = InviteOps = (
        StorageOps
    ) = PageOps = BackgroundJobOps = object


CURR_DB_VERSION = "0043"


# ============================================================================
def resolve_db_url() -> str:
    """get the mongo db url, either from MONGO_DB_URL or
    from separate username, password and host settings"""
    db_url = os.environ.get("MONGO_DB_URL")
    if db_url:
        return db_url

    mongo_user = urllib.parse.quote_plus(os.environ["MONGO_INITDB_ROOT_USERNAME"])
    mongo_pass = urllib.parse.quote_plus(os.environ["MONGO_INITDB_ROOT_PASSWORD"])
    mongo_host = os.environ["MONGO_HOST"]

    return f"mongodb://{mongo_user}:{mongo_pass}@{mongo_host}:27017"


# ============================================================================
def init_db() -> tuple[AsyncIOMotorClient, AsyncIOMotorDatabase]:
    """initialize the mongodb connector"""

    db_url = resolve_db_url()

    client = AsyncIOMotorClient(
        db_url,
        tz_aware=True,
        uuidRepresentation="standard",
        connectTimeoutMS=120000,
        serverSelectionTimeoutMS=120000,
    )

    mdb = client["browsertrixcloud"]

    return client, mdb


# ============================================================================
async def ping_db(mdb) -> None:
    """run in loop until db is up, set db_inited['inited'] property to true"""
    print("Waiting DB", flush=True)
    while True:
        try:
            result = await mdb.command("ping")
            assert result.get("ok")
            print("DB reached")
            break
        # pylint: disable=broad-exception-caught
        except Exception:
            print("Retrying, waiting for DB to be ready")
            await asyncio.sleep(3)


# ============================================================================
async def update_and_prepare_db(
    # pylint: disable=R0913
    mdb: AsyncIOMotorDatabase,
    user_manager: UserManager,
    org_ops: OrgOps,
    crawl_ops: CrawlOps,
    crawl_config_ops: CrawlConfigOps,
    coll_ops: CollectionOps,
    invite_ops: InviteOps,
    storage_ops: StorageOps,
    page_ops: PageOps,
    background_job_ops: BackgroundJobOps,
) -> None:
    """Prepare database for application.

    - Run database migrations
    - Recreate indexes
    - Create/update superuser
    - Create/update default org

    """
    await ping_db(mdb)
    print("Database setup started", flush=True)
    if await run_db_migrations(
        mdb, user_manager, page_ops, org_ops, background_job_ops, coll_ops
    ):
        await drop_indexes(mdb)

    await create_indexes(
        org_ops,
        crawl_ops,
        crawl_config_ops,
        coll_ops,
        invite_ops,
        user_manager,
        page_ops,
        storage_ops,
    )
    await user_manager.create_super_user()
    await org_ops.create_default_org()
    await org_ops.check_all_org_default_storages(storage_ops)
    print("Database updated and ready", flush=True)


# ============================================================================
# pylint: disable=too-many-locals, too-many-arguments
async def run_db_migrations(
    mdb, user_manager, page_ops, org_ops, background_job_ops, coll_ops
):
    """Run database migrations."""

    # if first run, just set version and exit
    if not await user_manager.get_superuser():
        base_migration = BaseMigration(mdb, CURR_DB_VERSION)
        await base_migration.set_db_version()
        print(
            "New DB, no migration needed, set version to: " + CURR_DB_VERSION,
            flush=True,
        )
        return False

    migrations_run = False
    migrations_path = "/app/btrixcloud/migrations"
    module_files = [
        f
        for f in sorted(os.listdir(migrations_path))
        if not os.path.isdir(os.path.join(migrations_path, f))
        and not f.startswith("__")
    ]
    for module_file in module_files:
        module_path = os.path.join(migrations_path, module_file)
        try:
            migration_name = os.path.basename(module_file).rstrip(".py")
            spec = importlib.util.spec_from_file_location(
                f".migrations.{migration_name}", module_path
            )
            assert spec
            assert spec.loader
            migration_module = importlib.util.module_from_spec(spec)
            spec.loader.exec_module(migration_module)
            migration = migration_module.Migration(
                mdb,
                page_ops=page_ops,
                org_ops=org_ops,
                background_job_ops=background_job_ops,
                coll_ops=coll_ops,
            )
            if await migration.run():
                migrations_run = True
        except ImportError as err:
            print(
                f"Error importing Migration class from module {module_file}: {err}",
                flush=True,
            )
    return migrations_run


# ============================================================================
async def await_db_and_migrations(mdb, db_inited):
    """await that db is available and any migrations in progress finish"""
    await ping_db(mdb)
    print("Database setup started", flush=True)

    base_migration = BaseMigration(mdb, CURR_DB_VERSION)
    while await base_migration.migrate_up_needed(ignore_rerun=True):
        version = await base_migration.get_db_version()
        print(
            f"Waiting for migrations to finish, DB at {version}, latest {CURR_DB_VERSION}",
            flush=True,
        )

        await asyncio.sleep(5)

    db_inited["inited"] = True
    print("Database updated and ready", flush=True)


# ============================================================================
async def drop_indexes(mdb):
    """Drop all database indexes."""
    print("Dropping database indexes", flush=True)
    collection_names = await mdb.list_collection_names()
    for collection in collection_names:
        # Don't drop pages automatically, as these are large
        # indices and slow to recreate
        if collection == "pages":
            continue

        try:
            current_coll = mdb[collection]
            await current_coll.drop_indexes()
            print(f"Indexes for collection {collection} dropped")
        except InvalidName:
            continue


# ============================================================================
# pylint: disable=too-many-arguments
async def create_indexes(
    org_ops,
    crawl_ops,
    crawl_config_ops,
    coll_ops,
    invite_ops,
    user_manager,
    page_ops,
    storage_ops,
):
    """Create database indexes."""
    print("Creating database indexes", flush=True)
    await org_ops.init_index()
    await crawl_ops.init_index()
    await crawl_config_ops.init_index()
    await coll_ops.init_index()
    await invite_ops.init_index()
    await user_manager.init_index()
    await page_ops.init_index()
    await storage_ops.init_index()


# ============================================================================
T = TypeVar("T")


# ============================================================================
class BaseMongoModel(BaseModel):
    """Base pydantic model that is also a mongo doc"""

    id: Optional[Union[UUID, str]]

    @property
    def id_str(self):
        """Return id as str"""
        return str(self.id)

    @classmethod
    def from_dict(cls: Type[T], data: dict) -> T:
        """convert dict from mongo to a class"""
        if not data:
            return cls()
        data["id"] = data.pop("_id")
        return cls(**data)

    def serialize(self, **opts):
        """convert class to dict"""
        return self.dict(
            exclude_unset=True, exclude_defaults=True, exclude_none=True, **opts
        )

    def to_dict(self, **opts):
        """convert to dict for mongo"""
        res = self.dict(**opts)
        res["_id"] = res.pop("id", "")
        if not res["_id"]:
            res["_id"] = uuid4()
        return res