import hashlib
import importlib
import re
import urllib.request
from typing import List

import httpx
from fastapi.exceptions import HTTPException
from loguru import logger

from lnbits.helpers import InstallableExtension
from lnbits.settings import settings

from . import db as core_db
from .crud import update_migration_version


async def migrate_extension_database(ext, current_version):
    try:
        ext_migrations = importlib.import_module(f"{ext.module_name}.migrations")
        ext_db = importlib.import_module(ext.module_name).db
    except ImportError:
        raise ImportError(
            f"Please make sure that the extension `{ext.code}` has a migrations file."
        )

    async with ext_db.connect() as ext_conn:
        await run_migration(ext_conn, ext_migrations, current_version)


async def run_migration(db, migrations_module, current_version):
    matcher = re.compile(r"^m(\d\d\d)_")
    db_name = migrations_module.__name__.split(".")[-2]
    for key, migrate in migrations_module.__dict__.items():
        match = match = matcher.match(key)
        if match:
            version = int(match.group(1))
            if version > current_version:
                logger.debug(f"running migration {db_name}.{version}")
                print(f"running migration {db_name}.{version}")
                await migrate(db)

                if db.schema == None:
                    await update_migration_version(db, db_name, version)
                else:
                    async with core_db.connect() as conn:
                        await update_migration_version(conn, db_name, version)


async def get_installable_extensions() -> List[InstallableExtension]:
    extension_list: List[InstallableExtension] = []

    async with httpx.AsyncClient() as client:
        for url in settings.lnbits_extensions_manifests:
            resp = await client.get(url)
            if resp.status_code != 200:
                raise HTTPException(
                    status_code=404,
                    detail=f"Unable to fetch extension list for repository: {url}",
                )
            for e in resp.json()["extensions"]:
                extension_list += [
                    InstallableExtension(
                        id=e["id"],
                        name=e["name"],
                        archive=e["archive"],
                        hash=e["hash"],
                        short_description=e["shortDescription"],
                        details=e["details"] if "details" in e else "",
                        icon=e["icon"],
                        dependencies=e["dependencies"] if "dependencies" in e else [],
                    )
                ]

    return extension_list


def download_url(url, save_path):
    with urllib.request.urlopen(url) as dl_file:
        with open(save_path, "wb") as out_file:
            out_file.write(dl_file.read())


def file_hash(filename):
    h = hashlib.sha256()
    b = bytearray(128 * 1024)
    mv = memoryview(b)
    with open(filename, "rb", buffering=0) as f:
        while n := f.readinto(mv):
            h.update(mv[:n])
    return h.hexdigest()