#!/usr/bin/env python3

# Libervia: an XMPP client
# Copyright (C) 2009-2026 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


from pathlib import Path
import shutil

from libervia.backend.core.constants import Const as C

from .core import (
    DB_FILE,
    DbDriver,
    FILES_FILE_TPL,
    GlobalHandler,
    Handler,
    ProfileHandler,
    Report,
    Staging,
    get_db_driver,
    sqlite_db_config,
)
from .gpg import GpgHandler
from .pie import ParamsHandler, PepHandler, PrivateHandler, RosterHandler


class FilesHandler(GlobalHandler):
    name = "files"

    def export(
        self,
        local_dir: Path,
        staging: Staging,
        report: Report,
        profiles: list[str] | None = None,
    ) -> None:
        """Copy the file sharing blobs to the staging

        @param local_dir: local data directory
        @param staging: staging where the blobs are copied
        @param report: export report
        """
        files_dir = local_dir / C.FILES_DIR
        if not files_dir.is_dir():
            return
        count = 0
        for path in sorted(files_dir.rglob("*")):
            if path.is_file():
                staging.add_file(
                    FILES_FILE_TPL.format(path=path.relative_to(files_dir).as_posix()),
                    path,
                    0o600,
                )
                count += 1
        if count:
            report.done.append(f"files: {count} file(s)")

    def import_(
        self,
        local_dir: Path,
        staging: Staging,
        report: Report,
        profiles: list[str] | None = None,
        force: bool = False,
    ) -> None:
        """Copy the staged file sharing blobs to the local data directory

        The blobs are content-addressed (the name is the content hash), so overwriting an
        existing file is safe and repairs a corrupted one.

        @param local_dir: local data directory
        @param staging: staging holding the blobs
        @param report: import report
        """
        files_dir = local_dir / C.FILES_DIR
        # entry name prefix, derived from the staging name template
        prefix = FILES_FILE_TPL.split("{}")[0]
        count = 0
        for name in staging.names():
            if not name.startswith(prefix):
                continue
            dst = files_dir / name[len(prefix) :]
            dst.parent.mkdir(parents=True, exist_ok=True)
            shutil.copyfile(staging.path(name), dst)
            count += 1
        if count:
            report.done.append(f"files: {count} file(s)")


class DbHandler(GlobalHandler):
    name = "db"

    def _driver(self, local_dir: Path) -> DbDriver:
        return get_db_driver(sqlite_db_config(local_dir))

    def export(
        self,
        local_dir: Path,
        staging: Staging,
        report: Report,
        profiles: list[str] | None = None,
    ) -> None:
        """Write a snapshot of the database to the staging

        @param report: export report
        """
        self._driver(local_dir).snapshot(staging)

    def import_(
        self,
        local_dir: Path,
        staging: Staging,
        report: Report,
        profiles: list[str] | None = None,
        force: bool = False,
    ) -> None:
        """Restore the database snapshot from the staging (destructive)

        @param report: import report
        @param force: the restore is destructive, it requires force
        """
        if DB_FILE not in staging:
            return
        res = self._driver(local_dir).restore(staging, force)
        report.done.extend(res.done)
        report.skipped.extend(res.skipped)


# one handler per data type, in export order (the order is semantic: the database restore
# comes last, it replaces the database)
REGISTRY: list[Handler] = [
    ParamsHandler(),
    PrivateHandler(),
    RosterHandler(),
    PepHandler(),
    GpgHandler(),
    FilesHandler(),
    DbHandler(),
]

# "db" is a non-portable copy of the database (it will be migrated automatically on start
# if the Libervia version is newer): it covers all the data, while the portable types
# don't cover everything yet.
DATA_TYPES: tuple[str, ...] = tuple(handler.name for handler in REGISTRY)

# data types stored in the database: a database restore brings them back, so
# there is no need to import them on top of it
DB_BACKED_TYPES: tuple[str, ...] = tuple(
    handler.name
    for handler in REGISTRY
    if isinstance(handler, ProfileHandler) and handler.uses_db
)