"""
    Onionr - Private P2P Communication

    Manager for upload 'sessions'
"""
from __future__ import annotations
"""
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
"""
from typing import Iterable, Union

from onionrutils import bytesconverter
from onionrutils import localcommand
from etc import onionrvalues
from etc import waitforsetvar
from utils import reconstructhash

from . import session

class BlockUploadSessionManager:
    """Holds block UploadSession instances. Optionally accepts iterable of sessions to added on init

    Arguments: old_session: iterable of old UploadSession objects"""
    def __init__(self, old_sessions:Iterable=None):
        #self._too_many: TooMany = None
        if old_sessions is None:
            self.sessions = []
        else:
            self.sessions = old_session
    
    def add_session(self, session_or_block: Union(str, bytes, session.UploadSession))->session.UploadSession:
        """Create (or add existing) block upload session from a str/bytes block hex hash, existing UploadSession"""
        if isinstance(session_or_block, session.UploadSession): 
            if not session_or_block in self.sessions:
                self.sessions.append(session_or_block)
            return session_or_block
        try:
            return self.get_session(session_or_block)
        except KeyError:
            pass
        # convert bytes hash to str
        if isinstance(session_or_block, bytes): session_or_block = bytesconverter.bytes_to_str(session_or_block)
        # intentionally not elif
        if isinstance(session_or_block, str):
            new_session = session.UploadSession(session_or_block)
            self.sessions.append(new_session)
            return new_session

    def get_session(self, block_hash: Union(str, bytes))->session.UploadSession:
        block_hash = reconstructhash.deconstruct_hash(bytesconverter.bytes_to_str(block_hash))
        for session in self.sessions:
            if session.block_hash == block_hash: return session
        raise KeyError

    def clean_session(self, specific_session: Union[str, UploadSession]=None):
        comm_inst: OnionrCommunicatorDaemon = self._too_many.get_by_string("OnionrCommunicatorDaemon")
        sessions_to_delete = []
        if comm_inst.getUptime() < 120: return
        onlinePeerCount = len(comm_inst.onlinePeers)
        
        # If we have no online peers right now,
        if onlinePeerCount == 0: return

        for session in self.sessions:
            # if over 50% of peers that were online for a session have become unavailable, don't kill sessions
            if session.total_success_count > onlinePeerCount:
                if onlinePeerCount / session.total_success_count >= 0.5: return
            # Clean sessions if they have uploaded to enough online peers
            if session.total_success_count <= 0: continue
            if (session.total_success_count / onlinePeerCount) >= onionrvalues.MIN_BLOCK_UPLOAD_PEER_PERCENT:
                sessions_to_delete.append(session)
        for session in sessions_to_delete:
            self.sessions.remove(session)
            # TODO cleanup to one round of search
            # Remove the blocks from the sessions, upload list, and waitforshare list
            try:
                comm_inst.blocksToUpload.remove(reconstructhash.reconstruct_hash(session.block_hash))
            except ValueError:
                pass
            try:
                comm_inst.blocksToUpload.remove(session.block_hash)
            except ValueError:
                pass
            localcommand.local_command('waitforshare/{session.block_hash}')