import asyncio
import time
from pathlib import Path
from typing import Callable, List, Tuple

from blspy import AugSchemeMPL, G2Element, G1Element

from staidelta.consensus.pot_iterations import calculate_iterations_quality, calculate_sp_interval_iters
from staidelta.harvester.harvester import Harvester
from staidelta.plotting.util import PlotInfo, parse_plot_info
from staidelta.protocols import harvester_protocol
from staidelta.protocols.farmer_protocol import FarmingInfo
from staidelta.protocols.harvester_protocol import Plot
from staidelta.protocols.protocol_message_types import ProtocolMessageTypes
from staidelta.server.outbound_message import make_msg
from staidelta.server.ws_connection import WSStaiDeltaConnection
from staidelta.types.blockchain_format.proof_of_space import ProofOfSpace
from staidelta.types.blockchain_format.sized_bytes import bytes32
from staidelta.util.api_decorators import api_request, peer_required
from staidelta.util.ints import uint8, uint32, uint64
from staidelta.wallet.derive_keys import master_sk_to_local_sk


class HarvesterAPI:
    harvester: Harvester

    def __init__(self, harvester: Harvester):
        self.harvester = harvester

    def _set_state_changed_callback(self, callback: Callable):
        self.harvester.state_changed_callback = callback

    @api_request
    async def harvester_handshake(self, harvester_handshake: harvester_protocol.HarvesterHandshake):
        """
        Handshake between the harvester and farmer. The harvester receives the pool public keys,
        as well as the farmer pks, which must be put into the plots, before the plotting process begins.
        We cannot use any plots which have different keys in them.
        """
        self.harvester.plot_manager.set_public_keys(
            harvester_handshake.farmer_public_keys, harvester_handshake.pool_public_keys
        )

        self.harvester.plot_manager.start_refreshing()

    @peer_required
    @api_request
    async def new_signage_point_harvester(
        self, new_challenge: harvester_protocol.NewSignagePointHarvester, peer: WSStaiDeltaConnection
    ):
        """
        The harvester receives a new signage point from the farmer, this happens at the start of each slot.
        The harvester does a few things:
        1. The harvester applies the plot filter for each of the plots, to select the proportion which are eligible
        for this signage point and challenge.
        2. The harvester gets the qualities for each plot. This is approximately 7 reads per plot which qualifies.
        Note that each plot may have 0, 1, 2, etc qualities for that challenge: but on average it will have 1.
        3. Checks the required_iters for each quality and the given signage point, to see which are eligible for
        inclusion (required_iters < sp_interval_iters).
        4. Looks up the full proof of space in the plot for each quality, approximately 64 reads per quality
        5. Returns the proof of space to the farmer
        """
        if not self.harvester.plot_manager.public_keys_available():
            # This means that we have not received the handshake yet
            return None

        start = time.time()
        assert len(new_challenge.challenge_hash) == 32

        loop = asyncio.get_running_loop()

        def blocking_lookup(filename: Path, plot_info: PlotInfo) -> List[Tuple[bytes32, ProofOfSpace]]:
            # Uses the DiskProver object to lookup qualities. This is a blocking call,
            # so it should be run in a thread pool.
            try:
                plot_id = plot_info.prover.get_id()
                sp_challenge_hash = ProofOfSpace.calculate_pos_challenge(
                    plot_id,
                    new_challenge.challenge_hash,
                    new_challenge.sp_hash,
                )
                try:
                    quality_strings = plot_info.prover.get_qualities_for_challenge(sp_challenge_hash)
                except Exception as e:
                    self.harvester.log.error(f"Error using prover object {e}")
                    self.harvester.log.error(
                        f"File: {filename} Plot ID: {plot_id.hex()}, "
                        f"challenge: {sp_challenge_hash}, plot_info: {plot_info}"
                    )
                    return []

                responses: List[Tuple[bytes32, ProofOfSpace]] = []
                if quality_strings is not None:
                    difficulty = new_challenge.difficulty
                    sub_slot_iters = new_challenge.sub_slot_iters
                    if plot_info.pool_contract_puzzle_hash is not None:
                        # If we are pooling, override the difficulty and sub slot iters with the pool threshold info.
                        # This will mean more proofs actually get found, but they are only submitted to the pool,
                        # not the blockchain
                        for pool_difficulty in new_challenge.pool_difficulties:
                            if pool_difficulty.pool_contract_puzzle_hash == plot_info.pool_contract_puzzle_hash:
                                difficulty = pool_difficulty.difficulty
                                sub_slot_iters = pool_difficulty.sub_slot_iters

                    # Found proofs of space (on average 1 is expected per plot)
                    for index, quality_str in enumerate(quality_strings):
                        required_iters: uint64 = calculate_iterations_quality(
                            self.harvester.constants.DIFFICULTY_CONSTANT_FACTOR,
                            quality_str,
                            plot_info.prover.get_size(),
                            difficulty,
                            new_challenge.sp_hash,
                        )
                        sp_interval_iters = calculate_sp_interval_iters(self.harvester.constants, sub_slot_iters)
                        if required_iters < sp_interval_iters:
                            # Found a very good proof of space! will fetch the whole proof from disk,
                            # then send to farmer
                            try:
                                proof_xs = plot_info.prover.get_full_proof(
                                    sp_challenge_hash, index, self.harvester.parallel_read
                                )
                            except Exception as e:
                                self.harvester.log.error(f"Exception fetching full proof for {filename}. {e}")
                                self.harvester.log.error(
                                    f"File: {filename} Plot ID: {plot_id.hex()}, challenge: {sp_challenge_hash}, "
                                    f"plot_info: {plot_info}"
                                )
                                continue

                            # Look up local_sk from plot to save locked memory
                            (
                                pool_public_key_or_puzzle_hash,
                                farmer_public_key,
                                local_master_sk,
                            ) = parse_plot_info(plot_info.prover.get_memo())
                            local_sk = master_sk_to_local_sk(local_master_sk)
                            responses.append(
                                (
                                    quality_str,
                                    ProofOfSpace(
                                        sp_challenge_hash,
                                        plot_info.pool_public_key,
                                        plot_info.pool_contract_puzzle_hash,
                                        local_sk.get_g1(),
                                        uint8(plot_info.prover.get_size()),
                                        proof_xs,
                                        farmer_public_key,
                                    ),
                                )
                            )
                return responses
            except Exception as e:
                self.harvester.log.error(f"Unknown error: {e}")
                return []

        async def lookup_challenge(
            filename: Path, plot_info: PlotInfo
        ) -> Tuple[Path, List[harvester_protocol.NewProofOfSpace]]:
            # Executes a DiskProverLookup in a thread pool, and returns responses
            all_responses: List[harvester_protocol.NewProofOfSpace] = []
            if self.harvester._is_shutdown:
                return filename, []
            proofs_of_space_and_q: List[Tuple[bytes32, ProofOfSpace]] = await loop.run_in_executor(
                self.harvester.executor, blocking_lookup, filename, plot_info
            )
            for quality_str, proof_of_space in proofs_of_space_and_q:
                all_responses.append(
                    harvester_protocol.NewProofOfSpace(
                        new_challenge.challenge_hash,
                        new_challenge.sp_hash,
                        quality_str.hex() + str(filename.resolve()),
                        proof_of_space,
                        new_challenge.signage_point_index,
                    )
                )
            return filename, all_responses

        awaitables = []
        passed = 0
        total = 0
        with self.harvester.plot_manager:
            for try_plot_filename, try_plot_info in self.harvester.plot_manager.plots.items():
                try:
                    if try_plot_filename.exists():
                        # Passes the plot filter (does not check sp filter yet though, since we have not reached sp)
                        # This is being executed at the beginning of the slot
                        total += 1
                        if ProofOfSpace.passes_plot_filter(
                            self.harvester.constants,
                            try_plot_info.prover.get_id(),
                            new_challenge.challenge_hash,
                            new_challenge.sp_hash,
                        ):
                            passed += 1
                            awaitables.append(lookup_challenge(try_plot_filename, try_plot_info))
                except Exception as e:
                    self.harvester.log.error(f"Error plot file {try_plot_filename} may no longer exist {e}")

        # Concurrently executes all lookups on disk, to take advantage of multiple disk parallelism
        total_proofs_found = 0
        for filename_sublist_awaitable in asyncio.as_completed(awaitables):
            filename, sublist = await filename_sublist_awaitable
            time_taken = time.time() - start
            if time_taken > 5:
                self.harvester.log.warning(
                    f"Looking up qualities on {filename} took: {time_taken}. This should be below 5 seconds "
                    f"to minimize risk of losing rewards."
                )
            else:
                pass
                # If you want additional logs, uncomment the following line
                # self.harvester.log.debug(f"Looking up qualities on {filename} took: {time_taken}")
            for response in sublist:
                total_proofs_found += 1
                msg = make_msg(ProtocolMessageTypes.new_proof_of_space, response)
                await peer.send_message(msg)

        now = uint64(int(time.time()))
        farming_info = FarmingInfo(
            new_challenge.challenge_hash,
            new_challenge.sp_hash,
            now,
            uint32(passed),
            uint32(total_proofs_found),
            uint32(total),
        )
        pass_msg = make_msg(ProtocolMessageTypes.farming_info, farming_info)
        await peer.send_message(pass_msg)
        self.harvester.log.info(
            f"{len(awaitables)} plots were eligible for farming {new_challenge.challenge_hash.hex()[:10]}..."
            f" Found {total_proofs_found} proofs. Time: {time.time() - start:.5f} s. "
            f"Total {self.harvester.plot_manager.plot_count()} plots"
        )

    @api_request
    async def request_signatures(self, request: harvester_protocol.RequestSignatures):
        """
        The farmer requests a signature on the header hash, for one of the proofs that we found.
        A signature is created on the header hash using the harvester private key. This can also
        be used for pooling.
        """
        plot_filename = Path(request.plot_identifier[64:]).resolve()
        with self.harvester.plot_manager:
            try:
                plot_info = self.harvester.plot_manager.plots[plot_filename]
            except KeyError:
                self.harvester.log.warning(f"KeyError plot {plot_filename} does not exist.")
                return None

            # Look up local_sk from plot to save locked memory
            (
                pool_public_key_or_puzzle_hash,
                farmer_public_key,
                local_master_sk,
            ) = parse_plot_info(plot_info.prover.get_memo())
            local_sk = master_sk_to_local_sk(local_master_sk)

        if isinstance(pool_public_key_or_puzzle_hash, G1Element):
            include_taproot = False
        else:
            assert isinstance(pool_public_key_or_puzzle_hash, bytes32)
            include_taproot = True

        agg_pk = ProofOfSpace.generate_plot_public_key(local_sk.get_g1(), farmer_public_key, include_taproot)

        # This is only a partial signature. When combined with the farmer's half, it will
        # form a complete PrependSignature.
        message_signatures: List[Tuple[bytes32, G2Element]] = []
        for message in request.messages:
            signature: G2Element = AugSchemeMPL.sign(local_sk, message, agg_pk)
            message_signatures.append((message, signature))

        response: harvester_protocol.RespondSignatures = harvester_protocol.RespondSignatures(
            request.plot_identifier,
            request.challenge_hash,
            request.sp_hash,
            local_sk.get_g1(),
            farmer_public_key,
            message_signatures,
        )

        return make_msg(ProtocolMessageTypes.respond_signatures, response)

    @api_request
    async def request_plots(self, _: harvester_protocol.RequestPlots):
        plots_response = []
        plots, failed_to_open_filenames, no_key_filenames = self.harvester.get_plots()
        for plot in plots:
            plots_response.append(
                Plot(
                    plot["filename"],
                    plot["size"],
                    plot["plot_id"],
                    plot["pool_public_key"],
                    plot["pool_contract_puzzle_hash"],
                    plot["plot_public_key"],
                    plot["file_size"],
                    plot["time_modified"],
                    plot["farmer_public_key"],
                )
            )

        response = harvester_protocol.RespondPlots(plots_response, failed_to_open_filenames, no_key_filenames)
        return make_msg(ProtocolMessageTypes.respond_plots, response)
