import json
import logging
import os
import uuid
from dataclasses import dataclass
from typing import Any, List, Optional

import torch

from sglang.srt.mem_cache.hicache_storage import (
    HiCacheStorage,
    HiCacheStorageConfig,
    HiCacheStorageExtraInfo,
)
from sglang.srt.mem_cache.memory_pool_host import HostKVCache

DEFAULT_GLOBAL_SEGMENT_SIZE = 4 * 1024 * 1024 * 1024  # 4 GiB
DEFAULT_LOCAL_BUFFER_SIZE = 16 * 1024 * 1024  # 16 MB
DEFAULT_MOONCAKE_CONFIG_PATH_ENV = "SGLANG_HICACHE_MOONCAKE_CONFIG_PATH"
logger = logging.getLogger(__name__)


@dataclass
class MooncakeStoreConfig:
    local_hostname: str
    metadata_server: str
    global_segment_size: int
    local_buffer_size: int
    protocol: str
    device_name: str
    master_server_address: str

    @staticmethod
    def from_file() -> "MooncakeStoreConfig":
        """Load the config from a JSON file."""
        file_path = os.getenv(DEFAULT_MOONCAKE_CONFIG_PATH_ENV)
        try:
            with open(file_path) as fin:
                config = json.load(fin)
        except Exception as e:
            raise RuntimeError(f"Failed to load config from {file_path}: {str(e)}")

        return MooncakeStoreConfig(
            local_hostname=config.get("local_hostname"),
            metadata_server=config.get("metadata_server"),
            global_segment_size=config.get(
                "global_segment_size", DEFAULT_GLOBAL_SEGMENT_SIZE
            ),
            # Zero copy interface does not need local buffer
            local_buffer_size=DEFAULT_LOCAL_BUFFER_SIZE,
            protocol=config.get("protocol", "tcp"),
            device_name=config.get("device_name", "auto"),
            master_server_address=config.get("master_server_address"),
        )

    @staticmethod
    def load_from_env() -> "MooncakeStoreConfig":
        """Load config from a file specified in the environment variable.
        export MOONCAKE_MASTER=10.13.3.232:50051
        export MOONCAKE_PROTOCOL="rdma"
        export MOONCAKE_DEVICE="auto"
        export MOONCAKE_TE_META_DATA_SERVER="P2PHANDSHAKE"
        """
        # other required environment variables...
        if not os.getenv("MOONCAKE_MASTER"):
            raise ValueError("The environment variable 'MOONCAKE_MASTER' is not set.")
        return MooncakeStoreConfig(
            local_hostname=os.getenv("LOCAL_HOSTNAME", "localhost"),
            metadata_server=os.getenv("MOONCAKE_TE_META_DATA_SERVER", "P2PHANDSHAKE"),
            global_segment_size=int(
                os.getenv("MOONCAKE_GLOBAL_SEGMENT_SIZE", DEFAULT_GLOBAL_SEGMENT_SIZE)
            ),
            # Zero copy interface does not need local buffer
            local_buffer_size=DEFAULT_LOCAL_BUFFER_SIZE,
            protocol=os.getenv("MOONCAKE_PROTOCOL", "tcp"),
            device_name=os.getenv("MOONCAKE_DEVICE", "auto"),
            master_server_address=os.getenv("MOONCAKE_MASTER"),
        )

    @staticmethod
    def load_from_extra_config(extra_config: dict) -> "MooncakeStoreConfig":
        """Load config from extra_config dictionary."""
        if "master_server_address" not in extra_config:
            raise ValueError("master_server_address is required in extra_config")

        return MooncakeStoreConfig(
            local_hostname=extra_config.get("local_hostname", "localhost"),
            metadata_server=extra_config.get("metadata_server", "P2PHANDSHAKE"),
            global_segment_size=extra_config.get(
                "global_segment_size", DEFAULT_GLOBAL_SEGMENT_SIZE
            ),
            local_buffer_size=extra_config.get(
                "local_buffer_size", DEFAULT_LOCAL_BUFFER_SIZE
            ),
            protocol=extra_config.get("protocol", "tcp"),
            device_name=extra_config.get("device_name", "auto"),
            master_server_address=extra_config["master_server_address"],
        )

    def __post_init__(self):
        if self.device_name == "auto":
            os.environ["MC_MS_AUTO_DISC"] = "1"
            os.environ["MC_MS_FILTERS"] = (
                "mlx5_bond_0, mlx5_bond_1, mlx5_bond_2, mlx5_bond_3"
            )


class MooncakeStore(HiCacheStorage):

    def __init__(self, storage_config: HiCacheStorageConfig = None):
        try:
            from mooncake.store import MooncakeDistributedStore
        except ImportError as e:
            raise ImportError(
                "Please install mooncake by following the instructions at "
                "https://kvcache-ai.github.io/Mooncake/getting_started/build.html"
                "to run SGLang with MooncakeConnector."
            ) from e

        try:
            self.store = MooncakeDistributedStore()

            extra_config = (
                getattr(storage_config, "extra_config", None)
                if storage_config
                else None
            )
            # Load configuration with master_server_address prioritized from extra_config if available
            if (
                extra_config is not None
                and extra_config.get("master_server_address") is not None
            ):
                # Load from extra_config
                self.config = MooncakeStoreConfig.load_from_extra_config(extra_config)
                logger.info(
                    "Mooncake Configuration loaded from extra_config successfully."
                )
            elif os.getenv(DEFAULT_MOONCAKE_CONFIG_PATH_ENV):
                # Load from config file
                self.config = MooncakeStoreConfig.from_file()
                logger.info("Mooncake Configuration loaded from file successfully.")
            else:
                # Load from environment variables
                self.config = MooncakeStoreConfig.load_from_env()
                logger.info("Mooncake Configuration loaded from env successfully.")

            tp_scale_factor = 1 if storage_config is None else storage_config.tp_size

            per_tp_global_segment_size = (
                self.config.global_segment_size // tp_scale_factor
            )
            per_tp_local_buffer_size = self.config.local_buffer_size // tp_scale_factor

            ret_code = self.store.setup(
                self.config.local_hostname,
                self.config.metadata_server,
                per_tp_global_segment_size,
                per_tp_local_buffer_size,
                self.config.protocol,
                self.config.device_name,
                self.config.master_server_address,
            )
            if ret_code:
                logger.error(f"failed to setup mooncake store, error code: {ret_code}")

            logger.info("Connect to Mooncake store successfully.")
            self.warmup()
            logger.info("Mooncake store warmup successfully.")

            if storage_config is not None:
                self.is_mla_backend = storage_config.is_mla_model
                self.local_rank = storage_config.tp_rank
            else:
                self.is_mla_backend = False
                self.local_rank = 0

        except ValueError as e:
            logger.error("Configuration loading failed: %s", e)
            raise
        except Exception as exc:
            logger.error("An error occurred while loading the configuration: %s", exc)
            raise

    def warmup(self):
        warmup_key = "sglang_mooncake_store_warmup_key" + uuid.uuid4().hex
        warmup_value = bytes(4 * 1024)  # 4 KB
        assert self.store.put(warmup_key, warmup_value) == 0
        assert self.store.is_exist(warmup_key) == 1
        assert self.store.get(warmup_key) == warmup_value

    def register_mem_pool_host(self, mem_pool_host: HostKVCache):
        super().register_mem_pool_host(mem_pool_host)
        assert (
            self.mem_pool_host.layout == "page_first"
        ), "mooncake store storage backend only support page first layout"
        buffer = self.mem_pool_host.kv_buffer
        try:
            buffer_ptr = buffer.data_ptr()
            buffer_size = buffer.numel() * buffer.element_size()
            ret_code = self.store.register_buffer(buffer_ptr, buffer_size)
            if ret_code:
                logger.error(f"failed to register buffer, error code: {ret_code}")
        except TypeError as err:
            logger.error("Failed to register buffer to Mooncake Store: %s", err)
            raise TypeError("Mooncake Store Register Buffer Error.") from err

    def _get_mha_buffer_meta(self, keys, indices):
        ptr_list, element_size_list = self.mem_pool_host.get_page_buffer_meta(indices)
        key_list = []
        for key_ in keys:
            key_list.append(f"{key_}_{self.local_rank}_k")
            key_list.append(f"{key_}_{self.local_rank}_v")
        assert len(key_list) == len(ptr_list)
        return key_list, ptr_list, element_size_list

    def _get_mla_buffer_meta(self, keys, indices):
        ptr_list, element_size_list = self.mem_pool_host.get_page_buffer_meta(indices)
        key_list = []
        for key_ in keys:
            key_list.append(f"{key_}_k")
        assert len(key_list) == len(ptr_list)
        return key_list, ptr_list, element_size_list

    def _batch_preprocess(self, keys, host_indices):
        assert len(keys) > 0
        assert len(keys) == len(host_indices) // self.mem_pool_host.page_size
        if self.is_mla_backend:
            return self._get_mla_buffer_meta(keys, host_indices)
        else:
            return self._get_mha_buffer_meta(keys, host_indices)

    def _batch_postprocess(self, results: List[int], is_set_operate=False):
        """
        refer to https://github.com/kvcache-ai/Mooncake/blob/main/mooncake-store/include/pybind_client.h
        for batch_get_into, results is Vector of integers,
            where each element is the number of bytes read on success, or a negative value on error
        for batch_put_from, results is Vector of integers,
            where each element is 0 on success, or a negative value on error
        """
        if self.is_mla_backend:
            return [k_res == 0 if is_set_operate else k_res > 0 for k_res in results]
        else:
            kv_pairs = zip(results[::2], results[1::2])
            return [
                (
                    (k_res == 0 and v_res == 0)
                    if is_set_operate
                    else (k_res > 0 and v_res > 0)
                )
                for k_res, v_res in kv_pairs
            ]

    def batch_get_v1(
        self,
        keys: List[str],
        host_indices: torch.Tensor,
        extra_info: Optional[HiCacheStorageExtraInfo] = None,
    ) -> List[bool]:
        key_strs, buffer_ptrs, buffer_sizes = self._batch_preprocess(keys, host_indices)
        get_results = self._get_batch_zero_copy_impl(
            key_strs, buffer_ptrs, buffer_sizes
        )
        return self._batch_postprocess(get_results, is_set_operate=False)

    def batch_set_v1(
        self,
        keys: List[str],
        host_indices: torch.Tensor,
        extra_info: Optional[HiCacheStorageExtraInfo] = None,
    ) -> List[bool]:
        key_strs, buffer_ptrs, buffer_sizes = self._batch_preprocess(keys, host_indices)
        exist_result = self._batch_exist(key_strs)

        set_keys = []
        set_buffer_ptrs = []
        set_buffer_sizes = []
        set_indices = []
        set_results = [-1] * len(keys)
        for i in range(len(keys)):
            if exist_result[i] != 1:
                set_keys.append(keys[i])
                set_buffer_ptrs.append(buffer_ptrs[i])
                set_buffer_sizes.append(buffer_sizes[i])
                set_indices.append(i)
            else:
                set_results[i] = 0

        # Only set non-existing keys to storage
        if len(set_keys) > 0:
            put_results = self._put_batch_zero_copy_impl(
                key_strs, buffer_ptrs, buffer_sizes
            )
            for i in range(len(set_indices)):
                set_results[set_indices[i]] = put_results[i]

        return self._batch_postprocess(set_results, is_set_operate=True)

    def set(
        self,
        key,
        value: Optional[Any] = None,
        target_location: Optional[List[int]] = None,
        target_sizes: Optional[List[int]] = None,
    ) -> bool:
        # Only support zero copy set for now
        assert target_location is not None and target_sizes is not None
        exist_result = self._batch_exist([key])
        if exist_result[0] == 1:
            return True
        put_result = self._put_batch_zero_copy_impl(
            [key], [target_location], [target_sizes]
        )
        return put_result[0] == 0

    def batch_set(
        self,
        keys: List[str],
        values: Optional[List[torch.Tensor]] = None,
        target_locations: Optional[List[int]] = None,
        target_sizes: Optional[List[int]] = None,
    ) -> bool:
        # Only support zero copy set for now
        assert target_locations is not None and target_sizes is not None
        assert len(keys) == len(target_locations) == len(target_sizes)

        if len(keys) == 0:
            return False

        for i in range(len(keys)):
            if (
                keys[i] is None
                or target_locations[i] is None
                or target_sizes[i] is None
            ):
                return False

        exist_result = self._batch_exist(keys)
        set_keys = []
        set_target_locations = []
        set_target_sizes = []
        set_indices = []
        for i in range(len(keys)):
            if exist_result[i] != 1:
                set_keys.append(keys[i])
                set_target_locations.append(target_locations[i])
                set_target_sizes.append(target_sizes[i])
                set_indices.append(i)
        # Only set non-existing keys to storage
        put_result = self._put_batch_zero_copy_impl(
            set_keys, set_target_locations, set_target_sizes
        )
        for i in range(len(set_indices)):
            if put_result[i] == 0:
                exist_result[set_indices[i]] = 1

        success_count = 0
        for i in range(len(keys)):
            if exist_result[i] == 0:
                break
            success_count += 1
        # TODO: return the number of consecutive successful operations from the start.
        return success_count == len(keys)

    def get(
        self,
        key,
        target_location: Optional[Any] = None,
        target_sizes: Optional[Any] = None,
    ) -> bool:
        assert target_location is not None and target_sizes is not None
        get_result = self._get_batch_zero_copy_impl(
            [key], [target_location], [target_sizes]
        )
        return get_result[0] >= 0

    def batch_get(
        self,
        keys: List[str],
        target_locations: Optional[Any] = None,
        target_sizes: Optional[Any] = None,
    ) -> int:
        assert len(keys) == len(target_locations) == len(target_sizes)
        if len(keys) == 0:
            return 0
        get_result = self._get_batch_zero_copy_impl(
            keys, target_locations, target_sizes
        )
        if self.is_mla_backend:
            key_multiplier = 1
        else:
            key_multiplier = 2
        for i in range(len(keys)):
            if get_result[i] < 0:
                return i // key_multiplier
        return len(keys) // key_multiplier

    def exists(self, key) -> bool:
        exist_result = self._batch_exist([key])
        return exist_result[0] == 1

    def batch_exists(self, keys) -> int:
        if self.is_mla_backend:
            query_keys = [f"{key}_k" for key in keys]
            key_multiplier = 1
        else:
            query_keys = []
            for key in keys:
                query_keys.append(f"{key}_{self.local_rank}_k")
                query_keys.append(f"{key}_{self.local_rank}_v")
            key_multiplier = 2

        exist_result = self._batch_exist(query_keys)
        for i in range(len(query_keys)):
            if exist_result[i] != 1:
                return i // key_multiplier
        return len(query_keys) // key_multiplier

    def close(self):
        # MooncakeDistributedStore will automatically call the destructor, so
        # it is unnecessary to close it manually.
        pass

    def clear(self) -> None:
        self.store.remove_all()

    def _put_batch_zero_copy_impl(
        self, key_strs: List[str], buffer_ptrs: List[int], buffer_sizes: List[int]
    ) -> List[int]:
        return self.store.batch_put_from(key_strs, buffer_ptrs, buffer_sizes)

    def _get_batch_zero_copy_impl(
        self, key_strs: List[str], buffer_ptrs: List[int], buffer_sizes: List[int]
    ) -> List[int]:
        return self.store.batch_get_into(key_strs, buffer_ptrs, buffer_sizes)

    def _batch_exist(self, key_strs: List[str]) -> List[int]:
        return self.store.batch_is_exist(key_strs)
