from typing import Any, Dict, List, Union
from utils.log import quick_log
from fastapi import APIRouter, HTTPException, Request, Response, status
from pydantic import BaseModel
import gc
import copy

router = APIRouter()

trie = None
dtrie: Dict = {}
max_trie_len = 3000
loop_start_id = 1  # to prevent preloaded prompts from being deleted
loop_del_trie_id = loop_start_id


def init():
    global trie
    try:
        import cyac

        # import mmap
        # import os
        #
        # if os.path.exists("state_cache.trie"):
        #     with open("state_cache.trie", "r") as bf:
        #         buff_object = mmap.mmap(bf.fileno(), 0, access=mmap.ACCESS_READ)
        #     trie = cyac.Trie.from_buff(buff_object, copy=False)
        # else:
        trie = cyac.Trie()
    except ModuleNotFoundError:
        print("cyac not found")


@router.post("/disable-state-cache", tags=["State Cache"])
def disable_state_cache():
    global trie, dtrie

    trie = None
    dtrie = {}
    gc.collect()

    return "success"


@router.post("/enable-state-cache", tags=["State Cache"])
def enable_state_cache():
    global trie, dtrie
    try:
        import cyac

        trie = cyac.Trie()
        dtrie = {}
        gc.collect()

        return "success"
    except ModuleNotFoundError:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "cyac not found")


class AddStateBody(BaseModel):
    prompt: str
    tokens: List[Union[str, int]]
    state: Any
    logits: Any


@router.post("/add-state", tags=["State Cache"])
def add_state(body: AddStateBody):
    global trie, dtrie, loop_del_trie_id
    if trie is None:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "trie not loaded")

    import torch

    try:
        id: int = trie.insert(body.prompt)
        device: torch.device = body.state[0].device
        dtrie[id] = {
            "tokens": copy.deepcopy(body.tokens),
            "state": [tensor.cpu() for tensor in body.state]
            if device != torch.device("cpu")
            else copy.deepcopy(body.state),
            "logits": copy.deepcopy(body.logits),
            "device": device,
        }

        if len(trie) >= max_trie_len:
            del_prompt = trie[loop_del_trie_id]
            trie.remove(del_prompt)
            dtrie[loop_del_trie_id] = None
            loop_del_trie_id = loop_del_trie_id + 1
            if loop_del_trie_id >= max_trie_len:
                loop_del_trie_id = loop_start_id

        quick_log(
            None,
            None,
            f"New Trie Id: {id}\nTrie Len: {len(trie)}\nTrie Buff Size: {trie.buff_size()}\nDtrie Buff Size Of Id: {_get_a_dtrie_buff_size(dtrie[id])}",
        )
        return "success"
    except Exception as e:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST, f"insert failed, bad prompt.\n{e}"
        )


@router.post("/reset-state", tags=["State Cache"])
def reset_state():
    global trie, dtrie
    if trie is None:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "trie not loaded")

    import cyac

    trie = cyac.Trie()
    dtrie = {}
    gc.collect()

    return "success"


class LongestPrefixStateBody(BaseModel):
    prompt: str


def _get_a_dtrie_buff_size(dtrie_v):
    # print(sys.getsizeof(dtrie_v["tokens"][0]))  # str
    # print(sys.getsizeof(dtrie_v["tokens"][0]) * len(dtrie_v["tokens"]))
    # print(dtrie_v["state"][0][0].element_size())
    # print(dtrie_v["state"][0].nelement())
    # print(len(dtrie_v["state"]))
    # print(
    #     len(dtrie_v["state"])
    #     * dtrie_v["state"][0].nelement()
    #     * dtrie_v["state"][0][0].element_size()
    # )
    # print(dtrie_v["logits"][0].element_size())
    # print(dtrie_v["logits"].nelement())
    # print(dtrie_v["logits"][0].element_size() * dtrie_v["logits"].nelement())
    return 54 * len(dtrie_v["tokens"]) + 491520 + 262144 + 28  # TODO


@router.post("/longest-prefix-state", tags=["State Cache"])
def longest_prefix_state(body: LongestPrefixStateBody, request: Request):
    global trie
    if trie is None:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "trie not loaded")

    import torch

    id = -1
    try:
        for id, len in trie.prefix(body.prompt):
            pass
    except:
        pass
    if id != -1:
        v = dtrie[id]
        device: torch.device = v["device"]
        prompt: str = trie[id]

        quick_log(request, body, "Hit:\n" + prompt)
        return {
            "prompt": prompt,
            "tokens": v["tokens"],
            "state": [tensor.to(device) for tensor in v["state"]]
            if device != torch.device("cpu")
            else v["state"],
            "logits": v["logits"],
            "device": device.type,
        }
    else:
        return {
            "prompt": "",
            "tokens": [],
            "state": None,
            "logits": None,
            "device": None,
        }


@router.post("/save-state", tags=["State Cache"])
def save_state():
    global trie
    if trie is None:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "trie not loaded")

    # trie.save("state_cache.trie")

    return "not implemented"