#
#  Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#
import logging
import re
from collections import defaultdict, Counter
from copy import deepcopy
from typing import Callable
import trio
import networkx as nx

from graphrag.general.graph_prompt import SUMMARIZE_DESCRIPTIONS_PROMPT
from graphrag.utils import get_llm_cache, set_llm_cache, handle_single_entity_extraction, \
    handle_single_relationship_extraction, split_string_by_multi_markers, flat_uniq_list, chat_limiter, get_from_to, GraphChange
from rag.llm.chat_model import Base as CompletionLLM
from rag.prompts import message_fit_in
from rag.utils import truncate

GRAPH_FIELD_SEP = "<SEP>"
DEFAULT_ENTITY_TYPES = ["organization", "person", "geo", "event", "category"]
ENTITY_EXTRACTION_MAX_GLEANINGS = 2


class Extractor:
    _llm: CompletionLLM

    def __init__(
        self,
        llm_invoker: CompletionLLM,
        language: str | None = "English",
        entity_types: list[str] | None = None,
    ):
        self._llm = llm_invoker
        self._language = language
        self._entity_types = entity_types or DEFAULT_ENTITY_TYPES

    def _chat(self, system, history, gen_conf):
        hist = deepcopy(history)
        conf = deepcopy(gen_conf)
        response = get_llm_cache(self._llm.llm_name, system, hist, conf)
        if response:
            return response
        _, system_msg = message_fit_in([{"role": "system", "content": system}], int(self._llm.max_length * 0.92))
        response = self._llm.chat(system_msg[0]["content"], hist, conf)
        response = re.sub(r"^.*</think>", "", response, flags=re.DOTALL)
        if response.find("**ERROR**") >= 0:
            logging.warning(f"Extractor._chat got error. response: {response}")
            return ""
        set_llm_cache(self._llm.llm_name, system, response, history, gen_conf)
        return response

    def _entities_and_relations(self, chunk_key: str, records: list, tuple_delimiter: str):
        maybe_nodes = defaultdict(list)
        maybe_edges = defaultdict(list)
        ent_types = [t.lower() for t in self._entity_types]
        for record in records:
            record_attributes = split_string_by_multi_markers(
                record, [tuple_delimiter]
            )

            if_entities = handle_single_entity_extraction(
                record_attributes, chunk_key
            )
            if if_entities is not None and if_entities.get("entity_type", "unknown").lower() in ent_types:
                maybe_nodes[if_entities["entity_name"]].append(if_entities)
                continue

            if_relation = handle_single_relationship_extraction(
                record_attributes, chunk_key
            )
            if if_relation is not None:
                maybe_edges[(if_relation["src_id"], if_relation["tgt_id"])].append(
                    if_relation
                )
        return dict(maybe_nodes), dict(maybe_edges)

    async def __call__(
        self, doc_id: str, chunks: list[str],
            callback: Callable | None = None
    ):

        self.callback = callback
        start_ts = trio.current_time()
        out_results = []
        async with trio.open_nursery() as nursery:
            for i, ck in enumerate(chunks):
                ck = truncate(ck, int(self._llm.max_length*0.8))
                nursery.start_soon(self._process_single_content, (doc_id, ck), i, len(chunks), out_results)

        maybe_nodes = defaultdict(list)
        maybe_edges = defaultdict(list)
        sum_token_count = 0
        for m_nodes, m_edges, token_count in out_results:
            for k, v in m_nodes.items():
                maybe_nodes[k].extend(v)
            for k, v in m_edges.items():
                maybe_edges[tuple(sorted(k))].extend(v)
            sum_token_count += token_count
        now = trio.current_time()
        if callback:
            callback(msg = f"Entities and relationships extraction done, {len(maybe_nodes)} nodes, {len(maybe_edges)} edges, {sum_token_count} tokens, {now-start_ts:.2f}s.")
        start_ts = now
        logging.info("Entities merging...")
        all_entities_data = []
        async with trio.open_nursery() as nursery:
            for en_nm, ents in maybe_nodes.items():
                nursery.start_soon(self._merge_nodes, en_nm, ents, all_entities_data)
        now = trio.current_time()
        if callback:
            callback(msg = f"Entities merging done, {now-start_ts:.2f}s.")

        start_ts = now
        logging.info("Relationships merging...")
        all_relationships_data = []
        async with trio.open_nursery() as nursery:
            for (src, tgt), rels in maybe_edges.items():
                nursery.start_soon(self._merge_edges, src, tgt, rels, all_relationships_data)
        now = trio.current_time()
        if callback:
            callback(msg = f"Relationships merging done, {now-start_ts:.2f}s.")

        if not len(all_entities_data) and not len(all_relationships_data):
            logging.warning(
                "Didn't extract any entities and relationships, maybe your LLM is not working"
            )

        if not len(all_entities_data):
            logging.warning("Didn't extract any entities")
        if not len(all_relationships_data):
            logging.warning("Didn't extract any relationships")

        return all_entities_data, all_relationships_data

    async def _merge_nodes(self, entity_name: str, entities: list[dict], all_relationships_data):
        if not entities:
            return
        entity_type = sorted(
            Counter(
                [dp["entity_type"] for dp in entities]
            ).items(),
            key=lambda x: x[1],
            reverse=True,
        )[0][0]
        description = GRAPH_FIELD_SEP.join(
            sorted(set([dp["description"] for dp in entities]))
        )
        already_source_ids = flat_uniq_list(entities, "source_id")
        description = await self._handle_entity_relation_summary(entity_name, description)
        node_data = dict(
            entity_type=entity_type,
            description=description,
            source_id=already_source_ids,
        )
        node_data["entity_name"] = entity_name
        all_relationships_data.append(node_data)

    async def _merge_edges(
            self,
            src_id: str,
            tgt_id: str,
            edges_data: list[dict],
            all_relationships_data=None
    ):
        if not edges_data:
            return
        weight = sum([edge["weight"] for edge in edges_data])
        description = GRAPH_FIELD_SEP.join(sorted(set([edge["description"] for edge in edges_data])))
        description = await self._handle_entity_relation_summary(f"{src_id} -> {tgt_id}", description)
        keywords = flat_uniq_list(edges_data, "keywords")
        source_id = flat_uniq_list(edges_data, "source_id")
        edge_data = dict(
            src_id=src_id,
            tgt_id=tgt_id,
            description=description,
            keywords=keywords,
            weight=weight,
            source_id=source_id
        )
        all_relationships_data.append(edge_data)

    async def _merge_graph_nodes(self, graph: nx.Graph, nodes: list[str], change: GraphChange):
        if len(nodes) <= 1:
            return
        change.added_updated_nodes.add(nodes[0])
        change.removed_nodes.update(nodes[1:])
        nodes_set = set(nodes)
        node0_attrs = graph.nodes[nodes[0]]
        node0_neighbors = set(graph.neighbors(nodes[0]))
        for node1 in nodes[1:]:
            # Merge two nodes, keep "entity_name", "entity_type", "page_rank" unchanged.
            node1_attrs = graph.nodes[node1]
            node0_attrs["description"] += f"{GRAPH_FIELD_SEP}{node1_attrs['description']}"
            node0_attrs["source_id"] = sorted(set(node0_attrs["source_id"] + node1_attrs["source_id"]))
            for neighbor in graph.neighbors(node1):
                change.removed_edges.add(get_from_to(node1, neighbor))
                if neighbor not in nodes_set:
                    edge1_attrs = graph.get_edge_data(node1, neighbor)
                    if neighbor in node0_neighbors:
                        # Merge two edges
                        change.added_updated_edges.add(get_from_to(nodes[0], neighbor))
                        edge0_attrs = graph.get_edge_data(nodes[0], neighbor)
                        edge0_attrs["weight"] += edge1_attrs["weight"]
                        edge0_attrs["description"] += f"{GRAPH_FIELD_SEP}{edge1_attrs['description']}"
                        for attr in ["keywords", "source_id"]:
                            edge0_attrs[attr] = sorted(set(edge0_attrs[attr] + edge1_attrs[attr]))
                        edge0_attrs["description"] = await self._handle_entity_relation_summary(f"({nodes[0]}, {neighbor})", edge0_attrs["description"])
                        graph.add_edge(nodes[0], neighbor, **edge0_attrs)
                    else:
                        graph.add_edge(nodes[0], neighbor, **edge1_attrs)
            graph.remove_node(node1)
        node0_attrs["description"] = await self._handle_entity_relation_summary(nodes[0], node0_attrs["description"])
        graph.nodes[nodes[0]].update(node0_attrs)

    async def _handle_entity_relation_summary(
            self,
            entity_or_relation_name: str,
            description: str
    ) -> str:
        summary_max_tokens = 512
        use_description = truncate(description, summary_max_tokens)
        description_list=use_description.split(GRAPH_FIELD_SEP),
        if len(description_list) <= 12:
            return use_description
        prompt_template = SUMMARIZE_DESCRIPTIONS_PROMPT
        context_base = dict(
            entity_name=entity_or_relation_name,
            description_list=description_list,
            language=self._language,
        )
        use_prompt = prompt_template.format(**context_base)
        logging.info(f"Trigger summary: {entity_or_relation_name}")
        async with chat_limiter:
            summary = await trio.to_thread.run_sync(lambda: self._chat(use_prompt, [{"role": "user", "content": "Output: "}], {"temperature": 0.8}))
        return summary