#
#  Copyright 2025 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 json
import logging
import os

import networkx as nx
import trio

from api import settings
from api.db.services.document_service import DocumentService
from api.utils import get_uuid
from api.utils.api_utils import timeout
from graphrag.entity_resolution import EntityResolution
from graphrag.general.community_reports_extractor import CommunityReportsExtractor
from graphrag.general.extractor import Extractor
from graphrag.general.graph_extractor import GraphExtractor as GeneralKGExt
from graphrag.light.graph_extractor import GraphExtractor as LightKGExt
from graphrag.utils import (
    GraphChange,
    chunk_id,
    does_graph_contains,
    get_graph,
    graph_merge,
    set_graph,
    tidy_graph,
)
from rag.nlp import rag_tokenizer, search
from rag.utils.redis_conn import RedisDistributedLock


async def run_graphrag(
    row: dict,
    language,
    with_resolution: bool,
    with_community: bool,
    chat_model,
    embedding_model,
    callback,
):
    enable_timeout_assertion = os.environ.get("ENABLE_TIMEOUT_ASSERTION")
    start = trio.current_time()
    tenant_id, kb_id, doc_id = row["tenant_id"], str(row["kb_id"]), row["doc_id"]
    chunks = []
    for d in settings.retriever.chunk_list(doc_id, tenant_id, [kb_id], fields=["content_with_weight", "doc_id"], sort_by_position=True):
        chunks.append(d["content_with_weight"])

    with trio.fail_after(max(120, len(chunks) * 60 * 10) if enable_timeout_assertion else 10000000000):
        subgraph = await generate_subgraph(
            LightKGExt if "method" not in row["kb_parser_config"].get("graphrag", {}) or row["kb_parser_config"]["graphrag"]["method"] != "general" else GeneralKGExt,
            tenant_id,
            kb_id,
            doc_id,
            chunks,
            language,
            row["kb_parser_config"]["graphrag"].get("entity_types", []),
            chat_model,
            embedding_model,
            callback,
        )

    if not subgraph:
        return

    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=1200)
    await graphrag_task_lock.spin_acquire()
    callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")

    try:
        subgraph_nodes = set(subgraph.nodes())
        new_graph = await merge_subgraph(
            tenant_id,
            kb_id,
            doc_id,
            subgraph,
            embedding_model,
            callback,
        )
        assert new_graph is not None

        if not with_resolution and not with_community:
            return

        if with_resolution:
            await graphrag_task_lock.spin_acquire()
            callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")
            await resolve_entities(
                new_graph,
                subgraph_nodes,
                tenant_id,
                kb_id,
                doc_id,
                chat_model,
                embedding_model,
                callback,
            )
        if with_community:
            await graphrag_task_lock.spin_acquire()
            callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")
            await extract_community(
                new_graph,
                tenant_id,
                kb_id,
                doc_id,
                chat_model,
                embedding_model,
                callback,
            )
    finally:
        graphrag_task_lock.release()
    now = trio.current_time()
    callback(msg=f"GraphRAG for doc {doc_id} done in {now - start:.2f} seconds.")
    return


async def run_graphrag_for_kb(
    row: dict,
    doc_ids: list[str],
    language: str,
    kb_parser_config: dict,
    chat_model,
    embedding_model,
    callback,
    *,
    with_resolution: bool = True,
    with_community: bool = True,
    max_parallel_docs: int = 4,
) -> dict:
    tenant_id, kb_id = row["tenant_id"], row["kb_id"]
    enable_timeout_assertion = os.environ.get("ENABLE_TIMEOUT_ASSERTION")
    start = trio.current_time()
    fields_for_chunks = ["content_with_weight", "doc_id"]

    if not doc_ids:
        logging.info(f"Fetching all docs for {kb_id}")
        docs, _ = DocumentService.get_by_kb_id(
            kb_id=kb_id,
            page_number=0,
            items_per_page=0,
            orderby="create_time",
            desc=False,
            keywords="",
            run_status=[],
            types=[],
            suffix=[],
        )
        doc_ids = [doc["id"] for doc in docs]

    doc_ids = list(dict.fromkeys(doc_ids))
    if not doc_ids:
        callback(msg=f"[GraphRAG] kb:{kb_id} has no processable doc_id.")
        return {"ok_docs": [], "failed_docs": [], "total_docs": 0, "total_chunks": 0, "seconds": 0.0}

    def load_doc_chunks(doc_id: str) -> list[str]:
        from rag.utils import num_tokens_from_string

        chunks = []
        current_chunk = ""

        for d in settings.retriever.chunk_list(
            doc_id,
            tenant_id,
            [kb_id],
            fields=fields_for_chunks,
            sort_by_position=True,
        ):
            content = d["content_with_weight"]
            if num_tokens_from_string(current_chunk + content) < 1024:
                current_chunk += content
            else:
                if current_chunk:
                    chunks.append(current_chunk)
                current_chunk = content

        if current_chunk:
            chunks.append(current_chunk)

        return chunks

    all_doc_chunks: dict[str, list[str]] = {}
    total_chunks = 0
    for doc_id in doc_ids:
        chunks = load_doc_chunks(doc_id)
        all_doc_chunks[doc_id] = chunks
        total_chunks += len(chunks)

    if total_chunks == 0:
        callback(msg=f"[GraphRAG] kb:{kb_id} has no available chunks in all documents, skip.")
        return {"ok_docs": [], "failed_docs": doc_ids, "total_docs": len(doc_ids), "total_chunks": 0, "seconds": 0.0}

    semaphore = trio.Semaphore(max_parallel_docs)

    subgraphs: dict[str, object] = {}
    failed_docs: list[tuple[str, str]] = []  # (doc_id, error)

    async def build_one(doc_id: str):
        chunks = all_doc_chunks.get(doc_id, [])
        if not chunks:
            callback(msg=f"[GraphRAG] doc:{doc_id} has no available chunks, skip generation.")
            return

        kg_extractor = LightKGExt if ("method" not in kb_parser_config.get("graphrag", {}) or kb_parser_config["graphrag"]["method"] != "general") else GeneralKGExt

        deadline = max(120, len(chunks) * 60 * 10) if enable_timeout_assertion else 10000000000

        async with semaphore:
            try:
                msg = f"[GraphRAG] build_subgraph doc:{doc_id}"
                callback(msg=f"{msg} start (chunks={len(chunks)}, timeout={deadline}s)")
                with trio.fail_after(deadline):
                    sg = await generate_subgraph(
                        kg_extractor,
                        tenant_id,
                        kb_id,
                        doc_id,
                        chunks,
                        language,
                        kb_parser_config.get("graphrag", {}).get("entity_types", []),
                        chat_model,
                        embedding_model,
                        callback,
                    )
                if sg:
                    subgraphs[doc_id] = sg
                    callback(msg=f"{msg} done")
                else:
                    failed_docs.append((doc_id, "subgraph is empty"))
                    callback(msg=f"{msg} empty")
            except Exception as e:
                failed_docs.append((doc_id, repr(e)))
                callback(msg=f"[GraphRAG] build_subgraph doc:{doc_id} FAILED: {e!r}")

    async with trio.open_nursery() as nursery:
        for doc_id in doc_ids:
            nursery.start_soon(build_one, doc_id)

    ok_docs = [d for d in doc_ids if d in subgraphs]
    if not ok_docs:
        callback(msg=f"[GraphRAG] kb:{kb_id} no subgraphs generated successfully, end.")
        now = trio.current_time()
        return {"ok_docs": [], "failed_docs": failed_docs, "total_docs": len(doc_ids), "total_chunks": total_chunks, "seconds": now - start}

    kb_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value="batch_merge", timeout=1200)
    await kb_lock.spin_acquire()
    callback(msg=f"[GraphRAG] kb:{kb_id} merge lock acquired")

    try:
        union_nodes: set = set()
        final_graph = None

        for doc_id in ok_docs:
            sg = subgraphs[doc_id]
            union_nodes.update(set(sg.nodes()))

            new_graph = await merge_subgraph(
                tenant_id,
                kb_id,
                doc_id,
                sg,
                embedding_model,
                callback,
            )
            if new_graph is not None:
                final_graph = new_graph

        if final_graph is None:
            callback(msg=f"[GraphRAG] kb:{kb_id} merge finished (no in-memory graph returned).")
        else:
            callback(msg=f"[GraphRAG] kb:{kb_id} merge finished, graph ready.")
    finally:
        kb_lock.release()

    if not with_resolution and not with_community:
        now = trio.current_time()
        callback(msg=f"[GraphRAG] KB merge done in {now - start:.2f}s. ok={len(ok_docs)} / total={len(doc_ids)}")
        return {"ok_docs": ok_docs, "failed_docs": failed_docs, "total_docs": len(doc_ids), "total_chunks": total_chunks, "seconds": now - start}

    await kb_lock.spin_acquire()
    callback(msg=f"[GraphRAG] kb:{kb_id} post-merge lock acquired for resolution/community")

    try:
        subgraph_nodes = set()
        for sg in subgraphs.values():
            subgraph_nodes.update(set(sg.nodes()))

        if with_resolution:
            await resolve_entities(
                final_graph,
                subgraph_nodes,
                tenant_id,
                kb_id,
                None,
                chat_model,
                embedding_model,
                callback,
            )

        if with_community:
            await extract_community(
                final_graph,
                tenant_id,
                kb_id,
                None,
                chat_model,
                embedding_model,
                callback,
            )
    finally:
        kb_lock.release()

    now = trio.current_time()
    callback(msg=f"[GraphRAG] GraphRAG for KB {kb_id} done in {now - start:.2f} seconds. ok={len(ok_docs)} failed={len(failed_docs)} total_docs={len(doc_ids)} total_chunks={total_chunks}")
    return {
        "ok_docs": ok_docs,
        "failed_docs": failed_docs,  # [(doc_id, error), ...]
        "total_docs": len(doc_ids),
        "total_chunks": total_chunks,
        "seconds": now - start,
    }


async def generate_subgraph(
    extractor: Extractor,
    tenant_id: str,
    kb_id: str,
    doc_id: str,
    chunks: list[str],
    language,
    entity_types,
    llm_bdl,
    embed_bdl,
    callback,
):
    contains = await does_graph_contains(tenant_id, kb_id, doc_id)
    if contains:
        callback(msg=f"Graph already contains {doc_id}")
        return None
    start = trio.current_time()
    ext = extractor(
        llm_bdl,
        language=language,
        entity_types=entity_types,
    )
    ents, rels = await ext(doc_id, chunks, callback)
    subgraph = nx.Graph()
    for ent in ents:
        assert "description" in ent, f"entity {ent} does not have description"
        ent["source_id"] = [doc_id]
        subgraph.add_node(ent["entity_name"], **ent)

    ignored_rels = 0
    for rel in rels:
        assert "description" in rel, f"relation {rel} does not have description"
        if not subgraph.has_node(rel["src_id"]) or not subgraph.has_node(rel["tgt_id"]):
            ignored_rels += 1
            continue
        rel["source_id"] = [doc_id]
        subgraph.add_edge(
            rel["src_id"],
            rel["tgt_id"],
            **rel,
        )
    if ignored_rels:
        callback(msg=f"ignored {ignored_rels} relations due to missing entities.")
    tidy_graph(subgraph, callback, check_attribute=False)

    subgraph.graph["source_id"] = [doc_id]
    chunk = {
        "content_with_weight": json.dumps(nx.node_link_data(subgraph, edges="edges"), ensure_ascii=False),
        "knowledge_graph_kwd": "subgraph",
        "kb_id": kb_id,
        "source_id": [doc_id],
        "available_int": 0,
        "removed_kwd": "N",
    }
    cid = chunk_id(chunk)
    await trio.to_thread.run_sync(settings.docStoreConn.delete, {"knowledge_graph_kwd": "subgraph", "source_id": doc_id}, search.index_name(tenant_id), kb_id)
    await trio.to_thread.run_sync(settings.docStoreConn.insert, [{"id": cid, **chunk}], search.index_name(tenant_id), kb_id)
    now = trio.current_time()
    callback(msg=f"generated subgraph for doc {doc_id} in {now - start:.2f} seconds.")
    return subgraph


@timeout(60 * 3)
async def merge_subgraph(
    tenant_id: str,
    kb_id: str,
    doc_id: str,
    subgraph: nx.Graph,
    embedding_model,
    callback,
):
    start = trio.current_time()
    change = GraphChange()
    old_graph = await get_graph(tenant_id, kb_id, subgraph.graph["source_id"])
    if old_graph is not None:
        logging.info("Merge with an exiting graph...................")
        tidy_graph(old_graph, callback)
        new_graph = graph_merge(old_graph, subgraph, change)
    else:
        new_graph = subgraph
        change.added_updated_nodes = set(new_graph.nodes())
        change.added_updated_edges = set(new_graph.edges())
    pr = nx.pagerank(new_graph)
    for node_name, pagerank in pr.items():
        new_graph.nodes[node_name]["pagerank"] = pagerank

    await set_graph(tenant_id, kb_id, embedding_model, new_graph, change, callback)
    now = trio.current_time()
    callback(msg=f"merging subgraph for doc {doc_id} into the global graph done in {now - start:.2f} seconds.")
    return new_graph


@timeout(60 * 30, 1)
async def resolve_entities(
    graph,
    subgraph_nodes: set[str],
    tenant_id: str,
    kb_id: str,
    doc_id: str,
    llm_bdl,
    embed_bdl,
    callback,
):
    start = trio.current_time()
    er = EntityResolution(
        llm_bdl,
    )
    reso = await er(graph, subgraph_nodes, callback=callback)
    graph = reso.graph
    change = reso.change
    callback(msg=f"Graph resolution removed {len(change.removed_nodes)} nodes and {len(change.removed_edges)} edges.")
    callback(msg="Graph resolution updated pagerank.")

    await set_graph(tenant_id, kb_id, embed_bdl, graph, change, callback)
    now = trio.current_time()
    callback(msg=f"Graph resolution done in {now - start:.2f}s.")


@timeout(60 * 30, 1)
async def extract_community(
    graph,
    tenant_id: str,
    kb_id: str,
    doc_id: str,
    llm_bdl,
    embed_bdl,
    callback,
):
    start = trio.current_time()
    ext = CommunityReportsExtractor(
        llm_bdl,
    )
    cr = await ext(graph, callback=callback)
    community_structure = cr.structured_output
    community_reports = cr.output
    doc_ids = graph.graph["source_id"]

    now = trio.current_time()
    callback(msg=f"Graph extracted {len(cr.structured_output)} communities in {now - start:.2f}s.")
    start = now
    chunks = []
    for stru, rep in zip(community_structure, community_reports):
        obj = {
            "report": rep,
            "evidences": "\n".join([f.get("explanation", "") for f in stru["findings"]]),
        }
        chunk = {
            "id": get_uuid(),
            "docnm_kwd": stru["title"],
            "title_tks": rag_tokenizer.tokenize(stru["title"]),
            "content_with_weight": json.dumps(obj, ensure_ascii=False),
            "content_ltks": rag_tokenizer.tokenize(obj["report"] + " " + obj["evidences"]),
            "knowledge_graph_kwd": "community_report",
            "weight_flt": stru["weight"],
            "entities_kwd": stru["entities"],
            "important_kwd": stru["entities"],
            "kb_id": kb_id,
            "source_id": list(doc_ids),
            "available_int": 0,
        }
        chunk["content_sm_ltks"] = rag_tokenizer.fine_grained_tokenize(chunk["content_ltks"])
        chunks.append(chunk)

    await trio.to_thread.run_sync(
        lambda: settings.docStoreConn.delete(
            {"knowledge_graph_kwd": "community_report", "kb_id": kb_id},
            search.index_name(tenant_id),
            kb_id,
        )
    )
    es_bulk_size = 4
    for b in range(0, len(chunks), es_bulk_size):
        doc_store_result = await trio.to_thread.run_sync(lambda: settings.docStoreConn.insert(chunks[b : b + es_bulk_size], search.index_name(tenant_id), kb_id))
        if doc_store_result:
            error_message = f"Insert chunk error: {doc_store_result}, please check log file and Elasticsearch/Infinity status!"
            raise Exception(error_message)

    now = trio.current_time()
    callback(msg=f"Graph indexed {len(cr.structured_output)} communities in {now - start:.2f}s.")
    return community_structure, community_reports
