"""Memory V2 记忆 API 路由。

所有端点用 ``/api/memory/v2`` 前缀。Memory V2 重写后,旧的 facts/history
端点 (``/api/memory``、``/memory/facts`` 等) 已移除。

端点:
- ``GET    /memory/v2``          读取 builtin 本地记忆 (USER.md / MEMORY.md)
- ``POST   /memory/v2/entries``  新增一条记忆条目
- ``PUT    /memory/v2/entries``  替换一条记忆条目
- ``DELETE /memory/v2/entries``  删除一条记忆条目
- ``GET    /memory/v2/config``   读取生效配置 + 用户可改字段白名单
- ``PATCH  /memory/v2/config``   写入 per-user 配置覆盖 (白名单字段)
- ``DELETE /memory/v2/config``   撤销 per-user 配置覆盖
- ``POST   /memory/v2/search``   代理 Hindsight 检索 (recall / reflect)

可选 ``agent`` 查询参数:省略或传 ``global`` 表示全局桶;传 agent 名表示该
agent 的工作记忆桶。USER.md 始终是 per-user 全局的;MEMORY.md 按 agent 隔离。
"""

from __future__ import annotations

from typing import Any

from fastapi import APIRouter, HTTPException, Query, Request
from pydantic import BaseModel, Field

from app.gateway.deps import get_memory_config_store
from deerflow.config.agents_config import AGENT_NAME_PATTERN
from deerflow.config.memory_config import (
    USER_WRITABLE_FIELDS,
    delete_user_memory_override_db,
    get_effective_memory_config,
    save_user_memory_override_db,
)
from deerflow.config.paths import get_paths
from deerflow.runtime.user_context import get_effective_user_id

router = APIRouter(prefix="/api", tags=["memory"])


# 表示"全局桶 (无 agent)"的 agent 取值。
_GLOBAL_AGENT_VALUES: frozenset[str] = frozenset({"", "global", "__global__", "default"})


def _resolve_agent_name(agent: str | None) -> str | None:
    """校验 ``agent`` 查询参数,把全局哨兵规整为 ``None``。

    返回 ``None`` 表示全局桶,否则返回小写的 agent 名。非法名抛 400。
    """
    if agent is None:
        return None
    stripped = agent.strip()
    if stripped.lower() in _GLOBAL_AGENT_VALUES:
        return None
    if not AGENT_NAME_PATTERN.match(stripped):
        raise HTTPException(
            status_code=400,
            detail=f"Invalid agent name {stripped!r}: must match {AGENT_NAME_PATTERN.pattern}",
        )
    return stripped.lower()


_AgentQuery = Query(
    None,
    description="可选 agent 名。省略或传 'global' 表示全局桶;传 agent 名表示该 agent 的工作记忆桶。",
    examples=["my-agent"],
    pattern=r"^[A-Za-z0-9-]+$|^global$|^$",
)


# ===========================================================================
# 响应 / 请求模型
# ===========================================================================


class MemoryFact(BaseModel):
    """V1 记忆中的单条事实。"""

    id: str = Field(default="", description="事实 UUID")
    content: str = Field(default="", description="事实文本")
    category: str = Field(default="knowledge", description="事实类别")
    confidence: float = Field(default=0.0, description="置信度 0-1")
    createdAt: str = Field(default="", description="创建时间 ISO 格式")
    sourceError: str = Field(default="", description="纠错类事实：被纠正的原错误描述")


class MemoryV2DataResponse(BaseModel):
    """Memory 数据视图 —— V1/V2 共用,多余字段各版本置空。"""

    # V2 字段
    user_entries: list[str] = Field(default_factory=list, description="V2: USER.md 条目 (用户画像)")
    memory_entries: list[str] = Field(default_factory=list, description="V2: MEMORY.md 条目 (agent 工作笔记)")
    user_usage: str = Field(default="", description="字符/计数用量描述")
    memory_usage: str = Field(default="", description="字符/计数用量描述")

    # V1 字段
    facts: list[MemoryFact] = Field(default_factory=list, description="V1: facts 列表 (含置信度)")
    user_context: dict[str, str] = Field(default_factory=dict, description="V1: userContext 摘要")
    history: dict[str, str] = Field(default_factory=dict, description="V1: history 历史摘要")


class MemoryV2ConfigResponse(BaseModel):
    """Memory 生效配置 (含三层覆盖合并结果) + 用户可改字段白名单 + 版本号。"""

    config: dict[str, Any] = Field(..., description="按 per-user 覆盖合并后的生效配置")
    writable_fields: list[str] = Field(..., description="用户可在运行时覆盖的字段 (点号路径)")
    version: str = Field(default="v2", description="当前记忆版本:v1 或 v2")


class MemoryConfigPatchRequest(BaseModel):
    """Memory V2 配置覆盖请求。

    overrides 支持嵌套形式 ``{"injection": {"enabled": false}}`` 或点号扁平形式
    ``{"injection.enabled": false}``;非白名单字段会被忽略。
    """

    overrides: dict[str, Any] = Field(..., description="要写入 per-user 覆盖的字段")


class MemoryEntryCreateRequest(BaseModel):
    """新增一条 V2 记忆条目。"""

    target: str = Field(..., description="memory(工作笔记) 或 user(用户画像)")
    content: str = Field(..., min_length=1, description="条目内容")


class MemoryEntryReplaceRequest(BaseModel):
    """替换一条 V2 记忆条目。"""

    target: str = Field(..., description="memory 或 user")
    old_text: str = Field(..., min_length=1, description="短唯一子串,定位要替换的条目")
    content: str = Field(..., min_length=1, description="新内容")


class MemorySearchRequest(BaseModel):
    """Hindsight 检索请求。"""

    query: str = Field(..., min_length=1, description="检索查询")
    mode: str = Field(default="recall", description="recall(返回原始片段) 或 reflect(LLM 综合)")


class MemorySearchResponse(BaseModel):
    """Hindsight 检索结果。"""

    available: bool = Field(..., description="Hindsight 是否可用 (未配置/未装包时为 false)")
    results: list[str] = Field(default_factory=list, description="recall 模式的检索结果")
    text: str = Field(default="", description="reflect 模式的综合结论")


# ===========================================================================
# 辅助函数
# ===========================================================================


def _is_v1(user_id: str) -> bool:
    """判断当前用户是否处于 V1 记忆模式。"""
    config = get_effective_memory_config(user_id)
    return getattr(config, "version", "v2") == "v1"


def _build_v1_provider(user_id: str, agent_name: str | None = None):
    """构建并初始化 V1BuiltinProvider。"""
    from deerflow.agents.memory.providers.v1_builtin import V1BuiltinProvider

    config = get_effective_memory_config(user_id)
    v1_cfg = config.v1
    provider = V1BuiltinProvider(
        max_facts=v1_cfg.max_facts,
        fact_confidence_threshold=v1_cfg.fact_confidence_threshold,
        debounce_seconds=v1_cfg.debounce_seconds,
        model_name=v1_cfg.model_name,
        token_budget=v1_cfg.token_budget,
    )
    provider.initialize(
        user_id=user_id,
        agent_id=agent_name,
        base_dir=str(get_paths().base_dir),
    )
    return provider


def _build_builtin_provider(user_id: str, agent_name: str | None):
    """按生效配置构建并初始化一个 V2 builtin provider。"""
    from deerflow.agents.memory.providers.builtin import BuiltinFileProvider

    config = get_effective_memory_config(user_id)
    provider = BuiltinFileProvider(
        memory_char_limit=config.builtin.memory_char_limit,
        user_char_limit=config.builtin.user_char_limit,
        deduplicate_on_load=config.builtin.deduplicate_on_load,
        security=config.security,
    )
    provider.initialize(
        user_id=user_id,
        agent_id=agent_name or "default",
        base_dir=str(get_paths().base_dir),
    )
    return provider


def _validate_v2_target(target: str) -> str:
    """校验 V2 entries 的 target,非法时抛 400。"""
    if target not in ("memory", "user"):
        raise HTTPException(status_code=400, detail=f"非法 target '{target}',只能是 'memory' 或 'user'。")
    return target


def _v2_data_response(provider) -> MemoryV2DataResponse:
    """从 V2 builtin provider 读出当前数据。"""
    return MemoryV2DataResponse(
        user_entries=provider.read("user"),
        memory_entries=provider.read("memory"),
        user_usage=provider.usage("user"),
        memory_usage=provider.usage("memory"),
    )


def _v1_data_response(provider) -> MemoryV2DataResponse:
    """从 V1 provider 读出当前数据,转换为统一响应格式。

    支持新格式 {user: {workContext: {summary, updatedAt}}} 和老格式 {userContext: {workContext: str}}。
    """
    data = provider.read_v1_data()
    raw_facts = data.get("facts", [])
    facts = [
        MemoryFact(
            id=str(f.get("id", "")),
            content=str(f.get("content", "")),
            category=str(f.get("category", "knowledge")),
            confidence=float(f.get("confidence", 0)),
            createdAt=str(f.get("createdAt", "")),
            sourceError=str(f.get("sourceError", "")),
        )
        for f in raw_facts
    ]

    def _extract_section(section: dict) -> dict[str, str]:
        """从 {key: {summary: str, updatedAt: str}} 或 {key: str} 中提取摘要字符串。"""
        result = {}
        for k, v in section.items():
            if isinstance(v, dict):
                summary = v.get("summary", "")
            else:
                summary = str(v)
            if summary:
                result[k] = summary
        return result

    # 新格式用 "user" key，老格式用 "userContext" key（已由 storage 迁移，此处兜底）
    ctx_raw = data.get("user") or data.get("userContext") or {}
    history_raw = data.get("history") or {}

    return MemoryV2DataResponse(
        facts=sorted(facts, key=lambda f: f.confidence, reverse=True),
        user_context=_extract_section(ctx_raw),
        history=_extract_section(history_raw),
        memory_usage=provider.usage_text(),
    )


def _raise_if_write_failed(result: dict) -> None:
    """builtin provider 写操作失败时抛 400。"""
    if not result.get("success"):
        raise HTTPException(status_code=400, detail=result.get("error", "记忆写入失败。"))


# ===========================================================================
# 数据端点
# ===========================================================================


@router.get(
    "/memory/v2",
    response_model=MemoryV2DataResponse,
    summary="Get Memory Data",
    description="读取记忆数据。V1 模式返回 facts 列表;V2 模式返回 USER.md / MEMORY.md 条目。",
)
async def get_memory_v2(agent: str | None = _AgentQuery) -> MemoryV2DataResponse:
    """读取当前用户的本地记忆。"""
    agent_name = _resolve_agent_name(agent)
    user_id = get_effective_user_id()
    try:
        if _is_v1(user_id):
            provider = _build_v1_provider(user_id, agent_name)
            return _v1_data_response(provider)
        provider = _build_builtin_provider(user_id, agent_name)
        return _v2_data_response(provider)
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to read memory data.") from exc


def _assert_not_v1(user_id: str) -> None:
    """V1 模式下写入操作返回 400。"""
    if _is_v1(user_id):
        raise HTTPException(status_code=400, detail="V1 模式下记忆由系统自动提取,不支持手动修改。")


@router.post(
    "/memory/v2/entries",
    response_model=MemoryV2DataResponse,
    summary="Add Memory V2 Entry",
    description="手动往 USER.md / MEMORY.md 新增一条记忆条目 (仅 V2 模式)。",
)
async def add_memory_v2_entry(
    request: MemoryEntryCreateRequest,
    agent: str | None = _AgentQuery,
) -> MemoryV2DataResponse:
    """手动新增一条 V2 记忆条目。"""
    user_id = get_effective_user_id()
    _assert_not_v1(user_id)
    _validate_v2_target(request.target)
    try:
        provider = _build_builtin_provider(user_id, _resolve_agent_name(agent))
        result = provider.add(request.target, request.content)
    except HTTPException:
        raise
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to add memory entry.") from exc
    _raise_if_write_failed(result)
    return _v2_data_response(provider)


@router.put(
    "/memory/v2/entries",
    response_model=MemoryV2DataResponse,
    summary="Replace Memory V2 Entry",
    description="用 old_text 定位一条记忆条目并替换为新内容 (仅 V2 模式)。",
)
async def replace_memory_v2_entry(
    request: MemoryEntryReplaceRequest,
    agent: str | None = _AgentQuery,
) -> MemoryV2DataResponse:
    """手动替换一条 V2 记忆条目。"""
    user_id = get_effective_user_id()
    _assert_not_v1(user_id)
    _validate_v2_target(request.target)
    try:
        provider = _build_builtin_provider(user_id, _resolve_agent_name(agent))
        result = provider.replace(request.target, request.old_text, request.content)
    except HTTPException:
        raise
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to replace memory entry.") from exc
    _raise_if_write_failed(result)
    return _v2_data_response(provider)


@router.delete(
    "/memory/v2/entries",
    response_model=MemoryV2DataResponse,
    summary="Delete Memory V2 Entry",
    description="用 old_text 定位并删除一条记忆条目 (仅 V2 模式)。",
)
async def delete_memory_v2_entry(
    target: str = Query(..., description="memory 或 user"),
    old_text: str = Query(..., min_length=1, description="短唯一子串,定位要删除的条目"),
    agent: str | None = _AgentQuery,
) -> MemoryV2DataResponse:
    """手动删除一条 V2 记忆条目。"""
    user_id = get_effective_user_id()
    _assert_not_v1(user_id)
    _validate_v2_target(target)
    try:
        provider = _build_builtin_provider(user_id, _resolve_agent_name(agent))
        result = provider.remove(target, old_text)
    except HTTPException:
        raise
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to delete memory entry.") from exc
    _raise_if_write_failed(result)
    return _v2_data_response(provider)


# ===========================================================================
# 配置端点
# ===========================================================================


@router.get(
    "/memory/v2/config",
    response_model=MemoryV2ConfigResponse,
    summary="Get Memory V2 Effective Config",
    description="读取按 per-user 覆盖合并后的生效记忆配置,以及用户可改字段白名单。",
)
async def get_memory_v2_config() -> MemoryV2ConfigResponse:
    """读取当前用户的生效记忆配置。"""
    user_id = get_effective_user_id()
    config = get_effective_memory_config(user_id)
    return MemoryV2ConfigResponse(
        config=config.model_dump(),
        writable_fields=sorted(USER_WRITABLE_FIELDS),
        version=getattr(config, "version", "v2"),
    )


@router.patch(
    "/memory/v2/config",
    response_model=MemoryV2ConfigResponse,
    summary="Patch Memory V2 Config",
    description="把 hindsight.recall_budget 写入当前用户的 per-user 配置覆盖 (DB 存储)。",
)
async def patch_memory_v2_config(request: MemoryConfigPatchRequest, req: Request) -> MemoryV2ConfigResponse:
    """更新当前用户的 per-user 记忆配置覆盖 (仅 hindsight.recall_budget)。"""
    user_id = get_effective_user_id()
    store = get_memory_config_store(req)
    try:
        await save_user_memory_override_db(user_id, request.overrides, store)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to save memory config override.") from exc

    config = get_effective_memory_config(user_id)
    return MemoryV2ConfigResponse(
        config=config.model_dump(),
        writable_fields=sorted(USER_WRITABLE_FIELDS),
        version=getattr(config, "version", "v2"),
    )


@router.delete(
    "/memory/v2/config",
    response_model=MemoryV2ConfigResponse,
    summary="Delete Memory V2 Config Override",
    description=(
        "撤销当前用户的 per-user 配置覆盖。传 ?field=hindsight.recall_budget 只撤销该字段;"
        "不传 field 则清空全部覆盖。"
    ),
)
async def delete_memory_v2_config(
    req: Request,
    field: str | None = Query(None, description="要撤销的点号路径字段;省略则清空全部覆盖"),
) -> MemoryV2ConfigResponse:
    """撤销当前用户的 per-user 记忆配置覆盖。"""
    user_id = get_effective_user_id()
    store = get_memory_config_store(req)
    try:
        await delete_user_memory_override_db(user_id, field, store)
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to delete memory config override.") from exc

    config = get_effective_memory_config(user_id)
    return MemoryV2ConfigResponse(
        config=config.model_dump(),
        writable_fields=sorted(USER_WRITABLE_FIELDS),
        version=getattr(config, "version", "v2"),
    )


# ===========================================================================
# Hindsight 检索代理端点
# ===========================================================================


@router.post(
    "/memory/v2/search",
    response_model=MemorySearchResponse,
    summary="Search Hindsight Memory",
    description=(
        "代理 Hindsight 检索。mode=recall 返回原始记忆片段;mode=reflect 返回 LLM 综合结论。"
        "Hindsight 未配置或不可用时返回 available=false。"
    ),
)
async def search_memory_v2(
    request: MemorySearchRequest,
    agent: str | None = _AgentQuery,
) -> MemorySearchResponse:
    """代理 Hindsight 检索 (recall / reflect)。"""
    user_id = get_effective_user_id()
    config = get_effective_memory_config(user_id)
    if not config.enabled or config.provider != "hindsight":
        return MemorySearchResponse(available=False)

    try:
        from deerflow.agents.memory.providers.hindsight import HindsightProvider

        provider = HindsightProvider(config.hindsight)
        if not provider.is_available():
            return MemorySearchResponse(available=False)
        provider.initialize(
            user_id=user_id,
            agent_id=_resolve_agent_name(agent) or "default",
            thread_id="",
            base_dir="",
        )
        if request.mode == "reflect":
            text = provider.reflect(request.query)
            return MemorySearchResponse(available=True, text=text)
        results = provider.recall(request.query)
        return MemorySearchResponse(available=True, results=results)
    except HTTPException:
        raise
    except Exception as exc:  # noqa: BLE001
        raise HTTPException(status_code=500, detail="Failed to search Hindsight memory.") from exc