"""面向前端的请求/响应 DTO。与 DB 模型解耦,**响应里的 key 一律打码**。

凭证 DTO 字段对齐前端 ComponentsModelsPage 的 ModelResource:
JSON 用 camelCase(modelId/interfaceType/apiUrl/apiKey),Python 内部用 snake_case,
靠 Pydantic alias 自动互转。FastAPI 响应默认 by_alias=True,所以出参也是 camelCase。
"""

from __future__ import annotations

from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, model_validator
from pydantic.alias_generators import to_camel

RuntimeMode = Literal["pipeline", "realtime"]
ModelType = Literal["LLM", "ASR", "TTS", "Realtime", "Embedding"]
InterfaceType = Literal["openai", "xfyun", "dashscope", "gemini"]
AssistantType = Literal["prompt", "workflow", "dify", "fastgpt", "opencode"]

# 外部应用类型:其 config.apiKey 是该助手私有密钥,读时打码 / 写时哨兵
EXTERNAL_TYPES = {"dify", "fastgpt", "opencode"}


class CamelModel(BaseModel):
    """JSON camelCase ↔ Python snake_case。protected_namespaces 关掉以允许 model_id。"""

    model_config = ConfigDict(
        alias_generator=to_camel,
        populate_by_name=True,
        protected_namespaces=(),
    )


# 各 type 允许的瘦字段(其余字段写入时清零,防止跨类型脏数据)
ALLOWED_FIELDS: dict[str, set[str]] = {
    "prompt": {"prompt"},
    "workflow": {"graph"},
    "dify": {"api_url", "api_key"},
    "fastgpt": {"app_id", "api_url", "api_key"},
    "opencode": {"prompt", "api_url", "api_key"},
}


# ---------- 助手(单表 STI:瘦类型真列 + workflow 图 JSON 列) ----------
class AssistantUpsert(CamelModel):
    name: str
    type: AssistantType = "prompt"
    runtime_mode: RuntimeMode = "pipeline"
    greeting: str = ""
    enable_interrupt: bool = True

    # 引用注册资源(FK id;None=未选)
    llm_credential_id: str | None = None
    asr_credential_id: str | None = None
    tts_credential_id: str | None = None
    realtime_credential_id: str | None = None
    knowledge_base_id: str | None = None

    # 瘦类型专属(真列);按 type 取用,无关字段写入时清零
    prompt: str = ""
    api_url: str = ""
    api_key: str = ""  # 写时:占位符/空 → 保留旧(哨兵)
    app_id: str = ""
    # workflow 专属:图
    graph: dict[str, Any] = {}

    @model_validator(mode="after")
    def _strip_irrelevant_fields(self):
        allowed = ALLOWED_FIELDS[self.type]
        for field in ("prompt", "api_url", "api_key", "app_id"):
            if field not in allowed:
                setattr(self, field, "")
        if "graph" not in allowed:
            self.graph = {}
        return self


class AssistantOut(AssistantUpsert):
    id: str
    updated_at: str | None = None


# ---------- 知识库 ----------
class KnowledgeBaseUpsert(CamelModel):
    name: str
    description: str = ""
    embedding_credential_id: str | None = None


class KnowledgeBaseOut(KnowledgeBaseUpsert):
    id: str
    status: str = "active"
    updated_at: str | None = None


# ---------- 模型凭证(对齐前端 ModelResource) ----------
class CredentialUpsert(CamelModel):
    name: str = ""                              # 资源名称
    model_id: str = ""                          # 模型ID
    type: ModelType                             # LLM/ASR/TTS/Realtime/Embedding
    interface_type: InterfaceType = "openai"    # openai/xfyun/dashscope/gemini
    api_url: str = ""
    api_key: str = ""                           # 写时:占位符/空表示不改
    is_default: bool = False


class CredentialOut(CamelModel):
    id: str
    name: str
    model_id: str
    type: str
    interface_type: str
    api_url: str
    api_key: str                                # 读时:打码后的值
    is_default: bool