from datetime import datetime
from typing import Any

from pydantic import BaseModel, Field, model_validator


class ChildConversationItem(BaseModel):
    conversation_id: int
    conversation_type: int
    conversation_type_name: str
    peer_type: str
    peer_id: str
    peer_name: str | None = None
    last_message_preview: str | None = None
    last_message_at: datetime | None = None
    message_count: int


class ChildConversationListResponse(BaseModel):
    items: list[ChildConversationItem]
    total: int
    next_cursor: int | None = None


class ChildConversationMessageItem(BaseModel):
    id: int
    conversation_id: int
    seq: int
    sender_type: str
    sender_id: str
    receiver_type: str
    receiver_id: str
    content_type: int
    content_text: str | None = None
    content_json: dict[str, Any] | None = None
    media_file_key: str | None = None
    media_duration_ms: int | None = None
    media_mime_type: str | None = None
    media_size_bytes: int | None = None
    media_transcript_text: str | None = None
    client_msg_id: str | None = None
    sender_name_snapshot: str | None = None
    sender_avatar_snapshot: str | None = None
    receiver_name_snapshot: str | None = None
    receiver_avatar_snapshot: str | None = None
    ext_json: dict[str, Any] | None = None
    created_at: datetime


class ChildConversationMessageListResponse(BaseModel):
    conversation_id: int
    has_more: bool
    next_cursor_seq: int | None = None
    items: list[ChildConversationMessageItem]


class BaseConversationMessageCreateRequest(BaseModel):
    content_type: int = Field(ge=1, le=4)
    content_text: str | None = None
    content_json: dict[str, Any] | None = None
    media_file_key: str | None = None
    media_duration_ms: int | None = Field(default=None, ge=0)
    media_mime_type: str | None = None
    media_size_bytes: int | None = Field(default=None, ge=0)
    media_transcript_text: str | None = None
    client_msg_id: str = Field(min_length=1, max_length=64)
    ext_json: dict[str, Any] | None = None

    @model_validator(mode="after")
    def validate_message_payload(self) -> "BaseConversationMessageCreateRequest":
        if self.content_type == 1 and not self.content_text:
            raise ValueError("content_text is required when content_type=1")
        if self.content_type == 2 and not self.media_file_key:
            raise ValueError("media_file_key is required when content_type=2")
        if self.content_type == 3 and not self.media_file_key:
            raise ValueError("media_file_key is required when content_type=3")
        if self.content_type == 4 and self.content_json is None:
            raise ValueError("content_json is required when content_type=4")
        return self


class ParentChildMessageCreateRequest(BaseConversationMessageCreateRequest):
    pass


class DeviceMessageCreateRequest(BaseConversationMessageCreateRequest):
    conversation_type: int = Field(ge=1, le=2)
    peer_child_id: int | None = Field(default=None, ge=1)
    parent_user_id: int | None = Field(default=None, ge=1)

    @model_validator(mode="after")
    def validate_target(self) -> "DeviceMessageCreateRequest":
        if self.conversation_type == 1:
            if self.peer_child_id is None:
                raise ValueError("peer_child_id is required when conversation_type=1")
            if self.parent_user_id is not None:
                raise ValueError("parent_user_id must be empty when conversation_type=1")
        if self.conversation_type == 2:
            if self.parent_user_id is None:
                raise ValueError("parent_user_id is required when conversation_type=2")
            if self.peer_child_id is not None:
                raise ValueError("peer_child_id must be empty when conversation_type=2")
        return self


class ConversationMessageCreateResponse(BaseModel):
    idempotent: bool
    conversation_id: int
    conversation_type: int
    conversation_type_name: str
    message: ChildConversationMessageItem