from datetime import datetime
from typing import Any

from pydantic import BaseModel, Field, model_validator


class MessageCreateRequest(BaseModel):
    peer_user_id: int = Field(gt=0)
    client_msg_id: str = Field(min_length=1, max_length=64)
    content_type: int = Field(description="1-text 2-audio 3-image 4-json")
    content_text: str | None = Field(default=None)
    content_json: dict[str, Any] | None = None
    media_file_key: str | None = Field(default=None, max_length=255)
    media_duration_ms: int | None = Field(default=None, ge=0)

    @model_validator(mode="after")
    def validate_message_fields(self) -> "MessageCreateRequest":
        if self.content_type not in {1, 2, 3, 4}:
            raise ValueError("content_type must be one of 1, 2, 3, 4")

        if self.content_type == 1 and not (self.content_text and self.content_text.strip()):
            raise ValueError("content_text is required when content_type is 1")

        if self.content_type in {2, 3} and not self.media_file_key:
            raise ValueError("media_file_key is required when content_type is 2 or 3")

        if self.content_type == 4 and self.content_json is None:
            raise ValueError("content_json is required when content_type is 4")

        return self


class MessageItem(BaseModel):
    id: int
    conversation_id: int
    seq: int
    sender_user_id: int | None
    role: int
    content_type: int
    content_text: str | None
    content_json: dict[str, Any] | None
    media_file_key: str | None
    media_duration_ms: int | None
    client_msg_id: str | None
    created_at: datetime


class MessageCreateResponse(BaseModel):
    idempotent: bool
    message: MessageItem


class MessageListResponse(BaseModel):
    conversation_id: int
    has_more: bool
    next_cursor_seq: int | None
    items: list[MessageItem]