"""Pydantic schemas for session branches and fork points."""
from __future__ import annotations
from typing import Any
from uuid import UUID
from datetime import datetime
from pydantic import BaseModel, Field


class BranchCreate(BaseModel):
    label: str = Field(..., max_length=200)
    status: str = "untried"


class BranchUpdate(BaseModel):
    status: str = Field(..., pattern="^(active|dead_end|solved|untried|revived)$")
    status_reason: str | None = None


class BranchResponse(BaseModel):
    id: UUID
    session_id: UUID
    parent_branch_id: UUID | None
    fork_point_step_id: UUID | None
    branch_order: int
    label: str
    status: str
    status_reason: str | None
    status_changed_at: datetime | None
    context_summary: dict[str, Any] | None
    evidence_from_branch_id: UUID | None
    evidence_description: str | None
    step_count: int = 0
    created_at: datetime
    updated_at: datetime
    model_config = {"from_attributes": True}


class BranchTreeResponse(BaseModel):
    branches: list[BranchResponse]
    active_branch_id: UUID | None


class ForkOption(BaseModel):
    label: str = Field(..., max_length=200)
    description: str = Field(..., max_length=500)


class ForkCreateRequest(BaseModel):
    fork_reason: str = Field(..., min_length=5, max_length=2000)
    options: list[ForkOption] = Field(..., min_length=2, max_length=10)


class ForkPointResponse(BaseModel):
    id: UUID
    session_id: UUID
    parent_branch_id: UUID
    trigger_step_id: UUID | None
    fork_reason: str
    options: list[dict[str, Any]]
    created_at: datetime
    model_config = {"from_attributes": True}


class BranchSwitchResponse(BaseModel):
    active_branch_id: UUID
    branch: BranchResponse
    conversation_messages: list[dict[str, Any]]


class ReviveRequest(BaseModel):
    evidence_from_branch_id: UUID
    evidence_description: str = Field(..., min_length=5, max_length=2000)


class BranchMessageRequest(BaseModel):
    message: str = Field(..., min_length=1, max_length=8000)
    upload_ids: list[UUID] = Field(default_factory=list, max_length=10)


class BranchMessageResponse(BaseModel):
    content: str
    branch_id: UUID
    step_id: UUID | None = None