"""Pydantic schemas for the Tasks plugin."""

from __future__ import annotations

from datetime import datetime
from typing import Any

from pydantic import BaseModel, Field


TASK_STATUSES = "^(open|in_progress|review|blocked|done|cancelled)$"
TASK_TYPES = "^(todo|approval|follow_up|review|goal|milestone|agent_subtask)$"
ASSIGNEE_TYPES = "^(user|agent|group)$"
CREATOR_TYPES = "^(user|agent|workflow|system)$"


class TaskCreate(BaseModel):
    """Schema for creating a task."""
    title: str = Field(..., min_length=1, max_length=255)
    description: str | None = None
    status: str = Field(default="open", pattern=TASK_STATUSES)
    priority: str = Field(default="medium", pattern="^(low|medium|high|urgent)$")
    due_date: datetime | None = None
    assigned_to: str | None = None
    contact_id: str | None = None
    # F.14 polymorphic fields
    assignee_type: str = Field(default="user", pattern=ASSIGNEE_TYPES)
    assignee_id: str | None = None
    entity_type: str | None = None
    entity_id: str | None = None
    creator_type: str = Field(default="user", pattern=CREATOR_TYPES)
    creator_id: str | None = None
    parent_task_id: str | None = None
    depends_on: list[str] = Field(default_factory=list)
    task_type: str = Field(default="todo", pattern=TASK_TYPES)
    success_criteria: dict[str, Any] | None = None
    target_date: datetime | None = None
    progress: int = Field(default=0, ge=0, le=100)


class TaskUpdate(BaseModel):
    """Schema for updating a task."""
    title: str | None = Field(default=None, min_length=1, max_length=255)
    description: str | None = None
    status: str | None = Field(default=None, pattern=TASK_STATUSES)
    priority: str | None = Field(default=None, pattern="^(low|medium|high|urgent)$")
    due_date: datetime | None = None
    assigned_to: str | None = None
    contact_id: str | None = None
    assignee_type: str | None = Field(default=None, pattern=ASSIGNEE_TYPES)
    assignee_id: str | None = None
    entity_type: str | None = None
    entity_id: str | None = None
    creator_type: str | None = Field(default=None, pattern=CREATOR_TYPES)
    creator_id: str | None = None
    parent_task_id: str | None = None
    depends_on: list[str] | None = None
    task_type: str | None = Field(default=None, pattern=TASK_TYPES)
    success_criteria: dict[str, Any] | None = None
    target_date: datetime | None = None
    progress: int | None = Field(default=None, ge=0, le=100)


class TaskAssignRequest(BaseModel):
    """Schema for assigning a task (polymorphic)."""
    assigned_to: str | None = None
    assignee_type: str = Field(default="user", pattern=ASSIGNEE_TYPES)
    assignee_id: str | None = None


class TaskStatusRequest(BaseModel):
    """Schema for updating task status."""
    status: str = Field(..., pattern=TASK_STATUSES)


class TaskDependencyRequest(BaseModel):
    """Schema for adding/removing a task dependency."""
    depends_on: str = Field(..., description="Task ID this task depends on")


class TaskResponse(BaseModel):
    """Schema for task response."""
    id: str
    title: str
    description: str | None = None
    status: str
    priority: str
    due_date: datetime | None = None
    assigned_to: str | None = None
    contact_id: str | None = None
    assignee_type: str = "user"
    assignee_id: str | None = None
    entity_type: str | None = None
    entity_id: str | None = None
    creator_type: str = "user"
    creator_id: str | None = None
    parent_task_id: str | None = None
    depends_on: list[str] = Field(default_factory=list)
    task_type: str = "todo"
    success_criteria: dict[str, Any] | None = None
    target_date: datetime | None = None
    progress: int = 0
    created_by: str | None = None
    created_at: datetime
    updated_at: datetime


class TaskListResponse(BaseModel):
    """Paginated task list response."""
    items: list[TaskResponse]
    total: int
    page: int
    page_size: int