from pydantic import BaseModel, ConfigDict, Field, model_validator
from datetime import datetime, date
from typing import Optional, List, Literal
from app.schemas.project_task import ProjectTaskResponse

ProjectStatus = Literal["not_started", "in_progress", "completed", "blocked", "review", "on_hold"]


class ProjectCreate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    name: str = Field(min_length=1, max_length=255)
    description: Optional[str] = Field(None, max_length=5000)
    status: ProjectStatus = "not_started"
    color: Optional[str] = Field(None, max_length=20)
    due_date: Optional[date] = None
    is_tracked: bool = False


class ProjectUpdate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    name: Optional[str] = Field(None, min_length=1, max_length=255)
    description: Optional[str] = Field(None, max_length=5000)
    status: Optional[ProjectStatus] = None
    color: Optional[str] = Field(None, max_length=20)
    due_date: Optional[date] = None
    is_tracked: Optional[bool] = None


class ProjectResponse(BaseModel):
    id: int
    user_id: int = 0
    name: str
    description: Optional[str]
    status: str
    color: Optional[str]
    due_date: Optional[date]
    is_tracked: bool
    member_count: int = 0
    created_at: datetime
    updated_at: datetime
    tasks: List[ProjectTaskResponse] = []

    model_config = ConfigDict(from_attributes=True)

    @model_validator(mode="before")
    @classmethod
    def compute_member_count(cls, data):  # type: ignore[override]
        """Compute member_count from eagerly loaded members relationship."""
        if hasattr(data, "members"):
            try:
                data = dict(
                    id=data.id,
                    user_id=data.user_id,
                    name=data.name,
                    description=data.description,
                    status=data.status,
                    color=data.color,
                    due_date=data.due_date,
                    is_tracked=data.is_tracked,
                    member_count=len([m for m in data.members if m.status == "accepted"]),
                    created_at=data.created_at,
                    updated_at=data.updated_at,
                    tasks=data.tasks,
                )
            except Exception:
                pass  # If members aren't loaded, default to 0
        return data


class TrackedTaskResponse(BaseModel):
    id: int
    title: str
    status: str
    priority: str
    due_date: date
    project_name: str
    project_id: int
    parent_task_title: Optional[str] = None