from pydantic import BaseModel
from typing import Optional, List
from datetime import datetime
from enum import Enum


class RiskLevel(str, Enum):
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    CRITICAL = "critical"


class ScheduleStatus(str, Enum):
    ON_TRACK = "on_track"
    AT_RISK = "at_risk"
    DELAYED = "delayed"


class ResourceStatus(str, Enum):
    ADEQUATE = "adequate"
    CONSTRAINED = "constrained"
    OVERLOADED = "overloaded"


class ProjectHealthBase(BaseModel):
    health_score: int
    risk_level: RiskLevel
    schedule_status: ScheduleStatus
    resource_status: ResourceStatus


class ProjectHealthResponse(ProjectHealthBase):
    id: str
    project_id: str
    last_updated: datetime

    class Config:
        from_attributes = True


class ProjectHealthWithDetails(ProjectHealthResponse):
    """Extended health response with project and computed metrics."""
    project_title: str
    project_status: str
    owner_name: Optional[str] = None
    space_name: Optional[str] = None
    task_count: int = 0
    completed_task_count: int = 0
    blocker_count: int = 0
    overdue_task_count: int = 0


class ProjectHealthSummary(BaseModel):
    """Aggregated health metrics across all projects."""
    total_projects: int
    healthy_count: int  # health_score >= 80
    at_risk_count: int  # health_score 50-79
    critical_count: int  # health_score < 50
    average_health_score: float
    projects_with_blockers: int
    projects_delayed: int


class ProjectHealthDashboardResponse(BaseModel):
    """Full dashboard response with project list and summary."""
    projects: List[ProjectHealthWithDetails]
    summary: ProjectHealthSummary