"""
Projects models - Quality Improvement (QI) projects tracking

This module implements QI project management:
- Project tracking
- Task management
- Milestone tracking
- Outcome measurement
"""
from django.db import models

from apps.core.models import StatusChoices, TimeStampedModel, UUIDModel


class QIProject(UUIDModel, TimeStampedModel):
    """
    Quality Improvement Project.
    
    Tracks improvement initiatives driven by PX feedback.
    """
    name = models.CharField(max_length=200)
    name_ar = models.CharField(max_length=200, blank=True)
    description = models.TextField()
    
    # Organization
    hospital = models.ForeignKey(
        'organizations.Hospital',
        on_delete=models.CASCADE,
        related_name='qi_projects'
    )
    department = models.ForeignKey(
        'organizations.Department',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='qi_projects'
    )
    
    # Project lead
    project_lead = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        related_name='led_projects'
    )
    
    # Team members
    team_members = models.ManyToManyField(
        'accounts.User',
        blank=True,
        related_name='qi_projects'
    )
    
    # Status
    status = models.CharField(
        max_length=20,
        choices=StatusChoices.choices,
        default=StatusChoices.PENDING,
        db_index=True
    )
    
    # Dates
    start_date = models.DateField(null=True, blank=True)
    target_completion_date = models.DateField(null=True, blank=True, db_index=True)
    actual_completion_date = models.DateField(null=True, blank=True)
    
    # Linked to PX Actions (optional)
    related_actions = models.ManyToManyField(
        'px_action_center.PXAction',
        blank=True,
        related_name='qi_projects'
    )
    
    # Outcomes
    outcome_description = models.TextField(blank=True)
    success_metrics = models.JSONField(
        default=dict,
        blank=True,
        help_text="Success metrics and results"
    )
    
    # Metadata
    metadata = models.JSONField(default=dict, blank=True)
    
    class Meta:
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['hospital', 'status', '-created_at']),
        ]
    
    def __str__(self):
        return f"{self.name} ({self.status})"


class QIProjectTask(UUIDModel, TimeStampedModel):
    """
    Task within a QI project.
    """
    project = models.ForeignKey(
        QIProject,
        on_delete=models.CASCADE,
        related_name='tasks'
    )
    
    title = models.CharField(max_length=500)
    description = models.TextField(blank=True)
    
    # Assignment
    assigned_to = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='qi_tasks'
    )
    
    # Status
    status = models.CharField(
        max_length=20,
        choices=StatusChoices.choices,
        default=StatusChoices.PENDING
    )
    
    # Dates
    due_date = models.DateField(null=True, blank=True)
    completed_date = models.DateField(null=True, blank=True)
    
    # Order
    order = models.IntegerField(default=0)
    
    class Meta:
        ordering = ['project', 'order']
    
    def __str__(self):
        return f"{self.project.name} - {self.title}"