HH/apps/complaints/models.py

"""
Complaints models - Complaint management with SLA tracking

This module implements the complaint management system that:
- Tracks complaints with SLA deadlines
- Manages complaint workflow (open → in progress → resolved → closed)
- Triggers resolution satisfaction surveys
- Creates PX actions for negative resolution satisfaction
- Maintains complaint timeline and attachments
"""
from datetime import timedelta

from django.conf import settings
from django.db import models
from django.utils import timezone

from apps.core.models import PriorityChoices, SeverityChoices, TimeStampedModel, UUIDModel


class ComplaintStatus(models.TextChoices):
    """Complaint status choices"""
    OPEN = 'open', 'Open'
    IN_PROGRESS = 'in_progress', 'In Progress'
    RESOLVED = 'resolved', 'Resolved'
    CLOSED = 'closed', 'Closed'
    CANCELLED = 'cancelled', 'Cancelled'


class ComplaintSource(models.TextChoices):
    """Complaint source choices"""
    PATIENT = 'patient', 'Patient'
    FAMILY = 'family', 'Family Member'
    STAFF = 'staff', 'Staff'
    SURVEY = 'survey', 'Survey'
    SOCIAL_MEDIA = 'social_media', 'Social Media'
    CALL_CENTER = 'call_center', 'Call Center'
    MOH = 'moh', 'Ministry of Health'
    CHI = 'chi', 'Council of Health Insurance'
    OTHER = 'other', 'Other'


class Complaint(UUIDModel, TimeStampedModel):
    """
    Complaint model with SLA tracking.
    
    Workflow:
    1. OPEN - Complaint received
    2. IN_PROGRESS - Being investigated
    3. RESOLVED - Solution provided
    4. CLOSED - Confirmed closed (triggers resolution satisfaction survey)
    
    SLA:
    - Calculated based on severity and hospital configuration
    - Reminders sent before due date
    - Escalation triggered when overdue
    """
    # Patient and encounter information
    patient = models.ForeignKey(
        'organizations.Patient',
        on_delete=models.CASCADE,
        related_name='complaints'
    )
    encounter_id = models.CharField(
        max_length=100,
        blank=True,
        db_index=True,
        help_text="Related encounter ID if applicable"
    )
    
    # Organization
    hospital = models.ForeignKey(
        'organizations.Hospital',
        on_delete=models.CASCADE,
        related_name='complaints'
    )
    department = models.ForeignKey(
        'organizations.Department',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='complaints'
    )
    physician = models.ForeignKey(
        'organizations.Physician',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='complaints'
    )
    
    # Complaint details
    title = models.CharField(max_length=500)
    description = models.TextField()
    
    # Classification
    category = models.CharField(
        max_length=100,
        choices=[
            ('clinical_care', 'Clinical Care'),
            ('staff_behavior', 'Staff Behavior'),
            ('facility', 'Facility & Environment'),
            ('wait_time', 'Wait Time'),
            ('billing', 'Billing'),
            ('communication', 'Communication'),
            ('other', 'Other'),
        ],
        db_index=True
    )
    subcategory = models.CharField(max_length=100, blank=True)
    
    # Priority and severity
    priority = models.CharField(
        max_length=20,
        choices=PriorityChoices.choices,
        default=PriorityChoices.MEDIUM,
        db_index=True
    )
    severity = models.CharField(
        max_length=20,
        choices=SeverityChoices.choices,
        default=SeverityChoices.MEDIUM,
        db_index=True
    )
    
    # Source
    source = models.CharField(
        max_length=50,
        choices=ComplaintSource.choices,
        default=ComplaintSource.PATIENT,
        db_index=True
    )
    
    # Status and workflow
    status = models.CharField(
        max_length=20,
        choices=ComplaintStatus.choices,
        default=ComplaintStatus.OPEN,
        db_index=True
    )
    
    # Assignment
    assigned_to = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='assigned_complaints'
    )
    assigned_at = models.DateTimeField(null=True, blank=True)
    
    # SLA tracking
    due_at = models.DateTimeField(
        db_index=True,
        help_text="SLA deadline"
    )
    is_overdue = models.BooleanField(default=False, db_index=True)
    reminder_sent_at = models.DateTimeField(null=True, blank=True)
    escalated_at = models.DateTimeField(null=True, blank=True)
    
    # Resolution
    resolution = models.TextField(blank=True)
    resolved_at = models.DateTimeField(null=True, blank=True)
    resolved_by = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='resolved_complaints'
    )
    
    # Closure
    closed_at = models.DateTimeField(null=True, blank=True)
    closed_by = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='closed_complaints'
    )
    
    # Resolution satisfaction survey
    resolution_survey = models.ForeignKey(
        'surveys.SurveyInstance',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='complaint_resolution'
    )
    resolution_survey_sent_at = models.DateTimeField(null=True, blank=True)
    
    # Metadata
    metadata = models.JSONField(default=dict, blank=True)
    
    class Meta:
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['status', '-created_at']),
            models.Index(fields=['hospital', 'status', '-created_at']),
            models.Index(fields=['is_overdue', 'status']),
            models.Index(fields=['due_at', 'status']),
        ]
    
    def __str__(self):
        return f"{self.title} - {self.patient.get_full_name()} ({self.status})"
    
    def save(self, *args, **kwargs):
        """Calculate SLA due date on creation"""
        if not self.due_at:
            self.due_at = self.calculate_sla_due_date()
        super().save(*args, **kwargs)
    
    def calculate_sla_due_date(self):
        """
        Calculate SLA due date based on severity and hospital configuration.
        
        Uses settings.SLA_DEFAULTS if no hospital-specific config exists.
        """
        sla_hours = settings.SLA_DEFAULTS['complaint'].get(
            self.severity,
            settings.SLA_DEFAULTS['complaint']['medium']
        )
        return timezone.now() + timedelta(hours=sla_hours)
    
    def check_overdue(self):
        """Check if complaint is overdue and update status"""
        if self.status in [ComplaintStatus.CLOSED, ComplaintStatus.CANCELLED]:
            return False
        
        if timezone.now() > self.due_at:
            if not self.is_overdue:
                self.is_overdue = True
                self.save(update_fields=['is_overdue'])
            return True
        return False


class ComplaintAttachment(UUIDModel, TimeStampedModel):
    """Complaint attachment (images, documents, etc.)"""
    complaint = models.ForeignKey(
        Complaint,
        on_delete=models.CASCADE,
        related_name='attachments'
    )
    
    file = models.FileField(upload_to='complaints/%Y/%m/%d/')
    filename = models.CharField(max_length=500)
    file_type = models.CharField(max_length=100, blank=True)
    file_size = models.IntegerField(help_text="File size in bytes")
    
    uploaded_by = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        related_name='complaint_attachments'
    )
    
    description = models.TextField(blank=True)
    
    class Meta:
        ordering = ['-created_at']
    
    def __str__(self):
        return f"{self.complaint} - {self.filename}"


class ComplaintUpdate(UUIDModel, TimeStampedModel):
    """
    Complaint update/timeline entry.
    
    Tracks all updates, status changes, and communications.
    """
    complaint = models.ForeignKey(
        Complaint,
        on_delete=models.CASCADE,
        related_name='updates'
    )
    
    # Update details
    update_type = models.CharField(
        max_length=50,
        choices=[
            ('status_change', 'Status Change'),
            ('assignment', 'Assignment'),
            ('note', 'Note'),
            ('resolution', 'Resolution'),
            ('escalation', 'Escalation'),
            ('communication', 'Communication'),
        ],
        db_index=True
    )
    
    message = models.TextField()
    
    # User who made the update
    created_by = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        related_name='complaint_updates'
    )
    
    # Status change tracking
    old_status = models.CharField(max_length=20, blank=True)
    new_status = models.CharField(max_length=20, blank=True)
    
    # Metadata
    metadata = models.JSONField(default=dict, blank=True)
    
    class Meta:
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['complaint', '-created_at']),
        ]
    
    def __str__(self):
        return f"{self.complaint} - {self.update_type} - {self.created_at.strftime('%Y-%m-%d %H:%M')}"


class Inquiry(UUIDModel, TimeStampedModel):
    """
    Inquiry model for general questions/requests.
    
    Similar to complaints but for non-complaint inquiries.
    """
    # Patient information
    patient = models.ForeignKey(
        'organizations.Patient',
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name='inquiries'
    )
    
    # Contact information (if patient not in system)
    contact_name = models.CharField(max_length=200, blank=True)
    contact_phone = models.CharField(max_length=20, blank=True)
    contact_email = models.EmailField(blank=True)
    
    # Organization
    hospital = models.ForeignKey(
        'organizations.Hospital',
        on_delete=models.CASCADE,
        related_name='inquiries'
    )
    department = models.ForeignKey(
        'organizations.Department',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='inquiries'
    )
    
    # Inquiry details
    subject = models.CharField(max_length=500)
    message = models.TextField()
    
    # Category
    category = models.CharField(
        max_length=100,
        choices=[
            ('appointment', 'Appointment'),
            ('billing', 'Billing'),
            ('medical_records', 'Medical Records'),
            ('general', 'General Information'),
            ('other', 'Other'),
        ]
    )
    
    # Status
    status = models.CharField(
        max_length=20,
        choices=[
            ('open', 'Open'),
            ('in_progress', 'In Progress'),
            ('resolved', 'Resolved'),
            ('closed', 'Closed'),
        ],
        default='open',
        db_index=True
    )
    
    # Assignment
    assigned_to = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='assigned_inquiries'
    )
    
    # Response
    response = models.TextField(blank=True)
    responded_at = models.DateTimeField(null=True, blank=True)
    responded_by = models.ForeignKey(
        'accounts.User',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='responded_inquiries'
    )
    
    class Meta:
        ordering = ['-created_at']
        verbose_name_plural = 'Inquiries'
        indexes = [
            models.Index(fields=['status', '-created_at']),
            models.Index(fields=['hospital', 'status']),
        ]
    
    def __str__(self):
        return f"{self.subject} ({self.status})"