"""
Django REST Framework serializers for MDT app.
"""

from rest_framework import serializers
from .models import (
    MDTNote,
    MDTContribution,
    MDTApproval,
    MDTMention,
    MDTAttachment,
)


class MDTContributionSerializer(serializers.ModelSerializer):
    """Serializer for MDT contributions."""
    
    contributor_name = serializers.CharField(source='contributor.get_full_name', read_only=True)
    clinic_name = serializers.CharField(source='clinic.name_en', read_only=True)
    mentioned_user_names = serializers.SerializerMethodField()
    
    class Meta:
        model = MDTContribution
        fields = [
            'id', 'mdt_note', 'contributor', 'contributor_name',
            'clinic', 'clinic_name', 'content', 'is_final',
            'mentioned_users', 'mentioned_user_names',
            'created_at', 'edited_at',
        ]
        read_only_fields = ['id', 'created_at', 'edited_at']
    
    def get_mentioned_user_names(self, obj):
        """Get names of mentioned users."""
        return [user.get_full_name() for user in obj.mentioned_users.all()]


class MDTApprovalSerializer(serializers.ModelSerializer):
    """Serializer for MDT approvals."""
    
    approver_name = serializers.CharField(source='approver.get_full_name', read_only=True)
    clinic_name = serializers.CharField(source='clinic.name_en', read_only=True)
    
    class Meta:
        model = MDTApproval
        fields = [
            'id', 'mdt_note', 'approver', 'approver_name',
            'clinic', 'clinic_name', 'approved', 'approved_at',
            'comments', 'created_at',
        ]
        read_only_fields = ['id', 'created_at', 'approved_at']


class MDTMentionSerializer(serializers.ModelSerializer):
    """Serializer for MDT mentions."""
    
    mentioned_user_name = serializers.CharField(source='mentioned_user.get_full_name', read_only=True)
    contribution_content = serializers.CharField(source='contribution.content', read_only=True)
    
    class Meta:
        model = MDTMention
        fields = [
            'id', 'contribution', 'contribution_content',
            'mentioned_user', 'mentioned_user_name',
            'notified_at', 'viewed_at', 'created_at',
        ]
        read_only_fields = ['id', 'created_at', 'notified_at', 'viewed_at']


class MDTAttachmentSerializer(serializers.ModelSerializer):
    """Serializer for MDT attachments."""
    
    uploaded_by_name = serializers.CharField(source='uploaded_by.get_full_name', read_only=True)
    file_type_display = serializers.CharField(source='get_file_type_display', read_only=True)
    file_url = serializers.SerializerMethodField()
    
    class Meta:
        model = MDTAttachment
        fields = [
            'id', 'mdt_note', 'file', 'file_url', 'file_type',
            'file_type_display', 'description',
            'uploaded_by', 'uploaded_by_name', 'created_at',
        ]
        read_only_fields = ['id', 'created_at']
    
    def get_file_url(self, obj):
        """Get full URL for file."""
        request = self.context.get('request')
        if obj.file and request:
            return request.build_absolute_uri(obj.file.url)
        return None


class MDTNoteSerializer(serializers.ModelSerializer):
    """Serializer for MDT notes."""
    
    patient_name = serializers.CharField(source='patient.get_full_name', read_only=True)
    initiated_by_name = serializers.CharField(source='initiated_by.get_full_name', read_only=True)
    status_display = serializers.CharField(source='get_status_display', read_only=True)
    
    # Nested serializers
    contributions = MDTContributionSerializer(many=True, read_only=True)
    approvals = MDTApprovalSerializer(many=True, read_only=True)
    attachments = MDTAttachmentSerializer(many=True, read_only=True)
    
    # Computed fields
    is_editable = serializers.BooleanField(read_only=True)
    can_finalize = serializers.BooleanField(read_only=True)
    contributor_count = serializers.SerializerMethodField()
    approval_count = serializers.SerializerMethodField()
    
    class Meta:
        model = MDTNote
        fields = [
            'id', 'patient', 'patient_name', 'tenant',
            'title', 'purpose', 'status', 'status_display',
            'initiated_by', 'initiated_by_name',
            'version', 'summary', 'recommendations',
            'finalized_at', 'is_editable', 'can_finalize',
            'contributor_count', 'approval_count',
            'contributions', 'approvals', 'attachments',
            'created_at', 'updated_at',
        ]
        read_only_fields = ['id', 'created_at', 'updated_at', 'finalized_at', 'version']
    
    def get_contributor_count(self, obj):
        """Get number of contributors."""
        return obj.contributions.count()
    
    def get_approval_count(self, obj):
        """Get number of approvals."""
        return obj.approvals.filter(approved=True).count()


class MDTNoteListSerializer(serializers.ModelSerializer):
    """Lightweight serializer for MDT note lists."""
    
    patient_name = serializers.CharField(source='patient.get_full_name', read_only=True)
    initiated_by_name = serializers.CharField(source='initiated_by.get_full_name', read_only=True)
    status_display = serializers.CharField(source='get_status_display', read_only=True)
    contributor_count = serializers.SerializerMethodField()
    approval_count = serializers.SerializerMethodField()
    
    class Meta:
        model = MDTNote
        fields = [
            'id', 'patient', 'patient_name', 'title', 'purpose',
            'status', 'status_display', 'initiated_by', 'initiated_by_name',
            'contributor_count', 'approval_count',
            'finalized_at', 'created_at', 'updated_at',
        ]
        read_only_fields = ['id', 'created_at', 'updated_at', 'finalized_at']
    
    def get_contributor_count(self, obj):
        """Get number of contributors."""
        return obj.contributions.count()
    
    def get_approval_count(self, obj):
        """Get number of approvals."""
        return obj.approvals.filter(approved=True).count()