from rest_framework import serializers
from .models import Task, Report, ReportSource, TaskLog


class TaskSerializer(serializers.ModelSerializer):
    """任务序列化器"""
    
    report_count = serializers.ReadOnlyField()
    has_new_report = serializers.ReadOnlyField()
    
    class Meta:
        model = Task
        fields = [
            'id', 'title', 'description', 'requirement', 'type', 'status',
            'schedule_config', 'sources_config', 'web_search_enabled',
            'last_report_time', 'next_run_time', 'created_at', 'updated_at',
            'report_count', 'has_new_report'
        ]
        read_only_fields = ['id', 'created_at', 'updated_at', 'last_report_time']


class CreateTaskSerializer(serializers.Serializer):
    """创建任务的序列化器"""
    
    requirement = serializers.CharField(max_length=5000, help_text='用户需求描述')
    type = serializers.ChoiceField(choices=['single', 'scheduled'], help_text='任务类型')
    schedule = serializers.JSONField(required=False, allow_null=True, help_text='周期任务配置')
    presetSources = serializers.ListField(
        child=serializers.DictField(),
        required=False,
        default=list,
        help_text='预设信息源'
    )
    customSources = serializers.ListField(
        child=serializers.DictField(),
        required=False,
        default=list,
        help_text='自定义信息源'
    )
    webSearchEnabled = serializers.BooleanField(default=True, help_text='是否启用联网搜索')
    
    def validate_schedule(self, value):
        """验证周期任务配置"""
        task_type = self.initial_data.get('type')
        
        # 单次任务允许schedule为None或null
        if task_type == 'single':
            return None
        
        # 周期任务必须有schedule配置
        if task_type == 'scheduled':
            if not value:
                raise serializers.ValidationError('周期任务必须提供执行周期配置')
            
            required_fields = ['frequency', 'time']
            for field in required_fields:
                if field not in value:
                    raise serializers.ValidationError(f'周期任务配置缺少必要字段: {field}')
        
        return value


class ReportSourceSerializer(serializers.ModelSerializer):
    """报告来源序列化器"""
    
    class Meta:
        model = ReportSource
        fields = [
            'id', 'source_type', 'source_name', 'source_url',
            'extracted_content', 'collected_at'
        ]


class ReportSerializer(serializers.ModelSerializer):
    """报告序列化器"""
    
    task_title = serializers.CharField(source='task.title', read_only=True)
    sources = ReportSourceSerializer(many=True, read_only=True)
    
    class Meta:
        model = Report
        fields = [
            'id', 'task_id', 'task_title', 'title', 'summary', 'content',
            'source_tag', 'word_count', 'status', 'generated_at',
            'created_at', 'updated_at', 'sources'
        ]
        read_only_fields = ['id', 'created_at', 'updated_at', 'word_count']


class ReportListSerializer(serializers.ModelSerializer):
    """报告列表序列化器（不包含content字段）"""
    
    task_title = serializers.CharField(source='task.title', read_only=True)
    
    class Meta:
        model = Report
        fields = [
            'id', 'task_id', 'task_title', 'title', 'summary',
            'source_tag', 'word_count', 'status', 'generated_at'
        ]


class TaskLogSerializer(serializers.ModelSerializer):
    """任务日志序列化器"""
    
    class Meta:
        model = TaskLog
        fields = [
            'id', 'action_type', 'message', 'error_details', 'created_at'
        ]
        read_only_fields = ['id', 'created_at']


class TaskDetailSerializer(TaskSerializer):
    """任务详情序列化器"""
    
    logs = TaskLogSerializer(many=True, read_only=True)
    recent_reports = serializers.SerializerMethodField()
    
    class Meta(TaskSerializer.Meta):
        fields = TaskSerializer.Meta.fields + ['logs', 'recent_reports']
    
    def get_recent_reports(self, obj):
        """获取最近的3个报告"""
        recent_reports = obj.reports.filter(status='completed')[:3]
        return ReportListSerializer(recent_reports, many=True).data


class UpdateTaskStatusSerializer(serializers.Serializer):
    """更新任务状态的序列化器"""
    
    status = serializers.ChoiceField(choices=['running', 'paused'], help_text='任务状态')


class TaskStatisticsSerializer(serializers.Serializer):
    """任务统计序列化器"""
    
    total_tasks = serializers.IntegerField()
    running_tasks = serializers.IntegerField()
    paused_tasks = serializers.IntegerField()
    error_tasks = serializers.IntegerField()
    completed_tasks = serializers.IntegerField()
    today_reports = serializers.IntegerField()
    weekly_reports = serializers.IntegerField()


class ReportStatisticsSerializer(serializers.Serializer):
    """报告统计序列化器"""
    
    total_reports = serializers.IntegerField()
    generated_today = serializers.IntegerField()
    average_word_count = serializers.FloatField()
    source_distribution = serializers.DictField()
    daily_generation = serializers.ListField(child=serializers.DictField())