from django.db import models
from django.utils import timezone
import json


class Website(models.Model):
    name = models.CharField(max_length=100, unique=True)
    base_url = models.URLField()
    description = models.TextField(blank=True, null=True)
    article_list_url = models.URLField(blank=True, null=True)
    article_selector = models.CharField(max_length=255, blank=True, null=True)
    content_selector = models.CharField(max_length=255, blank=True, null=True)
    enabled = models.BooleanField(default=True)

    def __str__(self):
        return self.name


class Article(models.Model):
    website = models.ForeignKey(Website, on_delete=models.CASCADE)
    title = models.CharField(max_length=300)
    url = models.URLField(unique=True)
    pub_date = models.DateTimeField(null=True, blank=True)
    content = models.TextField()  # html内容
    created_at = models.DateTimeField(auto_now_add=True)
    media_files = models.JSONField(default=list, blank=True)

    def __str__(self):
        return self.title


class CrawlTask(models.Model):
    """爬取任务模型"""
    TASK_STATUS_CHOICES = [
        ('pending', '等待中'),
        ('running', '运行中'),
        ('completed', '已完成'),
        ('failed', '失败'),
        ('cancelled', '已取消'),
    ]
    
    TASK_TYPE_CHOICES = [
        ('keyword', '关键词搜索'),
        ('historical', '历史文章'),
        ('full_site', '全站爬取'),
    ]
    
    name = models.CharField(max_length=200, verbose_name="任务名称")
    task_type = models.CharField(max_length=20, choices=TASK_TYPE_CHOICES, default='keyword', verbose_name="任务类型")
    keyword = models.CharField(max_length=200, blank=True, null=True, verbose_name="搜索关键词")
    websites = models.ManyToManyField(Website, blank=True, verbose_name="目标网站")
    start_date = models.DateField(blank=True, null=True, verbose_name="开始日期")
    end_date = models.DateField(blank=True, null=True, verbose_name="结束日期")
    max_pages = models.IntegerField(default=10, verbose_name="最大页数")
    max_articles = models.IntegerField(default=100, verbose_name="最大文章数")
    
    status = models.CharField(max_length=20, choices=TASK_STATUS_CHOICES, default='pending', verbose_name="状态")
    progress = models.IntegerField(default=0, verbose_name="进度百分比")
    current_website = models.CharField(max_length=100, blank=True, null=True, verbose_name="当前网站")
    current_action = models.CharField(max_length=200, blank=True, null=True, verbose_name="当前操作")
    
    total_articles = models.IntegerField(default=0, verbose_name="总文章数")
    success_count = models.IntegerField(default=0, verbose_name="成功数")
    failed_count = models.IntegerField(default=0, verbose_name="失败数")
    
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
    started_at = models.DateTimeField(blank=True, null=True, verbose_name="开始时间")
    completed_at = models.DateTimeField(blank=True, null=True, verbose_name="完成时间")
    
    error_message = models.TextField(blank=True, null=True, verbose_name="错误信息")
    result_details = models.JSONField(default=dict, blank=True, verbose_name="结果详情")
    
    created_by = models.CharField(max_length=100, blank=True, null=True, verbose_name="创建者")
    
    class Meta:
        verbose_name = "爬取任务"
        verbose_name_plural = "爬取任务"
        ordering = ['-created_at']
    
    def __str__(self):
        return f"{self.name} ({self.get_status_display()})"
    
    def get_websites_display(self):
        """获取网站列表的显示文本"""
        try:
            websites = self.websites.all()
            if not websites:
                return "所有网站"
            # 确保网站名称是字符串并可以被join处理
            website_names = [str(w.name) for w in websites if w.name]
            return ", ".join(website_names) if website_names else "所有网站"
        except Exception:
            # 如果出现任何异常，返回默认值
            return "所有网站"
    
    def get_duration(self):
        """获取任务执行时长"""
        if not self.started_at:
            return None
        end_time = self.completed_at or timezone.now()
        return end_time - self.started_at
    
    def is_running(self):
        """判断任务是否正在运行"""
        return self.status == 'running'
    
    def can_cancel(self):
        """判断任务是否可以取消"""
        return self.status in ['pending', 'running']
    
    def get_progress_display(self):
        """获取进度显示文本"""
        if self.status == 'pending':
            return "等待开始"
        elif self.status == 'running':
            if self.current_website and self.current_action:
                return f"正在处理 {self.current_website}: {self.current_action}"
            return f"运行中 ({self.progress}%)"
        elif self.status == 'completed':
            return f"已完成 ({self.success_count}/{self.total_articles})"
        elif self.status == 'failed':
            return f"失败: {self.error_message[:50]}..." if self.error_message else "失败"
        elif self.status == 'cancelled':
            return "已取消"
        return "未知状态"