from django.db import models
from django.core.validators import FileExtensionValidator
import hashlib


class LobsterMemory(models.Model):
    """龙虾记忆文件模型"""

    STATUS_CHOICES = [
        ('consistent', '一致'),
        ('local_newer', '本地更新'),
        ('db_newer', '数据库更新'),
        ('conflict', '冲突'),
    ]

    lobster_id = models.CharField(max_length=50, help_text='龙虾ID')

    file_path = models.CharField(max_length=500, help_text='文件相对路径')

    content = models.TextField(help_text='文件内容')

    hash = models.CharField(max_length=64, help_text='SHA256哈希')

    status = models.CharField(
        max_length=20,
        choices=STATUS_CHOICES,
        default='consistent',
        help_text='同步状态'
    )

    version = models.IntegerField(default=1, help_text='版本号')

    size = models.IntegerField(default=0, help_text='文件大小（字节）')

    created_at = models.DateTimeField(auto_now_add=True, help_text='创建时间')

    updated_at = models.DateTimeField(auto_now=True, help_text='更新时间')

    class Meta:
        db_table = 'lobster_memory'
        unique_together = ('lobster_id', 'file_path', 'version')
        ordering = ['-updated_at']
        indexes = [
            models.Index(fields=['lobster_id', 'file_path']),
            models.Index(fields=['status']),
            models.Index(fields=['updated_at']),
        ]

    def __str__(self):
        return f"{self.lobster_id}/{self.file_path} (v{self.version})"

    def compute_hash(self, content):
        """计算SHA256哈希"""
        return hashlib.sha256(content.encode('utf-8')).hexdigest()

    def save(self, *args, **kwargs):
        """保存时自动计算哈希和大小"""
        if self.content:
            self.hash = self.compute_hash(self.content)
            self.size = len(self.content.encode('utf-8'))
        super().save(*args, **kwargs)


class SyncHistory(models.Model):
    """同步操作历史记录"""

    ACTION_CHOICES = [
        ('sync_to_db', '同步到数据库'),
        ('sync_to_local', '同步到本地'),
        ('auto_sync', '自动同步'),
        ('manual_merge', '手动合并'),
    ]

    STATUS_CHOICES = [
        ('success', '成功'),
        ('failed', '失败'),
        ('partial', '部分成功'),
    ]

    lobster_id = models.CharField(max_length=50, help_text='龙虾ID')

    file_path = models.CharField(max_length=500, help_text='文件相对路径')

    action = models.CharField(
        max_length=20,
        choices=ACTION_CHOICES,
        help_text='操作类型'
    )

    status = models.CharField(
        max_length=20,
        choices=STATUS_CHOICES,
        help_text='操作状态'
    )

    old_version = models.IntegerField(null=True, blank=True, help_text='操作前版本')

    new_version = models.IntegerField(null=True, blank=True, help_text='操作后版本')

    old_hash = models.CharField(max_length=64, null=True, blank=True, help_text='操作前哈希')

    new_hash = models.CharField(max_length=64, null=True, blank=True, help_text='操作后哈希')

    file_size = models.IntegerField(default=0, help_text='文件大小（字节）')

    operator = models.CharField(max_length=50, default='system', help_text='操作者')

    error_message = models.TextField(null=True, blank=True, help_text='错误信息')

    execution_time = models.FloatField(default=0, help_text='执行时间（秒）')

    created_at = models.DateTimeField(auto_now_add=True, help_text='操作时间')

    class Meta:
        db_table = 'sync_history'
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['lobster_id', 'file_path']),
            models.Index(fields=['action']),
            models.Index(fields=['status']),
            models.Index(fields=['created_at']),
        ]

    def __str__(self):
        return f"{self.action} - {self.lobster_id}/{self.file_path} ({self.status})"