"""
Plugin Distribution System Models

Tracks plugins, versions, and installations across sites.
"""
from django.db import models
from django.conf import settings
from django.utils import timezone


class Plugin(models.Model):
    """
    Represents a plugin type (WordPress, Shopify, etc.)
    
    Each plugin can have multiple versions and be installed on multiple sites.
    """
    
    PLATFORM_CHOICES = [
        ('wordpress', 'WordPress'),
        ('shopify', 'Shopify'),
        ('custom', 'Custom Site'),
    ]
    
    name = models.CharField(
        max_length=100,
        help_text="Human-readable plugin name (e.g., 'IGNY8 WP Bridge')"
    )
    slug = models.SlugField(
        unique=True,
        help_text="URL-safe identifier (e.g., 'igny8-wp-bridge')"
    )
    platform = models.CharField(
        max_length=20,
        choices=PLATFORM_CHOICES,
        help_text="Target platform for this plugin"
    )
    description = models.TextField(
        blank=True,
        help_text="Plugin description for display in download pages"
    )
    homepage_url = models.URLField(
        blank=True,
        help_text="Plugin homepage or documentation URL"
    )
    is_active = models.BooleanField(
        default=True,
        db_index=True,
        help_text="Whether this plugin is available for download"
    )
    
    # Timestamps
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'plugins'
        ordering = ['name']
        verbose_name = 'Plugin'
        verbose_name_plural = 'Plugins'

    def __str__(self):
        return f"{self.name} ({self.platform})"
    
    def get_latest_version(self):
        """Get the latest released version of this plugin."""
        return self.versions.filter(
            status='released'
        ).first()
    
    def get_download_count(self):
        """Get total download count across all versions."""
        return self.downloads.count()


class PluginVersion(models.Model):
    """
    Tracks each version of a plugin.
    
    Versions follow semantic versioning (major.minor.patch).
    """
    
    STATUS_CHOICES = [
        ('draft', 'Draft'),           # In development - NOT available for download
        ('released', 'Released'),     # Available for download and updates
        ('deprecated', 'Deprecated'), # Old version, not recommended
    ]
    
    plugin = models.ForeignKey(
        Plugin,
        on_delete=models.CASCADE,
        related_name='versions',
        help_text="Plugin this version belongs to"
    )
    version = models.CharField(
        max_length=20,
        help_text="Semantic version string (e.g., '1.0.0', '1.0.1')"
    )
    version_code = models.IntegerField(
        null=True,
        blank=True,
        help_text="Numeric version for comparison (1.0.1 -> 10001). Auto-calculated."
    )
    status = models.CharField(
        max_length=20,
        choices=STATUS_CHOICES,
        default='draft',
        db_index=True,
        help_text="Release status of this version"
    )
    
    # File info
    file_path = models.CharField(
        max_length=500,
        blank=True,
        default='',
        help_text="Relative path to ZIP file in dist/ directory. Auto-generated on release."
    )
    file_size = models.IntegerField(
        default=0,
        help_text="File size in bytes"
    )
    checksum = models.CharField(
        max_length=64,
        blank=True,
        help_text="SHA256 checksum for integrity verification"
    )
    
    # Release info
    changelog = models.TextField(
        blank=True,
        help_text="What's new in this version (supports Markdown)"
    )
    min_api_version = models.CharField(
        max_length=20,
        default='1.0',
        help_text="Minimum IGNY8 API version required"
    )
    min_platform_version = models.CharField(
        max_length=20,
        blank=True,
        help_text="Minimum platform version (e.g., WordPress 5.0)"
    )
    min_php_version = models.CharField(
        max_length=10,
        default='7.4',
        help_text="Minimum PHP version required (for WordPress plugins)"
    )
    
    # Timestamps
    created_at = models.DateTimeField(auto_now_add=True)
    released_at = models.DateTimeField(
        null=True,
        blank=True,
        help_text="When this version was released"
    )
    
    # Auto-update control
    force_update = models.BooleanField(
        default=False,
        help_text="Force update for critical security fixes"
    )
    
    class Meta:
        db_table = 'plugin_versions'
        unique_together = ['plugin', 'version']
        ordering = ['-version_code']
        verbose_name = 'Plugin Version'
        verbose_name_plural = 'Plugin Versions'

    def __str__(self):
        return f"{self.plugin.name} v{self.version}"
    
    def save(self, *args, **kwargs):
        """Calculate version_code from version string if not set."""
        if not self.version_code:
            self.version_code = self.parse_version_code(self.version)
        super().save(*args, **kwargs)
    
    @staticmethod
    def parse_version_code(version_string):
        """
        Convert version string to numeric code for comparison.
        
        '1.0.0' -> 10000
        '1.0.1' -> 10001
        '1.2.3' -> 10203
        '2.0.0' -> 20000
        """
        try:
            parts = version_string.split('.')
            major = int(parts[0]) if len(parts) > 0 else 0
            minor = int(parts[1]) if len(parts) > 1 else 0
            patch = int(parts[2]) if len(parts) > 2 else 0
            return major * 10000 + minor * 100 + patch
        except (ValueError, IndexError):
            return 0
    
    def release(self):
        """Mark this version as released."""
        self.status = 'released'
        self.released_at = timezone.now()
        self.save(update_fields=['status', 'released_at'])
    
    def get_download_count(self):
        """Get download count for this version."""
        return self.downloads.count()


class PluginInstallation(models.Model):
    """
    Tracks where plugins are installed (per site).
    
    This allows us to:
    - Notify sites about available updates
    - Track version distribution
    - Monitor plugin health
    """
    
    site = models.ForeignKey(
        'igny8_core_auth.Site',
        on_delete=models.CASCADE,
        related_name='plugin_installations',
        help_text="Site where plugin is installed"
    )
    plugin = models.ForeignKey(
        Plugin,
        on_delete=models.CASCADE,
        related_name='installations',
        help_text="Installed plugin"
    )
    current_version = models.ForeignKey(
        PluginVersion,
        on_delete=models.SET_NULL,
        null=True,
        related_name='current_installations',
        help_text="Currently installed version"
    )
    
    # Installation status
    is_active = models.BooleanField(
        default=True,
        db_index=True,
        help_text="Whether the plugin is currently active"
    )
    last_health_check = models.DateTimeField(
        null=True,
        blank=True,
        help_text="Last successful health check timestamp"
    )
    health_status = models.CharField(
        max_length=20,
        default='unknown',
        choices=[
            ('healthy', 'Healthy'),
            ('outdated', 'Outdated'),
            ('error', 'Error'),
            ('unknown', 'Unknown'),
        ],
        help_text="Current health status"
    )
    
    # Update tracking
    pending_update = models.ForeignKey(
        PluginVersion,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='pending_installations',
        help_text="Pending version update"
    )
    update_notified_at = models.DateTimeField(
        null=True,
        blank=True,
        help_text="When site was notified about pending update"
    )
    
    # Timestamps
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'plugin_installations'
        unique_together = ['site', 'plugin']
        ordering = ['-updated_at']
        verbose_name = 'Plugin Installation'
        verbose_name_plural = 'Plugin Installations'

    def __str__(self):
        version_str = f" v{self.current_version.version}" if self.current_version else ""
        return f"{self.plugin.name}{version_str} on {self.site.name}"
    
    def check_for_update(self):
        """Check if an update is available for this installation."""
        latest = self.plugin.get_latest_version()
        if not latest or not self.current_version:
            return None
        
        if latest.version_code > self.current_version.version_code:
            return latest
        return None
    
    def update_health_status(self):
        """Update health status based on current state."""
        latest = self.plugin.get_latest_version()
        
        if not self.current_version:
            self.health_status = 'unknown'
        elif latest and latest.version_code > self.current_version.version_code:
            self.health_status = 'outdated'
        else:
            self.health_status = 'healthy'
        
        self.last_health_check = timezone.now()
        self.save(update_fields=['health_status', 'last_health_check'])


class PluginDownload(models.Model):
    """
    Tracks plugin download events for analytics.
    """
    
    plugin = models.ForeignKey(
        Plugin,
        on_delete=models.CASCADE,
        related_name='downloads'
    )
    version = models.ForeignKey(
        PluginVersion,
        on_delete=models.CASCADE,
        related_name='downloads'
    )
    
    # Download context
    site = models.ForeignKey(
        'igny8_core_auth.Site',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='plugin_downloads',
        help_text="Site that initiated the download (if authenticated)"
    )
    account = models.ForeignKey(
        'igny8_core_auth.Account',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='plugin_downloads',
        help_text="Account that initiated the download"
    )
    
    # Request info
    ip_address = models.GenericIPAddressField(
        null=True,
        blank=True
    )
    user_agent = models.CharField(
        max_length=500,
        blank=True
    )
    
    # Download type
    download_type = models.CharField(
        max_length=20,
        default='manual',
        choices=[
            ('manual', 'Manual Download'),
            ('update', 'Auto Update'),
            ('api', 'API Download'),
        ]
    )
    
    created_at = models.DateTimeField(auto_now_add=True)
    
    class Meta:
        db_table = 'plugin_downloads'
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['plugin', 'created_at']),
            models.Index(fields=['version', 'created_at']),
        ]
        verbose_name = 'Plugin Download'
        verbose_name_plural = 'Plugin Downloads'

    def __str__(self):
        return f"Download: {self.plugin.name} v{self.version.version}"