"""
Template service for applying HTML/CSS templates to generated content
"""

import json
import random
from pathlib import Path
from typing import Optional, Dict
from src.core.config import get_config
from src.database.repositories import GeneratedContentRepository


class TemplateService:
    """Service for loading, selecting, and applying HTML templates"""
    
    def __init__(self, content_repo: Optional[GeneratedContentRepository] = None):
        self.templates_dir = Path(__file__).parent / "templates"
        self._template_cache: Dict[str, str] = {}
        self.content_repo = content_repo
    
    def get_available_templates(self) -> list[str]:
        """
        Get list of available template names
        
        Returns:
            List of template names without .html extension
        """
        templates = []
        for template_file in self.templates_dir.glob("*.html"):
            templates.append(template_file.stem)
        return sorted(templates)
    
    def load_template(self, template_name: str) -> str:
        """
        Load a template file by name
        
        Args:
            template_name: Name of template (without .html extension)
        
        Returns:
            Template content as string
        
        Raises:
            FileNotFoundError: If template doesn't exist
        """
        if template_name in self._template_cache:
            return self._template_cache[template_name]
        
        template_path = self.templates_dir / f"{template_name}.html"
        
        if not template_path.exists():
            available = self.get_available_templates()
            raise FileNotFoundError(
                f"Template '{template_name}' not found. Available templates: {', '.join(available)}"
            )
        
        with open(template_path, 'r', encoding='utf-8') as f:
            template_content = f.read()
        
        self._template_cache[template_name] = template_content
        return template_content
    
    def select_template_for_content(
        self, 
        site_deployment_id: Optional[int] = None,
        site_deployment_repo=None
    ) -> str:
        """
        Select appropriate template based on site deployment
        
        Args:
            site_deployment_id: Optional site deployment ID
            site_deployment_repo: Optional repository for querying site deployments
        
        Returns:
            Template name to use
        
        Logic:
            1. If site_deployment_id exists:
               - Query custom_hostname from SiteDeployment
               - Check config mappings for hostname
               - If mapping exists, use it
               - If no mapping, randomly select and persist to config
            2. If site_deployment_id is null: randomly select (don't persist)
        """
        config = get_config()
        
        if site_deployment_id and site_deployment_repo:
            site_deployment = site_deployment_repo.get_by_id(site_deployment_id)
            
            if site_deployment:
                hostname = site_deployment.custom_hostname or site_deployment.pull_zone_bcdn_hostname
                
                if hostname in config.templates.mappings:
                    return config.templates.mappings[hostname]
                
                template_name = self._select_random_template()
                self._persist_template_mapping(hostname, template_name)
                return template_name
        
        return self._select_random_template()
    
    def _select_random_template(self) -> str:
        """
        Randomly select a template from available templates
        
        Returns:
            Template name
        """
        available = self.get_available_templates()
        if not available:
            return "basic"
        
        return random.choice(available)
    
    def _persist_template_mapping(self, hostname: str, template_name: str) -> None:
        """
        Save template mapping to master.config.json
        
        Args:
            hostname: Custom hostname to map
            template_name: Template to assign
        """
        config_path = Path("master.config.json")
        
        try:
            with open(config_path, 'r', encoding='utf-8') as f:
                config_data = json.load(f)
            
            if "templates" not in config_data:
                config_data["templates"] = {"default": "basic", "mappings": {}}
            
            if "mappings" not in config_data["templates"]:
                config_data["templates"]["mappings"] = {}
            
            config_data["templates"]["mappings"][hostname] = template_name
            
            with open(config_path, 'w', encoding='utf-8') as f:
                json.dump(config_data, f, indent=2)
        
        except Exception as e:
            print(f"Warning: Failed to persist template mapping: {e}")
    
    def format_content(
        self, 
        content: str, 
        title: str, 
        meta_description: str, 
        template_name: str
    ) -> str:
        """
        Format content using specified template
        
        Args:
            content: Raw HTML content (h2, h3, p tags)
            title: Article title
            meta_description: Meta description for SEO
            template_name: Name of template to use
        
        Returns:
            Complete formatted HTML document
        
        Raises:
            FileNotFoundError: If template doesn't exist
        """
        config = get_config()
        
        try:
            template = self.load_template(template_name)
        except FileNotFoundError:
            fallback_template = config.templates.default
            print(f"Warning: Template '{template_name}' not found, using '{fallback_template}'")
            template = self.load_template(fallback_template)
        
        formatted_html = template.replace("{{ title }}", self._escape_html(title))
        formatted_html = formatted_html.replace("{{ meta_description }}", self._escape_html(meta_description))
        formatted_html = formatted_html.replace("{{ content }}", content)
        
        return formatted_html
    
    def _escape_html(self, text: str) -> str:
        """
        Escape HTML special characters in text
        
        Args:
            text: Text to escape
        
        Returns:
            Escaped text
        """
        replacements = {
            '&': '&',
            '<': '&lt;',
            '>': '&gt;',
            '"': '&quot;',
            "'": '&#39;'
        }
        
        for char, escaped in replacements.items():
            text = text.replace(char, escaped)
        
        return text