"""
Report generation service.
Generates PDF and JSON reports from inspection results.
"""

import json
import logging
from datetime import datetime
from pathlib import Path
from typing import Optional
from urllib.parse import urlparse

from jinja2 import Environment, FileSystemLoader
from slugify import slugify

logger = logging.getLogger(__name__)

TEMPLATES_DIR = Path(__file__).parent.parent / "templates"

# Grade color mapping
GRADE_COLORS = {
    "A+": "#22C55E",
    "A": "#22C55E",
    "B": "#3B82F6",
    "C": "#F59E0B",
    "D": "#F97316",
    "F": "#EF4444",
}

SEVERITY_COLORS = {
    "critical": "#EF4444",
    "major": "#F97316",
    "minor": "#EAB308",
    "info": "#3B82F6",
}

CATEGORY_LABELS = {
    "html_css": "HTML/CSS 표준",
    "accessibility": "접근성 (WCAG)",
    "seo": "SEO 최적화",
    "performance_security": "성능/보안",
}


class ReportService:
    """PDF and JSON report generation service."""

    def __init__(self):
        self.env = Environment(
            loader=FileSystemLoader(str(TEMPLATES_DIR)),
            autoescape=True,
        )
        # Register custom filters
        self.env.filters["grade_color"] = lambda g: GRADE_COLORS.get(g, "#6B7280")
        self.env.filters["severity_color"] = lambda s: SEVERITY_COLORS.get(s, "#6B7280")
        self.env.filters["category_label"] = lambda c: CATEGORY_LABELS.get(c, c)

    async def generate_pdf(self, inspection: dict) -> bytes:
        """Generate PDF report from inspection result."""
        try:
            from weasyprint import HTML

            template = self.env.get_template("report.html")
            html_string = template.render(
                inspection=inspection,
                generated_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S UTC"),
                grade_colors=GRADE_COLORS,
                severity_colors=SEVERITY_COLORS,
                category_labels=CATEGORY_LABELS,
            )
            pdf_bytes = HTML(string=html_string).write_pdf()
            return pdf_bytes

        except ImportError:
            logger.error("WeasyPrint is not installed")
            raise RuntimeError("PDF generation is not available (WeasyPrint not installed)")
        except Exception as e:
            logger.error("PDF generation failed: %s", str(e))
            raise RuntimeError(f"PDF generation failed: {str(e)}")

    async def generate_json(self, inspection: dict) -> bytes:
        """Generate JSON report from inspection result."""
        # Remove MongoDB internal fields
        clean_data = {k: v for k, v in inspection.items() if k != "_id"}
        json_str = json.dumps(clean_data, ensure_ascii=False, indent=2, default=str)
        return json_str.encode("utf-8")

    @staticmethod
    def generate_filename(url: str, extension: str) -> str:
        """Generate download filename: web-inspector-{url-slug}-{date}.{ext}"""
        parsed = urlparse(url)
        hostname = parsed.hostname or "unknown"
        url_slug = slugify(hostname, max_length=50)
        date_str = datetime.utcnow().strftime("%Y-%m-%d")
        return f"web-inspector-{url_slug}-{date_str}.{extension}"