#!/usr/bin/env python3
"""
PDF Accessibility Checker — Cloud Run HTTP Service

Flask app wrapping EnterprisePDFChecker for serverless execution.
Receives PDF via multipart POST, runs checks, uploads page images to GCS,
returns full result JSON.
"""

import os
import json
import tempfile
import logging
from pathlib import Path

from flask import Flask, request, jsonify
from google.cloud import storage

from enterprise_pdf_checker import EnterprisePDFChecker

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s [cloudrun] %(levelname)s: %(message)s'
)
logger = logging.getLogger('cloudrun')

app = Flask(__name__)

GCS_BUCKET_NAME = os.getenv('STORAGE_BUCKET', 'pdf-pages')


def upload_images_to_gcs(images_dir: Path, job_id: str) -> dict:
    """Upload page images to GCS and return {page_num: public_url} mapping."""
    client = storage.Client()
    bucket = client.bucket(GCS_BUCKET_NAME)
    page_images = {}

    for image_file in sorted(images_dir.glob('page_*.png')):
        # Extract page number from filename (page_1.png -> 1)
        page_num = int(image_file.stem.split('_')[1])
        blob_name = f"{job_id}/{image_file.name}"
        blob = bucket.blob(blob_name)
        blob.upload_from_filename(str(image_file), content_type='image/png')
        # Bucket has uniform bucket-level access with allUsers objectViewer,
        # so objects are public by default — no need for blob.make_public()
        public_url = f"https://storage.googleapis.com/{GCS_BUCKET_NAME}/{blob_name}"
        page_images[page_num] = public_url
        logger.info("Uploaded %s -> %s", image_file.name, public_url)

    return page_images


@app.route('/check', methods=['POST'])
def check_pdf():
    """Accept multipart PDF upload, run accessibility checks, return results."""
    pdf_file = request.files.get('pdf')
    if not pdf_file:
        return jsonify({'success': False, 'error': 'No PDF file provided'}), 400

    job_id = request.form.get('job_id', 'unknown')
    quick_mode = request.form.get('quick_mode', 'false').lower() in ('true', '1', 'yes')
    original_filename = request.form.get('original_filename', pdf_file.filename or 'document.pdf')

    logger.info("Received job %s: %s (quick=%s)", job_id, original_filename, quick_mode)

    tmp_pdf = None
    images_dir = None

    try:
        # Save uploaded PDF to temp file
        tmp_pdf = tempfile.NamedTemporaryFile(suffix='.pdf', delete=False)
        pdf_file.save(tmp_pdf)
        tmp_pdf.close()

        # Run accessibility checks
        config = {
            'anthropic_api_key': os.getenv('ANTHROPIC_API_KEY'),
            'google_api_key': os.getenv('GOOGLE_API_KEY'),
        }

        checker = EnterprisePDFChecker(tmp_pdf.name, config, quick_mode=quick_mode)
        checker.check_all()

        # Generate page images to a temp directory
        images_dir = tempfile.mkdtemp(prefix='pdf_images_')
        images_path = Path(images_dir)
        checker._generate_page_images(images_path)

        # Get results before uploading images (page_images has local filenames)
        results = checker.to_dict()

        # Upload images to GCS and replace local filenames with public URLs
        if checker.page_images:
            gcs_urls = upload_images_to_gcs(images_path, job_id)
            results['page_images'] = gcs_urls

        # Add grade based on score
        score = results.get('accessibility_score', 0)
        if score >= 90:
            results['grade'] = 'A'
        elif score >= 80:
            results['grade'] = 'B'
        elif score >= 70:
            results['grade'] = 'C'
        elif score >= 60:
            results['grade'] = 'D'
        else:
            results['grade'] = 'F'

        logger.info("Job %s completed: score=%s grade=%s issues=%d",
                     job_id, results['accessibility_score'],
                     results['grade'], results['total_issues'])

        return jsonify({'success': True, 'data': results})

    except Exception as e:
        logger.error("Job %s failed: %s", job_id, str(e), exc_info=True)
        return jsonify({'success': False, 'error': str(e)}), 500

    finally:
        # Clean up temp files
        if tmp_pdf and os.path.exists(tmp_pdf.name):
            os.unlink(tmp_pdf.name)
        if images_dir and os.path.exists(images_dir):
            import shutil
            shutil.rmtree(images_dir, ignore_errors=True)


@app.route('/health', methods=['GET'])
def health():
    return jsonify({'status': 'ok'})


if __name__ == '__main__':
    port = int(os.getenv('PORT', 8080))
    app.run(host='0.0.0.0', port=port, debug=False)