"""
Generate Document Preview Step

Universal step for generating document previews.
Can be triggered by any document sync flow.

Flow:
1. Load document from EspoCRM
2. Download file attachment
3. Generate preview (PDF, DOCX, Images → WebP)
4. Upload preview to EspoCRM
5. Update document metadata

Event: document.generate_preview
Input: entity_id, entity_type (default: 'CDokumente')
"""

from typing import Dict, Any
from motia import FlowContext, queue
import tempfile
import os


config = {
    "name": "Generate Document Preview",
    "description": "Generates preview image for documents",
    "flows": ["document-preview"],
    "triggers": [queue("document.generate_preview")],
    "enqueues": [],
}


async def handler(event_data: Dict[str, Any], ctx: FlowContext[Any]) -> None:
    """
    Generate preview for a document.
    
    Args:
        event_data: {
            'entity_id': str,          # Required: Document ID
            'entity_type': str,        # Optional: 'CDokumente' (default) or 'Document'
        }
    """
    from services.document_sync_utils import DocumentSync
    
    entity_id = event_data.get('entity_id')
    entity_type = event_data.get('entity_type', 'CDokumente')
    
    if not entity_id:
        ctx.logger.error("❌ Missing entity_id in event data")
        return
    
    ctx.logger.info("=" * 80)
    ctx.logger.info(f"🖼️  GENERATE DOCUMENT PREVIEW")
    ctx.logger.info("=" * 80)
    ctx.logger.info(f"Entity Type: {entity_type}")
    ctx.logger.info(f"Document ID: {entity_id}")
    ctx.logger.info("=" * 80)
    
    # Initialize sync utils
    sync_utils = DocumentSync(ctx)
    
    try:
        # Step 1: Get download info from EspoCRM
        ctx.logger.info("📥 Step 1: Getting download info from EspoCRM...")
        download_info = await sync_utils.get_document_download_info(entity_id, entity_type)
        
        if not download_info:
            ctx.logger.warn("⚠️  No download info available - skipping preview generation")
            return
        
        attachment_id = download_info['attachment_id']
        filename = download_info['filename']
        mime_type = download_info['mime_type']
        
        ctx.logger.info(f"   Filename: {filename}")
        ctx.logger.info(f"   MIME Type: {mime_type}")
        ctx.logger.info(f"   Attachment ID: {attachment_id}")
        
        # Step 2: Download file from EspoCRM
        ctx.logger.info("📥 Step 2: Downloading file from EspoCRM...")
        file_content = await sync_utils.espocrm.download_attachment(attachment_id)
        ctx.logger.info(f"   Downloaded: {len(file_content)} bytes")
        
        # Step 3: Save to temporary file for preview generation
        ctx.logger.info("💾 Step 3: Saving to temporary file...")
        with tempfile.NamedTemporaryFile(mode='wb', delete=False, suffix=os.path.splitext(filename)[1]) as tmp_file:
            tmp_file.write(file_content)
            tmp_path = tmp_file.name
        
        try:
            # Step 4: Generate preview (600x800 WebP)
            ctx.logger.info(f"🖼️  Step 4: Generating preview (600x800 WebP)...")
            preview_data = await sync_utils.generate_thumbnail(
                tmp_path,
                mime_type,
                max_width=600,
                max_height=800
            )
            
            if preview_data:
                ctx.logger.info(f"✅ Preview generated: {len(preview_data)} bytes WebP")
                
                # Step 5: Upload preview to EspoCRM
                ctx.logger.info(f"📤 Step 5: Uploading preview to EspoCRM...")
                await sync_utils._upload_preview_to_espocrm(entity_id, preview_data, entity_type)
                ctx.logger.info(f"✅ Preview uploaded successfully")
                
                ctx.logger.info("=" * 80)
                ctx.logger.info("✅ PREVIEW GENERATION COMPLETE")
                ctx.logger.info("=" * 80)
            else:
                ctx.logger.warn("⚠️  Preview generation returned no data")
                ctx.logger.info("=" * 80)
                ctx.logger.info("⚠️  PREVIEW GENERATION FAILED")
                ctx.logger.info("=" * 80)
        
        finally:
            # Cleanup temporary file
            if os.path.exists(tmp_path):
                os.remove(tmp_path)
                ctx.logger.debug(f"🗑️  Removed temporary file: {tmp_path}")
    
    except Exception as e:
        ctx.logger.error(f"❌ Preview generation failed: {e}")
        ctx.logger.info("=" * 80)
        ctx.logger.info("❌ PREVIEW GENERATION ERROR")
        ctx.logger.info("=" * 80)
        import traceback
        ctx.logger.debug(traceback.format_exc())
        # Don't raise - preview generation is optional