from fastapi import FastAPI, UploadFile, File, Request, Form
from fastapi.responses import HTMLResponse, FileResponse
from fastapi.templating import Jinja2Templates
from fastapi.staticfiles import StaticFiles
import pandas as pd
import json
from pathlib import Path
import shutil
from typing import List

app = FastAPI(title="JSON Price Converter")

# Create folders
UPLOAD_DIR = Path("uploads")
UPLOAD_DIR.mkdir(exist_ok=True)

# Templates
templates = Jinja2Templates(directory="templates")

# Mount static if needed (optional)
# app.mount("/static", StaticFiles(directory="static"), name="static")

def extract_price_from_json(data: dict, filename: str) -> list:
    price_records = []
    product_name = data.get('name', [{}])[0].get('value', 'Unknown Product')
    product_id = data.get('id')
    currency = data.get('currency')
    price_type = data.get('priceType')
    external_id = data.get('externalId', [{}])[0].get('id') if data.get('externalId') else None
    description = data.get('description', [{}])[0].get('value', '')

    for record in data.get('priceRecord', []):
        params = {p['name']: p['value'] for p in record.get('parameter', [])}
        
        for price_item in record.get('price', []):
            row = {
                'filename': filename,
                'product_id': product_id,
                'product_name': product_name,
                'description': description,
                'currency': currency,
                'price_type': price_type,
                'tier_counter': params.get('TIERED_PRICING_COUNTER'),
                'sales_channel': params.get('SalesChannel'),
                'amount_idr': price_item.get('taxIncludedAmount', {}).get('value'),
                'valid_from': price_item.get('validFor', {}).get('startDateTime'),
                'valid_until': price_item.get('validFor', {}).get('endDateTime'),
                'price_record_id': record.get('priceRecordId'),
                'priority': record.get('priority'),
                'external_id': external_id,
            }
            price_records.append(row)
    return price_records


@app.get("/", response_class=HTMLResponse)
async def home(request: Request):
    return templates.TemplateResponse("index.html", {"request": request})


@app.post("/upload")
async def upload_files(files: List[UploadFile] = File(...)):
    all_rows = []
    
    for file in files:
        if not file.filename.endswith('.json'):
            continue
            
        content = await file.read()
        try:
            data = json.loads(content)
            rows = extract_price_from_json(data, file.filename)
            all_rows.extend(rows)
        except Exception as e:
            print(f"Error processing {file.filename}: {e}")

    if not all_rows:
        return {"error": "No valid JSON files processed"}

    df = pd.DataFrame(all_rows)
    
    # Save results
    csv_path = UPLOAD_DIR / "all_prices_table.csv"
    excel_path = UPLOAD_DIR / "all_prices_table.xlsx"
    
    df.to_csv(csv_path, index=False)
    df.to_excel(excel_path, index=False)
    
    return {
        "message": f"Successfully processed {len(files)} files",
        "total_rows": len(df),
        "download_csv": "/download/csv",
        "download_excel": "/download/excel",
        "preview": df.head(10).to_dict(orient="records")  # for display
    }


@app.get("/download/csv")
async def download_csv():
    file_path = UPLOAD_DIR / "all_prices_table.csv"
    if not file_path.exists():
        return {"error": "No file available"}
    return FileResponse(file_path, media_type="text/csv", filename="all_prices_table.csv")


@app.get("/download/excel")
async def download_excel():
    file_path = UPLOAD_DIR / "all_prices_table.xlsx"
    if not file_path.exists():
        return {"error": "No file available"}
    return FileResponse(file_path, media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", 
                       filename="all_prices_table.xlsx")


# Run with: uvicorn main:app --reload
if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)