from fastapi import FastAPI, BackgroundTasks
from fastapi.responses import FileResponse
from pydantic import BaseModel
import os
from datetime import datetime

# This imports the functions from your massive script (which we will upload next)
from report_generator import (
    calculate_metrics, get_ai_analysis, chart_daily_completion, 
    chart_goal_proximity_gauge, chart_dow_performance, 
    chart_score_breakdown, build_pdf
)

app = FastAPI(title="FocusDesk AI Analytics Server")

# This tells the server what JSON structure to expect from Flutter
class ReportContext(BaseModel):
    user_profile: dict
    strategy: dict
    today_plan: dict
    history: list

# Deletes the PDF from the server after it is sent to the user to save space
def cleanup_file(filepath: str):
    if os.path.exists(filepath):
        os.remove(filepath)

@app.post("/generate_report")
async def generate_report(data: ReportContext, background_tasks: BackgroundTasks):
    context_data = data.model_dump()
    
    try:
        metrics = calculate_metrics(context_data)
        ai_sections = get_ai_analysis(context_data, metrics)
        
        chart_daily = chart_daily_completion(metrics["daily_rates"])
        chart_gauge = chart_goal_proximity_gauge(metrics["goal_proximity"])
        chart_dow = chart_dow_performance(metrics["dow_avg"])
        chart_radar = chart_score_breakdown(metrics)
        
        name = context_data["user_profile"]["name"].replace(" ", "_")
        timestamp = datetime.now().strftime("%Y%m%d%H%M%S")
        output_path = f"temp_report_{name}_{timestamp}.pdf"
        
        # Build the PDF using your awesome layout
        build_pdf(
            context_data, metrics, ai_sections,
            chart_daily, chart_gauge, chart_dow, chart_radar,
            output_path
        )
        
        # Schedule the cleanup, then send the file!
        background_tasks.add_task(cleanup_file, output_path)
        
        return FileResponse(
            path=output_path, 
            media_type="application/pdf", 
            filename=f"FocusDesk_{name}.pdf"
        )
        
    except Exception as e:
        return {"error": str(e)}