from fastapi import FastAPI, HTTPException, Depends
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
import requests
import os
import pandas as pd

app = FastAPI(title="Trading Dashboard API")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# Serve static files
app.mount("/static", StaticFiles(directory="dashboard/public"), name="static")

@app.get("/")
async def read_index():
    return FileResponse('dashboard/public/index.html')

DB_USER = os.getenv("DB_USER", "admin")
DB_PASSWORD = os.getenv("DB_PASSWORD", "quest")
DB_AUTH = (DB_USER, DB_PASSWORD) if DB_USER and DB_PASSWORD else None
DB_HOST = os.getenv("DB_HOST", "questdb")

@app.get("/api/trades")
async def get_trades(isin: str = None, days: int = 7):
    query = f"select * from trades where timestamp > dateadd('d', -{days}, now())"
    if isin:
        query += f" and isin = '{isin}'"
    query += " order by timestamp asc"
    
    try:
        response = requests.get(f"http://{DB_HOST}:9000/exec", params={'query': query}, auth=DB_AUTH)
        if response.status_code == 200:
            return response.json()
        throw_http_error(response)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/api/metadata")
async def get_metadata():
    query = "select * from metadata"
    try:
        response = requests.get(f"http://{DB_HOST}:9000/exec", params={'query': query}, auth=DB_AUTH)
        if response.status_code == 200:
            return response.json()
        throw_http_error(response)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/api/summary")
async def get_summary():
    # Coalesce null values to 'Unknown' and group properly
    query = """
    select 
        coalesce(m.continent, 'Unknown') as continent, 
        count(*) as trade_count, 
        sum(t.price * t.quantity) as total_volume
    from trades t
    left join metadata m on t.isin = m.isin
    group by continent
    """
    try:
        response = requests.get(f"http://{DB_HOST}:9000/exec", params={'query': query}, auth=DB_AUTH)
        if response.status_code == 200:
            return response.json()
        throw_http_error(response)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/api/comparison")
async def get_comparison(days: int = 7):
    # Aggregated volume per exchange per day
    # QuestDB date_trunc('day', timestamp) is good. 
    # We ensure we get exchange, day, and metrics.
    query = f"""
    select 
        exchange, 
        date_trunc('day', timestamp) as day, 
        sum(price * quantity) as daily_volume, 
        count(*) as trade_count
    from trades 
    where timestamp > dateadd('d', -{days}, now())
    group by exchange, day
    order by day asc
    """
    try:
        response = requests.get(f"http://{DB_HOST}:9000/exec", params={'query': query}, auth=DB_AUTH)
        if response.status_code == 200:
            return response.json()
        throw_http_error(response)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

def throw_http_error(res):
    raise HTTPException(status_code=res.status_code, detail=f"QuestDB error: {res.text}")

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)