from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException, WebDriverException
import time
import logging
import os
import shutil
from pathlib import Path


app = FastAPI()

# Configure CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

class VideoRequest(BaseModel):
    url: str

class TranscriptResponse(BaseModel):
    success: bool
    transcript: list[str] | None
    error: str | None
    processing_time: float

def init_driver():
    options = Options()
    options.add_argument("--headless=new")
    options.add_argument("--no-sandbox")
    options.add_argument("--disable-dev-shm-usage")
    options.add_argument("--disable-gpu")
    
    # Try multiple possible Chrome binary locations
    possible_chrome_paths = [
        "/usr/bin/google-chrome",
        "/usr/bin/google-chrome-stable",
        "/usr/lib/chromium-browser/chrome",
        "/usr/bin/chromium"
    ]
    chrome_path = None
    for path in possible_chrome_paths:
        if os.path.exists(path):
            chrome_path = path
            break
    
    if not chrome_path:
        logger.error(f"No Chrome binary found in paths: {possible_chrome_paths}")
        raise Exception(f"No Chrome binary found in paths: {possible_chrome_paths}")
    
    options.binary_location = chrome_path
    logger.info(f"Using Chrome binary: {chrome_path}")
    
    try:
        chromedriver_path = "/usr/bin/chromedriver"
        if not os.path.exists(chromedriver_path):
            logger.error(f"ChromeDriver not found at {chromedriver_path}")
            raise Exception(f"ChromeDriver not found at {chromedriver_path}")
        
        service = Service(executable_path=chromedriver_path)
        driver = webdriver.Chrome(service=service, options=options)
        logger.info("ChromeDriver initialized successfully")
        return driver
    except Exception as e:
        logger.error(f"Driver initialization failed: {str(e)}")
        raise Exception(f"Driver initialization failed: {str(e)}")

@app.post("/transcript", response_model=TranscriptResponse)
async def get_transcript(request: VideoRequest):
    start_time = time.time()
    driver = None
    
    try:
        video_url = request.url
        if not ("youtube.com" in video_url or "youtu.be" in video_url):
            raise HTTPException(status_code=400, detail="Invalid YouTube URL")

        driver = init_driver()
        logger.info(f"Processing URL: {video_url}")
        driver.get(video_url)

        # Handle cookie consent if it appears
        try:
            cookie_button = WebDriverWait(driver, 5).until(
                EC.element_to_be_clickable((By.XPATH, "//*[contains(text(), 'Accept all')]"))
            )
            cookie_button.click()
            logger.info("Accepted cookies")
        except TimeoutException:
            logger.info("No cookie consent found")
            pass

        # Click more button
        more_button = WebDriverWait(driver, 10).until(
            EC.element_to_be_clickable((By.ID, "expand"))
        )
        driver.execute_script("arguments[0].click();", more_button)

        # Click transcript button
        transcript_button = WebDriverWait(driver, 10).until(
            EC.element_to_be_clickable((By.CSS_SELECTOR, "button[aria-label='Show transcript']"))
        )
        driver.execute_script("arguments[0].click();", transcript_button)

        # Wait for transcript
        WebDriverWait(driver, 15).until(
            EC.presence_of_element_located((By.ID, "segments-container"))
        )

        # Extract transcript
        segments = driver.find_elements(By.CSS_SELECTOR, "div.ytd-transcript-segment-renderer")
        transcript = []
        for segment in segments:
            try:
                text = segment.find_element(By.CLASS_NAME, "segment-text").text.strip()
                if text:
                    transcript.append(text)
            except:
                continue

        if not transcript:
            raise HTTPException(status_code=404, detail="No transcript available")

        return TranscriptResponse(
            success=True,
            transcript=transcript,
            error=None,
            processing_time=time.time() - start_time
        )

    except TimeoutException as e:
        error_msg = "Timed out waiting for page elements - the video might not have transcripts"
        logger.error(error_msg)
        return TranscriptResponse(
            success=False,
            transcript=None,
            error=error_msg,
            processing_time=time.time() - start_time
        )
    except Exception as e:
        logger.error(f"Error: {str(e)}")
        return TranscriptResponse(
            success=False,
            transcript=None,
            error=str(e),
            processing_time=time.time() - start_time
        )
    finally:
        if driver:
            driver.quit()



app = FastAPI()

@app.get("/health")
def health_check():
    chrome_path = shutil.which("google-chrome")
    chromedriver_path = shutil.which("chromedriver")
    return {
        "ChromePath": chrome_path,
        "ChromeDriverPath": chromedriver_path,
        "ChromeExists": Path(chrome_path or "").exists(),
        "ChromeDriverExists": Path(chromedriver_path or "").exists()
    }


@app.get("/")
async def root():
    return {"message": "Welcome to YouTube Transcript API"}

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=int(os.getenv("PORT", 7860)))