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

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")
    options.binary_location = "/usr/bin/google-chrome"
    
    try:
        # Use explicit ChromeDriver path
        service = Service(executable_path="/usr/bin/chromedriver")
        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.get("/health")
async def health_check():
    paths = {
        "chrome": "/usr/bin/google-chrome",
        "chromedriver": "/usr/bin/chromedriver"
    }
    exists = {name: os.path.exists(path) for name, path in paths.items()}
    
    chrome_version = "Not found"
    chromedriver_version = "Not found"
    
    if exists["chrome"]:
        try:
            chrome_version = os.popen("/usr/bin/google-chrome --version").read().strip()
        except Exception as e:
            logger.error(f"Failed to get Chrome version: {str(e)}")
            
    if exists["chromedriver"]:
        try:
            chromedriver_version = os.popen("/usr/bin/chromedriver --version").read().strip()
        except Exception as e:
            logger.error(f"Failed to get ChromeDriver version: {str(e)}")
    
    status = "OK" if all(exists.values()) else "ERROR"
    logger.info(f"Health check: Chrome={chrome_version}, ChromeDriver={chromedriver_version}, Paths={exists}")
    
    return {
        "status": status,
        "paths": exists,
        "chrome_version": chrome_version,
        "chromedriver_version": chromedriver_version,
        "working": all(exists.values())
    }

@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)))