import asyncio
import aiofiles
import asyncpraw
import os
import json
import logging
import tempfile
import numpy as np
import platform
import shutil

from pydantic import BaseModel
from typing import List, Optional

from fastapi import (
    FastAPI,
    BackgroundTasks,
    Request,
    HTTPException,
    Body,
    WebSocket,
    WebSocketDisconnect,
)
from fastapi.responses import HTMLResponse, JSONResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates

from moviepy.editor import (
    VideoFileClip,
    CompositeVideoClip,
    TextClip,
    ImageClip,
    ColorClip,
)
from moviepy.config import change_settings
from PIL import Image, ImageDraw

import google.generativeai as genai
from google.generativeai.types import HarmBlockThreshold, HarmCategory

from concurrent.futures import ProcessPoolExecutor

# Import your RedDownloader (ensure it’s installed/in your PYTHONPATH)
from RedDownloader import RedDownloader

# Load environment variables (make sure you have a .env file with the keys)
from dotenv import load_dotenv

load_dotenv()

# Configure logging
logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s"
)

# Global list to store live log messages
live_logs = []


class LiveLogHandler(logging.Handler):
    def __init__(self):
        super().__init__()

    def emit(self, record):
        log_entry = self.format(record)
        live_logs.append(log_entry)
        # Keep only the last 100 messages to avoid unbounded growth
        if len(live_logs) > 100:
            live_logs.pop(0)


# Add the custom logging handler to the root logger
live_log_handler = LiveLogHandler()
live_log_handler.setFormatter(
    logging.Formatter("%(asctime)s - %(levelname)s - %(message)s")
)
logging.getLogger().addHandler(live_log_handler)

if platform.system() == "Windows":
    # Change ImageMagick binary path (adjust as needed)
    change_settings(
        {
            "IMAGEMAGICK_BINARY": r"C:\Program Files\ImageMagick-7.1.1-Q16-HDRI\magick.exe"
        }
    )

# Constants and paths
BACKGROUND_IMAGE = "background.png"
PROCESSED_VIDEOS_FILE = "processed_videos.json"
MAX_VIDEO_DURATION = 60  # seconds
FONT_PATH = "font/Montserrat-Black.ttf"
OUTPUT_DIR = "output"

# Reddit API credentials from environment
CLIENT_ID = os.environ.get("REDDIT_CLIENT_ID")
CLIENT_SECRET = os.environ.get("REDDIT_CLIENT_SECRET")
USER_AGENT = os.environ.get("REDDIT_USER_AGENT")
USERNAME = os.environ.get("REDDIT_USERNAME")
PASSWORD = os.environ.get("REDDIT_PASSWORD")

# Global in‐memory settings and processing state
subreddits = [
    "Damnthatsinteresting",
    "interestingasfuck",
    "BeAmazed",
    "nextfuckinglevel",
]
processing_results = {}  # keys: post id; values: { status, video_url, generated_title, generated_caption }


class VideoItem(BaseModel):
    id: str
    title: str
    ups: int
    url: str
    subreddit: str
    duration: Optional[int] = None
    thumbnail: Optional[str] = None


# Limit the number of workers to a reasonable number (e.g., 2 or 4) to avoid overwhelming your system.
process_executor = ProcessPoolExecutor(max_workers=2)

# ------------------ Helper Functions (largely re‐using your code) ------------------


async def initialize_reddit():
    return asyncpraw.Reddit(
        client_id=CLIENT_ID,
        client_secret=CLIENT_SECRET,
        user_agent=USER_AGENT,
        username=USERNAME,
        password=PASSWORD,
    )


async def load_processed_videos():
    if os.path.exists(PROCESSED_VIDEOS_FILE):
        async with aiofiles.open(PROCESSED_VIDEOS_FILE, "r") as f:
            try:
                return json.loads(await f.read())
            except json.JSONDecodeError:
                logging.error(
                    "Error decoding JSON in processed_videos.json. Starting with an empty list."
                )
                return []
    return []


async def save_processed_videos(processed_videos):
    async with aiofiles.open(PROCESSED_VIDEOS_FILE, "w") as f:
        await f.write(json.dumps(processed_videos))


async def get_n_comments(submission, n=3):
    """Gets the top n comments from a Reddit submission."""
    try:
        comments = await submission.comments()
        await comments.replace_more(limit=None)
        top_comments = [comment.body for comment in comments]
        return top_comments[:n]
    except Exception as e:
        logging.error(f"Error getting comments: {e}")
        return []


async def fetch_trending_videos(reddit, processed_videos, subreddit_name):
    """Fetch trending video posts from a subreddit without downloading them."""
    posts_list = []
    try:
        subreddit = await reddit.subreddit(subreddit_name)
        async for post in subreddit.hot(limit=10):
            if post.is_video and post.id not in processed_videos:
                try:
                    duration = post.media["reddit_video"]["duration"]
                    if duration <= MAX_VIDEO_DURATION:
                        width = post.media["reddit_video"]["width"]
                        height = post.media["reddit_video"]["height"]
                        # Only include posts with a vertical-ish ratio
                        if (height / width) >= 1.6:
                            # --- TASK 4: Skip videos with no audio ---
                            if not post.media["reddit_video"].get("has_audio", True):
                                logging.warning(
                                    f"Skipping post {post.id} due to no audio"
                                )
                                continue
                            posts_list.append(post)
                        else:
                            logging.warning(
                                f"Skipping post {post.id} due to ratio: width {width} > height {height}"
                            )
                    else:
                        logging.warning(
                            f"Skipping post {post.id} due to exceeding max duration."
                        )
                except KeyError:
                    logging.warning(
                        f"Skipping post {post.id} due to missing video dimensions/duration."
                    )
        return posts_list
    except Exception as e:
        logging.error(f"Error fetching videos from subreddit {subreddit_name}: {e}")
        return []


async def download_video(url, filename):
    """
    Offload the synchronous RedDownloader.Download call to a thread.
    """
    loop = asyncio.get_running_loop()

    def blocking_download():
        try:
            # This call is blocking.
            RedDownloader.Download(url, quality=720, output=filename.split('.')[0])
            return os.path.exists(filename)
        except Exception as e:
            logging.error(f"Error downloading video: {e}")
            return False

    exists = await loop.run_in_executor(None, blocking_download)
    if exists:
        logging.info(f"Video downloaded to {filename}")
        return filename
    else:
        logging.error(f"Video file not found after download: {filename}")
        return None


async def generate_title_and_caption(title, comments, first_frame, api_key):
    genai.configure(api_key=api_key)
    generation_config = genai.GenerationConfig(
        temperature=1, max_output_tokens=8192, response_mime_type="application/json"
    )

    model = genai.GenerativeModel(
        model_name="gemini-2.0-flash",
        generation_config=generation_config,
        safety_settings={
            HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT: HarmBlockThreshold.BLOCK_NONE,
            HarmCategory.HARM_CATEGORY_HARASSMENT: HarmBlockThreshold.BLOCK_NONE,
            HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT: HarmBlockThreshold.BLOCK_NONE,
            HarmCategory.HARM_CATEGORY_HATE_SPEECH: HarmBlockThreshold.BLOCK_NONE,
        },
        system_instruction=(
            "Generate a JSON object which contains a short youtube video title of max 15 words, "
            "and also a very interesting and informational paragraph describing the subject and any informative interesting knowledge derived from the comments, "
            "based on the provided video title, first frame image and comments info. Do not refer to the video or comments explicitly. "
            "Return a JSON object with keys 'title' and 'caption'."
        ),
    )
    try:
        with tempfile.NamedTemporaryFile(
            suffix=".png", delete=False
        ) as temp_image_file:
            image = Image.fromarray(first_frame, mode="RGB")
            image.save(temp_image_file.name)
            temp_image_file.flush()
            image = Image.open(temp_image_file.name)
            parts = [f"Title: {title}\n\nComments: {comments}", image]
            response = await model.generate_content_async(
                [{"role": "user", "parts": parts}]
            )
            image.close()
            temp_image_file.close()
            if os.path.exists(temp_image_file.name):
                os.remove(temp_image_file.name)

            try:
                response_json = json.loads(response.text)
                generated_title = response_json["title"]
                generated_caption = response_json["caption"]
                return generated_title, generated_caption
            except (json.JSONDecodeError, KeyError, TypeError) as json_err:
                logging.error(
                    f"Error parsing JSON response: {json_err}, Response Text: {response.text}"
                )
                return None, None

    except Exception as e:
        logging.error(f"Error generating title and caption: {e}")
        return None, None


def round_corners(clip, radius):
    mask = Image.new("RGB", clip.size, 0)
    draw = ImageDraw.Draw(mask)
    draw.rounded_rectangle([(0, 0), clip.size], radius, fill=255)
    return clip.set_mask(ImageClip(np.array(mask), ismask=True))


def create_text_clip(text, font_area, font_size, color):
    width = font_area[2] - font_area[0]
    height = font_area[3] - font_area[1]

    txt_clip = TextClip(
        text,
        fontsize=font_size,
        color=color,
        font=FONT_PATH,
        size=(width, None),
        method="caption",
        align="center",
    )

    if txt_clip.h > height:
        scale_factor = height / txt_clip.h
        new_font_size = int(font_size * scale_factor)
        txt_clip = TextClip(
            text,
            fontsize=new_font_size,
            color=color,
            font=FONT_PATH,
            size=(width, None),
            method="caption",
            align="center",
        )

    vertical_offset = 8
    txt_y = (height - txt_clip.h) / 4 + vertical_offset

    bg_clip = ColorClip(size=(width, height), color=(0, 0, 0, 0))

    final_clip = CompositeVideoClip(
        [bg_clip, txt_clip.set_position((width / 2 - txt_clip.w / 2, txt_y))]
    )

    return final_clip.set_position((font_area[0], font_area[1]))


def calculate_text_color(frame, x, y, width, height):
    region = frame[y : y + height, x : x + width]
    if region.shape[-1] == 3:
        grayscale = np.dot(region[..., :3], [0.2989, 0.5870, 0.1140])
    else:
        grayscale = region
    mean_brightness = np.mean(grayscale)
    relative_luminance = mean_brightness / 255
    white_contrast = (1.0 + 0.05) / (relative_luminance + 0.05)
    black_contrast = (relative_luminance + 0.05) / (0.0 + 0.05)
    return "white" if white_contrast > black_contrast else "black"


def create_watermark_clip(
    watermark_text, frame, x_pos, y_pos, width, height, video_duration
):
    optimal_color = calculate_text_color(frame, int(x_pos), int(y_pos), width, height)
    watermark_clip = TextClip(
        watermark_text,
        fontsize=30,
        color=optimal_color,
        font=FONT_PATH,
    )
    watermark_width = watermark_clip.w
    watermark_x = (720 - watermark_width) / 2
    return watermark_clip.set_position((watermark_x, 1140)).set_duration(video_duration)


def generate_video(
    video_path, title, comments, api_key, post_id, watermark_text="@damnsointeresting"
):
    try:
        output_dir = os.path.join(OUTPUT_DIR, post_id)
        os.makedirs(output_dir, exist_ok=True)
        video = VideoFileClip(video_path)
        first_frame = video.get_frame(0)
        bg = ImageClip(BACKGROUND_IMAGE).set_duration(video.duration)
        audio = video.audio

        video_area = (40, 290, 680, 1220)
        video_width = video_area[2] - video_area[0]
        video_height = video_area[3] - video_area[1]
        video_ratio = video.w / video.h
        if video_ratio > video_width / video_height:
            new_width, new_height = video_width, int(video_width / video_ratio)
        else:
            new_width, new_height = int(video_height * video_ratio), video_height
        video = video.resize(width=new_width, height=new_height)
        x_pos = video_area[0] + (video_width - new_width) / 2
        y_pos = video_area[1] + (video_height - new_height) / 2
        video = video.set_position((x_pos, y_pos))
        video = round_corners(video, 40)

        generated_title, generated_caption = asyncio.run(
            generate_title_and_caption(title, comments, first_frame, api_key)
        )
        if not generated_title or not generated_caption:
            logging.error("Failed to generate title or caption. Skipping video.")
            return None, None

        title_clip = create_text_clip(
            generated_title, (45, 190, 675, 285), 35, "white"
        ).set_duration(video.duration)
        watermark_clip = create_watermark_clip(
            watermark_text, first_frame, 210, 1140, 300, 40, video.duration
        )

        final = CompositeVideoClip(
            [bg, video, title_clip, watermark_clip], size=(720, 1280)
        )
        final = final.set_duration(video.duration)

        if audio:
            final = final.set_audio(audio)

        output_filename = os.path.join(output_dir, f"{post_id}.mp4")
        final.write_videofile(output_filename, fps=30)

        caption_filepath = os.path.join(output_dir, f"{post_id}.txt")
        with open(caption_filepath, "w") as f:
            f.write(
                f"Title:\n{generated_title.strip()}\n\nCaption:\n{generated_caption.strip()}"
            )

        return output_filename, generated_title, generated_caption
    except Exception as e:
        logging.error(f"Error processing video: {e}")
        return None, None, None
    finally:
        if "video" in locals():
            video.close()
        if "final" in locals():
            final.close()


# ------------------ FastAPI App and Endpoints ------------------

app = FastAPI()

# Mount static directories (for output videos and any static assets)
if not os.path.exists(OUTPUT_DIR):
    os.makedirs(OUTPUT_DIR)
if not os.path.exists("static"):
    os.makedirs("static")
app.mount("/output", StaticFiles(directory=OUTPUT_DIR), name="output")
app.mount("/static", StaticFiles(directory="static"), name="static")

templates = Jinja2Templates(directory="templates")


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


@app.get("/api/videos")
async def get_videos():
    reddit = await initialize_reddit()
    processed_videos = await load_processed_videos()
    all_posts = []
    for subreddit_name in subreddits:
        posts = await fetch_trending_videos(reddit, processed_videos, subreddit_name)
        for post in posts:
            try:
                duration = post.media["reddit_video"]["duration"]
            except KeyError:
                duration = None

            # Add preview_video if available from the reddit_video media.
            preview_video = None
            try:
                reddit_video = post.media.get("reddit_video")
                if reddit_video and "fallback_url" in reddit_video:
                    preview_video = reddit_video["fallback_url"]
            except Exception:
                preview_video = None

            video_info = {
                "id": post.id,
                "title": post.title,
                "ups": post.ups,
                "url": post.url,
                "subreddit": subreddit_name,
                "duration": duration,
                "thumbnail": post.thumbnail if hasattr(post, "thumbnail") else None,
                "preview_video": preview_video,
            }
            all_posts.append(video_info)
    await reddit.close()
    all_posts.sort(key=lambda x: x["ups"], reverse=True)
    return JSONResponse(content=all_posts)


@app.post("/api/process")
async def process_selected_videos(
    background_tasks: BackgroundTasks,
    videos: List[VideoItem] = Body(...),
):
    if not videos:
        raise HTTPException(status_code=400, detail="No videos provided")
    for video_info in videos:
        video_id = video_info.id  # now you can access attributes directly
        if video_id in processing_results:
            continue  # already processing or processed
        processing_results[video_id] = {"status": "pending"}
        background_tasks.add_task(process_video_task, video_info.dict())
    return JSONResponse(
        content={
            "message": "Processing started",
            "video_ids": [video.id for video in videos],
        }
    )


async def process_video_task(video_info: dict):
    video_id = video_info.get("id")
    try:
        api_key = os.environ.get("GOOGLE_API_KEY")
        if not api_key:
            processing_results[video_id] = {"status": "error", "error": "Missing GOOGLE_API_KEY"}
            return

        reddit = await initialize_reddit()
        submission = await reddit.submission(id=video_id)
        comments = await get_n_comments(submission, 5)
        comments_string = "\n\n".join(comments) if comments else "No comments found."

        temp_video_filename = f"{video_id}.mp4"
        downloaded_video = await download_video(video_info.get("url"), temp_video_filename)
        if not downloaded_video:
            processing_results[video_id] = {"status": "error", "error": "Failed to download video"}
            await reddit.close()
            return

        # Offload heavy MoviePy processing using the process pool.
        loop = asyncio.get_running_loop()
        result = await loop.run_in_executor(
            process_executor,
            generate_video,  # blocking function using MoviePy
            downloaded_video,
            video_info.get("title"),
            comments_string,
            api_key,
            f"{video_id}",
            "@damnsointeresting"
        )

        if result and result[0]:
            output_file, generated_title, generated_caption = result
            video_url = f"/output/{video_id}/{video_id}.mp4"
            processing_results[video_id] = {
                "status": "completed",
                "video_url": video_url,
                "generated_title": generated_title,
                "generated_caption": generated_caption
            }
        else:
            processing_results[video_id] = {"status": "error", "error": "Video processing failed"}

        if os.path.exists(temp_video_filename):
            os.remove(temp_video_filename)
        await reddit.close()
    except Exception as e:
        processing_results[video_id] = {"status": "error", "error": str(e)}


@app.get("/api/results")
async def get_results():
    return JSONResponse(content=processing_results)


@app.get("/api/settings")
async def get_settings():
    return JSONResponse(content={"subreddits": subreddits})


@app.post("/api/settings")
async def update_settings(data: dict):
    new_subs = data.get("subreddits")
    if not isinstance(new_subs, list):
        raise HTTPException(status_code=400, detail="subreddits must be a list")
    global subreddits
    subreddits = new_subs
    return JSONResponse(
        content={"message": "Settings updated", "subreddits": subreddits}
    )


@app.delete("/api/video/{video_id}")
async def delete_video(video_id: str):
    video_folder = os.path.join(OUTPUT_DIR, video_id)
    if os.path.exists(video_folder):
        try:
            shutil.rmtree(video_folder)
            # Remove from our in‐memory processing_results if present.
            if video_id in processing_results:
                del processing_results[video_id]
            return JSONResponse(content={"message": f"Video {video_id} deleted."})
        except Exception as e:
            raise HTTPException(status_code=500, detail=f"Error deleting video: {e}")
    else:
        raise HTTPException(status_code=404, detail="Video not found.")


@app.websocket("/ws/logs")
async def websocket_logs(websocket: WebSocket):
    await websocket.accept()
    last_index = 0
    try:
        while True:
            # Sleep briefly to prevent busy looping
            await asyncio.sleep(1)
            # If new log messages are available, send them to the client.
            if last_index < len(live_logs):
                for log in live_logs[last_index:]:
                    await websocket.send_text(log)
                last_index = len(live_logs)
    except WebSocketDisconnect:
        logging.info("Client disconnected from live logs websocket")


# To run the app:
#   uvicorn main:app --reload