"""
FB Auto Poster
==============
AI image generation + scheduled automatic posting to a Facebook Page.

Designed to run as a Hugging Face Gradio Space.

What it does
------------
1. Aap bahut saare prompts (ek line mein ek) daalte hain.
2. Bot har prompt se AI image generate karta hai (Hugging Face Inference API).
3. Har post ek queue mein chala jaata hai (image + caption).
4. Ek scheduler roz set kiye gaye time par queue se agli post apne aap
   Facebook Page par upload kar deta hai.

Required Space secrets / env vars
---------------------------------
FB_PAGE_ID              -> aapke Facebook Page ka numeric ID
FB_PAGE_ACCESS_TOKEN    -> long-lived Page access token (setup guide dekhein)
HF_TOKEN                -> Hugging Face token (image generate karne ke liye)

Optional env vars
-----------------
IMAGE_MODEL   (default: black-forest-labs/FLUX.1-schnell)
POST_TIMES    (default: 09:00,14:00,19:00  -> IST)
GRAPH_VERSION (default: v21.0)
"""

import os
import io
import json
import time
import logging
import threading
import datetime

import requests
import gradio as gr
from PIL import Image
from huggingface_hub import InferenceClient
from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.triggers.cron import CronTrigger

# --------------------------------------------------------------------------
# Configuration
# --------------------------------------------------------------------------
FB_PAGE_ID = os.getenv("FB_PAGE_ID", "").strip()
FB_TOKEN = os.getenv("FB_PAGE_ACCESS_TOKEN", "").strip()
HF_TOKEN = os.getenv("HF_TOKEN", "").strip()

IMAGE_MODEL = os.getenv("IMAGE_MODEL", "black-forest-labs/FLUX.1-schnell").strip()
GRAPH_VER = os.getenv("GRAPH_VERSION", "v21.0").strip()
DEFAULT_TIMES = os.getenv("POST_TIMES", "09:00,14:00,19:00").strip()
TIMEZONE = os.getenv("TIMEZONE", "Asia/Kolkata").strip()

STATE_FILE = os.getenv("STATE_FILE", "state.json")
IMAGES_DIR = os.getenv("IMAGES_DIR", "generated_images")
os.makedirs(IMAGES_DIR, exist_ok=True)

# --------------------------------------------------------------------------
# Logging (kept in memory so the UI can show it)
# --------------------------------------------------------------------------
LOG_BUFFER = []


class BufferHandler(logging.Handler):
    def emit(self, record):
        LOG_BUFFER.append(self.format(record))
        del LOG_BUFFER[:-400]


logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s | %(levelname)s | %(message)s",
    handlers=[logging.StreamHandler(), BufferHandler()],
)
log = logging.getLogger("autoposter")

# --------------------------------------------------------------------------
# State (queue + schedule). Persisted to a JSON file.
# --------------------------------------------------------------------------
def _default_state():
    return {
        "queue": [],
        "times": [t.strip() for t in DEFAULT_TIMES.split(",") if t.strip()],
        "enabled": False,
        "history": [],
    }


def load_state():
    if os.path.exists(STATE_FILE):
        try:
            with open(STATE_FILE) as f:
                data = json.load(f)
            data.setdefault("queue", [])
            data.setdefault("times", _default_state()["times"])
            data.setdefault("enabled", False)
            data.setdefault("history", [])
            return data
        except Exception as e:
            log.warning(f"state.json padha nahi ja saka, naya bana rahe hain: {e}")
    return _default_state()


def save_state(state):
    with open(STATE_FILE, "w") as f:
        json.dump(state, f, indent=2, ensure_ascii=False)


STATE = load_state()
LOCK = threading.RLock()


def new_id():
    return int(time.time() * 1000) % 10**12


# --------------------------------------------------------------------------
# Image generation (Hugging Face Inference API)
# --------------------------------------------------------------------------
_client = None


def get_client():
    global _client
    if _client is None:
        _client = InferenceClient(token=HF_TOKEN or None)
    return _client


def generate_image(prompt):
    """Prompt se ek AI image banata hai, disk par save karta hai."""
    prompt = (prompt or "").strip()
    if not prompt:
        raise ValueError("Prompt khaali hai")
    log.info(f"Image generate ho rahi hai: {prompt[:70]}")
    result = get_client().text_to_image(prompt, model=IMAGE_MODEL)
    if isinstance(result, (bytes, bytearray)):
        img = Image.open(io.BytesIO(result))
    elif isinstance(result, Image.Image):
        img = result
    else:
        img = Image.open(io.BytesIO(result))
    path = os.path.join(IMAGES_DIR, f"img_{new_id()}.png")
    img.convert("RGB").save(path)
    log.info(f"Image ban gayi -> {path}")
    return path, img


# --------------------------------------------------------------------------
# Facebook Graph API
# --------------------------------------------------------------------------
def _fb_check_config():
    if not FB_PAGE_ID or not FB_TOKEN:
        raise RuntimeError(
            "FB_PAGE_ID ya FB_PAGE_ACCESS_TOKEN set nahi hai. "
            "Space ke Settings -> Secrets mein daalein."
        )


def _fb_result(resp):
    try:
        data = resp.json()
    except Exception:
        data = {"raw": resp.text}
    if resp.status_code >= 400:
        log.error(f"Facebook error {resp.status_code}: {data}")
        raise RuntimeError(f"Facebook error {resp.status_code}: {data}")
    log.info(f"Facebook post publish ho gaya: {data}")
    return data


def fb_post_photo(image_path, caption):
    """Image + caption ko page par post karta hai."""
    _fb_check_config()
    url = f"https://graph.facebook.com/{GRAPH_VER}/{FB_PAGE_ID}/photos"
    with open(image_path, "rb") as f:
        resp = requests.post(
            url,
            data={"message": caption or "", "access_token": FB_TOKEN},
            files={"source": f},
            timeout=180,
        )
    return _fb_result(resp)


def fb_post_text(caption):
    """Sirf text post (bina image)."""
    _fb_check_config()
    url = f"https://graph.facebook.com/{GRAPH_VER}/{FB_PAGE_ID}/feed"
    resp = requests.post(
        url,
        data={"message": caption or "", "access_token": FB_TOKEN},
        timeout=60,
    )
    return _fb_result(resp)


def fb_page_info():
    _fb_check_config()
    url = f"https://graph.facebook.com/{GRAPH_VER}/{FB_PAGE_ID}"
    resp = requests.get(
        url, params={"fields": "name,fan_count", "access_token": FB_TOKEN}, timeout=30
    )
    if resp.status_code >= 400:
        raise RuntimeError(f"Facebook error {resp.status_code}: {resp.text}")
    return resp.json()


# --------------------------------------------------------------------------
# Scheduler
# --------------------------------------------------------------------------
scheduler = BackgroundScheduler(timezone=TIMEZONE)


def publish_next(reason="schedule"):
    """Queue se agli pending post publish karta hai."""
    with LOCK:
        pending = [q for q in STATE["queue"] if q.get("status") == "pending"]
        if not pending:
            log.info("Queue khaali hai - abhi post karne ke liye kuch nahi.")
            return None

        item = pending[0]
        try:
            if not item.get("image") or not os.path.exists(item["image"]):
                path, _ = generate_image(item["prompt"])
                item["image"] = path
            caption = item.get("caption") or item["prompt"]
            res = fb_post_photo(item["image"], caption)
            item["status"] = "posted"
            item["posted_at"] = datetime.datetime.now().isoformat(timespec="seconds")
            item["fb_post_id"] = res.get("id") or res.get("post_id")
            STATE["history"].append(
                {
                    "time": item["posted_at"],
                    "caption": caption,
                    "image": item.get("image"),
                    "reason": reason,
                }
            )
            log.info(f"POST OK ({reason}): {caption[:60]}")
        except Exception as e:
            item["status"] = "error"
            item["error"] = str(e)
            log.error(f"Post FAIL: {e}")
        save_state(STATE)
        return item


def rebuild_jobs(times):
    scheduler.remove_all_jobs()
    for t in times:
        try:
            hh, mm = t.strip().split(":")
            scheduler.add_job(
                publish_next,
                CronTrigger(hour=int(hh), minute=int(mm), timezone=TIMEZONE),
                kwargs={"reason": "schedule"},
                id=f"job_{t}",
                replace_existing=True,
            )
            log.info(f"Scheduled: roz {t} ({TIMEZONE})")
        except Exception as e:
            log.warning(f"Galat time '{t}': {e}")
    if not scheduler.running and times:
        scheduler.start()


# --------------------------------------------------------------------------
# UI callbacks
# --------------------------------------------------------------------------
def queue_rows():
    rows = []
    for q in STATE["queue"]:
        rows.append(
            [
                q.get("id"),
                q.get("status", "pending"),
                (q.get("caption") or q.get("prompt") or "")[:60],
                (q.get("image") or "").split("/")[-1],
            ]
        )
    return rows


def ui_generate_and_queue(prompts_text, captions_text, limit):
    prompts = [p.strip() for p in (prompts_text or "").split("\n") if p.strip()]
    caps = [c.strip() for c in (captions_text or "").split("\n")] if captions_text else []
    if not prompts:
        return [], queue_rows(), "Koi prompt nahi mila. Ek line mein ek prompt likhein."
    try:
        limit = int(limit)
        if limit > 0:
            prompts = prompts[:limit]
    except Exception:
        pass

    previews, added = [], 0
    for i, p in enumerate(prompts):
        try:
            path, img = generate_image(p)
        except Exception as e:
            log.error(f"Generate fail ('{p[:40]}'): {e}")
            continue
        with LOCK:
            STATE["queue"].append(
                {
                    "id": new_id(),
                    "prompt": p,
                    "caption": caps[i] if i < len(caps) else "",
                    "image": path,
                    "status": "pending",
                }
            )
            added += 1
        previews.append(img)
    with LOCK:
        save_state(STATE)
    msg = f"{added} post queue mein add ho gaye (images ready)."
    if added < len(prompts):
        msg += " Kuch prompts fail hue - Logs tab dekhein."
    return previews, queue_rows(), msg


def ui_start(times_text):
    times = [t.strip() for t in (times_text or "").split(",") if t.strip()]
    if not times:
        return "Kam se kam ek time daalein, jaise: 09:00,14:00,19:00"
    with LOCK:
        STATE["times"] = times
        STATE["enabled"] = True
        save_state(STATE)
    rebuild_jobs(times)
    return f"Scheduler CHALU. Roz {', '.join(times)} ({TIMEZONE}) par queue se post hoga."


def ui_stop():
    with LOCK:
        STATE["enabled"] = False
        save_state(STATE)
    scheduler.remove_all_jobs()
    return "Scheduler BAND kar diya. Queue safe hai."


def ui_post_now():
    item = publish_next(reason="manual")
    if item is None:
        return "Queue khaali hai.", queue_rows()
    if item.get("status") == "posted":
        return f"Post ho gaya! FB id: {item.get('fb_post_id')}", queue_rows()
    return f"Post fail: {item.get('error')}", queue_rows()


def ui_clear_posted():
    with LOCK:
        STATE["queue"] = [q for q in STATE["queue"] if q.get("status") != "posted"]
        save_state(STATE)
    return queue_rows(), "Posted items queue se hata diye."


def ui_reset_all():
    with LOCK:
        STATE["queue"] = []
        STATE["history"] = []
        save_state(STATE)
    return queue_rows(), "Poori queue clear kar di."


def ui_logs():
    return "\n".join(LOG_BUFFER[-250:]) or "(abhi koi log nahi)"


def ui_test_fb():
    try:
        info = fb_page_info()
        return f"Facebook connected ✔  Page: {info.get('name')}  | Fans: {info.get('fan_count', 'NA')}"
    except Exception as e:
        return f"Facebook connection fail: {e}"


# --------------------------------------------------------------------------
# Gradio UI
# --------------------------------------------------------------------------
with gr.Blocks(title="FB Auto Poster") as demo:
    gr.Markdown(
        "# 📮 FB Auto Poster\n"
        "AI images banao aur apne Facebook Page par **roz automatic** post karo.\n\n"
        "> Pehle Space ke **Secrets** mein `FB_PAGE_ID`, `FB_PAGE_ACCESS_TOKEN` aur "
        "`HF_TOKEN` daalna zaroori hai (README dekhein)."
    )

    with gr.Tab("1️⃣ Content banayein"):
        gr.Markdown(
            "Ek line mein ek **prompt** likhein. Har prompt se ek image banegi aur "
            "queue mein add ho jayegi. Captions optional hain - khaali chhodein to "
            "prompt hi caption ban jayega."
        )
        with gr.Row():
            prompts_in = gr.Textbox(
                label="Prompts (ek line mein ek)",
                lines=8,
                placeholder="Diwali sale banner, bright colors, product in center\nMorning coffee flat-lay, warm tones, instagram style",
            )
            captions_in = gr.Textbox(
                label="Captions (optional, ek line mein ek)",
                lines=8,
                placeholder="🪔 Diwali Dhamaka - 50% OFF!\nStart your day right ☕",
            )
        with gr.Row():
            limit_in = gr.Number(label="Max images is baar (0 = sab)", value=0)
            gen_btn = gr.Button("🖼️ Images banao & Queue mein daalo", variant="primary")
        gen_status = gr.Textbox(label="Status", interactive=False)
        gallery = gr.Gallery(label="Generated images", columns=4, height=320)

    with gr.Tab("2️⃣ Queue & Schedule"):
        gr.Markdown(
            "Schedule set karein (IST). Bot roz in time par queue se agli post "
            "apne aap publish karega."
        )
        with gr.Row():
            times_in = gr.Textbox(label="Post times (comma se alag, 24h)", value="09:00,14:00,19:00")
            with gr.Column():
                start_btn = gr.Button("▶️ Start scheduler", variant="primary")
                stop_btn = gr.Button("⏸️ Stop scheduler")
        sched_status = gr.Textbox(label="Scheduler status", interactive=False)
        with gr.Row():
            post_now_btn = gr.Button("🚀 Post next now")
            test_btn = gr.Button("🔌 Test Facebook connection")
        queue_df = gr.Dataframe(
            headers=["id", "status", "caption/prompt", "image"],
            value=queue_rows(),
            interactive=False,
            label="Queue",
        )
        with gr.Row():
            clear_btn = gr.Button("🧹 Posted items hatao")
            reset_btn = gr.Button("🗑️ Poori queue clear karo")

    with gr.Tab("3️⃣ Logs"):
        logs_out = gr.Textbox(label="Recent logs", lines=22, interactive=False)
        logs_btn = gr.Button("🔄 Refresh logs")

    # wiring
    gen_btn.click(
        ui_generate_and_queue,
        inputs=[prompts_in, captions_in, limit_in],
        outputs=[gallery, queue_df, gen_status],
    )
    start_btn.click(ui_start, inputs=[times_in], outputs=[sched_status])
    stop_btn.click(ui_stop, outputs=[sched_status])
    post_now_btn.click(ui_post_now, outputs=[sched_status, queue_df])
    test_btn.click(ui_test_fb, outputs=[sched_status])
    clear_btn.click(ui_clear_posted, outputs=[queue_df, sched_status])
    reset_btn.click(ui_reset_all, outputs=[queue_df, sched_status])
    logs_btn.click(ui_logs, outputs=[logs_out])

    demo.load(ui_logs, outputs=[logs_out])


# --------------------------------------------------------------------------
# Resume scheduler if it was running before a restart
# --------------------------------------------------------------------------
if STATE.get("enabled") and STATE.get("times"):
    try:
        rebuild_jobs(STATE["times"])
        log.info("Scheduler saved state se dobara chalu kar diya.")
    except Exception as e:
        log.error(f"Scheduler resume fail: {e}")


if __name__ == "__main__":
    demo.queue(default_concurrency_limit=2).launch()