"""
Video Download Middleware API
==============================
Flow:
  1. POST /download  → triggers GitHub Action → returns job_id
  2. GET  /status/{job_id} → returns pending / processing / done / failed
  3. GET  /file/{job_id}   → streams the video file (only when done)

n8n webhooks:
  - POST /n8n/callback  → n8n calls this when the video is ready (from "downlode video1" node)
"""

import os
import uuid
import time
import asyncio
import logging
from pathlib import Path
from typing import Optional

import httpx
import aiofiles
from fastapi import FastAPI, HTTPException, BackgroundTasks, Request
from fastapi.responses import StreamingResponse, JSONResponse
from pydantic import BaseModel

# ─── Config ────────────────────────────────────────────────────────────────────
GITHUB_TOKEN   = os.getenv("GITHUB_TOKEN", "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")
GITHUB_REPO    = os.getenv("GITHUB_REPO",  "expher510/AutoClip-Pipeline")
WORKFLOW_FILE  = os.getenv("WORKFLOW_FILE", "video-download.yml")

# Public URL of THIS api (so n8n can call back)
# e.g. https://my-api.hf.space  or  https://xxxxx.ngrok.io
PUBLIC_URL     = os.getenv("PUBLIC_URL", "https://your-api-public-url.com")

# اختياري - لو موجود الـ API هو اللي يشغل n8n
# لو None، n8n هو اللي يبعت callback للـ API
N8N_TRIGGER_URL = os.getenv("N8N_TRIGGER_URL", None)

VIDEOS_DIR = Path("videos")
VIDEOS_DIR.mkdir(exist_ok=True)

# ─── In-memory job store ────────────────────────────────────────────────────────
# job_id → {status, filename, file_path, video_url, error, created_at, run_id}
jobs: dict[str, dict] = {}

# ─── App ───────────────────────────────────────────────────────────────────────
app = FastAPI(
    title="EGDownloader API",
    description="Bridges client ↔ n8n/GitHub Action video pipeline",
    version="1.0.0",
    docs_url="/",
    redoc_url="/redoc",
)

logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
log = logging.getLogger(__name__)


# ══════════════════════════════════════════════════════════════════════════════
# 1. REQUEST DOWNLOAD
# ══════════════════════════════════════════════════════════════════════════════
class DownloadRequest(BaseModel):
    url: str
    cookies_txt: Optional[str] = ""   # optional – paste Netscape cookie text


@app.post("/download/shorts", summary="Start a YouTube Shorts download job")
async def download_shorts(body: DownloadRequest):
    """
    نفس /download بالظبط، بس بيحوّل Shorts URL لـ watch URL الأول.
    https://youtube.com/shorts/VIDEO_ID  →  https://youtube.com/watch?v=VIDEO_ID
    """
    if "/shorts/" in body.url:
        video_id = body.url.split("/shorts/")[1].split("?")[0]
        body.url = f"https://www.youtube.com/watch?v={video_id}"

    return await start_download(body)


@app.post("/download", summary="Start a video download job")
async def start_download(body: DownloadRequest):
    """
    طريقتين للشغل:

    1) Push mode (الـ default - اللي عندك دلوقتي):
       N8N_TRIGGER_URL = None
       n8n هو اللي يشغل GitHub Action وبعدين يبعت callback على /n8n/callback/{job_id}
       الـ client بس يعمل polling على /status/{job_id}

    2) Trigger mode:
       N8N_TRIGGER_URL = "https://..."
       الـ API هو اللي يبعت trigger لـ n8n، وn8n يرد بـ callback
    """
    job_id = str(uuid.uuid4())

    jobs[job_id] = {
        "status":     "pending",
        "video_url":  body.url,
        "filename":   None,
        "file_path":  None,
        "run_id":     None,
        "error":      None,
        "created_at": time.time(),
        "mode":       "trigger" if N8N_TRIGGER_URL else "push",
    }

    # ── Trigger mode: الـ API يشغل n8n ────────────────────────────────────────
    if N8N_TRIGGER_URL:
        payload = {
            "url":         body.url,
            "cookies_txt": body.cookies_txt or "",
            "n8n_webhook": f"{PUBLIC_URL}/n8n/callback/{job_id}",
        }
        try:
            async with httpx.AsyncClient(timeout=15) as client:
                r = await client.post(N8N_TRIGGER_URL, json=payload)
                r.raise_for_status()
            jobs[job_id]["status"] = "processing"
            log.info(f"[{job_id}] triggered n8n → {r.status_code}")
        except Exception as exc:
            jobs[job_id]["status"] = "failed"
            jobs[job_id]["error"]  = str(exc)
            log.error(f"[{job_id}] failed to trigger n8n: {exc}")
            raise HTTPException(status_code=502, detail=f"Could not trigger pipeline: {exc}")

    # ── Push mode: n8n هو اللي هيبعت callback لما يخلص ───────────────────────
    else:
        jobs[job_id]["status"] = "pending"
        log.info(f"[{job_id}] job created (push mode) - waiting for n8n callback")

    return {
        "job_id":  job_id,
        "status":  jobs[job_id]["status"],
        "mode":    jobs[job_id]["mode"],
        "callback_url": f"{PUBLIC_URL}/n8n/callback/{job_id}",
    }


# ══════════════════════════════════════════════════════════════════════════════
# 2. POLL STATUS
# ══════════════════════════════════════════════════════════════════════════════
@app.get("/status/{job_id}", summary="Poll download status")
async def get_status(job_id: str):
    """
    Returns one of: pending | processing | done | failed
    When done, also returns filename & download_url.
    """
    job = jobs.get(job_id)
    if not job:
        raise HTTPException(status_code=404, detail="Job not found")

    resp = {
        "job_id":    job_id,
        "status":    job["status"],
        "video_url": job["video_url"],
        "created_at": job["created_at"],
    }

    if job["status"] == "done":
        resp["filename"]     = job["filename"]
        resp["download_url"] = f"{PUBLIC_URL}/file/{job_id}"

    if job["status"] == "failed":
        resp["error"] = job["error"]

    return resp


# ══════════════════════════════════════════════════════════════════════════════
# 3. DOWNLOAD FILE
# ══════════════════════════════════════════════════════════════════════════════
@app.get("/file/{job_id}", summary="Download the finished video")
async def download_file(job_id: str):
    job = jobs.get(job_id)
    if not job:
        raise HTTPException(status_code=404, detail="Job not found")
    if job["status"] != "done":
        raise HTTPException(status_code=425, detail=f"Not ready yet – status: {job['status']}")

    file_path: Path = job["file_path"]
    if not file_path or not file_path.exists():
        raise HTTPException(status_code=410, detail="File no longer available on server")

    filename = job["filename"] or file_path.name

    async def file_streamer():
        async with aiofiles.open(file_path, "rb") as f:
            while chunk := await f.read(1024 * 512):   # 512 KB chunks
                yield chunk

    return StreamingResponse(
        file_streamer(),
        media_type="video/mp4",
        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
    )


# ══════════════════════════════════════════════════════════════════════════════
# 4. n8n CALLBACK  (n8n POSTs the finished binary here)
#    This replaces the "downlode video1" webhook that was in n8n
# ══════════════════════════════════════════════════════════════════════════════
@app.post("/n8n/callback/{job_id}", include_in_schema=False)
async def n8n_callback(job_id: str, request: Request):
    """
    n8n calls this endpoint (instead of its own 'downlode video1' webhook).
    It sends either:
      a) A JSON body with {status, run_id, filename, video_url}  → we then
         fetch the artifact from GitHub ourselves, OR
      b) Raw binary (the video file) directly in the body.
    """
    job = jobs.get(job_id)
    if not job:
        log.warning(f"[{job_id}] callback for unknown job")
        return {"ok": False, "reason": "unknown job"}

    content_type = request.headers.get("content-type", "")

    # ── Case A: JSON notification (status + run_id) ──────────────────────────
    if "application/json" in content_type:
        data = await request.json()
        log.info(f"[{job_id}] JSON callback: {data}")

        if data.get("status") == "success":
            run_id   = data.get("run_id")
            filename = data.get("filename", f"{job_id}.mp4")
            jobs[job_id]["run_id"]   = run_id
            jobs[job_id]["filename"] = filename

            # Fetch the artifact binary from GitHub in the background
            asyncio.create_task(_fetch_github_artifact(job_id, run_id, filename))
        else:
            jobs[job_id]["status"] = "failed"
            jobs[job_id]["error"]  = data.get("error", "n8n reported failure")

        return {"ok": True}

    # ── Case B: Raw binary video ──────────────────────────────────────────────
    body = await request.body()
    if not body:
        jobs[job_id]["status"] = "failed"
        jobs[job_id]["error"]  = "empty callback body"
        return {"ok": False}

    filename  = request.headers.get("x-filename", f"{job_id}.mp4")
    file_path = VIDEOS_DIR / f"{job_id}_{filename}"

    async with aiofiles.open(file_path, "wb") as f:
        await f.write(body)

    jobs[job_id]["status"]    = "done"
    jobs[job_id]["filename"]  = filename
    jobs[job_id]["file_path"] = file_path
    log.info(f"[{job_id}] saved {file_path} ({len(body)/1024/1024:.1f} MB)")

    return {"ok": True}


# ══════════════════════════════════════════════════════════════════════════════
# 5. BACKGROUND: fetch artifact from GitHub (used in Case A above)
# ══════════════════════════════════════════════════════════════════════════════
async def _fetch_github_artifact(job_id: str, run_id: str, filename: str):
    """Polls GitHub until the artifact is ready, then downloads it."""
    artifacts_url = f"https://api.github.com/repos/{GITHUB_REPO}/actions/runs/{run_id}/artifacts"
    headers = {
        "Authorization": f"token {GITHUB_TOKEN}",
        "Accept": "application/vnd.github+json",
    }

    for attempt in range(20):          # up to ~5 minutes
        await asyncio.sleep(15)
        try:
            async with httpx.AsyncClient(timeout=30) as client:
                r = await client.get(artifacts_url, headers=headers)
                r.raise_for_status()
                artifacts = r.json().get("artifacts", [])

            if not artifacts:
                log.info(f"[{job_id}] no artifacts yet (attempt {attempt+1})")
                continue

            artifact = artifacts[0]
            dl_url   = artifact["archive_download_url"]

            # Download the zip (GitHub wraps artifacts in a zip)
            async with httpx.AsyncClient(
                timeout=300,
                follow_redirects=True,
                headers=headers,
            ) as client:
                resp = await client.get(dl_url)
                resp.raise_for_status()

            # Save & unzip
            zip_path  = VIDEOS_DIR / f"{job_id}.zip"
            async with aiofiles.open(zip_path, "wb") as f:
                await f.write(resp.content)

            # Extract the video
            import zipfile
            with zipfile.ZipFile(zip_path, "r") as z:
                names = z.namelist()
                video_name = next((n for n in names if n.endswith(".mp4")), names[0])
                z.extract(video_name, VIDEOS_DIR)
                extracted = VIDEOS_DIR / video_name

            zip_path.unlink(missing_ok=True)

            jobs[job_id]["status"]    = "done"
            jobs[job_id]["filename"]  = video_name
            jobs[job_id]["file_path"] = extracted
            log.info(f"[{job_id}] artifact saved → {extracted}")
            return

        except Exception as exc:
            log.error(f"[{job_id}] artifact fetch error: {exc}")

    jobs[job_id]["status"] = "failed"
    jobs[job_id]["error"]  = "artifact never became available"


# ══════════════════════════════════════════════════════════════════════════════
# 6. EXTRA UTILS
# ══════════════════════════════════════════════════════════════════════════════
@app.get("/jobs", summary="List all jobs (debug)")
async def list_jobs():
    return {
        jid: {k: v for k, v in j.items() if k != "file_path"}
        for jid, j in jobs.items()
    }


@app.delete("/job/{job_id}", summary="Delete a finished job and its file")
async def delete_job(job_id: str):
    job = jobs.pop(job_id, None)
    if not job:
        raise HTTPException(status_code=404, detail="Job not found")
    if job.get("file_path") and Path(job["file_path"]).exists():
        Path(job["file_path"]).unlink()
    return {"deleted": job_id}


@app.get("/health")
async def health():
    return {"status": "ok", "jobs": len(jobs)}