"""
reels.biba.live — FastAPI backend.

Endpoints:
  GET  /                   — frontend HTML
  POST /api/upload         — naloži video file
  POST /api/youtube        — submit YouTube URL
  POST /api/process/{id}   — start processing job
  GET  /api/jobs           — list vseh jobov
  GET  /api/jobs/{id}      — status job-a
  GET  /api/stream/{id}    — SSE progress stream
  GET  /api/download/{id}  — download finalni reel
  GET  /api/preview/{id}   — preview video stream
  DELETE /api/jobs/{id}    — pobriši job + datoteke
"""
import asyncio
import json
import os
import secrets
import shutil
import subprocess
import time
import uuid
from pathlib import Path
from typing import Optional

from fastapi import (
    FastAPI, UploadFile, File, Form, HTTPException, Depends,
    BackgroundTasks, Request, status
)
from fastapi.responses import (
    FileResponse, HTMLResponse, StreamingResponse, JSONResponse
)
from fastapi.staticfiles import StaticFiles
from fastapi.security import HTTPBasic, HTTPBasicCredentials
from pydantic import BaseModel


# ────────────────────────────────────────────────────────────────
# Config
# ────────────────────────────────────────────────────────────────
DATA_DIR = Path(os.environ.get("DATA_DIR", "/data"))
UPLOAD_DIR = DATA_DIR / "uploads"
OUTPUT_DIR = DATA_DIR / "outputs"
JOBS_DIR = DATA_DIR / "jobs"
SCRIPTS_DIR = Path(__file__).parent.parent / "scripts"

UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
JOBS_DIR.mkdir(parents=True, exist_ok=True)

AUTH_USER = os.environ.get("AUTH_USER", "sebastjan")
AUTH_PASS = os.environ.get("AUTH_PASS", "change-me-in-coolify-env")

MAX_UPLOAD_MB = int(os.environ.get("MAX_UPLOAD_MB", "2000"))


# ────────────────────────────────────────────────────────────────
# Auth
# ────────────────────────────────────────────────────────────────
security = HTTPBasic()


def check_auth(creds: HTTPBasicCredentials = Depends(security)):
    correct_user = secrets.compare_digest(creds.username, AUTH_USER)
    correct_pass = secrets.compare_digest(creds.password, AUTH_PASS)
    if not (correct_user and correct_pass):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Napačno geslo",
            headers={"WWW-Authenticate": "Basic"},
        )
    return creds.username


# ────────────────────────────────────────────────────────────────
# Job state (filesystem-based, persistent prek restartov)
# ────────────────────────────────────────────────────────────────
def job_path(job_id):
    return JOBS_DIR / f"{job_id}.json"


def load_job(job_id):
    p = job_path(job_id)
    if not p.exists():
        return None
    return json.loads(p.read_text())


def save_job(job):
    job_path(job["id"]).write_text(json.dumps(job, ensure_ascii=False, indent=2))


def update_job(job_id, **kwargs):
    job = load_job(job_id)
    if not job:
        return None
    job.update(kwargs)
    job["updated_at"] = time.time()
    save_job(job)
    return job


def list_jobs():
    out = []
    for f in sorted(JOBS_DIR.glob("*.json"), reverse=True):
        try:
            out.append(json.loads(f.read_text()))
        except Exception:
            pass
    return out


# ────────────────────────────────────────────────────────────────
# Pipeline runner (background task)
# ────────────────────────────────────────────────────────────────
def run_subprocess_logged(cmd, job_id, step_name):
    """Pokliče subprocess, logi gredo v job."""
    update_job(job_id, current_step=step_name, status="processing")
    proc = subprocess.run(cmd, capture_output=True, text=True)
    if proc.returncode != 0:
        # Combine stdout + stderr za diagnostiko
        err_msg = (proc.stderr or "") + "\n" + (proc.stdout or "")
        update_job(
            job_id,
            status="failed",
            error=f"{step_name}: {err_msg[-800:].strip()}",
        )
        return False
    # Tudi pri success-u beleži stderr za diagnostiko (samo zadnji del)
    if proc.stderr and proc.stderr.strip():
        update_job(job_id, last_step_log=proc.stderr[-500:].strip())
    return True


def process_job(job_id):
    """Glavni pipeline: download (če YT) → find_chorus (če auto) → reframe → subs."""
    job = load_job(job_id)
    if not job:
        return

    try:
        # ── 1. Source preparation ─────────────────────────────
        if job["source_type"] == "youtube":
            update_job(job_id, status="downloading", current_step="YouTube download")
            input_path = UPLOAD_DIR / f"{job_id}_yt.mp4"
            cmd = [
                "python3", str(SCRIPTS_DIR / "yt_download.py"),
                job["youtube_url"], str(input_path),
            ]
            if not run_subprocess_logged(cmd, job_id, "YouTube download"):
                return
            update_job(job_id, input_path=str(input_path))
        else:
            input_path = Path(job["input_path"])

        # ── 2. Smart analysis (če auto_chorus) ──────────────────────────
        if job.get("auto_chorus"):
            update_job(job_id, current_step="Analiza pesmi (transkript + energija)")
            analysis_path = OUTPUT_DIR / f"{job_id}.analysis.json"
            cmd = [
                "python3", str(SCRIPTS_DIR / "analyze.py"),
                str(input_path),
                "--target-duration", str(job.get("duration", 30)),
                "--max-duration", str(job.get("max_duration", 45)),
                "--min-duration", str(job.get("min_duration", 20)),
                "--output", str(analysis_path),
            ]
            if job.get("include_prebuild"):
                cmd += ["--include-prebuild"]
            # lang: če None ali 'auto', pusti analyze.py auto-detect
            if job.get("lang") and job["lang"] not in ("auto", ""):
                cmd += ["--lang", job["lang"]]
            cmd += ["--model", job.get("whisper_model", "small")]

            proc = subprocess.run(cmd, capture_output=True, text=True)
            if proc.returncode == 0 and analysis_path.exists():
                try:
                    with open(analysis_path, "r", encoding="utf-8") as f:
                        analysis = json.load(f)
                    cr = analysis["clip_range"]
                    fade = analysis["fade"]
                    update_job(
                        job_id,
                        analysis_summary={
                            "language": analysis["language"],
                            "language_probability": analysis["language_probability"],
                            "instrumental": analysis["instrumental"],
                            "clip_range": cr,
                            "fade": fade,
                            "chorus_preview": analysis["chorus"]["best"]["text_preview"]
                                if analysis.get("chorus") and analysis["chorus"].get("best") else None,
                            "video_duration": analysis.get("video_duration"),
                            "candidates": analysis["chorus"].get("all_candidates", [])[:5]
                                if analysis.get("chorus") else [],
                        },
                        # Cel transkript shranimo za UI prikaz
                        full_transcript=[
                            {"start": s["start"], "end": s["end"], "text": s["text"]}
                            for s in analysis.get("transcript", {}).get("segments", [])
                        ],
                        start=cr["start"],
                        duration=cr["duration"],
                        fade_in=fade["fade_in"],
                        fade_out=fade["fade_out"],
                        detected_language=analysis["language"],
                        is_instrumental=analysis["instrumental"],
                    )
                    # Auto-disable subs za instrumental
                    if analysis["instrumental"] and not job.get("no_subs"):
                        update_job(job_id, no_subs=True, auto_disabled_subs=True)
                    # Reload local dict
                    job = load_job(job_id)
                except (json.JSONDecodeError, KeyError) as e:
                    update_job(job_id, chorus_error=f"Analysis parse: {e}")
            else:
                update_job(job_id, chorus_error=(proc.stderr or "")[-500:])

        # ── 3. Reframe + subtitles (clip.py orchestrator) ─────
        output_path = OUTPUT_DIR / f"{job_id}.mp4"
        update_job(job_id, current_step="Reframe + subtitles")

        cmd = [
            "python3", str(SCRIPTS_DIR / "clip.py"),
            str(input_path), str(output_path),
            "--mode", job.get("mode", "track"),
            "--quality", job.get("quality", "medium"),
            "--style", job.get("subtitle_style", "reels"),
        ]
        if job.get("start") is not None:
            cmd += ["--start", str(job["start"])]
        if job.get("duration") is not None:
            cmd += ["--duration", str(job["duration"])]
        if job.get("fade_in", 0) > 0:
            cmd += ["--fade-in", str(job["fade_in"])]
        if job.get("fade_out", 0) > 0:
            cmd += ["--fade-out", str(job["fade_out"])]
        # lang: prefer detected_language če auto
        chosen_lang = job.get("lang")
        if chosen_lang in (None, "auto", ""):
            chosen_lang = job.get("detected_language")
        if chosen_lang:
            cmd += ["--lang", chosen_lang]
        if job.get("no_subs"):
            cmd += ["--no-subs"]
        cmd += ["--model", job.get("whisper_model", "small")]

        # DEBUG: zapiši natanko kakšen ukaz se izvede
        update_job(job_id, debug_clip_cmd=" ".join(cmd))

        if not run_subprocess_logged(cmd, job_id, "Reframe + subtitles"):
            return

        # ── Done ──────────────────────────────────────────────
        if output_path.exists():
            update_job(
                job_id,
                status="done",
                current_step="Končano",
                output_path=str(output_path),
                output_size_mb=round(output_path.stat().st_size / 1024 / 1024, 2),
            )
        else:
            update_job(
                job_id,
                status="failed",
                error="Output datoteka ne obstaja po obdelavi",
            )
    except Exception as e:
        update_job(job_id, status="failed", error=str(e))


# ────────────────────────────────────────────────────────────────
# FastAPI app
# ────────────────────────────────────────────────────────────────
app = FastAPI(title="Reels Clipper")
app.mount("/static", StaticFiles(directory=Path(__file__).parent.parent / "static"), name="static")


@app.get("/", response_class=HTMLResponse)
async def index(user: str = Depends(check_auth)):
    html = (Path(__file__).parent.parent / "templates" / "index.html").read_text()
    return html


@app.get("/healthz")
async def healthz():
    return {"ok": True}


# ────────────────────────────────────────────────────────────────
# Job models
# ────────────────────────────────────────────────────────────────
class YouTubeJobIn(BaseModel):
    url: str
    mode: str = "track"
    lang: Optional[str] = None
    auto_chorus: bool = True
    start: Optional[float] = None
    duration: Optional[float] = 30
    no_subs: bool = False
    subtitle_style: str = "reels"
    whisper_model: str = "small"
    quality: str = "medium"


class StartJobIn(BaseModel):
    job_id: str
    mode: str = "track"
    lang: Optional[str] = None  # None/auto = Whisper auto-detect
    auto_chorus: bool = True
    include_prebuild: bool = False  # vključi pre-chorus build-up
    start: Optional[float] = None
    duration: Optional[float] = 30
    max_duration: Optional[float] = 45
    min_duration: Optional[float] = 20
    no_subs: bool = False
    subtitle_style: str = "reels"
    whisper_model: str = "small"
    quality: str = "medium"


# ────────────────────────────────────────────────────────────────
# Upload (file)
# ────────────────────────────────────────────────────────────────
@app.post("/api/upload")
async def upload_video(
    file: UploadFile = File(...),
    user: str = Depends(check_auth),
):
    if not file.filename:
        raise HTTPException(400, "Brez imena")

    job_id = uuid.uuid4().hex[:12]
    ext = Path(file.filename).suffix or ".mp4"
    input_path = UPLOAD_DIR / f"{job_id}{ext}"

    size = 0
    with input_path.open("wb") as f:
        while chunk := await file.read(1024 * 1024):
            size += len(chunk)
            if size > MAX_UPLOAD_MB * 1024 * 1024:
                f.close()
                input_path.unlink(missing_ok=True)
                raise HTTPException(413, f"Prevelika datoteka (limit {MAX_UPLOAD_MB} MB)")
            f.write(chunk)

    job = {
        "id": job_id,
        "source_type": "upload",
        "filename": file.filename,
        "input_path": str(input_path),
        "size_mb": round(size / 1024 / 1024, 2),
        "status": "uploaded",
        "current_step": "Naloženo, čaka na obdelavo",
        "created_at": time.time(),
        "updated_at": time.time(),
    }
    save_job(job)
    return job


# ────────────────────────────────────────────────────────────────
# YouTube submit
# ────────────────────────────────────────────────────────────────
@app.post("/api/youtube")
async def submit_youtube(
    payload: YouTubeJobIn,
    background: BackgroundTasks,
    user: str = Depends(check_auth),
):
    job_id = uuid.uuid4().hex[:12]
    job = {
        "id": job_id,
        "source_type": "youtube",
        "youtube_url": payload.url,
        "status": "queued",
        "current_step": "V vrsti za YouTube prenos",
        "created_at": time.time(),
        "updated_at": time.time(),
        "mode": payload.mode,
        "lang": payload.lang,
        "auto_chorus": payload.auto_chorus,
        "start": payload.start,
        "duration": payload.duration,
        "no_subs": payload.no_subs,
        "subtitle_style": payload.subtitle_style,
        "whisper_model": payload.whisper_model,
        "quality": payload.quality,
    }
    save_job(job)
    background.add_task(process_job, job_id)
    return job


# ────────────────────────────────────────────────────────────────
# Start processing for uploaded job
# ────────────────────────────────────────────────────────────────
@app.post("/api/process")
async def start_processing(
    payload: StartJobIn,
    background: BackgroundTasks,
    user: str = Depends(check_auth),
):
    job = load_job(payload.job_id)
    if not job:
        raise HTTPException(404, "Job ne obstaja")

    update_job(
        payload.job_id,
        status="queued",
        mode=payload.mode,
        lang=payload.lang,
        auto_chorus=payload.auto_chorus,
        include_prebuild=payload.include_prebuild,
        start=payload.start,
        duration=payload.duration,
        max_duration=payload.max_duration,
        min_duration=payload.min_duration,
        no_subs=payload.no_subs,
        subtitle_style=payload.subtitle_style,
        whisper_model=payload.whisper_model,
        quality=payload.quality,
        current_step="V vrsti za obdelavo",
    )
    background.add_task(process_job, payload.job_id)
    return load_job(payload.job_id)


# ────────────────────────────────────────────────────────────────
# Job queries
# ────────────────────────────────────────────────────────────────
@app.get("/api/jobs")
async def get_jobs(user: str = Depends(check_auth)):
    return {"jobs": list_jobs()}


@app.get("/api/jobs/{job_id}")
async def get_job(job_id: str, user: str = Depends(check_auth)):
    job = load_job(job_id)
    if not job:
        raise HTTPException(404, "Ne obstaja")
    return job


@app.get("/api/stream/{job_id}")
async def stream_job(job_id: str, user: str = Depends(check_auth)):
    """Server-Sent Events za real-time status."""

    async def gen():
        last_status = None
        last_step = None
        for _ in range(600):  # max 10 min stream
            job = load_job(job_id)
            if not job:
                yield f"data: {json.dumps({'error': 'not found'})}\n\n"
                return
            if job["status"] != last_status or job.get("current_step") != last_step:
                yield f"data: {json.dumps(job, ensure_ascii=False)}\n\n"
                last_status = job["status"]
                last_step = job.get("current_step")
            if job["status"] in ("done", "failed"):
                return
            await asyncio.sleep(1)

    return StreamingResponse(gen(), media_type="text/event-stream")


# ────────────────────────────────────────────────────────────────
# Download / preview
# ────────────────────────────────────────────────────────────────
@app.get("/api/download/{job_id}")
async def download(job_id: str, user: str = Depends(check_auth)):
    job = load_job(job_id)
    if not job or job.get("status") != "done":
        raise HTTPException(404, "Ne pripravljen")
    out = Path(job["output_path"])
    if not out.exists():
        raise HTTPException(404, "Output ne obstaja")
    return FileResponse(
        out,
        media_type="video/mp4",
        filename=f"reel_{job_id}.mp4",
    )


@app.get("/api/preview/{job_id}")
async def preview(job_id: str, user: str = Depends(check_auth)):
    job = load_job(job_id)
    if not job or job.get("status") != "done":
        raise HTTPException(404, "Ne pripravljen")
    out = Path(job["output_path"])
    if not out.exists():
        raise HTTPException(404, "Output ne obstaja")
    return FileResponse(out, media_type="video/mp4")


@app.delete("/api/jobs/{job_id}")
async def delete_job(job_id: str, user: str = Depends(check_auth)):
    job = load_job(job_id)
    if not job:
        raise HTTPException(404, "Ne obstaja")
    for key in ("input_path", "output_path"):
        p = job.get(key)
        if p and Path(p).exists():
            Path(p).unlink(missing_ok=True)
    job_path(job_id).unlink(missing_ok=True)
    return {"deleted": job_id}