# capture_service.py
import os
import subprocess
import threading
import time
from pathlib import Path

from Core.error_events import record_error
from Core import settings as config
from Server import direct_camera_client

SERVER_DIR = Path(__file__).resolve().parent
PROJECT_ROOT = SERVER_DIR.parent

FIX_SCRIPT = str((PROJECT_ROOT / "Scripts" / "fix_realsense_usb.sh").resolve())
UPLOAD_NOW_FLAG = (PROJECT_ROOT / "Scripts" / "upload_now.flag").resolve()


def _touch_upload_now_flag():
    try:
        UPLOAD_NOW_FLAG.parent.mkdir(parents=True, exist_ok=True)
        UPLOAD_NOW_FLAG.write_text(str(time.time()), encoding="utf-8")
    except Exception as e:
        record_error("capture_service", "touch_upload_now_flag", e)


def _next_photo_name(out_dir: Path, prefix: str, ext: str) -> Path:
    base = out_dir / f"{prefix}.{ext}"
    if not base.exists():
        return base
    i = 1
    while True:
        p = out_dir / f"{prefix}({i}).{ext}"
        if not p.exists():
            return p
        i += 1


def take_photo_sync(prefix: str | None = None) -> str:
    """
    Captures one photo and returns the saved path or a compact error.
    Production runtime uses the direct camera service only.
    """
    retry_count = max(0, int(config.read_watchdog_camera_capture_retry_count()))
    retry_delay = max(0.0, float(config.read_watchdog_camera_capture_retry_delay_sec()))
    total_attempts = max(1, retry_count + 1)
    last_err = "[ERR] take_photo unknown error"

    for attempt in range(1, total_attempts + 1):
        try:
            env = os.environ.copy()
            env.setdefault("PHOTOS_DIR", str(Path(config.PHOTOS_DIR).resolve()))
            if prefix:
                env["PHOTO_PREFIX"] = prefix
            else:
                env.setdefault("PHOTO_PREFIX", "photo")
            if not direct_camera_client.is_enabled():
                last_err = "[ERR] direct camera service is disabled"
                record_error(
                    "capture_service",
                    "take_photo_sync_attempt_failed",
                    context={"attempt": attempt, "total_attempts": total_attempts, "reason": "direct_camera_disabled"},
                )
                continue

            saved = direct_camera_client.capture(
                prefix=env.get("PHOTO_PREFIX", "photo"),
                ext=env.get("PHOTO_EXT", "jpg").strip().lstrip(".") or "jpg",
                timeout=10.0,
            )
            _touch_upload_now_flag()
            return saved
        except Exception as e:
            last_err = f"[ERR] take_photo exception: {e}"
            record_error(
                "capture_service",
                "take_photo_sync_exception",
                e,
                {"attempt": attempt, "total_attempts": total_attempts},
            )

        if attempt < total_attempts and retry_delay > 0.0:
            time.sleep(retry_delay)

    return last_err


def take_photo_test_sync() -> str:
    """
    Takes a photo and deletes it immediately. Good as a camera health test.
    Returns "OK" or an error string.
    """
    result = take_photo_sync()
    if result.startswith("/"):
        try:
            p = Path(result)
            if p.exists():
                p.unlink()
            return "OK"
        except Exception as e:
            return f"[WARN] captured but delete failed: {e}"
    return result


def run_fix_realsense_sync() -> str:
    """
    Runs fix_realsense_usb.sh. NOTE: script uses sudo tee -> needs passwordless sudo to fully work.
    """
    try:
        if not Path(FIX_SCRIPT).exists():
            return f"[ERR] fix script not found: {FIX_SCRIPT}"

        p = subprocess.run(
            ["bash", FIX_SCRIPT],
            capture_output=True,
            text=True,
            timeout=20,
        )
        out = (p.stdout or "").strip()
        err = (p.stderr or "").strip()
        if p.returncode == 0:
            return out or "OK"
        return f"[ERR] fix script rc={p.returncode}\n{out}\n{err}".strip()
    except Exception as e:
        record_error("capture_service", "run_fix_realsense_sync_exception", e)
        return f"[ERR] fix exception: {e}"


def replay_file_integrity(path: Path) -> dict:
    """
    Checks:
    - file exists
    - has at least one frame with 'q'
    - has at least one trigger marker (meta contains trigger)
    """
    p = Path(path).resolve()
    out = {
        "ok": False,          # usable replay (has frames)
        "trigger_ok": False,  # has explicit trigger markers
        "path": str(p),
        "exists": False,
        "frames": 0,
        "triggers": 0,
        "error": "",
    }
    if not p.exists() or not p.is_file():
        out["error"] = "missing replay file"
        return out
    out["exists"] = True

    import json

    try:
        with p.open("r", encoding="utf-8") as f:
            for line in f:
                line = line.strip()
                if not line:
                    continue
                try:
                    d = json.loads(line)
                except Exception:
                    continue
                if isinstance(d, dict) and isinstance(d.get("q"), list):
                    out["frames"] += 1
                    meta = d.get("meta")
                    trig = False
                    if isinstance(meta, str) and ("trigger" in meta.lower()):
                        trig = True
                    elif isinstance(meta, dict) and bool(meta.get("trigger")):
                        trig = True
                    if trig:
                        out["triggers"] += 1
        out["ok"] = out["frames"] > 0
        out["trigger_ok"] = out["triggers"] > 0
        if out["frames"] <= 0:
            out["error"] = "replay has no valid frames"
        elif out["triggers"] <= 0:
            out["warning"] = "replay has no trigger markers; timed fallback capture will be used"
        return out
    except Exception as e:
        out["error"] = str(e)
        record_error("capture_service", "replay_file_integrity", e, {"path": str(p)})
        return out


def replay_timing_profile(path: Path, end_margin_sec: float | None = None) -> dict:
    """
    Returns replay timing information used to align countdown audio and fallback capture.

    If the replay contains explicit trigger markers, the first trigger offset is treated as the
    desired shot time. Otherwise the shot is scheduled slightly before the replay ends so capture
    happens before the arm starts returning home.
    """
    p = Path(path).resolve()
    margin = max(0.0, float(end_margin_sec if end_margin_sec is not None else config.REPLAY_CAPTURE_END_MARGIN_SEC))
    out = {
        "ok": False,
        "path": str(p),
        "exists": False,
        "frames": 0,
        "timed_frames": 0,
        "duration_sec": 0.0,
        "trigger_offsets_sec": [],
        "trigger_count": 0,
        "capture_offset_sec": max(0.0, min(config.PHOTO_DELAY_SEC, config.PHOTO_TOTAL_SEC)),
        "capture_source": "config_fallback",
        "end_margin_sec": margin,
        "error": "",
    }
    if not p.exists() or not p.is_file():
        out["error"] = "missing replay file"
        return out
    out["exists"] = True

    import json

    timed_offsets: list[float] = []
    trigger_offsets: list[float] = []
    first_t: float | None = None

    try:
        with p.open("r", encoding="utf-8") as f:
            for line in f:
                line = line.strip()
                if not line:
                    continue
                try:
                    d = json.loads(line)
                except Exception:
                    continue
                if not (isinstance(d, dict) and isinstance(d.get("q"), list)):
                    continue

                out["frames"] += 1
                try:
                    t_val = float(d.get("t"))
                except Exception:
                    continue

                if first_t is None:
                    first_t = t_val
                rel_t = max(0.0, t_val - first_t)
                timed_offsets.append(rel_t)
                out["timed_frames"] += 1

                meta = d.get("meta")
                if isinstance(meta, str) and ("trigger" in meta.lower()):
                    trigger_offsets.append(rel_t)
                elif isinstance(meta, dict) and bool(meta.get("trigger")):
                    trigger_offsets.append(rel_t)

        out["ok"] = out["frames"] > 0
        if not out["ok"]:
            out["error"] = "replay has no valid frames"
            return out

        if timed_offsets:
            duration_sec = max(0.0, timed_offsets[-1])
            out["duration_sec"] = duration_sec
            out["trigger_offsets_sec"] = [round(x, 3) for x in trigger_offsets]
            out["trigger_count"] = len(trigger_offsets)

            if trigger_offsets:
                out["capture_offset_sec"] = max(0.0, min(duration_sec, trigger_offsets[0]))
                out["capture_source"] = "trigger"
            elif duration_sec > 0.0:
                out["capture_offset_sec"] = max(0.0, duration_sec - margin)
                out["capture_source"] = "timed_end"
            else:
                out["capture_source"] = "config_fallback"
        else:
            out["error"] = "replay has no timestamped frames; config fallback timing will be used"

        return out
    except Exception as e:
        out["error"] = str(e)
        record_error("capture_service", "replay_timing_profile", e, {"path": str(p)})
        return out


def ensure_replay_integrity(active_replay: Path, fallback_replay: Path) -> tuple[Path, dict]:
    """
    Returns a valid replay path. If active invalid, tries fallback.
    """
    active = Path(active_replay).resolve()
    fallback = Path(fallback_replay).resolve()
    active_report = replay_file_integrity(active)
    if active_report.get("ok") and active_report.get("trigger_ok"):
        return active, {"selected": str(active), "active": active_report, "fallback_used": False}

    fallback_report = replay_file_integrity(fallback)
    if fallback_report.get("ok") and fallback_report.get("trigger_ok"):
        return fallback, {
            "selected": str(fallback),
            "active": active_report,
            "fallback": fallback_report,
            "fallback_used": True,
            "reason": "active replay missing trigger markers",
        }

    # Degraded mode: no trigger-marked file found, keep active if it has frames.
    if active_report.get("ok"):
        return active, {
            "selected": str(active),
            "active": active_report,
            "fallback": fallback_report,
            "fallback_used": False,
            "degraded_no_trigger": True,
        }

    # If both invalid, keep active and report both failures.
    return active, {
        "selected": str(active),
        "active": active_report,
        "fallback": fallback_report,
        "fallback_used": False,
    }


def capture_with_replay_sync(
    replay_runner,
    replay_file: Path,
    home_file: Path,
    delay_sec: float,
    prefix: str | None = None,
    speed: float = 1.0,
    finalize_timeout_sec: float = 4.0,
    cancel_event: threading.Event | None = None,
) -> str:
    """
    Unified capture pipeline:
      replay + trigger callback capture + fallback timed capture + upload flag.
    """
    delay_sec = max(0.0, float(delay_sec))
    done = threading.Event()
    lock = threading.Lock()
    result = {"value": None}
    capture_started = {"value": False}

    def _is_cancelled() -> bool:
        return bool(cancel_event is not None and cancel_event.is_set())

    def _capture_once(reason: str):
        if _is_cancelled():
            return
        with lock:
            if capture_started["value"]:
                return
            capture_started["value"] = True
        try:
            result["value"] = take_photo_sync(prefix=prefix)
        except Exception as e:
            record_error("capture_service", "capture_with_replay_capture_once", e, {"reason": reason})
            result["value"] = f"[ERR] capture failed ({reason}): {e}"
        finally:
            done.set()

    if replay_runner is not None and bool(getattr(replay_runner, "is_playing", False)):
        return "[ERR] replay busy"
    if _is_cancelled():
        return "[ERR] capture cancelled"

    try:
        if replay_runner is not None:
            def _trigger_cb(_frame):
                threading.Thread(target=lambda: _capture_once("trigger"), daemon=True).start()

            threading.Thread(
                target=lambda: replay_runner.run(replay_file, home_file, speed, trigger_callback=_trigger_cb),
                daemon=True,
            ).start()
    except Exception as e:
        record_error("capture_service", "capture_with_replay_start_replay", e)
        return f"[ERR] replay start failed: {e}"

    deadline = time.time() + delay_sec
    while (not done.is_set()) and (time.time() < deadline):
        if _is_cancelled():
            return "[ERR] capture cancelled"
        time.sleep(0.02)

    if (not done.is_set()) and (not _is_cancelled()):
        _capture_once("fallback")

    finalize_deadline = time.time() + max(0.1, finalize_timeout_sec)
    while not done.is_set():
        if _is_cancelled():
            return "[ERR] capture cancelled"
        if time.time() >= finalize_deadline:
            break
        time.sleep(0.02)
    if not done.is_set():
        record_error("capture_service", "capture_with_replay_timeout", context={"delay_sec": delay_sec})
        return "[ERR] capture pipeline timeout"

    return str(result["value"] or "[ERR] capture pipeline no result")