"""Command-line entry point for LiDAR–IMU calibration."""

from __future__ import annotations

import argparse
from datetime import datetime
from pathlib import Path
from typing import Any

from .contracts import CalibrationMode, CalibrationRequest, CalibrationStatus, SessionInput
from .phase_a_replay import run_phase_a_replay
from .pipeline import describe_pipeline, run_calibration


def _format_progress_value(value: Any) -> str:
    if isinstance(value, float):
        return f"{value:.3f}"
    if isinstance(value, (list, tuple, set)):
        return "[" + ",".join(str(item) for item in value) + "]"
    return str(value)


def _print_progress(event: dict[str, Any]) -> None:
    """Print one compact, immediately flushed progress line."""

    timestamp = datetime.now().strftime("%H:%M:%S")
    stage_index = event.get("stage_index", "?")
    stage_total = event.get("stage_total", "?")
    stage_name = event.get("stage", "unknown")
    message = event.get("event", "progress")
    fields = " ".join(
        f"{key}={_format_progress_value(value)}"
        for key, value in event.items()
        if key not in {"stage_index", "stage_total", "stage", "event"}
        and value is not None
    )
    suffix = f" | {fields}" if fields else ""
    print(
        f"[{timestamp}] [stage {stage_index}/{stage_total} {stage_name}] {message}{suffix}",
        flush=True,
    )


def _parse_session_imu_specs(
    specs: list[str] | None,
) -> dict[str, Path]:
    result: dict[str, Path] = {}
    for spec in specs or []:
        if "=" not in spec:
            raise SystemExit(
                "--session-imu must use SESSION_ID=PATH syntax"
            )
        session_id, raw_path = spec.split("=", 1)
        session_id = session_id.strip()
        if not session_id or not raw_path.strip():
            raise SystemExit(
                "--session-imu must use non-empty SESSION_ID=PATH"
            )
        if session_id in result:
            raise SystemExit(
                f"duplicate --session-imu for {session_id}"
            )
        result[session_id] = Path(raw_path.strip())
    return result


def _print_phase_a_progress(
    event: str,
    fields: dict[str, Any],
) -> None:
    _print_progress(
        {
            "stage_index": "A",
            "stage_total": "A",
            "stage": "phase_a_replay",
            "event": event,
            **fields,
        }
    )


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(description="LiDAR–IMU extrinsic calibration (V1)")
    subcommands = parser.add_subparsers(dest="command", required=True)

    plan = subcommands.add_parser("plan", help="显示标定阶段，不读取数据")
    plan.add_argument("--vehicle-config", help="车辆配置路径（仅展示，plan 不读取）")
    plan.add_argument(
        "--mode",
        choices=[mode.value for mode in CalibrationMode],
        default=CalibrationMode.ROTATION_ONLY.value,
    )

    run = subcommands.add_parser(
        "run",
        help="执行 V1 标定流水线（可重复 --imu/--lidar/--session-id 做多会话联合）",
    )
    run.add_argument(
        "--session-id",
        action="append",
        default=None,
        help="会话 ID（可重复；与 --imu/--lidar 一一对应）",
    )
    run.add_argument(
        "--imu",
        action="append",
        required=True,
        help="IMU CSV/NPZ 路径（可重复）",
    )
    run.add_argument(
        "--lidar",
        action="append",
        required=True,
        help="LiDAR 会话目录（可重复）",
    )
    run.add_argument("--vehicle-config", required=True, help="车辆配置 YAML")
    run.add_argument("--output", required=True, help="输出目录")
    run.add_argument(
        "--mode",
        choices=[mode.value for mode in CalibrationMode],
        default=CalibrationMode.ROTATION_ONLY.value,
    )
    run.add_argument("--max-iterations", type=int, default=2)
    run.add_argument("--time-offset-search-s", type=float, default=1.0)
    run.add_argument(
        "--fixed-time-offset-s",
        type=float,
        default=None,
        help="Skip |ω| δt search and use this constant (use 0 after host-UTC bridge)",
    )
    run.add_argument(
        "--session-time-offset-s",
        action="append",
        type=float,
        default=None,
        help="Per-session fixed time offset; repeat once per --imu/--lidar input",
    )
    run.add_argument(
        "--no-signed-time-refine",
        action="store_true",
        help="Disable signed 3-axis δt refine after hand-eye (recommended for host-bridged data)",
    )
    run.add_argument(
        "--max-signed-refine-shift-s",
        type=float,
        default=0.05,
        help="Max |Δδt| accepted by signed refine from the coarse estimate",
    )
    run.add_argument("--min-pair-rotation-deg", type=float, default=3.0)
    run.add_argument("--min-pair-translation-m", type=float, default=0.3)
    run.add_argument("--min-registration-fitness", type=float, default=0.5)
    run.add_argument("--max-imu-gap-s", type=float, default=0.05)
    run.add_argument("--max-lidar-gap-s", type=float, default=1.0)

    replay = subcommands.add_parser(
        "phase-a-replay",
        help="Replay Phase-A from cached motion pairs without rerunning GICP",
    )
    replay.add_argument("--motion-pairs", type=Path, required=True)
    replay.add_argument("--vehicle-config", type=Path, required=True)
    replay.add_argument("--output", type=Path, required=True)
    replay.add_argument(
        "--session-imu",
        action="append",
        default=None,
        metavar="SESSION_ID=PATH",
        help="Raw IMU mapping used only when cache lacks J_bg/cov",
    )
    replay.add_argument(
        "--exclude-session",
        action="append",
        default=None,
        help="Session ID to exclude; may be repeated",
    )
    replay.add_argument(
        "--strong-rotation-min-deg",
        type=float,
        default=1.0,
    )
    replay.add_argument(
        "--decorrelation-block-s",
        type=float,
        default=3.0,
        help="Per-session time-block length used to decorrelate factors",
    )
    replay.add_argument(
        "--max-pairs-per-block",
        type=int,
        default=1,
        help="Maximum factors kept in each decorrelation block",
    )
    replay.add_argument(
        "--bias-prior-sigma-rad-s",
        type=float,
        default=0.002,
    )
    replay.add_argument(
        "--yaw-std-max-deg",
        type=float,
        default=0.5,
    )
    replay.add_argument(
        "--loo-yaw-range-max-deg",
        type=float,
        default=1.0,
    )
    replay.add_argument(
        "--data-prior-difference-max-deg",
        type=float,
        default=1.0,
    )
    replay.add_argument("--max-nfev", type=int, default=200)

    return parser


def _build_sessions(args: argparse.Namespace) -> tuple[SessionInput, ...]:
    imus = [Path(p) for p in args.imu]
    lidars = [Path(p) for p in args.lidar]
    if len(imus) != len(lidars):
        raise SystemExit(f"--imu count ({len(imus)}) must match --lidar count ({len(lidars)})")
    if args.session_id is None:
        session_ids = [f"session{i}" for i in range(len(imus))]
    else:
        session_ids = list(args.session_id)
        if len(session_ids) != len(imus):
            raise SystemExit(
                f"--session-id count ({len(session_ids)}) must match --imu/--lidar ({len(imus)})"
            )
    if args.session_time_offset_s is None:
        session_offsets: list[float | None] = [None] * len(imus)
    else:
        session_offsets = list(args.session_time_offset_s)
        if len(session_offsets) != len(imus):
            raise SystemExit(
                f"--session-time-offset-s count ({len(session_offsets)}) must match "
                f"--imu/--lidar ({len(imus)})"
            )
    return tuple(
        SessionInput(
            session_id=sid,
            imu_source=imu,
            lidar_source=lidar,
            fixed_time_offset_s=offset,
        )
        for sid, imu, lidar, offset in zip(session_ids, imus, lidars, session_offsets)
    )


def main(argv: list[str] | None = None) -> int:
    parser = build_parser()
    args = parser.parse_args(argv)

    if args.command == "plan":
        request = CalibrationRequest(
            vehicle_config=Path(args.vehicle_config) if args.vehicle_config else None,
            requested_mode=CalibrationMode(args.mode),
        )
        print("LiDAR–IMU calibration stages:")
        print(f"requested mode: {request.requested_mode.value}")
        for index, stage in enumerate(describe_pipeline(request), start=1):
            print(f"{index}. {stage.name}: {stage.responsibility}")
        return 0

    if args.command == "phase-a-replay":
        summary = run_phase_a_replay(
            motion_pairs_path=args.motion_pairs,
            vehicle_config_path=args.vehicle_config,
            output_directory=args.output,
            imu_paths_by_session=_parse_session_imu_specs(
                args.session_imu
            ),
            excluded_sessions=set(args.exclude_session or []),
            strong_rotation_min_deg=args.strong_rotation_min_deg,
            decorrelation_block_s=args.decorrelation_block_s,
            max_pairs_per_block=args.max_pairs_per_block,
            bias_prior_sigma_rad_s=args.bias_prior_sigma_rad_s,
            yaw_std_max_deg=args.yaw_std_max_deg,
            leave_one_out_yaw_range_max_deg=(
                args.loo_yaw_range_max_deg
            ),
            data_prior_difference_max_deg=(
                args.data_prior_difference_max_deg
            ),
            max_nfev=args.max_nfev,
            progress_callback=_print_phase_a_progress,
        )
        print(f"status: {summary['status']}")
        print(f"acceptance_checks: {summary['acceptance_checks']}")
        for name, variant in summary["variants"].items():
            print(
                f"{name}: rpy_deg_xyz={variant['rpy_deg_xyz']} "
                f"RMS={variant['residual_rms_deg']:.6f} "
                f"P95={variant['residual_p95_deg']:.6f}"
            )
        print(
            "A1 marginalized yaw_std_deg: "
            f"{summary['marginal_observability_A1']['yaw_std_deg']}"
        )
        print(
            "leave_one_out_yaw_range_deg: "
            f"{summary['leave_one_out_yaw_range_deg']}"
        )
        print(f"report directory: {args.output}")
        return 0 if (summary["accepted"] or summary.get("partial_accepted")) else 2

    if args.command == "run":
        sessions = _build_sessions(args)
        request = CalibrationRequest(
            vehicle_config=Path(args.vehicle_config),
            sessions=sessions,
            requested_mode=CalibrationMode(args.mode),
            output_directory=Path(args.output),
            max_iterations=args.max_iterations,
            min_pair_rotation_deg=args.min_pair_rotation_deg,
            min_pair_translation_m=args.min_pair_translation_m,
            min_registration_fitness=args.min_registration_fitness,
            max_imu_gap_s=args.max_imu_gap_s,
            max_lidar_gap_s=args.max_lidar_gap_s,
            time_offset_search_s=args.time_offset_search_s,
            fixed_time_offset_s=args.fixed_time_offset_s,
            enable_signed_time_refine=not args.no_signed_time_refine,
            max_signed_refine_shift_s=args.max_signed_refine_shift_s,
        )
        result = run_calibration(request, progress_callback=_print_progress)
        print(f"status: {result.status.value}")
        print(f"message: {result.message}")
        if result.time_offset_s is not None:
            print(f"time_offset_s (first session; t_imu = t_lidar + dt): {result.time_offset_s:.6f}")
        joint = (result.details or {}).get("joint") or {}
        if joint:
            print(f"merged_pair_count: {joint.get('merged_pair_count')}")
            print(f"pair_counts_per_session: {joint.get('pair_counts_per_session')}")
        if result.T_IMU_lidar is not None:
            print("T_IMU_lidar:")
            print(result.T_IMU_lidar)
        print(f"report directory: {args.output}")
        return 0 if result.status != CalibrationStatus.BLOCKED else 2

    parser.error(f"unknown command {args.command}")
    return 2


if __name__ == "__main__":
    raise SystemExit(main())