#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import json
import math
import argparse
import random
from pathlib import Path
from typing import Any, Dict, List, Tuple, DefaultDict, Optional
from collections import defaultdict

# ---------------- Mapping helpers ----------------

def load_answer_maps(path: str) -> Tuple[Dict[str, int], Dict[int, str]]:
    """
    Loads the 2-entry list:
      [ {text->id}, { "0": "text", "1": "text", ... } ]
    Returns:
      text2id (normalized text -> id), id2text (int id -> canonical text)
    """
    with open(path, "r", encoding="utf-8") as f:
        data = json.load(f)

    if not isinstance(data, list) or len(data) < 2:
        raise ValueError("answer_dict file must be a list of two dicts: [text2id, id2text].")

    raw_text2id, raw_id2text = data[0], data[1]
    if not isinstance(raw_text2id, dict) or not isinstance(raw_id2text, dict):
        raise ValueError("Both elements in answer_dict must be dicts.")

    # Normalize text keys to a stable form for lookup
    def norm_text(s: str) -> str:
        return " ".join(s.strip().lower().split())

    text2id = {norm_text(k): int(v) for k, v in raw_text2id.items()}
    id2text = {int(k): str(v) for k, v in raw_id2text.items()}
    return text2id, id2text

def normalize_answer_text(s: str) -> str:
    """Canonicalize spacing/case for consistent lookup; keep original wording style simple."""
    return " ".join(s.strip().lower().split())

# ---------------- Data helpers ----------------

def pick_situation(d: Dict[str, Any]) -> str:
    return d.get("situation_text") or d.get("situation_multimodal") or ""

def get_location(d: Dict[str, Any]) -> List[float]:
    md = d.get("meta_data") or {}
    sp = md.get("start_point")
    loc = sp if isinstance(sp, (list, tuple)) and len(sp) >= 3 else d.get("location", [0, 0, 0])
    return [float(loc[0]), float(loc[1]), float(loc[2])]

def yaw_to_vec3(yaw: float) -> List[float]:
    return [math.cos(yaw), math.sin(yaw), 0.0]

def quat_to_yaw(q: List[float]) -> float:
    if len(q) != 4:
        return 0.0
    # try (x,y,z,w)
    x, y, z, w = map(float, q)
    try:
        siny_cosp = 2.0 * (w * z + x * y)
        cosy_cosp = 1.0 - 2.0 * (y * y + z * z)
        return math.atan2(siny_cosp, cosy_cosp)
    except Exception:
        pass
    # fallback (w,x,y,z)
    w, x, y, z = map(float, q)
    try:
        siny_cosp = 2.0 * (w * z + x * y)
        cosy_cosp = 1.0 - 2.0 * (y * y + z * z)
        return math.atan2(siny_cosp, cosy_cosp)
    except Exception:
        return 0.0

def get_orientation_vec(d: Dict[str, Any]) -> List[float]:
    md = d.get("meta_data") or {}
    if isinstance(md.get("start_ori"), (int, float)):
        return yaw_to_vec3(float(md["start_ori"]))
    q = d.get("orientation")
    if isinstance(q, (list, tuple)) and len(q) == 4:
        return yaw_to_vec3(quat_to_yaw(list(map(float, q))))
    if isinstance(q, (list, tuple)) and len(q) >= 3:
        return [float(q[0]), float(q[1]), float(q[2])]
    return [1.0, 0.0, 0.0]

# ---------------- Answer extraction (eight_direction) ----------------

def eight_direction_answer(item: Dict[str, Any], text2id: Dict[str, int], id2text: Dict[int, str]) -> Optional[str]:
    """
    Returns a SINGLE canonical text answer for eight_direction (e.g., 'turn left'),
    resolving from either [code, 'text'] or just code or text, using id<->text maps.
    """
    act = item.get("action") or item.get("meta_data", {}).get("action_type") or {}
    v = act.get("eight_direction")

    # Case A: list/tuple like [1, "turn left"] or [1]
    if isinstance(v, (list, tuple)) and len(v) > 0:
        # Prefer explicit string label when present
        if len(v) >= 2 and isinstance(v[1], str) and v[1].strip():
            return id2text.get(text2id.get(normalize_answer_text(v[1]), -999), v[1].strip())
        # Else map integer code to text
        if isinstance(v[0], int):
            return id2text.get(v[0], str(v[0]))

    # Case B: plain int code
    if isinstance(v, int):
        return id2text.get(v, str(v))

    # Case C: plain string
    if isinstance(v, str) and v.strip():
        norm = normalize_answer_text(v)
        # If mappable, return canonical text from id2text; else return original cleaned text
        if norm in text2id:
            return id2text.get(text2id[norm], v.strip())
        return v.strip()

    return None

# ---------------- Conversion ----------------

def convert_to_flat(nested: Dict[str, Any], text2id: Dict[str, int], id2text: Dict[int, str]) -> List[Dict[str, Any]]:
    """
    Convert nested JSON to flat records, keeping ONLY samples with eight_direction,
    and normalizing the answer to the canonical text form.
    """
    out = []
    for scan_id, steps in nested.items():
        if not isinstance(steps, dict):
            continue
        for idx_key, item in steps.items():
            if not isinstance(item, dict):
                continue

            answer_text = eight_direction_answer(item, text2id, id2text)
            if not answer_text:
                continue  # strictly keep eight_direction examples

            situation = pick_situation(item)
            location = get_location(item)
            orientation = get_orientation_vec(item)
            try:
                index = int(idx_key)
            except Exception:
                index = len(out)

            rec = {
                "question": "What action should I take next step?",
                "situation_text": situation,
                "answers": [answer_text],            # normalized canonical text (e.g., "turn left")
                "scan_id": item.get("scan_id") or scan_id,
                "location": location,                # [x, y, z]
                "interaction": item.get("interaction"),
                "orientation": orientation,          # [dx, dy, 0]
                "type": "navigation",
                "index": index,
                "question_id": f"{item.get('scan_id') or scan_id}_{index}",
            }
            out.append(rec)
    return out

# ---------------- Annotations ----------------

def records_to_annotations(records: List[Dict[str, Any]], text2id: Dict[str, int]) -> Dict[str, Any]:
    """
    Map flat records into 'annotations' format.
    - Sets answer_id using the provided text2id mapping.
    - If text not found in mapping, answer_id = -1.
    """
    ann_list: List[Dict[str, Any]] = []
    for r in records:
        dx, dy, _ = r["orientation"]
        x, y, z = r["location"]
        answers = r.get("answers") or []

        answers_obj = []
        for a in answers:
            norm = normalize_answer_text(str(a))
            ans_id = text2id.get(norm, -1)
            answers_obj.append(
                {
                    "answer": str(a),
                    "answer_confidence": "yes",
                    "answer_id": ans_id
                }
            )

        ann = {
            "scan_id": r["scan_id"],
            "question_type": r.get("type", "navigation"),
            "answer_type": "other",
            "question_id": r["question_id"],
            "answers": answers_obj,
            "rotation": {"_x": dx, "_y": dy, "_z": 0.0, "_w": 0.0},
            "position": {"x": x, "y": y, "z": z},
        }
        ann_list.append(ann)
    return {"annotations": ann_list}

# ---------------- Split by scene ----------------

def group_by_scene(records: List[Dict[str, Any]]) -> DefaultDict[str, List[Dict[str, Any]]]:
    buckets: DefaultDict[str, List[Dict[str, Any]]] = defaultdict(list)
    for r in records:
        buckets[r["scan_id"]].append(r)
    return buckets

def split_scenes(scene_ids: List[str], val_ratio: float, test_ratio: float, seed: int) -> Tuple[List[str], List[str], List[str]]:
    rnd = random.Random(seed)
    ids = list(scene_ids)
    rnd.shuffle(ids)
    n = len(ids)
    n_val = int(round(n * val_ratio))
    n_test = int(round(n * test_ratio))
    n_val = min(n_val, n)
    n_test = min(n_test, max(0, n - n_val))
    train = ids[n_val + n_test :]
    val   = ids[:n_val]
    test  = ids[n_val:n_val + n_test]
    return train, val, test

def flatten_from_ids(buckets: Dict[str, List[Dict[str, Any]]], ids: List[str]) -> List[Dict[str, Any]]:
    out: List[Dict[str, Any]] = []
    for sid in ids:
        out.extend(buckets.get(sid, []))
    return out

# ---------------- CLI ----------------

def main():
    parser = argparse.ArgumentParser(description="Convert & split dataset (8:1:1 by scene) and write annotation files with answer_id from answer_dict.")
    parser.add_argument("--input", type=str, default="msnn/msnn_scannet.json", help="Path to input JSON file")
    parser.add_argument("--output_dir", type=str, default=None, help="Directory to write outputs (default: input's directory)")
    parser.add_argument("--answer_dict", type=str, default="msnn/answer_dict.json", help="Path to the answer mapping JSON (list of two dicts)")
    parser.add_argument("--seed", type=int, default=42, help="Random seed for scene split")
    parser.add_argument("--val_ratio", type=float, default=0.1, help="Validation ratio (by scene)")
    parser.add_argument("--test_ratio", type=float, default=0.1, help="Test ratio (by scene)")
    args = parser.parse_args()

    # Load mappings
    text2id, id2text = load_answer_maps(args.answer_dict)

    # Load nested data
    with open(args.input, "r", encoding="utf-8") as f:
        nested = json.load(f)

    # Convert and group
    flat = convert_to_flat(nested, text2id, id2text)
    buckets = group_by_scene(flat)
    scene_ids = sorted(buckets.keys())
    train_ids, val_ids, test_ids = split_scenes(scene_ids, args.val_ratio, args.test_ratio, args.seed)

    train_recs = flatten_from_ids(buckets, train_ids)
    val_recs   = flatten_from_ids(buckets, val_ids)
    test_recs  = flatten_from_ids(buckets, test_ids)

    # Output dir
    out_dir = Path(args.output_dir) if args.output_dir else Path(args.input).parent
    out_dir.mkdir(parents=True, exist_ok=True)

    # Dataset filenames
    p_train = out_dir / "msnn_train_eight_direction.json"
    p_val   = out_dir / "msnn_val_eight_direction.json"
    p_test  = out_dir / "msnn_test_eight_direction.json"

    # Annotation filenames
    pa_train = out_dir / "msnn_train_eight_direction_annotations.json"
    pa_val   = out_dir / "msnn_val_eight_direction_annotations.json"
    pa_test  = out_dir / "msnn_test_eight_direction_annotations.json"

    # Write datasets
    with open(p_train, "w", encoding="utf-8") as f: json.dump(train_recs, f, ensure_ascii=False, indent=4)
    with open(p_val,   "w", encoding="utf-8") as f: json.dump(val_recs,   f, ensure_ascii=False, indent=4)
    with open(p_test,  "w", encoding="utf-8") as f: json.dump(test_recs,  f, ensure_ascii=False, indent=4)

    # Build & write annotations (with answer_id from mapping)
    with open(pa_train, "w", encoding="utf-8") as f: json.dump(records_to_annotations(train_recs, text2id), f, ensure_ascii=False, indent=4)
    with open(pa_val,   "w", encoding="utf-8") as f: json.dump(records_to_annotations(val_recs,   text2id), f, ensure_ascii=False, indent=4)
    with open(pa_test,  "w", encoding="utf-8") as f: json.dump(records_to_annotations(test_recs,  text2id), f, ensure_ascii=False, indent=4)

    print(f"Scenes: total={len(scene_ids)} | train={len(train_ids)} | val={len(val_ids)} | test={len(test_ids)}")
    print(f"Samples: train={len(train_recs)} | val={len(val_recs)} | test={len(test_recs)}")
    print("Wrote:")
    print(f"  {p_train}")
    print(f"  {p_val}")
    print(f"  {p_test}")
    print(f"  {pa_train}")
    print(f"  {pa_val}")
    print(f"  {pa_test}")

if __name__ == "__main__":
    main()