"""M01 마스터 데이터 파일 저장소 — `resources/master_data/` 첫 층 JSON 읽기·검사·쓰기.

계약: `resources/master_data/_화면_계약.md` · 파일 모양: `_틀.md`
검사·계산 엔진: `scripts/check_master.py`.
"""

from __future__ import annotations

import hashlib
import json
import os
import re
import sys
import threading
from decimal import Decimal
from pathlib import Path

SCRIPTS = Path(__file__).resolve().parents[1] / "resources/master_data/scripts"
sys.path.insert(0, str(SCRIPTS))

import check_master as cm  # noqa: E402

FOLDER: Path = cm.MASTER  # 시험은 사본 폴더로 바꿈
_CHAPTER = re.compile(r"_([^_]*\d+장)\.json$")  # 「공통3장」 · 「13장」
# ponytail: 저장은 한 번에 하나(프로세스 안 잠금) · 서버를 여럿 띄우면 파일 잠금으로
_LOCK = threading.Lock()


class StoreError(Exception):
    def __init__(self, status: int, detail):
        super().__init__(detail)
        self.status, self.detail = status, detail


# ── 읽기 ──────────────────────────────────────────────────────────────
def _path(file: str) -> Path:
    path = FOLDER / file
    if "/" in file or "\\" in file or file.startswith("_") or not path.is_file():
        raise StoreError(404, f"없는 파일 「{file}」")
    return path


def version_of(raw: bytes) -> str:
    return hashlib.sha256(raw).hexdigest()[:16]


def read(file: str) -> tuple[dict, str]:
    raw = _path(file).read_bytes()
    return json.loads(raw, parse_float=Decimal, parse_int=Decimal), version_of(raw)


def items_key(data: dict) -> str:
    return "표" if data.get("그룹") in cm.mf.TABLE_GROUPS else "줄"


def chapter_of(file: str) -> str:
    m = _CHAPTER.search(file)
    return m.group(1) if m else ""


def _hit(row: dict, q: str) -> bool:
    q = q.lower()
    return not q or q in str(row.get("열쇠", "")).lower() or q in str(row.get("이름", "")).lower()


def groups() -> list[dict]:
    out = {g: {"group": g, "files": 0, "rows": 0} for g in cm.mf.GROUPS}
    for data in cm.load(folder=FOLDER).values():
        slot = out.get(data.get("그룹"))
        if slot:
            slot["files"] += 1
            slot["rows"] += len(data.get(items_key(data)) or [])
    return list(out.values())


def files_of(group: str) -> list[dict]:
    if group not in cm.mf.GROUPS:
        raise StoreError(404, f"없는 그룹 「{group}」")
    out = []
    for path in sorted(FOLDER.glob(f"{group}_*.json")):
        data, version = read(path.name)
        out.append(
            {
                "file": path.name,
                "book": data.get("원문"),
                "chapter": chapter_of(path.name),
                "edition": data.get("판"),
                "rows": len(data.get(items_key(data)) or []),
                "version": version,
            }
        )
    return out


def rows(file: str, page: int, size: int, q: str) -> dict:
    data, version = read(file)
    hits = [r for r in data.get(items_key(data)) or [] if _hit(r, q)]
    page, size = max(page, 1), min(max(size, 1), 500)
    return {
        "file": file,
        "version": version,
        "total": len(hits),
        "page": page,
        "size": size,
        "rows": hits[(page - 1) * size : page * size],
    }


def tables(file: str, q: str) -> dict:
    data, version = read(file)
    if items_key(data) != "표":
        raise StoreError(400, f"표형 파일 아님 「{file}」")
    heads = ("열쇠", "이름", "기준", "출처", "조건", "값칸")
    return {
        "file": file,
        "version": version,
        "tables": [
            {**{k: t.get(k) for k in heads}, "count": len(t.get("줄") or [])}
            for t in data["표"]
            if _hit(t, q)
        ],
    }


def _one(data: dict, key: str) -> dict:
    for row in data.get(items_key(data)) or []:
        if str(row.get("열쇠")) == key:
            return row
    raise StoreError(404, f"없는 열쇠 「{key}」")


def table(file: str, key: str) -> dict:
    data, version = read(file)
    return {"file": file, "version": version, "table": _one(data, key)}


def _logic_files(files: dict[str, dict]):
    for name, data in files.items():
        if data.get("그룹") == "로직":
            yield name, data


def logics(book: str, chapter: str, q: str, blocked: int | None) -> list[dict]:
    files = cm.load(folder=FOLDER)
    whole = cm.mf.Master(files)
    out = []
    for name, data in _logic_files(files):
        if (book and data.get("원문") != book) or (chapter and chapter_of(name) != chapter):
            continue
        for row in data.get("줄") or []:
            if not _hit(row, q):
                continue
            reasons = cm.mf.check_logic(whole, data.get("원문"), row)[0]
            if blocked is not None and bool(reasons) != bool(blocked):
                continue
            out.append(
                {
                    "file": name,
                    "book": data.get("원문"),
                    "chapter": chapter_of(name),
                    **{k: row.get(k) for k in ("열쇠", "이름", "결과단위", "출처")},
                    "blocked": bool(reasons),
                    "reasons": reasons,
                }
            )
    return out


def logic(book: str, key: str) -> dict:
    files = cm.load(folder=FOLDER)
    for name, data in _logic_files(files):
        if data.get("원문") != book:
            continue
        for row in data.get("줄") or []:
            if str(row.get("열쇠")) == key:
                whole = cm.mf.Master(files)
                reasons = cm.mf.check_logic(whole, book, row)[0]
                _, version = read(name)
                return {
                    "file": name,
                    "version": version,
                    "logic": row,
                    "blocked": bool(reasons),
                    "reasons": reasons,
                    "prices": _prices(whole, row),
                }
    raise StoreError(404, f"없는 로직 「{book}:{key}」")


def _brief(ref: str, row: dict) -> dict:
    return {"ref": ref, **{k: row.get(k) for k in ("이름", "규격", "단위", "값", "값칸")}}


def _prices(whole, row: dict) -> dict:
    """호표 요소 → 요소 줄 요약(단가 자동 칸) · `{이름}` 낀 열쇠·하위 로직은 계산 때 정해짐."""
    out = {}
    for item in row.get("호표") or []:
        ref = str(item.get("요소", ""))
        if item.get("종류") != "로직" and "{" not in ref:
            try:
                out[ref] = _brief(ref, whole.get(ref))
            except cm.mf.FormulaError:
                out[ref] = None
    return out


def elements(group: str, q: str, limit: int) -> dict:
    """요소 찾기 창 — 그룹 전체에서 이름·열쇠 찾기 · `ref` 는 식에 그대로 넣는 `그룹:원문:열쇠`."""
    if group not in cm.mf.GROUPS:
        raise StoreError(404, f"없는 그룹 「{group}」")
    hits = []
    for name, data in cm.load(folder=FOLDER).items():
        if data.get("그룹") != group:
            continue
        for row in data.get(items_key(data)) or []:
            if _hit(row, q):
                ref = f"{group}:{data.get('원문')}:{row.get('열쇠')}"
                hits.append({**_brief(ref, row), "file": name})
    return {"total": len(hits), "items": hits[: min(max(limit, 1), 200)]}


# ── 시험 계산 ──────────────────────────────────────────────────────────
def _swap(files: dict, book: str, key: str, row: dict, file: str | None) -> None:
    """저장 전 시험 — 메모리 사본에서 그 로직을 고친 줄로 바꿈(없으면 `file` 에 더함)."""
    row = _dec(row)
    for name, data in _logic_files(files):
        if data.get("원문") == book:
            items = data.get("줄") or []
            for i, old in enumerate(items):
                if str(old.get("열쇠")) == key:
                    items[i] = row
                    return
    if file not in files or files[file].get("그룹") != "로직":
        raise StoreError(404, f"없는 로직 파일 「{file}」")
    files[file].setdefault("줄", []).append(row)


def calc(book: str, key: str, inputs: dict, row: dict | None = None, file: str | None = None):
    given = {k: _dec(v) for k, v in inputs.items()}
    files = cm.load(folder=FOLDER)
    if row is not None:
        _swap(files, book, key, row, file)
        key = str(row.get("열쇠", key))
    try:
        result = cm.calc(files, f"{book}:{key}", given)
    except (cm.mf.FormulaError, ArithmeticError, KeyError, TypeError, ValueError) as e:
        return {"ok": False, "reason": str(e) or type(e).__name__}
    if "결과" in result:
        return {"ok": True, "result": result["결과"], "middle": result["중간"]}
    return {
        "ok": True,
        "lines": result["줄"],
        "sums": {k: result[k] for k in cm.mf.BUNDLE},
        "middle": result["중간"],
    }


# ── 저장 ──────────────────────────────────────────────────────────────
def _dec(v):
    """화면이 보낸 수 → Decimal(파일을 읽은 모양과 같게)."""
    if isinstance(v, bool) or v is None:
        return v
    if isinstance(v, (int, float)):
        return Decimal(str(v))
    if isinstance(v, list):
        return [_dec(x) for x in v]
    if isinstance(v, dict):
        return {k: _dec(x) for k, x in v.items()}
    return v


def _apply(data: dict, changes: list[dict], file: str) -> None:
    items = data.setdefault(items_key(data), [])
    for ch in changes:
        op, key, row = ch.get("op"), ch.get("key"), _dec(ch.get("row"))
        if op not in ("edit", "add", "delete"):
            raise StoreError(400, f"모르는 op 「{op}」")
        if op != "add":
            at = next((i for i, r in enumerate(items) if str(r.get("열쇠")) == key), None)
            if at is None:
                raise StoreError(404, f"{file} · 없는 열쇠 「{key}」")
        if op != "delete" and not (isinstance(row, dict) and "열쇠" in row):
            raise StoreError(400, f"{file} · row 에 열쇠 없음")
        new_key = str(row["열쇠"]) if op != "delete" else None
        taken = {str(r.get("열쇠")) for i, r in enumerate(items) if op == "add" or i != at}
        if new_key in taken:
            raise StoreError(400, f"{file} · 열쇠 겹침 「{new_key}」")
        if op == "add":
            items.append(row)
        elif op == "edit":
            items[at] = row
        else:
            del items[at]


def save(batch: list[dict]) -> list[dict]:
    with _LOCK:
        stale = [p.get("file", "") for p in batch if read(p.get("file", ""))[1] != p.get("version")]
        if stale:
            raise StoreError(409, {"stale": stale})
        before, after = cm.load(folder=FOLDER), cm.load(folder=FOLDER)  # after = 고칠 사본
        names = [part["file"] for part in batch]
        for part in batch:
            _apply(after[part["file"]], part.get("changes") or [], part["file"])
        old = set(cm.check_saved(before, names))
        new = [x for x in cm.check_saved(after, names) if x not in old]
        if new:
            raise StoreError(422, {"errors": new})
        out = []
        for name in dict.fromkeys(names):
            old_text = (FOLDER / name).read_bytes().decode("utf-8")
            text = keep_shape(old_text, before[name], after[name]) or dump(after[name])
            tmp = FOLDER / f".{name}.tmp"
            tmp.write_text(text, encoding="utf-8", newline="\n")
            os.replace(tmp, FOLDER / name)
            out.append({"file": name, "version": version_of(text.encode("utf-8"))})
        return out


# ── 쓰기 모양 ─────────────────────────────────────────────────────────
def _atom(v) -> str:
    if isinstance(v, Decimal):
        return str(v)
    return json.dumps(v, ensure_ascii=False)


def _flat(v, tight: bool = False) -> str:
    if isinstance(v, dict):
        if not v:
            return "{}"
        body = ", ".join(f"{_atom(k)}: {_flat(x, tight)}" for k, x in v.items())
        return "{" + body + "}" if tight else "{ " + body + " }"
    if isinstance(v, list):
        return "[" + ", ".join(_flat(x, tight) for x in v) + "]"
    return _atom(v)


def _skip(text: str, pos: int) -> int:
    while text[pos] in " \t\r\n":
        pos += 1
    return pos


def keep_shape(old_text: str, before: dict, after: dict) -> str | None:
    """고친 요소만 새로 씀 — 안 바뀐 요소는 옛 글 그대로(한 줄 요소는 한 줄 · 들여쓰기 · 줄바꿈).
    머리가 바뀌었거나 옛 글을 못 읽으면 None(통째로 dump)."""
    key = items_key(after)
    head = lambda d: {k: v for k, v in d.items() if k != key}  # noqa: E731
    old_items, new_items = before.get(key) or [], after.get(key) or []
    if head(before) != head(after) or not old_items or not new_items:
        return None
    for m in re.finditer(rf'"{key}"\s*:\s*\[', old_text):  # 머리 속 같은 이름 칸은 건너뜀
        spans, pos, dec = [], m.end(), json.JSONDecoder()
        try:
            while old_text[pos := _skip(old_text, pos)] != "]":
                _, end = dec.raw_decode(old_text, pos)
                spans.append((pos, end))
                pos = _skip(old_text, end)
                pos += old_text[pos] == ","
        except (IndexError, ValueError):
            return None
        if len(spans) == len(old_items):
            break
    else:
        return None
    nl = "\r\n" if "\r\n" in old_text else "\n"
    lead = old_text[m.end() : spans[0][0]]
    indent = len(lead) - len(lead.rstrip(" "))
    olds = {str(r.get("열쇠")): (r, old_text[s:e]) for r, (s, e) in zip(old_items, spans)}
    shape, parts = old_text[spans[0][0] : spans[0][1]], []
    for row in new_items:
        was, text = olds.get(str(row.get("열쇠")), (None, None))
        shape = text or shape
        if was == row:
            parts.append(text)
        elif "\n" not in shape:
            parts.append(_flat(row, tight=shape.startswith('{"')))
        else:
            parts.append(dump(row, indent, expand=True).replace("\n", nl))
    out = old_text[: m.end()] + lead + ("," + lead).join(parts) + old_text[spans[-1][1] :]
    same = json.loads(out, parse_float=Decimal, parse_int=Decimal) == after
    return out if same else None


def dump(v, indent: int = 0, width: int = 160, expand: bool = False) -> str:
    """UTF-8 · 들여쓰기 2칸 · 한 줄에 들어가는 묶음은 한 줄로(expand 면 첫 층은 펼침)."""
    flat = _flat(v)
    if (
        not isinstance(v, (dict, list))
        or not v
        or (not expand and indent and len(flat) + indent <= width)
    ):
        return flat + ("" if indent else "\n")
    pad = " " * (indent + 2)
    if isinstance(v, dict):
        body = [f"{pad}{_atom(k)}: {dump(x, indent + 2, width)}" for k, x in v.items()]
        text = "{\n" + ",\n".join(body) + "\n" + " " * indent + "}"
    else:
        text = (
            "[\n"
            + ",\n".join(pad + dump(x, indent + 2, width) for x in v)
            + "\n"
            + " " * indent
            + "]"
        )
    return text + ("" if indent else "\n")