from __future__ import annotations

import json
from pathlib import Path
from typing import Any

from .models import SkillStep, StandardAnswer, StandardKind


def load_standard_from_file(path: Path) -> StandardAnswer | None:
    try:
        raw = json.loads(path.read_text(encoding="utf-8-sig"))
    except Exception:
        return None

    steps = normalize_steps(raw)
    if not steps:
        return None

    schema_version = raw.get("schemaVersion", "") if isinstance(raw, dict) else ""
    kind = StandardKind.assembly if "assembly" in str(schema_version).lower() else StandardKind.part
    title = path.stem
    modeling_plan = raw.get("modelingPlan") if isinstance(raw, dict) and isinstance(raw.get("modelingPlan"), dict) else {}
    approved_text = raw.get("approvedPlanText") if isinstance(raw, dict) else ""
    summary = str(modeling_plan.get("summary") or approved_text or "")
    return StandardAnswer(
        standard_id=make_standard_id(path.stem),
        title=title,
        kind=kind,
        source_path=str(path),
        source_type="local_json",
        tags=tags_for_text(f"{title} {summary}"),
        summary=summary,
        steps=steps,
        raw=raw if isinstance(raw, dict) else {"steps": raw},
    )


def normalize_steps(payload: Any) -> list[SkillStep]:
    raw_steps: list[Any] = []
    if isinstance(payload, list):
        raw_steps = payload
    elif isinstance(payload, dict):
        if isinstance(payload.get("steps"), list):
            raw_steps = payload["steps"]
        elif isinstance(payload.get("modelingPlan"), dict) and isinstance(payload["modelingPlan"].get("steps"), list):
            raw_steps = payload["modelingPlan"]["steps"]
        elif isinstance(payload.get("modeling_plan"), dict) and isinstance(payload["modeling_plan"].get("steps"), list):
            raw_steps = payload["modeling_plan"]["steps"]

    result: list[SkillStep] = []
    for index, item in enumerate(raw_steps, 1):
        if not isinstance(item, dict):
            continue
        skill = str(item.get("skill") or item.get("skillName") or item.get("skill_name") or "")
        if not skill:
            continue
        args = item.get("args") or item.get("arguments") or {}
        if not isinstance(args, dict):
            args = {}
        result.append(
            SkillStep(
                id=str(item.get("id") or f"step-{index:03d}"),
                order=int(item.get("step") or index),
                skill=skill,
                name=str(item.get("name") or item.get("source_feature") or skill),
                description=str(item.get("description") or item.get("note") or ""),
                arguments=args,
                source_feature=str(item.get("source_feature") or item.get("sourceFeature") or item.get("name") or ""),
                note=str(item.get("note") or item.get("description") or ""),
            )
        )
    return result


def make_standard_id(text: str) -> str:
    normalized = []
    for ch in text.lower():
        if ch.isalnum() or "\u4e00" <= ch <= "\u9fff":
            normalized.append(ch)
        else:
            normalized.append("-")
    return "-".join(part for part in "".join(normalized).split("-") if part)[:120] or "standard"


def tags_for_text(text: str) -> list[str]:
    tags: list[str] = []
    mapping = {
        "齿轮": "gear",
        "榻": "gear",
        "轴": "shaft",
        "箱": "housing",
        "端盖": "cover",
        "减速器": "reducer",
        "装配": "assembly",
        "assembly": "assembly",
        "shell": "shell",
        "抽壳": "shell",
        "loft": "loft",
        "放样": "loft",
    }
    lowered = text.lower()
    for key, tag in mapping.items():
        if key.lower() in lowered and tag not in tags:
            tags.append(tag)
    return tags