"""Render practical answer drafts from source-backed retrieval contracts."""

from __future__ import annotations

from typing import Any


def _as_list(value: Any) -> list[Any]:
    return value if isinstance(value, list) else []


def _first_text(*values: Any) -> str:
    for value in values:
        text = str(value or "").strip()
        if text:
            return text
    return ""


def _status_label(status: str) -> str:
    if status == "covered":
        return "근거 확인"
    if status == "missing":
        return "추가 확인 필요"
    return "상태 미확인"


def _markdown_link(label: str, url: str | None) -> str:
    if url and str(url).startswith("https://www.kcsc.re.kr/"):
        return f"[{label}]({url})"
    return label


def _numbered(items: list[str], *, empty: str) -> list[str]:
    if not items:
        return [f"- {empty}"]
    return [f"{index}. {item}" for index, item in enumerate(items, start=1)]


def _bullets(items: list[str], *, empty: str) -> list[str]:
    if not items:
        return [f"- {empty}"]
    return [f"- {item}" for item in items]


def build_practical_answer_sections(query: str, draft: dict[str, Any]) -> dict[str, Any]:
    """Build stable user-facing sections from a response draft.

    This intentionally does not infer new technical conclusions. It only
    restructures the concept contract and retrieved evidence into a readable
    answer shape.
    """
    outline = draft.get("answer_outline") or {}
    abstention = draft.get("abstention") or {}
    should_abstain = bool(abstention.get("should_abstain"))

    standards = []
    for item in _as_list(draft.get("basis_evidence"))[:8]:
        code = _first_text(item.get("code"))
        role = _first_text(item.get("role"), item.get("title"))
        status = _first_text(item.get("evidence_status"), "unknown")
        revision_note = f", {item.get('revision_date')}" if item.get("revision_date") else ""
        standards.append({
            "code": code,
            "title": _first_text(item.get("title")),
            "role": role,
            "evidence_status": status,
            "status_label": _status_label(status),
            "official_url": item.get("official_url"),
            "revision_date": item.get("revision_date"),
            "link_status": item.get("link_status"),
            "line": (
                f"{_markdown_link(code, item.get('official_url'))} - {role} ({_status_label(status)}{revision_note})"
                if role
                else f"{_markdown_link(code, item.get('official_url'))} ({_status_label(status)}{revision_note})"
            ),
        })

    evidence = []
    for item in _as_list(draft.get("evidence_summary"))[:5]:
        code = _first_text(item.get("code"))
        title = _first_text(item.get("title"))
        section = _first_text(item.get("section"))
        preview = _first_text(item.get("evidence_preview"))
        label = " / ".join(part for part in (code, section) if part)
        evidence.append({
            "label": label or code or title or "검색 근거",
            "title": title,
            "preview": preview,
            "official_url": item.get("official_url"),
            "revision_date": item.get("revision_date"),
            "link_status": item.get("link_status"),
        })

    required_inputs = [str(item) for item in _as_list(outline.get("required_inputs"))[:8]]
    compliance_workflow = [str(item) for item in _as_list(outline.get("compliance_workflow"))[:8]]
    cautions = [str(item) for item in _as_list(outline.get("evidence_cautions"))[:4]]

    if should_abstain:
        summary = "검색된 조항 근거가 부족해 자동 답변을 보류합니다. 기준명, 수치, 적합성 판단은 추가 검색 또는 수동 검토 후 확정해야 합니다."
    else:
        summary = "검색 근거와 실무 concept 매핑을 바탕으로 작성한 기준 검토 초안입니다. 구조 안전, 품질 판정, 보수 공법 확정은 책임기술자 검토가 필요합니다."

    return {
        "query": query,
        "summary": summary,
        "standard_priority": standards,
        "required_inputs": required_inputs,
        "compliance_workflow": compliance_workflow,
        "evidence_summary": evidence,
        "cautions": cautions,
        "should_abstain": should_abstain,
        "review_required": bool(draft.get("review_required")),
        "confidence": draft.get("confidence"),
    }


def render_practical_answer_markdown(query: str, draft: dict[str, Any]) -> str:
    """Render a concise Markdown answer from the structured draft."""
    sections = build_practical_answer_sections(query, draft)
    heading = "검토 보류" if sections["should_abstain"] else "검토 초안"

    lines: list[str] = [
        f"**{heading}**",
        sections["summary"],
        "",
        "**기준 우선순위**",
    ]

    standard_lines = [item["line"] for item in sections["standard_priority"] if item.get("line")]
    lines.extend(_numbered(standard_lines, empty="검색 근거가 없어 우선 적용 기준을 확정하지 않습니다."))

    lines.extend(["", "**필수 확인 조건**"])
    lines.extend(_bullets(sections["required_inputs"], empty="현장 조건과 설계 입력값을 추가 확인해야 합니다."))

    lines.extend(["", "**준수 체크리스트**"])
    lines.extend(_bullets(sections["compliance_workflow"], empty="검색된 조항 근거 확보 후 체크리스트를 확정합니다."))

    lines.extend(["", "**근거 요약**"])
    if sections["evidence_summary"]:
        for item in sections["evidence_summary"]:
            label = _markdown_link(item["label"], item.get("official_url"))
            preview = f": {item['preview']}" if item.get("preview") else ""
            lines.append(f"- {label}{preview}")
    else:
        lines.append("- 검색된 조항 근거가 없습니다.")

    lines.extend(["", "**주의**"])
    caution_lines = sections["cautions"] or [
        "검색 trace가 없는 기준은 최종 수치나 적합성 판단에 사용하지 않습니다.",
    ]
    lines.extend(_bullets(caution_lines, empty="검색 trace가 없는 기준은 최종 수치나 적합성 판단에 사용하지 않습니다."))

    return "\n".join(lines)