"""市場情報候選連結 preview 聚合。

只整理本次 diagnostics 結果供人工審核，不建立 campaign/product，不寫 DB。
"""


BAND_RANK = {
    "high": 3,
    "medium": 2,
    "low": 1,
}


def _band_allowed(candidate, min_band):
    if not min_band or min_band == "all":
        return True
    candidate_rank = BAND_RANK.get(candidate.get("confidence_band"), 0)
    min_rank = BAND_RANK.get(min_band, 0)
    return candidate_rank >= min_rank


def build_candidate_preview_from_discovery(discovery_result, *, min_band="all", limit=50):
    """把 manual discovery diagnostics 整理成人工審核 preview。"""
    candidates = []
    run_statuses = []

    for run in discovery_result.get("runs", []):
        platform_code = run.get("platform_code")
        run_statuses.append({
            "platform_code": platform_code,
            "status": run.get("status"),
            "sources_planned": run.get("sources_planned", 0),
            "sources_fetched": run.get("sources_fetched", 0),
            "errors": run.get("errors", 0),
        })

        for source_result in run.get("results", []):
            diagnostics = source_result.get("diagnostics") or {}
            for candidate in diagnostics.get("campaign_link_candidates", []):
                if not _band_allowed(candidate, min_band):
                    continue
                candidates.append({
                    "platform_code": platform_code,
                    "source_key": source_result.get("source_key"),
                    "source_name": source_result.get("name"),
                    "source_url": source_result.get("url"),
                    "source_status": source_result.get("status"),
                    "page_title": diagnostics.get("title"),
                    "page_hash": diagnostics.get("page_hash"),
                    "href": candidate.get("href"),
                    "text": candidate.get("text"),
                    "is_same_host": candidate.get("is_same_host"),
                    "score": candidate.get("score", 0),
                    "generic_score": candidate.get("generic_score", 0),
                    "platform_score": candidate.get("platform_score", 0),
                    "confidence_band": candidate.get("confidence_band"),
                    "confidence_reason": candidate.get("confidence_reason"),
                })

    candidates = sorted(
        candidates,
        key=lambda item: (
            BAND_RANK.get(item.get("confidence_band"), 0),
            item.get("score", 0),
            item.get("platform_score", 0),
        ),
        reverse=True,
    )

    return {
        "platform_code": discovery_result.get("platform_code", "all"),
        "fetch_requested": bool(discovery_result.get("fetch_requested")),
        "manual_fetch_allowed": bool(discovery_result.get("manual_fetch_allowed")),
        "mcp_fetch_gate": discovery_result.get("mcp_fetch_gate"),
        "mcp_fetch_gate_open": bool(
            (discovery_result.get("mcp_fetch_gate") or {}).get("manual_fetch_gate_open")
        ),
        "min_band": min_band or "all",
        "limit": limit,
        "candidate_count": len(candidates),
        "candidates": candidates[:limit],
        "run_statuses": run_statuses,
        "database_write_allowed": False,
        "scheduler_attached": False,
    }