"""结构化日志辅助：统一 ``event=`` 行格式与 Celery prerun 可提取的上下文字段。"""

from __future__ import annotations

from typing import Any


def format_log_event(event: str, **fields: Any) -> str:
    """
    生成单行 ``event=...`` 日志正文：``event`` 固定首位；``msg`` 固定末位（若提供）；其余键按字母序。

    ``None`` 与空字符串会跳过；浮点数默认保留一位小数（适用于 ``duration_ms``）。
    """
    parts: list[str] = [f"event={event}"]
    keys = sorted(k for k in fields if k != "msg")
    ordered = list(keys)
    if "msg" in fields:
        ordered.append("msg")
    for k in ordered:
        v = fields[k]
        if v is None:
            continue
        if isinstance(v, float):
            parts.append(f"{k}={v:.1f}")
        elif isinstance(v, bool):
            parts.append(f"{k}={str(v).lower()}")
        else:
            s = str(v).strip()
            if not s:
                continue
            parts.append(f"{k}={s}")
    return " ".join(parts)


def correlation_bind_kwargs(
    *,
    user_id: str | None = None,
    memoir_correlation_id: str | None = None,
    correlation_id: str | None = None,
    **more: str | None,
) -> dict[str, str]:
    """供 ``logger.bind(**...)``：``memoir_correlation_id`` 会以 ``correlation_id`` 写入（统一检索键）。"""
    out: dict[str, str] = {}
    uid = (user_id or "").strip()
    if uid:
        out["user_id"] = uid
    cid = (correlation_id or memoir_correlation_id or "").strip()
    if cid:
        out["correlation_id"] = cid
    for k, v in more.items():
        if v is None:
            continue
        s = str(v).strip()
        if s:
            out[str(k)] = s
    return out


# bind=True 任务的 positional 与字段名映射（kwargs 优先，缺位再填）
_TASK_POSITIONAL_FIELDS: dict[str, tuple[str, ...]] = {
    "app.tasks.memory_enrichment_tasks.embed_memory_source": ("user_id", "source_id"),
    "app.tasks.memory_enrichment_tasks.enrich_memory_source": ("user_id", "source_id"),
    "app.tasks.memory_compaction_tasks.memory_compaction_run": ("user_id",),
    "app.tasks.chapter_compose_tasks.recompose_chapter": ("chapter_id",),
    "app.tasks.memoir_quality_pass_tasks.memoir_quality_pass": ("user_id",),
    "app.tasks.memoir_tasks.process_memoir_phase2": ("user_id", "chapter_category"),
    "app.tasks.memoir_tasks.process_memoir_phase1": ("user_id",),
    "app.tasks.memoir_tasks.generate_chapter_content": ("user_id", "stage"),
    "app.tasks.chapter_cover_tasks.generate_chapter_cover": ("chapter_id",),
    "app.tasks.story_image_tasks.generate_story_image": ("story_id",),
    "app.tasks.story_title_tasks.generate_story_title_after_create": (
        "story_id",
        "chapter_category",
        "oral_scope",
        "user_id",
    ),
}

_KW_KEYS_COPY: tuple[str, ...] = (
    "user_id",
    "source_id",
    "chapter_id",
    "story_id",
    "chapter_category",
    "stage",
    "oral_scope",
)


def celery_prerun_extras(
    task_name: str | None,
    args: tuple[Any, ...],
    kwargs: dict[str, Any] | None,
) -> dict[str, str]:
    """
    从 Celery ``task_prerun`` 的 args/kwargs 提取 ``user_id``、``correlation_id`` 等，
    供 ``set_celery_log_extras`` 与任务体内 loguru 记录关联。
    """
    out: dict[str, str] = {}
    kw = dict(kwargs or {})

    mcid = kw.get("memoir_correlation_id")
    if mcid is not None:
        s = str(mcid).strip()
        if s:
            out["correlation_id"] = s

    for key in _KW_KEYS_COPY:
        if key not in kw:
            continue
        val = kw[key]
        if val is None:
            continue
        s = str(val).strip()
        if s:
            out[key] = s

    name = (task_name or "").strip()
    fields = _TASK_POSITIONAL_FIELDS.get(name)
    if fields and args:
        for i, field in enumerate(fields):
            if i >= len(args):
                break
            if field in out:
                continue
            val = args[i]
            if val is None:
                continue
            s = str(val).strip()
            if s:
                out[field] = s
    return out