from job.job_post.enums import RequisitionStatus
from job.job_post.models import JobPosts


def _status_label(value):
    if value in (None, ""):
        return None
    parsed = RequisitionStatus.parse(value)
    return parsed.label if parsed else value


def serialize_job_post_title(row) -> dict:
    """Inbox suggestion rail — title only until the recruiter expands the card."""
    return {
        "id": str(row.id),
        "title": row.title,
        "status": row.status,
        "is_active": row.is_active,
        "is_deleted": row.is_deleted,
    }


def _recruiter_payload(row, names=None):
    """Recruiter ids plus their mapped names, for the payloads that still send the
    flat shape (serialize_job_post, serialize_job_stats)."""
    names = names or {}
    ids = JobPosts.recruiter_ids_of(row)
    mapped = [names.get(i) for i in ids]
    # recruiter_name is the singular legacy field: the first id that resolved.
    recruiter_name = None
    for n in mapped:
        if n:
            recruiter_name = n
            break
    return {
        "current_recruiter_ids": ids,
        "recruiter_name": recruiter_name,
        "recruiter_names": [n for n in mapped if n],
        "recruiters": [{"id": i, "name": names.get(i)} for i in ids],
    }


def serialize_job_post(row, *, names=None) -> dict:
    return {
        "id": str(row.id),
        "title": row.title,
        # Talent Pool / candidate filters key off attached job_posts.department.
        "department": row.department or None,
        "department_id": str(row.department_id) if row.department_id else None,
        "employment_type": row.employment_type,
        "location": row.location,
        "experience_min": row.experience_min,
        "experience_max": row.experience_max,
        "requirements": list(row.requirements or []),
        "optional_skills": list(row.optional_skills or []),
        "salary": row.salary,
        "description": row.description,
        "post_text": row.post_text,
        "channel_id": row.channel_id,
        "platform": row.platform,
        "is_active": row.is_active,
        "is_deleted": row.is_deleted,
        "buffer_post_id": row.buffer_post_id,
        "buffer_external_link": row.buffer_external_link,
        "buffer_sent_at": row.buffer_sent_at.isoformat() if row.buffer_sent_at else None,
        "status": row.status,
        "buffer_error": row.buffer_error,
        "created_by": str(row.created_by) if row.created_by else None,
        "created_by_name": row.user.name if getattr(row, "user", None) else None,
        "created_at": row.created_at.isoformat() if row.created_at else None,
        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
        "requisition_id": str(row.requisition_id) if getattr(row, "requisition_id", None) else None,
        **_recruiter_payload(row, names),
    }


def serialize_job_row(row, *, people=None, applicant_count=0) -> dict:
    """Requisition view of a job post, for the Jobs screen and the job profile.

    Deliberately separate from serialize_job_post: that payload is shared by the
    inbox, candidate and matching paths. department is the one shared field —
    talent-pool filters key off it on attached job_posts.

    `people` is Users.job_people's shape — {"recruiters": {id: name},
    "hiring_manager": {id: name}} — so the two roles stay apart in the response.
    """
    req = getattr(row, "requisition", None)
    people = people or {}
    recruiters = people.get("recruiters") or {}
    hiring_manager = people.get("hiring_manager") or None
    return {
        "id": str(row.id),
        "title": row.title,
        # The linked department wins; the free-text column is the fallback, and is
        # still what fetch_jobs filters on, so reads and filters agree.
        "department": (row.department_ref.name if row.department_ref else None) or row.department or None,
        "department_id": str(row.department_id) if row.department_id else None,
        "location": row.location,
        "employment_type": row.employment_type,
        "vacancies": row.vacancies,
        "platform": row.platform or None,
        "requisition_status": row.requisition_status,
        "status": row.status,
        "experience_min": row.experience_min,
        "experience_max": row.experience_max,
        "salary": row.salary,
        "requirements": list(row.requirements or []),
        "optional_skills": list(row.optional_skills or []),
        "description": row.description,
        "is_active": row.is_active,
        "closed_at": row.closed_at.isoformat() if row.closed_at else None,
        "requisition_id": str(row.requisition_id) if getattr(row, "requisition_id", None) else None,
        "requisition_title": req.position_title if req else None,
        "requisition_department": req.department if req else None,
        "applicant_count": applicant_count,
        "created_by": str(row.created_by) if row.created_by else None,
        "created_by_name": row.user.name if getattr(row, "user", None) else None,
        "created_at": row.created_at.isoformat() if row.created_at else None,
        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
        "recruiters": recruiters,
        "hiring_manager": hiring_manager,
    }


def serialize_job_stats(row, *, names=None) -> dict:
    """One job post's live pipeline-stage counts. `row` is a mapping from fetch_job_stats."""
    created_at = row.get("created_at")
    payload = _recruiter_payload(row, names)
    if not payload["recruiter_name"] and row.get("recruiter_name"):
        payload["recruiter_name"] = row.get("recruiter_name")
    return {
        "job_post_id": str(row["job_post_id"]),
        "title": row["title"],
        "department": row["department"] or None,
        "location": row["location"],
        "requisition_status": row["requisition_status"],
        **payload,
        # Frontend computes days-open vs client clock; no server days_open field.
        "created_at": created_at.isoformat() if created_at else None,
        "total_applicants": int(row["total_applicants"] or 0),
        "shortlisting": int(row["shortlisting"] or 0),
        "screened": int(row["screened"] or 0),
        "assessment": int(row["assessment"] or 0),
        "interviewed": int(row["interviewed"] or 0),
        "offered": int(row["offered"] or 0),
        "on_hold": int(row["on_hold"] or 0),
        "rejected": int(row["rejected"] or 0),
        "approved": int(row["approved"] or 0),
        "hired": int(row["hired"] or 0),
        "reapplied": int(row.get("reapplied") or 0),
    }


def serialize_status_history(row, *, changed_by_name=None) -> dict:
    return {
        "id": str(row.id),
        "job_post_id": str(row.job_post_id) if row.job_post_id else None,
        "from_status": row.from_status,
        "from_label": _status_label(row.from_status),
        "to_status": row.to_status,
        "to_label": _status_label(row.to_status),
        "changed_by": str(row.changed_by) if row.changed_by else None,
        "changed_by_name": changed_by_name,
        "actor_kind": row.actor_kind,
        "created_at": row.created_at.isoformat() if row.created_at else None,
    }


def serialize_suggested_candidate(row, *, name=None, email=None, candidate=None, source=None, optional_matched=None) -> dict:
    """One suggested candidate on the job profile: the newest ats_results row for a
    person, with profile fields from its `candidates` row when one exists."""
    score = row.overall_score
    return {
        "id": str(row.id),
        "user_id": str(row.user_id) if row.user_id else None,
        "candidate_id": str(row.candidate_id) if row.candidate_id else None,
        "form_data_id": str(row.form_data_id) if row.form_data_id else None,
        "inbox_id": row.inbox_id,
        "name": name or (candidate.candidate_name if candidate else None) or email or None,
        "email": email or (candidate.candidate_email if candidate else None) or None,
        "current_title": candidate.job_title if candidate else None,
        "current_company": candidate.current_company if candidate else None,
        "years_experience": candidate.years_experience if candidate else None,
        "match_score": round(score) if score is not None else None,
        "band": row.band or None,
        "matched_keywords": list(candidate.matched_keywords or []) if candidate else [],
        "missing_keywords": list(candidate.missing_keywords or []) if candidate else [],
        "optional_matched": list(optional_matched or []),
        "summary": (candidate.summary_critique if candidate else None) or row.professional_summary or None,
        "source": source,
        "scored_candidate_id": str(candidate.id) if candidate else None,
        "created_at": row.created_at.isoformat() if row.created_at else None,
    }