"""Employment response decorators for `parse_employment_response`.

Pure module: no FastAPI imports, no HTTPException, and no module-level state.
Mirrors job/candidate/decorators.py — stacked wrappers that clean LLM output
before the task persists it:

    parse_employment_response -> clamp_phone -> prefer_extracted_phone
              -> clamp_linkedin_url -> clamp_education_to_resume
              -> clamp_company_to_resume

Generic factories (`clamp_field`, `clamp_in_resume`) bind a field name; the
assigned aliases below are what call sites stack.
"""

from __future__ import annotations

import re
from functools import wraps

from employment_agent.prompt import EDUCATION,NO_COMPANY,NO_LINKEDIN,NO_PHONE


def require_json_object(func):
    """Reject non-dict LLM payloads before field parsing runs."""

    @wraps(func)
    def wrapper(data,resume_text="",*args,**kwargs):
        if not isinstance(data,dict):
            raise RuntimeError(f"model did not return a JSON object: {data!r}")
        return func(data,resume_text,*args,**kwargs)

    return wrapper


def clamp_field(key,clean):
    """Run `clean(value, resume_text)` on one dict key; leave the rest alone."""

    def decorator(func):
        @wraps(func)
        def wrapper(data,resume_text="",*args,**kwargs):
            fields=func(data,resume_text,*args,**kwargs)
            fields[key]=clean(fields.get(key),resume_text)
            return fields
        return wrapper
    return decorator


def clamp_in_resume(key,sentinel):
    """Keep the field only when it appears in resume_text; else `sentinel`."""

    def clean(value,resume_text):
        text=(value or "").strip()
        if not text or text.lower()==sentinel.lower():
            return sentinel
        haystack=(resume_text or "").lower()
        if text.lower() not in haystack:
            return sentinel
        return text
    return clamp_field(key,clean)


def _clean_linkedin(value,resume_text):
    """Keep a LinkedIn URL only when the CV evidences it. Sentinel / invented → None."""
    url=(value or "").strip()
    if not url or url.lower() in (NO_LINKEDIN.lower(),"none","null","n/a","-"):
        return None
    lowered=url.lower()
    if "linkedin.com/company/" in lowered:
        return None
    if "linkedin.com" not in lowered and "lnkd.in" not in lowered:
        return None
    if not lowered.startswith("http://") and not lowered.startswith("https://"):
        url="https://"+url.lstrip("/")
    text=(resume_text or "").strip()
    if not text:
        return url
    from linkedin_utils import slug_from_url,slugs_from_text
    agent_slug=slug_from_url(url)
    if agent_slug:
        return url if agent_slug in slugs_from_text(text) else None
    if "lnkd.in" in lowered:
        from linkedin_utils import profile_url_from_text
        evidenced=profile_url_from_text(text)
        if evidenced and "lnkd.in" in evidenced.lower():
            return evidenced
    return None


def _clean_phone(value,resume_text):
    text=(value or "").strip()
    if not text or text.lower() in (NO_PHONE.lower(),"none","null","n/a","-"):
        return None
    digits=re.sub(r"\D","",text)
    if digits.startswith("00"):
        digits=digits[2:]
    if len(digits)<10 or len(digits)>15:
        return None
    if (resume_text or "").strip():
        haystack=re.sub(r"\D","",resume_text)
        if digits not in haystack:
            return None
    return text


def prefer_extracted_phone(func):
    """Merge CV regex phone with the LLM value; keep the longer complete number."""

    @wraps(func)
    def wrapper(data,resume_text="",*args,**kwargs):
        fields=func(data,resume_text,*args,**kwargs)
        from employment_agent.plugins import prefer_full_phone,scan_phone
        fields["phone"]=prefer_full_phone(fields.get("phone"),scan_phone(resume_text))
        return fields
    return wrapper


clamp_company_to_resume=clamp_in_resume("current_employment",NO_COMPANY)
clamp_education_to_resume=clamp_in_resume("education",EDUCATION)
clamp_linkedin_url=clamp_field("linkedin_url",_clean_linkedin)
clamp_phone=clamp_field("phone",_clean_phone)


@require_json_object
@clamp_company_to_resume
@clamp_education_to_resume
@clamp_linkedin_url
@prefer_extracted_phone
@clamp_phone
def parse_employment_response(data,resume_text=""):
    """Pull company, education, title, linkedin_url, and phone from the agent JSON."""
    def as_str(key):
        value=data.get(key)
        return value.strip() if isinstance(value,str) else ""
    return {
        "current_employment":as_str("current_employment"),
        "education":as_str("education"),
        "current_title":as_str("current_title"),
        "linkedin_url":as_str("linkedin_url"),
        "phone":as_str("phone"),
    }