"""Inbox Taskiq tasks — CV → job-post matching and ATS scoring."""

from __future__ import annotations

import logging
import uuid
from datetime import datetime,timezone

from fastapi import HTTPException

from agent.execute_agent import run_agent
from db_setup import session_scope
from employment_agent.execute_agent import run_employment_agent
from inbox.models import Inbox_Messages,Inbox,AtsResults
from inbox.plugins import extract_resume_text
from job.job_post.models import JobPosts
from job.job_post.serializers import serialize_job_post
from taskiq_management.broker_setup import MAX_RETRIES,RETRY_DELAY,broker
from taskiq_management.middleware import PermanentTaskError

logger=logging.getLogger("inbox.tasks")
_DONE=frozenset({"matched","skipped","no_text","failed","dlq"})


async def score_message_against_job(record_id:str,job_id:str,rescan_run_id=None) -> dict:
    """ATS-score one inbox CV against one job post — the no-upload path.

    The decoded attachment already on disk is the CV; the job post in the
    database is the JD. Idempotent: a (message, job) pair with an ats_results
    row is never paid for twice; re-runs are a no-op.
    """
    # Lazy imports: inbox.plugins imports job.candidate.views, so a top-level
    # import here would be circular.
    from job.candidate.views import CandidateScoring

    try:
        mid=uuid.UUID(str(record_id))
        jid=uuid.UUID(str(job_id))
    except ValueError:
        raise PermanentTaskError("record_id and job_id must be uuids")

    already=False
    results=[]
    async with session_scope() as session:
        link=await Inbox.get_inbox_by_message_id(session,mid)
        if link is not None:
            # (inbox, job) only — candidate_id is NULL when the CV email matched
            # a user, so already_scored must not depend on it.
            existing=await AtsResults.get_for_inbox_job(session,link.id,jid)
            if existing is not None:
                already=True
        if not already:
            job=await JobPosts.get_job_post_by_id(session,job_id)
            if job is None or job.is_deleted:
                raise PermanentTaskError("job post missing or deleted")
            service=CandidateScoring(session=session)
            try:
                # Attribute the rows to the job's owner — there is no request user
                # in a background task.
                results=await service.score_inbox(job_id,[record_id],{"id":str(job.created_by)},rescan_run_id=rescan_run_id)
            except HTTPException as exc:
                # 400/404 from score_inbox are permanent (no attachment, bad ids);
                # retrying cannot fix them.
                raise PermanentTaskError(str(exc.detail)) from exc
    if already:
        # Assigning a job already scored as a suggestion must still flip the
        # denormed chip from max-of-suggestions to that job.
        await denorm_message_ats_score(record_id)
        return {"status":"already_scored"}
    await denorm_message_ats_score(record_id)
    return {"status":"scored","results":len(results)}


async def denorm_message_ats_score(record_id:str) -> None:
    """Stamp inbox_messages.ats_score: assigned job if set, else max of suggestions."""
    async with session_scope() as session:
        msg=await Inbox_Messages.get_inbox_message_by_id(session,record_id)
        if msg is None:
            return
        link=await Inbox.get_inbox_by_message_id(session,record_id)
        if link is None:
            return
        rows=await AtsResults.get_latest_by_job_for_inbox(session,link.id)
        if not rows:
            return
        chosen=None
        assigned=msg.assigned_job_post_id
        if assigned:
            chosen=next((r for r in rows if str(r.job_post_id)==str(assigned)),None)
        if chosen is None:
            chosen=max(rows,key=lambda r:float(r.overall_score or 0))
        await Inbox_Messages.set_ats_score(session,record_id,chosen.overall_score,chosen.band)


async def score_message_against_jobs(record_id:str,job_ids) -> None:
    """Score one inbox CV against each job. Failures do not abort the rest."""
    seen=set()
    for raw in job_ids or []:
        job_id=str(raw or "").strip()
        if not job_id or job_id in seen:
            continue
        seen.add(job_id)
        try:
            outcome=await score_message_against_job(record_id,job_id)
            logger.info("ats auto-score %s vs %s: %s",record_id,job_id,outcome.get("status"))
        except Exception as exc:
            logger.warning("ats auto-score failed for %s vs %s: %s",record_id,job_id,exc)


@broker.task(
    task_name="g_sheet.score_form",
    retry_on_error=True,
    max_retries=MAX_RETRIES,
    delay=RETRY_DELAY,
)
async def score_form_data(form_data_id:str,job_id:str) -> dict:
    """ATS-score one Sheet Forms CV (extracted_data) against one job post."""
    from g_sheet.scoring import score_form_against_job

    try:
        uuid.UUID(str(form_data_id))
        uuid.UUID(str(job_id))
    except (TypeError,ValueError):
        raise PermanentTaskError("form_data_id and job_id must be uuids")
    result=await score_form_against_job(form_data_id,job_id)
    if result.get("status")=="failed":
        raise RuntimeError(result.get("error_code") or "form ats failed")
    return result


@broker.task(
    task_name="inbox.score_message",
    retry_on_error=True,
    max_retries=MAX_RETRIES,
    delay=RETRY_DELAY,
)
async def score_inbox_message(record_id:str,job_id:str) -> dict:
    return await score_message_against_job(record_id,job_id)


@broker.task(
    task_name="inbox.rescan_on_hold",
    retry_on_error=True,
    max_retries=MAX_RETRIES,
    delay=RETRY_DELAY,
)
async def rescan_on_hold_run(run_id:str,cursor:int=0) -> dict:
    """Score On-Hold CVs against every job post, in short idempotent chunks."""
    from g_sheet.scoring import score_form_against_job
    from inbox.views import Email

    async with session_scope() as session:
        prepared=await Email(session=session).prepare_on_hold_rescan_chunk(run_id,cursor)
    status=prepared.get("status")
    if status in ("completed","failed","missing"):
        return prepared
    for item in prepared.get("batch") or []:
        kind=item.get("kind")
        record_id=item.get("record_id")
        job_id=item.get("job_id")
        try:
            if kind=="form":
                await score_form_against_job(record_id,job_id,run_id)
            else:
                await score_message_against_job(record_id,job_id,run_id)
        except Exception as exc:
            logger.warning("on-hold rescan failed for %s vs %s: %s",record_id,job_id,exc)
    async with session_scope() as session:
        return await Email(session=session).finish_on_hold_rescan_chunk(
            run_id,prepared.get("next_cursor") or 0,bool(prepared.get("more")),
        )


@broker.task(
    task_name="inbox.match_message",
    retry_on_error=True,
    max_retries=MAX_RETRIES,
    delay=RETRY_DELAY,
)
async def match_inbox_message(record_id:str,force:bool=False) -> dict:
    if not record_id or not str(record_id).strip():
        raise PermanentTaskError("record_id is required")
    record_id=str(record_id).strip()

    async with session_scope() as session:
        row=await Inbox_Messages.get_inbox_message_by_id(session,record_id)
        if not row:
            raise PermanentTaskError(f"inbox message {record_id} not found")
        if not force and row.match_status in _DONE:
            return {"status":row.match_status,"skipped":True}
        if not row.attachment or not row.file_path:
            raise PermanentTaskError("message has no attachment to match")

        paths=[p.strip() for p in row.file_path.split(",") if p.strip()]
        subject=row.message_subject or ""
        body=row.message_body or ""
        row.match_status="processing"
        row.match_error=None
        row.matched_at=datetime.now(timezone.utc)
        session.add(row)
        await session.commit()

        posts=await JobPosts.get_active_job_posts(session)
        job_posts=[serialize_job_post(p) for p in posts]

    text,extract_err=await extract_resume_text(paths)
    if not text:
        async with session_scope() as session:
            await Inbox_Messages.set_match_result(
                session,record_id,status="no_text",error=extract_err or "no text extracted",
            )
        return {"status":"no_text","error":extract_err}

    result=await run_agent(subject=subject,resume_text=text,job_posts=job_posts)
    status=result.get("status") or "failed"
    # Extract the profile even when matching finds no job — On-Hold / unassigned
    # CVs still need name, title, years, and phone on every screen.
    fields=await run_employment_agent(
        resume_text=text if not body else f"{text}\n\n{body}",
    )
    current_employment=fields["current_employment"]
    education=fields["education"]
    current_title=fields["current_title"]
    linkedin_url=fields["linkedin_url"]
    phone=fields["phone"]
    city=fields.get("city") or None
    years=fields.get("years_experience")
    experience=(result.get("experience") or "").strip()
    if not experience and years is not None:
        experience=str(int(years)) if isinstance(years,(int,float)) and not isinstance(years,bool) else str(years)

    if status=="failed":
        async with session_scope() as session:
            await Inbox_Messages.set_match_result(
                session,
                record_id,
                resume_text=text,
                experience=experience,
                candidate_phone_number=phone if phone else "",
                current_employment=current_employment,
                current_title=current_title,
                candidate_education=education,
                linkedin_url=linkedin_url,
                city=city,
                suggested_job_post_ids=[],
                summary=result.get("summary") or "",
                reasoning=result.get("reasoning") or "",
                status="failed",
                error=result.get("error") or "agent returned failed status",
            )
        raise RuntimeError(result.get("error") or "agent returned failed status")

    async with session_scope() as session:
        await Inbox_Messages.set_match_result(
            session,
            record_id,
            resume_text=text,
            experience=experience,
            candidate_phone_number=phone if phone else "",
            current_employment=current_employment,
            current_title=current_title,
            candidate_education=education,
            linkedin_url=linkedin_url,
            city=city,
            suggested_job_post_ids=result.get("suggested_job_post_ids") or [],
            summary=result.get("summary") or "",
            reasoning=result.get("reasoning") or "",
            status=status,
            error=result.get("error") or "",
        )
    # Auto-score every suggested job. The list chip is the max until a recruiter
    # assigns one; assignment then re-runs ATS against that job_post_id.
    # Scoring failures must not fail the match; the match result is committed above.
    suggested=[str(j) for j in (result.get("suggested_job_post_ids") or []) if j]
    score_job_ids=list(suggested)
    async with session_scope() as session:
        fresh=await Inbox_Messages.get_inbox_message_by_id(session,record_id)
        if fresh is not None and fresh.assigned_job_post_id:
            assigned=str(fresh.assigned_job_post_id)
            if assigned not in score_job_ids:
                score_job_ids.append(assigned)
    await score_message_against_jobs(record_id,score_job_ids)

    return {
        "status":status,
        "suggested_job_post_ids":result.get("suggested_job_post_ids") or [],
        "current_employment":current_employment,
        "current_title":current_title,
        "education":education,
        "linkedin_url":linkedin_url,
    }